ADDITIVE MANUFACTURING SYSTEMS

PRIORITY APPLICATIONS

[0001] This Patent Application claims priority from U.S. Provisional Patent Application Serial No. 63/396,879 filed on August 10, 2022, and from U.S. Provisional Patent Application Serial No. 63/531,507 filed on August 08, 2023, each of which is entirely incorporated herein by reference.

BACKGROUND

[0002] Three-dimensional (3D) printing (e.g., additive manufacturing) is a process for making a three-dimensional object of any shape from a design. The design may be in the form of a data source such as an electronic data source or may be in the form of a hard copy. The hard copy may be a two-dimensional representation of a 3D object. The data source may be an electronic 3D model. 3D printing may be accomplished through an additive process in which successive layers of material are laid down one on top of another. This process may be controlled (e.g., computer controlled, manually controlled, or both). A 3D printer can be an industrial robot.

[0003] 3D printing can generate custom parts. A variety of materials can be used in a 3D printing process including elemental metal, metal alloy, ceramic, an allotrope of elemental carbon, or polymeric material. In some 3D printing processes (e.g., additive manufacturing), a first layer of hardened material is formed (e.g., by welding powder), and thereafter successive layers of hardened material are added one by one, wherein each new layer of hardened material is added on a pre-formed layer of hardened material, until the entire designed three-dimensional structure (3D object) is layer-wise materialized.

[0004] 3D models may be created with a computer aided design package, via 3D scanner, or manually. The manual modeling process of preparing geometric data for 3D computer graphics may be similar to plastic arts, such as sculpting or animating. 3D scanning is a process of analyzing and collecting digital data on the shape and appearance of a real object (e.g., real-life object). Based on this data, 3D models of the scanned object can be produced.

[0005] A number of 3D printing processes are currently available. They may differ in the manner layers are deposited to create the materialized 3D structure (e.g., hardened 3D structure). They may vary in the material or materials that are used to materialize the designed 3D object. Some methods melt, sinter, or soften material to produce the layers that form the 3D object. Examples for 3D printing methods include selective laser melting (SLM), selective laser sintering (SLS), direct metal laser sintering (DMLS) or fused deposition modeling (FDM). Other methods cure liquid materials using different technologies such as stereo lithography (SLA). In the method of laminated object manufacturing (LOM), thin layers (made inter alia of paper, polymer, or metal) are cut to shape and joined together.

[0006] At times, an orientation and dimensionality of requested three-dimensional object(s) to be printed in a build module of a three-dimensional (3D) printing system necessitates a dimension along a vertical axis (e.g., along a z-axis) that challenges accommodation of the 3D printing system in a facility, e.g., due to its large size. Such a challenge may be due to a method employed for the vertical translation of the build platform (e.g., build plate) located in the build module. For example, translating the build platform in fine, e.g., layerwise, increments along supportive structures (e.g., shafts) having a height of at least the range of travel, which in turn results in a build module having at least about twice the height of the range of travel. In this example, the height of the build module accommodates (i) a vertical translation range of the build platform and (ii) a vertical height requirement of the supportive structures (e.g., guide rails, shafts, encoder, lead screws, scissor jacks, or the like) of the build platform. At least one of the supportive structures may act an adjusting coupler, e.g., a distance adjusting coupler. At times, complexity of manufacturing a build module body may contribute to extended manufacturing timelines and/or elevated manufacturing cost.

SUMMARY

[0007] In some aspects, the present disclosure resolves the aforementioned hardships. [0008] In some aspects, a build platform assembly comprises two piston assemblies that move in coordinated fashion of two incremental movement types. In some embodiments, the two piston assemblies are vertically aligned and are disposed parallel to each other along the gravitational vector. In some embodiments, the first piston assembly is closer to the gravitational center than the second piston assembly. The second piston assembly may be supportive of a building platform. The build platform assembly may be translated, e.g., during a 3D printing process, at least in part in a movement similar to that of an inchworm. The build platform assembly may be translated, e.g., during a 3D printing process, at least in part by utilizing a combination of operations including (i) translation the first piston assembly in large increments (e.g., leaps), and (ii) within each of the large increments, translating the second piston assembly in small increments. The first piston assembly and the second piston assembly can each engage with a build module body to hold each of their positions. The first piston assembly and the second piston assembly can be coupled by an adjusting coupler (e.g., a shaft) configured to facilitate adjustment of a (e.g., vertical) gap between the first piston assembly and the second piston assembly. A length of travel (e.g., an extent of the large increments) can be set by a vertical extent of the adjusting coupler, e.g., shaft. For example, (a) the first piston assembly is disengaged, or disengages, from the build module body and then translates in a large increment while the second piston assembly is engaged with the build module body to hold (e.g., affix) it position, (b) the first piston assembly engages with the build module body and holds (e.g., affixes) a position , (c) the second piston assembly disengages from the build module body and then translates in small increments towards the first piston assembly until a minimal gap distance is reached between the first piston assembly and the second piston assembly, (d) the second piston assembly engages with the build module body to hold (e.g., affix) a position of the second piston assembly, (e) the first piston disengages with the build module body, and (f) optionally repeat operations (a) to (e) until the build platform assembly reaches a requested position (e.g., when the 3D object is complete). The multi-incremental traversal of the build platform assembly may imprint a structural signature of the 3D object(s) thus printed.

[0009] In another aspect, a device for three-dimensional printing, the device comprises: a first piston; an adjusting coupler (e.g., a shaft) configured to facilitate adjustment of a (e.g., vertical) gap, the adjusting coupler operatively coupled with the first piston; and a second piston being operatively coupled with the first piston at least in part using (e.g., through) the adjusting coupler (e.g., shaft), the second piston being configured to (i) translate to facilitate the three-dimensional printing, and (ii) engage with a build platform configured to carry one or more three-dimensional objects during the three-dimensional printing, the gap being disposed between the first piston and the second piston, the first piston being configured to translate, the first piston and the second piston being configured to translate relative to each other, to alter the gap, and the first piston and/or the second piston being configured for translation during the three-dimensional printing. In some embodiments, the first piston and/or the second piston being configured for repetitive translation. In some embodiments, the first piston and the second piston being configured for translation in a direction. In some embodiments, the first piston and the second piston are the same in at least one characteristic comprising (i) horizontal circumference shape, (ii) horizontal circumference length, (Hi) horizontal cross-section, (iv) horizontal location, (v) material makeup, or (vi) mechanism for affixing to a build module in which the first piston and the second piston are disposed during the three-dimensional printing. In some embodiments, the first piston and the second piston are different by at least one characteristic comprising (i) functionality, (ii) shape, (iii) density, (iv) vertical location, (v) connectivity to one or more components, (vi) material makeup, or (vii) mechanism for affixing to a build module in which the first piston and the second piston are disposed during the three-dimensional printing. In some embodiments, the first piston comprises one or more openings. In some embodiments, the second piston is devoid of one or more openings. In some embodiments, the second piston comprises a cavity for temperature conditioning. In some embodiments, the first piston is devoid of a cavity for temperature conditioning. In some embodiments, the first piston and the second piston have (e.g., substantially) the same shape and/or length of circumference. In some embodiments, the build platform is configured to carry one or more three-dimensional objects during a printing cycle of the three-dimensional printing. In some embodiments, the device further comprises (A) an energy source configured to generate an energy beam to irradiate a pre-transformed material and transform into a transformed material to form the one or more three-dimensional objects, (B) a material extruder configured to extrude material to print the one or more three-dimensional objects, (C) a material dispenser, and/or (D) a laminator configured to deposit layerwise laminated layer to print the one or more three-dimensional objects. In some embodiments, the first piston is oriented closer to a gravitational center than the second piston. In some embodiments, the gravitational center is a gravitational center of an environment in which the device is disposed. In some embodiments, the environment is Earth. In some embodiments, the first piston and the second piston are concentrically aligned along a central axis. In some embodiments, the central axis is a vertical axis. In some embodiments, the adjusting coupler comprises a shaft. In some embodiments, a length of the adjusting coupler (e.g., shaft) being aligned with the central axis. In some embodiments, the adjusting coupler (e.g., shaft) is operatively coupled between the first piston and the second piston, a length of the adjusting coupler (e.g., shaft) being aligned with the central axis. In some embodiments, the first piston is configured to translate vertically. In some embodiments, the first piston is configured to translate with respect to the second piston and along the adjusting coupler (e.g., shaft). In some embodiments, the second piston is configured to translate with respect to the first piston and along the adjusting coupler (e.g., shaft). In some embodiments, the device further comprises an actuator. In some embodiments, the actuator comprises, or is operatively coupled with, a servo motor operatively coupled with the adjusting coupler (e.g., shaft) and configured to facilitate the translation in a vertical direction. In some embodiments, the actuator is operatively coupled with the first piston or to the second piston. In some embodiments, the actuator is coupled with the second piston. In some embodiments, translating vertically comprises different translation types. In some embodiments, the different translation types comprise an initiation movement, a block movement, or a layerwise movement. In some embodiments, the initiation movement comprises a vertical movement of at least half a total length of translation of the first piston or second piston with respect to a build module body configured to house the first piston and the second piston. In some embodiments, the initiation movement utilizes a first translation mechanism, and a second translation mechanism is utilized for (i) the block movement, (ii) layerwise movement, or (iii) the block movement and the layerwise movement. In some embodiments, layerwise movement comprises a first type of incremental translation. In some embodiments, the layerwise movement comprises multi-incremental translation. In some embodiments, the layerwise movement has a vertical span that is smaller by at least about fifty times as compared to the vertical span of the block movement and/or of the initiation movement. In some embodiments, the device further comprises a build module body housing the first piston and the second piston, wherein the initiation movement has a vertical span that is larger than a third, or a half of the vertical span of the build module body. In some embodiments, the initiation movement has a vertical span that is larger than the vertical span of the block movement (e.g., at its full span). In some embodiments, the block movement is an incremental translation having a vertical span of a maximal extent between the first piston and second piston that depends at least in part on a length of the adjusting coupler (e.g., shaft). In some embodiments, facilitating the three- dimensional printing comprises facilitating vertical translation of the build platform relative to the build module body. In some embodiments, facilitating the three-dimensional printing comprises facilitating vertical translation of the build platform comprises an error in vertical positioning of the vertical translation less than about 10%, 5%, or 2% of the vertical translation of the second piston assembly. In some embodiments, facilitating the translation of the build platform comprises facilitating vertical translation of the build platform when a material bed is generated on a surface of the build platform and supported by the build platform. In some embodiments, the material bed generated on the surface of the build platform comprises a fundamental length scale of at least about 300mm, 400mm, 600mm, 1000mm, or 1200 mm. In some embodiments, the material bed formed on the surface of the build platform and supported by the build platform comprises a fundamental length scale of at least about 1000 kg. In some embodiments, facilitating the three-dimensional printing comprises facilitating deposition of pre-transformed material on a target surface. In some embodiments, the target surface comprises (i) an exposed surface of a material bed or (ii) a surface of the build platform. In some embodiments, facilitating deposition of pre-transformed material on the target surface comprises enlarging a volume of the material bed, wherein an exposed surface of the material is (e.g., substantially) at a same position after deposition of pre-transformed material on the target surface. In some embodiments, facilitating deposition of pre-transformed material on the target surface comprises layerwise deposition. In some embodiments, the pre-transformed material comprises powder material. In some embodiments, the pre-transformed material comprises elemental metal, metal alloy, ceramic, or an allotrope of carbon. In some embodiments, the device is configured to operate under a positive pressure atmosphere relative to an ambient atmosphere external to the device. In some embodiments, the device is configured to operate under an atmosphere depleted of a reactive agent relative to its concentration in an ambient atmosphere external to the device, the reactive agent being configured to react with a starting material of the three- dimensional printing at least during the three-dimensional printing. In some embodiments, the reactive agent comprises oxygen, water, or hydrogen sulfide. In some embodiments, the device further comprises an encoder. In some embodiments, the encoder comprises an optical encoder configured to measure linear motion of the first piston with respect to the second piston. In some embodiments, the device further comprises a sensor. In some embodiments, the sensor comprises a position sensitive device. In some embodiments, the sensor comprises an interferometric detector. In some embodiments, the sensor comprises a fiber-coupled interferometric laser encoder. In some embodiments, the sensor is a component of a metrological detection system configured to measure a position of the first piston. In some embodiments, the metrological detection system further comprises a mirror arranged on a surface of the first piston and configured to reflect an energy beam incident on the mirror to the sensor. In some embodiments, the mirror comprises a retroreflector. In some embodiments, the position of the first piston comprises (i) a vertical position aligned with an axis of vertical translation, (ii) a horizontal position about a plane perpendicular to the axis of the vertical translation, (iii) a pitch with respect to an axis of a first central horizontal axis of the first piston, (iii) a roll with respect to a second central horizontal axis of the first piston, (iv) a yaw or a roll with respect to an axis of the vertical translation. In some embodiments, the first central horizontal axis and the second central horizontal axis are perpendicular to each other. In some embodiments, the device further comprises a build module body configured to house the first piston, the second piston, and the adjusting coupler (e.g., shaft) during the three-dimensional printing. In some embodiments, the device further comprises an engagement mechanism configured to reversibly engage and disengage from a wall of the build module body, the engagement mechanism being operatively coupled with the first piston or with the second piston. In some embodiments, the engagement mechanism comprises a piezoelectric actuator, an eccentric mechanism, a lead screw, a sliding double wedge mechanism, or a locking ring. In some embodiments, the eccentric mechanism comprises a ring or circle. In some embodiments, the eccentric mechanism comprises the locking ring. In some embodiments, the first engagement mechanism comprises, or is operatively coupled with, (i) a first set of engagement features configured to engage with an internal surface of the build module along the first axis, the first portion comprising the first set of engagement features, and (ii) a second set of engagement features configured to engage with an internal surface of the build module along the first axis, the second portion comprising the second set of engagement features. In some embodiments, the build module comprises at least one first alignment feature and a piston assembly comprises respective at least one second alignment feature, the at least one first alignment feature configured to engage with the at least one second alignment feature to, during printing, align the build module with respect to the build platform assembly disposed in the build module, and the piston assembly being the first piston assembly and/or the second piston assembly. In some embodiments, the at least one first alignment feature comprises a protrusion, and where the at least one second alignment feature comprises a depression configured to engage with the protrusion for alignment of the build module with the piston assembly. In some embodiments, the at least one first alignment feature comprises a depression, and where the at least one second alignment feature comprises a protrusion configured to engage with the depression for alignment of the build module with the piston assembly. In some embodiments, engagement features of the first set of engagement features and of the second set of engagement features comprise pads. In some embodiments, the first piston assembly comprises, or is operatively coupled with, (i) a first push-pull actuator operatively coupled with the first set of engagement features, the first push-pull actuator configured to reversibly push and reversibly pull the engagement features along the first axis, and (ii) a second push-pull actuator operatively coupled with the second set of engagement features, the second push-pull actuator configured to reversibly push and reversibly pull the engagement features along the second axis. In some embodiments, each engagement feature is coupled with a pin, the engagement feature being of the first set of engagement features and of the second set of engagement features. In some embodiments, (i) the first push-pull actuator is operatively coupled with the first set of engagement features, each through its respective pin, and/or (ii) the second push-pull actuator is operatively coupled with the second set of engagement features, each through its respective pin. In some embodiments, the first piston assembly is operatively coupled with, or include, push-pull actuators, the push pull actuators comprise the first push-pull actuator and the second push-pull actuator. In some embodiments, each of the push-pull actuators comprise a ring, a secondary piston, a piezoelectric actuator, an eccentric mechanism, a lead screw, or a sliding double wedge mechanism. In some embodiments, the eccentric mechanism comprises the ring or a circle. In some embodiments, the first push-pull actuator and the second push-pull actuator are of the same type. In some embodiments, the first push-pull actuator and the second push-pull actuator are of a different type. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to exert (e.g., substantially) the same force during their respective push operation, and during their respective pull operation. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to cause their respective engagement features to exert (e.g., substantially) the same force onto the build module during their respective push operation, and during their respective pull operation. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate in coordination with each other. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate simultaneously with respect to each other. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate sequentially with respect to each other. In some embodiments, (A) the first set of engagement features comprises a first engagement feature and a second engagement feature, and where the first push-pull actuator is configured to actuate the first engagement feature (e.g., substantially) simultaneously with actuation of the second engagement feature and/or (B) the second set of engagement features comprises a third engagement feature and a fourth engagement feature, and where the second push-pull actuator is configured to actuate the third engagement feature (e.g., substantially) simultaneously with actuation of the fourth engagement feature. In some embodiments, (A) the first set of engagement features comprises a first engagement feature and a second engagement feature, and where the first push-pull actuator is configured to actuate the first engagement feature sequentially to actuation of the second engagement feature and/or (B) the second set of engagement features comprises a third engagement feature and a fourth engagement feature, and where the second push-pull actuator is configured to actuate the third engagement feature sequentially to actuation of the fourth engagement feature. In some embodiments, the engagement mechanism is operatively coupled with a selected piston among the first piston and the second piston and wherein the engagement mechanism is configured to engage the engagement mechanism with a wall of the build module body to affix the selected piston with respect to the wall. The disclosure regarding the selected piston can apply to each of the first piston and the second piston, either alone or in combination, e.g., respectively. In some embodiments, the engagement mechanism of the selected piston is configured to restrict translation of the selected piston with respect to the build module body. In some embodiments, engagement mechanism of the selected piston is configured to apply a hold force on the wall of the build module body sufficient to hold (i) the build platform, (ii) a material bed formed on the build platform, and (iii) the three-dimensional objects. In some embodiments, the engagement mechanism comprises a deformation engagement mechanism. In some embodiments, the deformation engagement mechanism comprises a portion configured to reversibly expand and contract. In some embodiments, the deformation engagement mechanism comprises a portion configured to reversibly distort to engage and disengage. In some embodiments, the engagement mechanism comprises a locking system. In some embodiments, the locking system comprises: a ring concentrically arranged with respect to a circumference of the selected piston and affixed to the selected piston with respect to the wall of the build module body. In some embodiments, the ring is arranged with respect to the selected piston to define a cavity between a portion of the ring and an outer surface of the selected piston. In some embodiments, the cavity is operatively coupled with a channel and configured to be reversibly pressurized and depressurized. In some embodiments, the cavity is configured to be reversibly pressurized by a hydraulic fluid. In some embodiments, the cavity is configured to be reversibly pressurized by at least about 5000 kilopascals. In some embodiments, the cavity is pressurized such that the ring applies at least about 22,000 kilograms of holding force on the wall of the build module body. In some embodiments, the engagement mechanism comprises a fastening engagement mechanism. In some embodiments, the fastening engagement mechanism comprises at least one reversibly moving engagement feature. In some embodiments, the reversibly moving engagement feature includes one or more of a pin, a pad (e.g., jaw), a flap, a support, or any combination thereof. In some embodiments, the fastening engagement mechanism comprises a plurality of pins. In some embodiments, the plurality of pins is arranged about an outer circumference of the selected piston and configured to engage with a plurality of receptacles arranged about an inner circumference of the build module body. In some embodiments, the fastening engagement mechanism further comprises a plurality of seals arranged with respect to the plurality of receptacles and configured to optionally engage with the plurality of receptacles. In some embodiments, the plurality of seals is configured to engage with the plurality of receptacles to (e.g., substantially) prevent pre-transformed, debris, or transformed material from an inner volume of the plurality of receptacles. In some embodiments, engaging the plurality of pins comprises supporting, by the plurality of pins, a bottom surface of the selected piston. In some embodiments, the fastening engagement mechanism comprises a plurality of pads. In some embodiments, the fastening engagement mechanism comprises a plurality of pads arranged about (i) an outer circumference of the selected piston, (ii) an inner circumference of the build module body, or (iii) any combination thereof. In some embodiments, when the fastening engagement mechanism is engaged, the plurality of pads applies a hold force between the selected piston and the wall of the build module body, the wall opposing at least a portion of a circumference of the selected piston. In some embodiments, the engagement mechanism comprises a magnetic engagement mechanism. In some embodiments, the magnetic engagement mechanism comprises a plurality of electro-magnets. In some embodiments, the build module body comprises a bottom portion that is closer to a gravitational center with respect to the build module body. In some embodiments, the bottom portion comprises a plurality of interconnects configured to selectively couple to (i) a gas source, (ii) a gas purge, (iii) a temperature adjustment manifold, (iv) an electrical connection, (v) a hydraulic source, or (vi) any combination of (i), (ii), (iii), (iv), and (v). In some embodiments, the device further comprises a translational mechanism operatively coupled with the first piston, the translational mechanism being operatively coupled with the bottom portion of the build module body. In some embodiments, the translation of the first piston comprises translation by the translational mechanism operatively coupled with the first piston. In some embodiments, the translational mechanism comprises telescopic hydraulic cylinders arranged to extend a length in a direction. The translational mechanism may or may not comprise the telescopic hydraulic cylinders arranged to extend a length in a direction. In some embodiments, the translational mechanism comprises a hydraulic valve, wherein opening the hydraulic valve allows compression of the translational mechanism and closing the hydraulic value allows extension (e.g., substantially) prevents compression of the translational mechanism. In some embodiments, the build module body further comprises an interlock. In some embodiments, the interlock is a limit switch. In some embodiments, the limit switch limits an extent of travel of the first piston and/or the second piston with respect to the build module body. In some embodiments, the limit switch limits an extent of travel of the translational mechanism. In some embodiments, the limit switch limits an extent of travel of the first piston adjacent to the bottom portion of the build module body. In some embodiments, the limit switch limits an extent of travel of the second piston and/or the build platform adjacent to a top of the build module body with respect to gravitation center. In some embodiments, the build module body further comprises a seal. In some embodiments, the seal is included, or is operatively coupled with a shutter, a lid, a closure, an envelope, or a flap. In some embodiments, the seal is arranged with respect to an upper-most portion of the build module body and opposite a bottom portion of the build module body. In some embodiments, the seal is gas tight. In some embodiments, the seal is a hermetic seal. In some embodiments, the seal is configured to facilitate retaining an internal atmosphere in the build module body for a time period, the internal atmosphere being different from an ambient atmosphere external to the build module. In some embodiments, the seal is configured to facilitate retaining for a time period (i) a positive pressure within the build module body relative to an ambient atmosphere external to the device and/or (ii) a reactive agent at a concentration lower than its concentration in an ambient atmosphere external to the build module, the reactive agent being configured to at least react with pre-transformed material of the three-dimensional printing during the three-dimensional printing. In some embodiments, the time period is at least the same or greater value than a time period to remove the three-dimensional objects from the build module body. In some embodiments, the seal is arranged between the first piston and the second piston and configured to (e.g., substantially) prevent pre-transformed, debris, or transformed material from a volume between the first piston and the second piston. In some embodiments, the seal comprises a bellow. In some embodiments, the device further comprises a plurality of guide rods arranged about a central axis of the first piston and the second piston, the guide rods being configured to guide the translation of the first piston with respect to the second piston, the translation being vertical. In some embodiments, the device further comprises a build module configured to house the adjusting coupler (e.g., shaft), first piston, second piston and build platform, and wherein the build module is configured to reversibly operatively couple wit a processing chamber during the three-dimensional printing, and reversibly decouple from the processing chamber after the three-dimensional printing. In some embodiments, the device is configured to facilitate printing one or more three-dimensional objects in an atmosphere maintained to be different from an ambient atmosphere by at least one characteristic, the ambient atmosphere being external to a build module and to a processing chamber. In some embodiments, the at least one characteristic comprises (i) a pressure above a pressure presiding in the ambient atmosphere, or (ii) a reactive agent being at a concentration lower than its concentration in the ambient atmosphere, the reactive agent being reactive with a starting material of the three-dimensional printing at least during the three-dimensional printing. The device further comprises temperature adjustment interconnects configured to adjust a temperature of the first piston, the second piston, and/or the build platform. In some embodiments, the temperature adjustment interconnects comprise a manifold. In some embodiments, the temperature adjustment interconnects comprise a channel. In some embodiments, the channel is disposed at least in part within a portion of the build platform and/or second piston. In some embodiments, the temperature adjustment interconnects comprise an internal chamber within a portion of the build platform and/or build platform assembly, e.g., within the second piston thereof. In some embodiments, the temperature adjustment interconnects are configured to receive a flow of a temperature adjustment agent from a source. In some embodiments, the temperature adjustment agent comprises a gas, a fluid, or a semisolid. In some embodiments, the temperature adjustment agent comprises water. In some embodiments, the temperature adjustment agent comprises a coolant. In some embodiments, the temperature adjustment interconnects are configured to reduce a temperature of (i) the build platform, (ii) the first piston, (iii) the second piston, (iv) a material bed and/or three-dimensional objects carried by the build platform during three-dimensional printing, or (v) any combination thereof. In some embodiments, the temperature adjustment interconnects are configured to reduce a temperature at a time comprising: during the three-dimensional printing, or after the three-dimensional printing. In some embodiments, the temperature adjustment interconnects are configured to reduce a temperature at a time comprising: (i) before disengagement of a build module in which a three-dimensional object is disposed during the three-dimensional printing, or (ii) after disengagement of the build module from a processing chamber. In some embodiments, the adjusting coupler is operatively coupled with an encoder, e.g., an optical or a magnetic encoder. In some embodiments, the adjusting coupler comprises a scissor jack, a lead screw, or gas (e.g., air) bearings.

[0010] In another aspect, a method of three-dimensional printing, the method comprises: providing the device in any of the above devices; and using the device during the three- dimensional printing. In some embodiments, the three-dimensional printing comprises connecting a particulate matter. In some embodiments, connecting comprises fusing. In some embodiments, fusing comprises melting. In some embodiments, the method for three- dimensional printing, the method comprises: (a) providing a device comprising: a first piston; and a second piston being operatively coupled with the first piston, the second piston being configured to (i) translate to facilitate the three-dimensional printing, and (ii) engage with a build platform configured to carry one or more three-dimensional objects during the three-dimensional printing, the first piston being configured to translate, the first piston and the second piston being configured to translate relative to each other, and the first piston and/or the second piston being configured for translation during the three-dimensional printing; (b) affixing the first piston; (c) translating the second piston to facilitate printing a first layer of transformed material as part of the one or more three-dimensional objects; and (d) affixing the second piston; (e) detaching the first piston; and (f) translating the first piston to facilitate accurate printing the second piston to facilitate printing a second layer of transformed material as part of the one or more three- dimensional objects that is carried by the build platform. In some embodiments, the method of facilitating three-dimensional printing, the method comprises: reversibly affixing a first piston to prevent its movement relative to a second piston to which the first piston is operatively coupled at least in part using (e.g., through) an adjusting coupler (e.g., a shaft) configured to facilitate adjustment of a (e.g., vertical) gap, the first piston and the second piston being configured to reversibly affix and release, the second piston being operatively coupled with a build platform above which one or more three-dimensional objects are printed during the three-dimensional printing, wherein affixation prevents movement and wherein release permits movement; translating the second piston relative to the first piston in a first direction along the adjusting coupler (e.g., shaft) and toward the first piston, the second piston being released to facilitate its translation relative to the first piston; affixing the second piston to prevent its movement relative to the first piston; releasing the first piston to facilitate its movement relative to the second piston; and translating the first piston relative to the second piston in the first direction along the adjusting coupler (e.g., shaft) and away from the second piston. In some embodiments, reversibly affixing the first piston and/or the second piston, is to a support. In some embodiments, the support is a wall of a build module configured to house the first piston, the second piston, the adjusting coupler (e.g., shaft), and the build platform. In some embodiments, reversibly affixing utilizes a first mechanism and where in translating utilizes a second mechanism. In some embodiments, the second mechanism comprises an actuator and a detector configured to detect translational span. In some embodiments, the first mechanism utilizes an engagement mechanism.

[0011] In another aspect, an apparatus for three-dimensional printing, the apparatus comprises at least one controller configured to (i) operatively couple to any of the above devices; and control, or direct control of, one or more operations associated with the device. In some embodiments, the at least one controller comprises at least one connector configured to connect to a power source. In some embodiments, the at least one controller being configured to operatively couple to a power source at least in part by (I) having a power socket and/or (II) being configured for wireless power transfer using inductive charging. In some embodiments, the at least one controller is included in, or comprises, a hierarchical control system. In some embodiments, the hierarchical control system comprises at least three hierarchical control levels. In some embodiments, the at least one controller is included in a control system configured to control a three-dimensional printer that prints one or more three-dimensional objects. In some embodiments, the device is a component of a three-dimensional printing system, and wherein the at least one controller is configured to (i) operatively couple to an other component of the three-dimensional printing system and (ii) direct operation of the other component. In some embodiments, the at least one controller is configured to direct operation of the other component at least in part for participation of the other component in three- dimensional printing. In some embodiments, the apparatus for three-dimensional printing, the apparatus comprises: at least one controller configured to: (a) operatively couple to a device comprising: a first piston; and a second piston being operatively coupled with the first piston, the second piston being configured to (i) translate to facilitate the three-dimensional printing, and (ii) engage with a build platform configured to carry one or more three-dimensional objects during the three-dimensional printing, the first piston being configured to translate, the first piston and the second piston being configured to translate relative to each other, and the first piston and/or the second piston being configured for translation during the three-dimensional printing; (b) direct affixation of the first piston; (c) direct translation of the second piston to facilitate printing a first layer of transformed material as part of the one or more three-dimensional objects; and (d) direct affixation of the second piston; (e) direct detachment of the first piston; and (f) direct translation of the first piston to facilitate accurate printing the second piston to facilitate printing a second layer of transformed material as part of the one or more three-dimensional objects that is carried by the build platform. In some embodiments, the apparatus for three-dimensional printing, the apparatus comprises at least one controller configured to: (A) operatively couple to a first piston and a second piston, the first piston being operatively coupled with the second piston through a shaftat least in part using an adjusting coupler (e.g., a shaft) configured to facilitate adjustment of a (e.g., vertical) gap a gap between the first piston and the second piston, the first piston and the second piston being configured to reversibly (e.g., horizontally) affix and release, the second piston being operatively coupled with a build platform above which one or more three-dimensional objects are printed during the three-dimensional printing process; (B) direct affixation of the first piston to prevent its movement relative to the second piston to, the affixation being reversible; (C) direct translation of the second piston relative to the first piston in a first direction along the adjusting coupler (e.g., shaft) and toward the first piston; (D) direct affixation of the second piston to prevent its movement relative to the first piston, the affixation being reversible; (E) direct release of the first piston to facilitate its movement relative to the second piston, the release being reversible; and (G) direct translation of the first piston relative to the second piston in the first direction along the adjusting coupler (e.g., shaft) and away from the second piston. In some embodiments, the at least one controller is configured to direct reversible affixation of the first piston and/or of the second piston, to a support. In some embodiments, the support is a wall of a build module configured to house the first piston, the second piston, the adjusting coupler (e.g., shaft), and the build platform. In some embodiments, the at least one controller is configured to direct reversible affixation at least in part by begin configured to direct a first mechanism; and wherein the at least one controller is configured to direct translation at least in part by being configured to direct a second mechanism. In some embodiments, the second mechanism comprises an actuator and a detector configured to detect translational span. In some embodiments, the first mechanism utilizes an engagement mechanism.

[0012] In another aspect, non-transitory computer readable program instructions for three- dimensional printing, the program instructions, when read by one or more processors operatively coupled with any of the above devices, cause the one or more processors to execute, or direct execution of, one or more operations associated with the device. In some embodiments, the program instructions are inscribed in or more media. In some embodiments, the non-transitory computer readable program instructions for three-dimensional printing, the program instructions, when read by the one or more processors operatively coupled with a device, cause the one or more processors to execute operations, the device comprising: a first piston; and a second piston being operatively coupled with the first piston, the second piston being configured to (i) translate to facilitate the three-dimensional printing, and (ii) engage with a build platform configured to carry one or more three-dimensional objects during the three- dimensional printing, the first piston being configured to translate, the first piston and the second piston being configured to translate relative to each other, and the first piston and/or the second piston being configured for translation during the three-dimensional printing; the operations comprise: (a) directing affixation of the first piston; (b) directing translation of the second piston to facilitate printing a first layer of transformed material as part of the one or more three- dimensional objects; and (c) directing affixation of the second piston; (d) directing detachment of the first piston; and (e) directing translation of the first piston to facilitate accurate printing the second piston to facilitate printing a second layer of transformed material as part of the one or more three-dimensional objects that is carried by the build platform. In some embodiments, the non-transitory computer readable program instructions for three-dimensional printing, the program instructions, when read by one or more processors operatively coupled with a device, cause the one or more processors to execute operations, the device comprises: a first piston; a second piston operatively coupled with the second piston through an adjusting coupler (e.g., a shaft) configured to facilitate adjustment of a (e.g., vertical) gap between the first piston and the second piston, the first piston and the second piston being configured to reversibly (e.g., horizontally) affix and release, the second piston being operatively coupled with a build platform above which one or more three-dimensional objects are printed during the three-dimensional printing process, the first piston being configured to translate, the first piston and the second piston being configured to translate relative to each other, and the first piston and/or the second piston being configured for translation during the three-dimensional printing, the operations comprising: (A) directing affixation of the first piston to prevent its movement relative to the second piston to, the affixation being reversible; (B) directing translation of the second piston relative to the first piston in a first direction along the adjusting coupler (e.g., shaft) and toward the first piston; (C) directing affixation of the second piston to prevent its movement relative to the first piston, the affixation being reversible; (D) directing release of the first piston to facilitate its movement relative to the second piston, the release being reversible; and (E) directing translation of the first piston relative to the second piston in the first direction along the adjusting coupler (e.g., shaft) and away from the second piston.

[0013] In another aspect, a system for three-dimensional printing, the system comprises: any of the above devices configured to perform three-dimensional printing; and an energy beam configured to irradiate a planar layer of powder material to print at least a portion of at least one three-dimensional object at least in part by using three-dimensional printing. In some embodiments, the system further comprises a scanner configured to translate the energy beam along a target surface, wherein the device is operatively coupled with the scanner. The system further comprises an energy source configured to generate the energy beam, wherein the device is operatively coupled with the energy source. The system further comprises at least one controller that (i) is operatively coupled with the device and (ii) direct one or more operations associated with the device. In some embodiments, the system is configured to operatively couple to at least one controller configured to (i) operatively couple to the system and (ii) direct one or more operations associated with the system. In some embodiments, the system for three-dimensional printing, the system comprising: a first piston; an adjusting coupler (e.g., a shaft) configured to facilitate adjustment of a (e.g., vertical) gap, the adjusting coupler operatively coupled with the first piston; and a second piston being operatively coupled with the first piston at least in part using (e.g., through) the adjusting coupler (e.g., shaft), the second piston being configured to (i) translate to facilitate the three-dimensional printing, and (ii) engage with a build platform configured to carry one or more three-dimensional objects during the three- dimensional printing, the gap being between the first piston and the second piston, the first piston being configured to translate, the first piston and the second piston being configured to translate relative to each other to alter the gap, and the first piston and/or the second piston being configured for translation during the three-dimensional printing; and (A) an energy source configured to generate an energy beam to irradiate a pre-transformed material and transform into a transformed material to form the one or more three-dimensional objects, (B) a material extruder configured to extrude material to print the one or more three-dimensional objects, (C) a material dispenser, and/or (D) a laminator configured to deposit layerwise laminated layer to print the one or more three-dimensional objects. In some embodiments, the system for three- dimensional printing, the system comprises: a first piston; a second piston operatively coupled with the second piston at least in part using (e.g., through) an adjusting coupler (e.g., a shaft) configured to facilitate adjustment of a (e.g., vertical) gap between the first piston and the second piston, the first piston and the second piston being configured to reversibly (e.g., horizontally) affix and release, the second piston being operatively coupled with a build platform above which one or more three-dimensional objects are printed during the three-dimensional printing, the first piston being configured to translate, the first piston and the second piston being configured to translate relative to each other, and the first piston and/or the second piston being configured for translation during the three-dimensional printing; and (A) an energy source configured to generate an energy beam to irradiate a pre-transformed material and transform into a transformed material to form the one or more three-dimensional objects, (B) a material extruder configured to extrude material to print the one or more three-dimensional objects, (C) a material dispenser, and/or (D) a laminator configured to deposit layerwise laminated layer to print the one or more three-dimensional objects.

[0014] In another aspect, a device for three-dimensional printing, the device comprises: a build platform assembly configured to engage with a build platform configured to carry one or more three-dimensional objects during the three-dimensional printing, the build platform assembly being configured to translate such that a first portion of the build platform assembly is configured to translate in a first translation type in a direction and a second portion of the build platform assembly is configured to translate in a second translation type in the direction. In some embodiments, the direction is a vertical direction. In some embodiments, the build platform is disposed in a build module, and wherein the direction is along a wall of the build module. In some embodiments, the build platform is disposed in a build module, and wherein the direction is (i) towards a floor of the build module or (ii) away from the floor of the build module. In some embodiments, the build platform is disposed in a build module. In some embodiments, the build platform is configured for disposition in the build module, and wherein during the printing, the build platform assembly is configured for translation towards a gravitational environmental center or away from the gravitational environmental center. In some embodiments, the device further comprises (A) an energy source configured to generate an energy beam to irradiate a pre-transformed material and transform into a transformed material to form the one or more three-dimensional objects, (B) a material extruder configured to extrude material to print the one or more three-dimensional objects, (C) a material dispenser, and/or (D) a laminator configured to deposit layerwise laminated layer to print the one or more three-dimensional objects. In some embodiments, the first portion of the build platform assembly comprises a first piston, and the second portion of the build platform assembly comprises a second piston. In some embodiments, the first piston and the second piston are the same in at least one characteristic comprising (i) horizontal circumference shape, (ii) horizontal circumference length, (iii) horizontal cross-section, (iv) horizontal location, (v) material makeup, or (vi) mechanism for affixing to a build module in which the first piston and the second piston are disposed during the three- dimensional printing. In some embodiments, the first piston and the second piston are different by at least one characteristic comprising (i) functionality, (ii) shape, (iii) density, (iv) vertical location, (v) connectivity to one or more components, (vi) material makeup, or (vii) mechanism for affixing to a build module in which the first piston and the second piston are disposed during the three-dimensional printing. In some embodiments, the first piston comprises one or more openings. In some embodiments, the second piston is devoid of one or more openings. In some embodiments, the second piston comprises a cavity for temperature conditioning. In some embodiments, the first piston is devoid of a cavity for temperature conditioning. In some embodiments, the first piston and the second piston have (e.g., substantially) the same shape and/or length of circumference. In some embodiments, the device is configured to translate translations including the first translation type and the second translation type, the translations selected from at least two members of the group comprising a layerwise translation, a block translation, or an initiation translation. In some embodiments, the device is configured to translate portions including the first portion and the second portion, the portions selected from two members of the group comprising a first piston assembly, a second piston assembly, or a translational mechanism. In some embodiments, the direction comprises an upward direction or a downward direction, with respect to the environmental gravitational center. In some embodiments, the first piston is oriented closer to a gravitational center than the second piston. In some embodiments, the gravitational center is a gravitational center of the Earth. In some embodiments, the first piston is aligned with the second piston along a central axis. In some embodiments, the central axis is a vertical axis. In some embodiments, the device further comprises an adjusting coupler (e.g., a shaft) configured to facilitate adjustment of a (e.g., vertical) gap between the first piston and the second piston operatively coupled between the first piston and the second piston. In some embodiments, the adjusting coupler comprises a shaft. In some embodiments, a length of the adjusting coupler (e.g., shaft) is aligned with the central axis. In some embodiments, the device further comprises an actuator. In some embodiments, the actuator comprises, or is operatively coupled with a servo motor operatively coupled with the adjusting coupler (e.g., shaft) and configured to facilitate the translation of the first translation type and the second translation type. In some embodiments, the actuator being coupled with the first piston or to the second piston. In some embodiments, the actuator being coupled with the first piston. In some embodiments, the first piston is configured to engage with the build platform. In some embodiments, the build platform assembly being configured for repetitive translation. In some embodiments, (i) the first translation type comprises a block movement and (ii) the second translation type comprises an incremental layerwise movement. In some embodiments, the block movement comprises a first translation of the first portion of the build platform assembly that is at least about half a full extent of vertical translation of the first portion of the build platform assembly with respect to the second portion of the build platform assembly. In some embodiments, the block movement comprises a first translation of the first portion of the build platform assembly that is (e.g., substantially) equal to a full extent of vertical translation of the first portion of the build platform assembly with respect to the second portion of the build platform assembly. In some embodiments, the block movement comprises a repetitive translation of the first portion of the build platform assembly along a build module body. In some embodiments, the second translation type comprises a plurality of incremental layerwise movements. In some embodiments, the incremental layerwise movement comprises a repetitive translation of the second portion of the build platform assembly with respect to the first portion of the build platform assembly. In some embodiments, the incremental layerwise movement comprises repetitive translation of the second portion of the build platform assembly towards the first portion of the build platform assembly. In some embodiments, the incremental layerwise movement of the second portion of the build platform assembly follows or precedes the block movement of the first portion of the build platform assembly. In some embodiments, the block movement and the incremental layerwise movement comprise translation downwards towards a gravitational center and/or a floor of a build module body. In some embodiments, the block movement comprises a first translation of a first piston of the build platform assembly. In some embodiments, the block movement comprises a translation of the first portion of the build platform assembly away from the second portion of the build platform assembly. In some embodiments, the block movement comprises translating the first portion of the build platform assembly away from the second portion of the build platform assembly by extending the first portion of the build platform assembly along an adjusting coupler (e.g., comprising a shaft, a lead screw, or a scissor jack) configured to facilitate adjustment of a (e.g., vertical) gap between the first portion and the second portion of the build platform assembly, the adjusting coupler coupled with the first portion and with the second portion of the build platform assembly. In some embodiments, the block movement comprises translating the first portion of the build platform assembly by less than about half a length of the adjusting coupler (e.g., shaft). In some embodiments, extending the first portion away from the second portion of the build platform assembly comprises translating the first portion to be closer to a gravitational center. In some embodiments, the second portion of the build platform assembly is held with respect to a build module body while the first portion of the build platform assembly is translated. In some embodiments, the incremental layerwise movement comprises a second translation of the second portion of the build platform assembly that is less than about half a full extent of translation of the second portion of the build platform assembly with respect to the first portion of the build platform assembly. In some embodiments, the incremental layerwise movement comprises a second vertical translation of the second portion of the build platform assembly that is less than about 0.1% of a full extent of translation of the second portion of the build platform assembly with respect to the first portion of the build platform assembly. In some embodiments, the incremental layerwise movement comprises a second vertical translation of the second portion of the build platform assembly that is less than about 0.05% of a full extent of translation of the second portion of the build platform assembly with respect to the first portion of the build platform assembly. In some embodiments, the incremental layerwise movement comprises a second vertical translation of the second portion of the build platform assembly that is less than about 0.025% of a full extent of translation of the second portion of the build platform assembly with respect to the first portion of the build platform assembly. In some embodiments, the incremental layerwise movement comprises a second translation of the second portion of the build platform assembly such that the second portion of the build platform assembly is translated towards the first portion of the build platform assembly along an adjusting coupler (e.g., a shaft) configured to facilitate adjustment of a (e.g., vertical) gap between the first portion and the second portion of the build platform assembly, the adjusting coupler coupled with the first portion and with the second portion of the build platform assembly. In some embodiments, the first translation type comprises an initiation movement and the second translation type comprises a block movement. In some embodiments, the initiation movement comprises a translation of the build platform assembly with respect to a build module body from a first position to a second position. In some embodiments, the initiation movement utilizes a first translation mechanism, and a second translation mechanism is utilized for (i) the block movement, (ii) layerwise movement, or (iii) the block movement and the layerwise movement. In some embodiments, the second position is above the first position with respect to a gravitational center and/or a bottom of the build module body. In some embodiments, the initiation movement comprises at least 50% of a vertical height of the build module body. In some embodiments, the second position is a top-most position of the build platform assembly with respect to the build module body. In some embodiments, the first position is a bottom-most position of the build platform assembly with respect to the build module body. In some embodiments, the build platform assembly comprises a translation mechanism configured to translate the build platform assembly from the first position to the second position. In some embodiments, the initiation movement positions the build platform at an initiation position with respect to a build module body to initiate the three- dimensional printing. In some embodiments, the block movement comprises translating the second portion of the build platform assembly away from the first portion of the build platform assembly by extending the second portion of the build platform assembly along an adjusting coupler (e.g., a shaft) configured to facilitate adjustment of a (e.g., vertical) gap between the first portion and the second portion of the build platform assembly, the adjusting coupler coupled with the first portion and with the second portion of the build platform assembly. In some embodiments, the initiation movement and the block movement comprise translation upwards and away from the gravitational center and/or away from a bottom of a build module body. In some embodiments, the device further comprises a build module body configured to retain the build platform assembly within an inner volume of the build module body during the three- dimensional printing. In some embodiments, the build module body further comprises a seal. In some embodiments, the seal is included, or is operatively coupled with a shutter, a lid, a closure, an envelope, or a flap. In some embodiments, the seal is arranged with respect to an uppermost portion of the build module body and opposite a bottom portion of the build module body. In some embodiments, the seal is gas tight. In some embodiments, the seal is a hermetic seal. In some embodiments, the seal is configured to facilitate retaining an internal atmosphere in the build module body for a time period, the internal atmosphere being different from an ambient atmosphere external to the build module. In some embodiments, the seal is configured to facilitate retaining for a time period (i) a positive pressure within the build module body relative to an ambient atmosphere external to the device and/or (ii) a reactive agent at a concentration lower than its concentration in an ambient atmosphere external to the build module, the reactive agent being configured to at least react with pre-transformed material of the three-dimensional printing during the three-dimensional printing. In some embodiments, the seal is arranged between the first piston and the second piston and configured to (e.g., substantially) prevent pre-transformed, debris, or transformed material from a volume between the first piston and the second piston. In some embodiments, the seal comprises a bellow. In some embodiments, the first portion of the build platform assembly comprises a first engagement mechanism and the second portion of the build platform assembly comprises a second engagement mechanism. In some embodiments, the first engagement mechanism of the first portion of the build platform assembly is configured to reversibly engage or disengage with a wall of the build module body before, during, or after the first translation type. In some embodiments, the first engagement mechanism is configured to engage the first portion of the build platform assembly with the wall of the build module body to affix the first portion of the build platform assembly with respect to the wall of the build module body. In some embodiments, the second engagement mechanism of the second portion of the build platform assembly is configured to reversibly engage or disengage with a wall of the build module body before, during, or after the second translation type. In some embodiments, the second engagement mechanism is configured to engage the second portion of the build platform assembly with the wall of the build module body to affix the second portion of the build platform assembly with respect to the wall of the build module body. In some embodiments, an engagement mechanism of the first engagement mechanism or second engagement mechanism is operatively coupled with a selected portion among the first portion and the second portion, and wherein the engagement mechanism is configured to engage the engagement mechanism with a wall of the build module body to affix the selected portion with respect to the wall. In some embodiments, the engagement mechanism of the selected portion is configured to restrict translation of the selected portion with respect to the build module body. In some embodiments, translation is a vertical translation. In some embodiments, engagement mechanism of the selected portion is configured to apply a hold force on the wall of the build module body sufficient to hold (i) the build platform, (ii) a material bed formed on the build platform, and (iii) the three-dimensional objects. In some embodiments, the engagement mechanism comprises a deformation engagement mechanism. In some embodiments, the deformation engagement mechanism comprises a portion configured to reversibly expand and contract. In some embodiments, the deformation engagement mechanism comprises a portion configured to reversibly distort to engage and disengage. In some embodiments, the engagement mechanism comprises a locking system. In some embodiments, the locking system comprises: a ring concentrically arranged with respect to a circumference of the selected portion and affixed to the selected portion with respect to the wall of the build module body. In some embodiments, the ring is arranged with respect to the selected portion to define a cavity between a portion of the ring and an outer surface of the selected portion. In some embodiments, the cavity is operatively coupled with a channel and configured to be reversibly pressurized and depressurized. In some embodiments, the cavity is configured to be reversibly pressurized by a hydraulic fluid. In some embodiments, the cavity is configured to be reversibly pressurized by at least about 5000 kilopascals. In some embodiments, the cavity is pressurized such that the ring applies at least about 22,000 kilograms of holding force on the wall of the build module body. In some embodiments, the engagement mechanism comprises a fastening engagement mechanism. In some embodiments, the fastening engagement mechanism comprises at least one reversibly moving engagement feature. In some embodiments, the reversibly moving engagement feature includes one or more of a pin, a pad, a flap, a support, or any combination thereof. In some embodiments, the fastening engagement mechanism comprises a plurality of pins. In some embodiments, the plurality of pins is arranged about an outer circumference of the selected portion and configured to engage with a plurality of receptacles arranged about an inner circumference of the build module body. In some embodiments, the fastening engagement mechanism further comprises a plurality of seals arranged with respect to the plurality of receptacles and configured to optionally engage with the plurality of receptacles. In some embodiments, the plurality of seals is configured to engage with the plurality of receptacles to (e.g., substantially) prevent pre-transformed, debris, or transformed material from an inner volume of the plurality of receptacles. In some embodiments, engaging the plurality of pins comprises supporting, by the plurality of pins, a bottom surface of the selected portion. In some embodiments, the fastening engagement mechanism comprises a plurality of pads. In some embodiments, the fastening engagement mechanism comprises a plurality of pads arranged about (i) an outer circumference of the selected portion, (ii) an inner circumference of the build module body, or (iii) any combination thereof. In some embodiments, when the fastening engagement mechanism is engaged, the plurality of pads applies a hold force between the selected portion and the wall of the build module body, the wall opposing at least a portion of a circumference of the selected portion. In some embodiments, the engagement mechanism comprises a magnetic engagement mechanism. In some embodiments, the magnetic engagement mechanism comprises a plurality of electro-magnets. In some embodiments, the first engagement mechanism comprises, or is operatively coupled with, (i) a first set of engagement features configured to engage with an internal surface of the build module along the first axis, the first portion comprising the first set of engagement features, and (ii) a second set of engagement features configured to engage with an internal surface of the build module along the first axis, the second portion comprising the second set of engagement features. In some embodiments, the build module comprises at least one first alignment feature and a piston assembly comprises respective at least one second alignment feature, the at least one first alignment feature configured to engage with the at least one second alignment feature to, during printing, align the build module with respect to the build platform assembly disposed in the build module, and the piston assembly being the first piston assembly and/or the second piston assembly. In some embodiments, the at least one first alignment feature comprises a protrusion, and where the at least one second alignment feature comprises a depression configured to engage with the protrusion for alignment of the build module with the piston assembly. In some embodiments, the at least one first alignment feature comprises a depression, and where the at least one second alignment feature comprises a protrusion configured to engage with the depression for alignment of the build module with the piston assembly. In some embodiments, engagement features of the first set of engagement features and of the second set of engagement features comprise pads. In some embodiments, the first piston assembly comprises, or is operatively coupled with, (i) a first push-pull actuator operatively coupled with the first set of engagement features, the first push-pull actuator configured to reversibly push and reversibly pull the engagement features along the first axis, and (ii) a second push-pull actuator operatively coupled with the second set of engagement features, the second push-pull actuator configured to reversibly push and reversibly pull the engagement features along the second axis. In some embodiments, each engagement feature is coupled with a pin, the engagement feature being of the first set of engagement features and of the second set of engagement features. In some embodiments, (i) the first push-pull actuator is operatively coupled with the first set of engagement features, each through its respective pin, and/or (ii) the second push-pull actuator is operatively coupled with the second set of engagement features, each through its respective pin. In some embodiments, the first piston assembly is operatively coupled with, or include, push-pull actuators, the push pull actuators comprise the first push-pull actuator and the second push-pull actuator. In some embodiments, each of the push-pull actuators comprise a ring, a secondary piston, a piezoelectric actuator, an eccentric mechanism, a lead screw, or a sliding double wedge mechanism. In some embodiments, the eccentric mechanism comprises the ring or a circle. In some embodiments, the first push-pull actuator and the second push-pull actuator are of the same type. In some embodiments, the first push-pull actuator and the second push-pull actuator are of a different type. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to exert (e.g., substantially) the same force during their respective push operation, and during their respective pull operation. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to cause their respective engagement features to exert (e.g., substantially) the same force onto the build module during their respective push operation, and during their respective pull operation. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate in coordination with each other. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate simultaneously with respect to each other. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate sequentially with respect to each other. In some embodiments, (A) the first set of engagement features comprises a first engagement feature and a second engagement feature, and where the first push-pull actuator is configured to actuate the first engagement feature (e.g., substantially) simultaneously with actuation of the second engagement feature and/or (B) the second set of engagement features comprises a third engagement feature and a fourth engagement feature, and where the second push-pull actuator is configured to actuate the third engagement feature (e.g., substantially) simultaneously with actuation of the fourth engagement feature. In some embodiments, (A) the first set of engagement features comprises a first engagement feature and a second engagement feature, and where the first push-pull actuator is configured to actuate the first engagement feature sequentially to actuation of the second engagement feature and/or (B) the second set of engagement features comprises a third engagement feature and a fourth engagement feature, and where the second push-pull actuator is configured to actuate the third engagement feature sequentially to actuation of the fourth engagement feature. In some embodiments, the device further comprises a sensor. In some embodiments, the sensor comprises a position sensitive device. In some embodiments, the sensor comprises an interferometric detector. In some embodiments, the sensor comprises a fiber-coupled interferometric laser encoder. In some embodiments, the sensor is a component of a metrological detection system configured to measure a position of the first portion of the build platform assembly. In some embodiments, the position of the first portion comprises (i) a vertical position aligned with an axis of vertical translation, (ii) a horizontal position about a plane perpendicular to the axis of the vertical translation, (iii) a pitch with respect to an axis of a first central horizontal axis of the first portion, (iii) a roll with respect to a second central horizontal axis of the first portion, (iv) a yaw or a roll with respect to an axis of the vertical translation. In some embodiments, the first central horizontal axis and the second central horizontal axis are perpendicular to each other. In some embodiments, the metrological detection system further comprises a mirror arranged on a surface of the first portion of the build platform assembly and configured to reflect an energy beam incident on the mirror to the sensor. In some embodiments, the device further comprises a build module body configured to retain a portion of the build platform assembly. In some embodiments, the build module body further comprises an interlock. In some embodiments, the interlock is a limit switch. In some embodiments, the limit switch limits an extent of travel of the build platform assembly with respect to the build module body. In some embodiments, the limit switch limits an extent of travel of the build platform assembly disposed adjacent to a floor (e.g., base of) of the build module body, e.g., body and between the build platform assembly and the floor of the module body. In some embodiments, the limit switch limits an extent of travel of the build platform assembly adjacent to a top of the build module body with respect to gravitation center. In some embodiments, the three- dimensional printing comprises vertical (e.g., stepwise, or incremental) translation of the build platform relative to the build module body. In some embodiments, the three-dimensional printing comprises (e.g., stepwise, or incremental) translation of the build platform in the direction, the (e.g., stepwise, or incremental) translation comprising an error in positioning of the translation less than about 10%, 5%, or 2% of the translation of the second portion of the build platform assembly and/or of the build platform. In some embodiments, translation of the build platform comprises facilitating translation of the build platform when a material bed is generated on a surface of the build platform and supported by the build platform. In some embodiments, the material bed generated on the surface of the build platform comprises a fundamental length scale of at least about 300mm, 400mm, 600mm, 1000mm, or 1200 mm. In some embodiments, the material bed formed on the surface of the build platform and supported by the build platform comprises a fundamental length scale of at least about 1000 kg. In some embodiments, the three-dimensional printing comprises facilitating deposition of pre-transformed material on a target surface. In some embodiments, the target surface comprises (i) an exposed surface of a material bed or (ii) a surface of the build platform. In some embodiments, facilitating deposition of pre-transformed material on the target surface comprises enlarging a volume of the material bed, wherein an exposed surface of the material is at a same position after deposition of pretransformed material on the target surface. In some embodiments, facilitating deposition of pretransformed material on the target surface comprises layerwise deposition. In some embodiments, the pre-transformed material comprises powder material. In some embodiments, the pre-transformed material comprises elemental metal, metal alloy, ceramic, or an allotrope of carbon. In some embodiments, the device is configured to operate under a positive pressure atmosphere relative to an ambient atmosphere external to the device. In some embodiments, the device is configured to operate under an atmosphere depleted of a reactive agent relative to its concentration in an ambient atmosphere external to the device, the reactive agent being configured to react with a starting material of the three-dimensional printing at least during the three-dimensional printing. In some embodiments, the reactive agent comprises oxygen, water, or hydrogen sulfide. In some embodiments, the device further comprises temperature adjustment interconnects configured to adjust a temperature of the first portion, the second portion, and/or the build platform. In some embodiments, the temperature adjustment interconnects comprise a manifold. In some embodiments, the temperature adjustment interconnects comprise a channel. In some embodiments, the channel is disposed at least in part within a portion of the build platform and/or second portion. In some embodiments, the temperature adjustment interconnects comprise an internal chamber within a portion of the build platform and/or build platform assembly, e.g., within the second portion thereof. In some embodiments, the temperature adjustment interconnects are configured to receive a flow of a temperature adjustment agent from a source. In some embodiments, the temperature adjustment agent comprises a gas, a fluid, or a semisolid. In some embodiments, the temperature adjustment agent comprises water. In some embodiments, the temperature adjustment agent comprises a coolant. In some embodiments, the temperature adjustment interconnects are configured to reduce a temperature of (i) the build platform, (ii) the first piston, (iii) the second piston, (iv) a material bed and/or three-dimensional objects carried by the build platform during three-dimensional printing, or (v) any combination thereof. In some embodiments, the temperature adjustment interconnects are configured to reduce a temperature at a time comprising: during the three-dimensional printing, or after the three-dimensional printing. In some embodiments, the temperature adjustment interconnects are configured to reduce a temperature at a time comprising: (i) before disengagement of a build module in which a three-dimensional object is disposed during the three-dimensional printing, or (ii) after disengagement of the build module from a processing chamber. In some embodiments, the adjusting coupler is operatively coupled with an encoder, e.g., an optical or a magnetic encoder. In some embodiments, the adjusting coupler comprises a scissor jack, a lead screw, or gas (e.g., air) bearings.

[0015] In some embodiments, the method of three-dimensional printing, the method comprises: providing any of the above devices; and using the device during the three- dimensional printing. In some embodiments, the three-dimensional printing comprises connecting a particulate matter. In some embodiments, connecting comprises fusing. In some embodiments, fusing comprises melting. In some embodiments, the method for three- dimensional printing, the method comprises: (a) Providing a device comprising: a build platform assembly configured to engage with a build platform configured to carry one or more three- dimensional objects during the three-dimensional printing, the build platform assembly being configured to translate such that a first portion of the build platform assembly is configured to translate in a first translation type in a direction and a second portion of the build platform assembly is configured to translate in a second translation type in the direction; (b) engaging the build platform with the build platform assembly; (a) affixing the first portion; (b) translating the second portion in the direction to facilitate printing a first layer of transformed material as part of the one or more three-dimensional objects; and (c) affixing the second portion; (d) detaching the first portion; and (e) translating the first portion in the direction of the second portion to facilitate printing a second layer of transformed material as part of the one or more three-dimensional objects that is carried by the build platform. In some embodiments, the method for three- dimensional printing, the method comprises: vertically translating in a direction a first portion of a build platform assembly in a first translation type, the first portion being operatively coupled with a build platform above which one or more three-dimensional objects are printed during the three-dimensional printing; and vertically translating in the direction a second portion of the build platform assembly relative to the first portion in a second translation type, the first translation type and the second translation type being different.

[0016] In another aspect, an apparatus for three-dimensional printing, the apparatus comprises at least one controller configured to (i) operatively couple any of the above devices; and control, or direct control of, one or more operations associated with the device. In some embodiments, the at least one controller comprises at least one connector configured to connect to a power source. In some embodiments, the at least one controller being configured to operatively couple to a power source at least in part by (I) having a power socket and/or (II) being configured for wireless power transfer using inductive charging. In some embodiments, the at least one controller is included in, or comprises, a hierarchical control system. In some embodiments, the hierarchical control system comprises at least three hierarchical control levels. In some embodiments, the at least one controller is included in a control system configured to control a three-dimensional printer that prints the one or more three-dimensional objects. In some embodiments, the device is a component of a three-dimensional printing system, and wherein the at least one controller is configured to (i) operatively couple to an other component of the three-dimensional printing system and (ii) direct operation of the other component. In some embodiments, the at least one controller is configured to direct operation of the other component at least in part for participation of the other component in three- dimensional printing. In some embodiments, the apparatus for three-dimensional printing, the apparatus comprises: at least one controller configured to: (a) operatively couple to a device comprising: a build platform assembly configured to engage with a build platform configured to carry one or more three-dimensional objects during the three-dimensional printing, the build platform assembly being configured to translate such that a first portion of the build platform assembly is configured to translate in a first translation type in a direction and a second portion of the build platform assembly is configured to translate in a second translation type in the direction; (q) direct engagement of the build platform with the build platform assembly; (b) direct affixation of the first portion; (c) direct translation of the second portion in the direction to facilitate printing a first layer of transformed material as part of the one or more three- dimensional objects; and (d) direct affixation the second portion; (e) direct detachment of the first portion; and (f) direct translation of the first portion in the direction to facilitate accurate printing the second piston to facilitate printing a second layer of transformed material as part of the one or more three-dimensional objects that is carried by the build platform. In some embodiments, the apparatus for three-dimensional printing, the apparatus comprises at least one controller configured to: (A) operatively couple to a build platform assembly supportive of a build platform configured to carry one or more three-dimensional objects during the three- dimensional printing; (B) direct vertical translation of a first portion of the build platform assembly comprises in a first translation type in a direction; and (C) direct vertical translation of a second portion of the build platform assembly comprises relative to the first portion in a second translation type in the direction, the first translation type and the second translation type being different.

[0017] In another aspect, non-transitory computer readable program instructions for three- dimensional printing, the program instructions, when read by one or more processors operatively coupled with any of the above devices, cause the one or more processors to execute, or direct execution of, one or more operations associated with the device. In some embodiments, the program instructions are inscribed in or more media. In some embodiments, the non-transitory computer readable program instructions for three-dimensional printing, the program instructions, when read by one or more processors operatively coupled with a device, cause the one or more processors to execute operations, the device comprising: a build platform assembly configured to engage with a build platform configured to carry one or more three- dimensional objects during the three-dimensional printing, the build platform assembly being configured to translate such that a first portion of the build platform assembly is configured to translate in a first translation type in a direction and a second portion of the build platform assembly is configured to translate in a second translation type in the direction; the operations comprise: (a) directing engagement of the build platform with the build platform assembly; (b) directing affixation of the first portion; (c) directing translation of the second portion in the direction to facilitate printing a first layer of transformed material as part of the one or more three-dimensional objects; and (d) directing affixation the second portion; (e) directing detachment of the first portion; and (f) directing translation of the first portion in the direction to facilitate accurate printing the second piston to facilitate printing a second layer of transformed material as part of the one or more three-dimensional objects that is carried by the build platform. In some embodiments, the non-transitory computer readable program instructions for three-dimensional printing, the program instructions, when read by one or more processors operatively coupled with a device, cause the one or more processors to execute operations, the device comprising: a build platform assembly supportive of a build platform configured to carry one or more three-dimensional objects during the three-dimensional printing, the operations comprise: (A) directing vertical translation in a direction a first portion of a build platform assembly in a first translation type, the first portion being operatively coupled with a build platform above which one or more three-dimensional objects are printed during the three- dimensional printing; and (B) directing vertical translation in the direction a second portion of the build platform assembly relative to the first portion in a second translation type, the first translation type and the second translation type being different.

[0018] In another aspect, a system for three-dimensional printing, the system comprises: any of the above devices configured to perform three-dimensional printing; and an energy beam configured to irradiate a planar layer of powder material to print at least a portion of at least one three-dimensional object at least in part by using three-dimensional printing. In some embodiments, the system further comprises a scanner configured to translate the energy beam along a target surface, wherein the device is operatively coupled with the scanner. In some embodiments, the system further comprises an energy source configured to generate the energy beam, wherein the device is operatively coupled with the energy source. In some embodiments, the system further comprises at least one controller that (i) is operatively coupled with the device and (ii) direct one or more operations associated with the device. In some embodiments, the system is configured to operatively couple to at least one controller configured to (i) operatively couple to the system and (ii) direct one or more operations associated with the system. In some embodiments, the system for three-dimensional printing, the system comprises: a build platform assembly configured to engage with a build platform configured to carry one or more three-dimensional objects during the three-dimensional printing, the build platform assembly being configured to translate such that a first portion of the build platform assembly is configured to translate in a first translation type in a direction and a second portion of the build platform assembly is configured to translate in a second translation type in the direction; and (A) an energy source configured to generate an energy beam to irradiate a pre-transformed material and transform into a transformed material to form the one or more three-dimensional objects, (B) a material extruder configured to extrude material to print the one or more three-dimensional objects, (C) a material dispenser, and/or (D) a laminator configured to deposit layerwise laminated layer to print the one or more three-dimensional objects. In some embodiments, the system for three-dimensional printing, the system comprises: a build platform assembly supportive of a build platform configured to carry one or more three-dimensional objects during the three-dimensional printing; and (A) an energy source configured to generate an energy beam to irradiate a pre-transformed material and transform into a transformed material to form the one or more three-dimensional objects, (B) a material extruder configured to extrude material to print the one or more three-dimensional objects, (C) a material dispenser, and/or (D) a laminator configured to deposit layerwise laminated layer to print the one or more three-dimensional objects.

[0019] In another aspect, a device for three-dimensional printing, the device comprises: a support; and a build platform assembly comprises a build platform configured to carry one or more three-dimensional objects during the three-dimensional printing, the build platform assembly being configured for a reversible engagement and reversible disengagement between the support and the build platform assembly, the device being: (I) configured for the reversible engagement and reversible disengagement at least in part by being configured to facilitate reversibly engage and reversibly disengage at least a portion (e.g., piston) of the build platform assembly with respect to the support, and/or (II) configured (a) for translation of the build platform assembly with respect to the support, and (b) for synchronization of the translation with the reversible engagement and reversible disengagement. In some embodiments, the support comprises a build module body configured to accommodate the build platform assembly. In some embodiments, the at least the portion of the build platform assembly comprises a first piston and a second piston. In some embodiments, the support comprises a wall of a build module body. In some embodiments, the support comprises a surface of a build module body. In some embodiments, the support comprises a ledge, pin, or flat configured to affix a vertical translation of a portion of the build platform assembly when the support is engaged. In some embodiments, the support comprises a plurality of receptacles configured to affix a vertical translation of a portion of the build platform assembly when an engagement mechanism of the build platform assembly is engaged with the plurality of receptacles of the support. In some embodiments, the device further comprises (A) an energy source configured to generate an energy beam to irradiate a pre-transformed material and transform into a transformed material to form the one or more three-dimensional objects, (B) a material extruder configured to extrude material to print the one or more three-dimensional objects, (C) a material dispenser, and/or (D) a laminator configured to deposit layerwise laminated layer to print the one or more three- dimensional objects. In some embodiments, the build platform assembly comprises a piston assembly. In some embodiments, the piston assembly comprises a first piston and a second piston. In some embodiments, the first piston and the second piston are the same in at least one characteristic comprising (i) horizontal circumference shape, (ii) horizontal circumference length, (iii) horizontal cross-section, (iv) horizontal location, (v) material makeup, or (vi) mechanism for affixing to a build module in which the first piston and the second piston are disposed during the three-dimensional printing. In some embodiments, the first piston and the second piston are different by at least one characteristic comprising (i) functionality, (ii) shape, (iii) density, (iv) vertical location, (v) connectivity to one or more components, (vi) material makeup, or (vii) mechanism for affixing to a build module in which the first piston and the second piston are disposed during the three-dimensional printing. In some embodiments, the first piston comprises one or more openings. In some embodiments, the second piston is devoid of one or more openings. In some embodiments, the second piston comprises a cavity for temperature conditioning. In some embodiments, the first piston is devoid of a cavity for temperature conditioning. In some embodiments, the first piston and the second piston have (e.g., substantially) the same shape and/or length of circumference. In some embodiments, the first piston of the build platform assembly is oriented closer to a gravitational center than the second piston of the build platform assembly. In some embodiments, the gravitational center is a gravitational center of the Earth. In some embodiments, the first piston of the build platform assembly is aligned with the second piston of the build platform assembly along a central axis. In some embodiments, the central axis is a vertical axis. In some embodiments, further comprising an adjusting coupler (e.g., a shaft) configured to facilitate adjustment of a (e.g., vertical) gap between the first piston and the second piston of the build platform assembly, the adjusting coupler coupled with the first piston and with the second piston of the build platform assembly. In some embodiments, the adjusting coupler comprises a shaft or a lead screw. In some embodiments, a length of the adjusting coupler being aligned with the central axis. In some embodiments, the device further comprises an actuator. In some embodiments, the actuator comprises, or is operatively coupled with, a servo motor operatively coupled with the adjusting coupler (e.g., shaft) and configured to facilitate the translation in a vertical direction. In some embodiments, the actuator is operatively coupled with the first piston or to the second piston. In some embodiments, the actuator is coupled with the second piston. In some embodiments, the device further comprises an encoder. In some embodiments, the encoder comprises an optical encoder configured to measure linear motion of the first piston with respect to the second piston. In some embodiments, the device further comprises a sensor. In some embodiments, the sensor comprises a position sensitive device. In some embodiments, the sensor comprises an interferometric detector. In some embodiments, the sensor comprises a fiber-coupled interferometric laser encoder. In some embodiments, the sensor is a component of a metrological detection system configured to measure a position of the first piston. In some embodiments, the metrological detection system further comprises a mirror arranged on a surface of the first piston and configured to reflect an energy beam incident on the mirror to the sensor. In some embodiments, the mirror comprises a retroreflector. In some embodiments, the position of the first piston comprises (i) a vertical position aligned with an axis of vertical translation, (ii) a horizontal position about a plane perpendicular to the axis of the vertical translation, (iii) a pitch with respect to an axis of a first central horizontal axis of the first piston, (iii) a roll with respect to a second central horizontal axis of the first piston, (iv) a yaw or a roll with respect to an axis of the vertical translation. In some embodiments, the first central horizontal axis and the second central horizontal axis are perpendicular to each other. In some embodiments, the device is configured for the reversible engagement and reversible disengagement at least in part by being configured to facilitate (A) reversibly affixing and reversibly releasing a first portion of the build platform assembly with respect to the support, and (B) reversibly releasing and reversibly affixing a second portion of the build platform assembly with respect to the support. The first portion may comprise a first piston assembly, and the second portion may comprise a second piston assembly. The first portion may comprise a first piston, and the second portion may comprise a second piston. In some embodiments, the device is configured for synchronization of the translation of the build platform assembly with the reversible engagement and disengagement at least in part by being configured to synchronize: (i) reversibly affixation of the first portion of the build platform assembly with respect to the support; (ii) release of the second portion of the build platform assembly with respect to the support; and (iii) vertically translation of the second portion of the build platform assembly with respect to the support. In some embodiments, the device is configured to facilitate vertical translation of the second portion of the build platform assembly with respect to the support at least in part being configured to facilitate a plurality of incremental layerwise movements, each layerwise movement comprising less than about 0.05% a total length of travel between the first portion and second portion of the build platform assembly. In some embodiments, the device is configured to facilitate vertical translation of the second portion of the build platform assembly in the plurality of incremental layerwise movements at least in part by being configured to facilitate synchronization of each incremental layerwise movement of the plurality of incremental layerwise movements with one or more other three-dimensional printing processes occurring during a print cycle. In some embodiments, the device is configured to facilitate the three- dimensional printing that comprises (i) depositing a layer of pre-transformed material on a target surface to generate a material bed, (ii) directing at least one energy onto the target surface, (iii) a combination thereof. In some embodiments, the material bed generated on the surface of the build platform comprises a fundamental length scale of at least about 300mm, 400mm, 600mm, 1000mm, or 1200 mm. In some embodiments, the material bed formed on the surface of the build platform and supported by the build platform comprises a fundamental length scale of at least about 1000 kg. In some embodiments, the target surface comprises (i) an exposed surface of the material bed or (ii) a surface of the build platform. In some embodiments, the deposition of pre-transformed material on the target surface comprises enlarging a volume of the material bed, wherein an exposed surface of the material is (e.g., substantially) at a same position after deposition of pre-transformed material on the target surface. In some embodiments, the deposition of pre-transformed material on the target surface comprises layerwise deposition. In some embodiments, the pre-transformed material comprises powder material. In some embodiments, the pre-transformed material comprises elemental metal, metal alloy, ceramic, or an allotrope of carbon. In some embodiments, the device is configured to operate under a positive pressure atmosphere relative to an ambient atmosphere external to the device. In some embodiments, the device is configured to operate under an atmosphere depleted of a reactive agent relative to its concentration in an ambient atmosphere external to the device, the reactive agent being configured to react with a starting material of the three-dimensional printing at least during the three-dimensional printing. In some embodiments, the reactive agent comprises oxygen, water, or hydrogen sulfide. In some embodiments, the device is configured to facilitate synchronization of the translation of the build platform assembly with the reversible engagement and disengagement at least in part by being configured for synchronization of: (I) reversible affixation of the second portion of the build platform assembly with respect to the support; (II) release of the first portion of the build platform assembly with respect to the support; and (III) vertical translation of the first portion of the build platform assembly with respect to the support. In some embodiments, the device is configured to facilitate vertical translation of the first portion of the build platform assembly with respect to the support at least in part by being configured to facilitate a block movement comprising more than at least about 50% of a total length of travel between the first portion and the second portion of the build platform assembly. In some embodiments, the build platform assembly comprises a first engagement mechanism operatively coupled with the first portion of the build platform assembly and configured to reversibly engage and disengage with the support to reversibly affix and release the first portion of the build platform assembly with respect to the support. In some embodiments, the build platform assembly comprises a second engagement mechanism operatively coupled with the second portion of the build platform assembly, the build platform assembly configured for reversible engagement and reversible disengage with the support to facilitate reversible affixation and reversible release of the second portion of the build platform assembly with respect to the support. In some embodiments, the first engagement mechanism and/or second engagement mechanism is configured to hold the portion of the build platform assembly by applying a hold force between the support and the respective first engagement mechanism and/or second engagement mechanism, the hold force being sufficient to hold (i) the build platform, (ii) a material bed formed on the build platform, (iii) the three-dimensional objects formed above the build platform; and (iv) any combination of (i) (ii) and (iii). In some embodiments, the first engagement mechanism and/or second engagement mechanism, comprises a hydraulic locking system. In some embodiments, first engagement mechanism and/or second engagement mechanism comprises a deformation engagement mechanism. In some embodiments, the deformation engagement mechanism comprises a portion configured to reversibly expand and contract. In some embodiments, the deformation engagement mechanism comprises a portion configured to reversibly distort to engage and disengage. In some embodiments, the first engagement mechanism and/or second engagement mechanism comprises a locking system. In some embodiments, the locking system comprises a ring concentrically arranged with respect to a circumference of a selected portion of the build platform assembly and affixed to the selected portion of the build platform assembly. In some embodiments, the ring is arranged with respect to the selected portion of the build platform assembly to define a cavity between a portion of the ring and an outer surface of the selected portion of the build platform assembly. In some embodiments, the cavity is operatively coupled with a channel and configured to be reversibly pressurized and depressurized. In some embodiments, the cavity is configured to be reversibly pressurized by a hydraulic fluid. In some embodiments, the cavity is configured to be reversibly pressurized by at least about 5000 kilopascals. In some embodiments, the cavity is pressurized such that the ring applies at least about 22,000 kilograms of holding force. In some embodiments, the first engagement mechanism and/or second engagement mechanism comprises a fastening engagement mechanism. In some embodiments, the fastening engagement mechanism comprises at least one reversibly moving engagement feature. In some embodiments, the reversibly moving engagement feature includes one or more of a pin, a pad, a flap, a support, or any combination thereof. In some embodiments, the fastening engagement mechanism comprises a plurality of pins. In some embodiments, the plurality of pins is arranged about an outer circumference of the selected portion of the build platform assembly and/or the second portion of the build platform assembly and configured to engage with a plurality of receptacles arranged about an inner circumference of a build module body. In some embodiments, the fastening engagement mechanism further comprises a plurality of seals arranged with respect to the plurality of receptacles and configured to optionally engage with the plurality of receptacles. In some embodiments, the plurality of seals is configured to engage with the plurality of receptacles to (e.g., substantially) prevent pre-transformed or transformed material from an inner volume of the plurality of receptacles. In some embodiments, engaging the plurality of pins comprises supporting, by the plurality of pins, a bottom surface of the first portion and/or the second portion. In some embodiments, the fastening engagement mechanism comprises a plurality of pads. In some embodiments, the fastening engagement mechanism comprises a plurality of pads arranged about (i) an outer circumference of the first portion of the build platform assembly, (ii) an outer circumference of the second portion of the build platform assembly, (iii) an inner circumference of a build module body, or (iv) any combination thereof. In some embodiments, when the fastening engagement mechanism is engaged, the plurality of pads applies a hold force between the first portion of the build platform assembly and/or the second portion of the build platform assembly and a wall of the build module body. In some embodiments, the first engagement mechanism and/or second engagement mechanism comprises a magnetic engagement mechanism. In some embodiments, the magnetic engagement mechanism comprises a plurality of electro-magnets. In some embodiments, the first engagement mechanism comprises, or is operatively coupled with, (i) a first set of engagement features configured to engage with an internal surface of the build module along the first axis, the first portion comprising the first set of engagement features, and (ii) a second set of engagement features configured to engage with an internal surface of the build module along the first axis, the second portion comprising the second set of engagement features. In some embodiments, the build module comprises at least one first alignment feature and a piston assembly comprises respective at least one second alignment feature, the at least one first alignment feature configured to engage with the at least one second alignment feature to, during printing, align the build module with respect to the build platform assembly disposed in the build module, and the piston assembly being the first piston assembly and/or the second piston assembly. In some embodiments, the at least one first alignment feature comprises a protrusion, and where the at least one second alignment feature comprises a depression configured to engage with the protrusion for alignment of the build module with the piston assembly. In some embodiments, the at least one first alignment feature comprises a depression, and where the at least one second alignment feature comprises a protrusion configured to engage with the depression for alignment of the build module with the piston assembly. In some embodiments, engagement features of the first set of engagement features and of the second set of engagement features comprise pads. In some embodiments, the first piston assembly comprises, or is operatively coupled with, (i) a first push-pull actuator operatively coupled with the first set of engagement features, the first push-pull actuator configured to reversibly push and reversibly pull the engagement features along the first axis, and (ii) a second push-pull actuator operatively coupled with the second set of engagement features, the second push-pull actuator configured to reversibly push and reversibly pull the engagement features along the second axis. In some embodiments, each engagement feature is coupled with a pin, the engagement feature being of the first set of engagement features and of the second set of engagement features. In some embodiments, (i) the first push-pull actuator is operatively coupled with the first set of engagement features, each through its respective pin, and/or (ii) the second push-pull actuator is operatively coupled with the second set of engagement features, each through its respective pin. In some embodiments, the first piston assembly is operatively coupled with, or include, push-pull actuators, the push pull actuators comprise the first push-pull actuator and the second push-pull actuator. In some embodiments, each of the push-pull actuators comprise a ring, a secondary piston, a piezoelectric actuator, an eccentric mechanism, a lead screw, or a sliding double wedge mechanism. In some embodiments, the eccentric mechanism comprises the ring or a circle. In some embodiments, the first push-pull actuator and the second push-pull actuator are of the same type. In some embodiments, the first push-pull actuator and the second push-pull actuator are of a different type. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to exert (e.g., substantially) the same force during their respective push operation, and during their respective pull operation. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to cause their respective engagement features to exert (e.g., substantially) the same force onto the build module during their respective push operation, and during their respective pull operation. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate in coordination with each other. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate simultaneously with respect to each other. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate sequentially with respect to each other. In some embodiments, (A) the first set of engagement features comprises a first engagement feature and a second engagement feature, and where the first push-pull actuator is configured to actuate the first engagement feature (e.g., substantially) simultaneously with actuation of the second engagement feature and/or (B) the second set of engagement features comprises a third engagement feature and a fourth engagement feature, and where the second push-pull actuator is configured to actuate the third engagement feature (e.g., substantially) simultaneously with actuation of the fourth engagement feature. In some embodiments, (A) the first set of engagement features comprises a first engagement feature and a second engagement feature, and where the first push-pull actuator is configured to actuate the first engagement feature sequentially to actuation of the second engagement feature and/or (B) the second set of engagement features comprises a third engagement feature and a fourth engagement feature, and where the second push-pull actuator is configured to actuate the third engagement feature sequentially to actuation of the fourth engagement feature. In some embodiments, the build module body comprises a bottom portion (e.g., floor) that is closer to a gravitational center with respect to the build module body. In some embodiments, the bottom portion comprises a plurality of interconnects configured to selectively couple to (i) a gas source, (ii) a gas purge, (iii) a temperature adjustment manifold, (iv) an electrical connection, (v) a hydraulic source, or (vi) any combination of (i), (ii), (iii), (iv), and (v). In some embodiments, the device further comprises a translational mechanism operatively coupled with the first piston, the translational mechanism being operatively coupled with the bottom portion of the build module body. In some embodiments, the vertical translation of the first piston comprises vertical translation by the translational mechanism operatively coupled with the first piston. In some embodiments, the translational mechanism comprises telescopic hydraulic cylinders arranged to extend a length in a vertical direction. In some embodiments, the translational mechanism comprises a hydraulic valve, wherein opening the hydraulic valve allows compression of the translational mechanism and closing the hydraulic value allows extension (e.g., substantially) prevents compression of the translational mechanism. In some embodiments, the build module body further comprises an interlock. In some embodiments, the interlock is a limit switch. In some embodiments, the limit switch limits an extent of travel of the first piston and/or the second piston with respect to the build module body. In some embodiments, the limit switch limits an extent of travel of the translational mechanism. In some embodiments, the limit switch limits an extent of travel of the first piston adjacent to the bottom portion of the build module body. In some embodiments, the limit switch limits an extent of travel of the second piston and/or the build platform adjacent to a top of the build module body with respect to gravitation center. In some embodiments, the build module body further comprises a seal. In some embodiments, the seal is included, or is operatively coupled with a shutter, a lid, a closure, an envelope, or a flap. In some embodiments, the seal is arranged with respect to an upper-most portion of the build module body and vertically opposite a bottom portion of the build module body. In some embodiments, the seal is gas tight. In some embodiments, the seal is a hermetic seal. In some embodiments, the seal is configured to facilitate retaining an internal atmosphere in the build module body for a time period, the internal atmosphere being different from an ambient atmosphere external to the build module. In some embodiments, the seal is configured to facilitate retaining for a time period (i) a positive pressure within the build module body relative to an ambient atmosphere external to the device and/or (ii) a reactive agent at a concentration lower than its concentration in an ambient atmosphere external to the build module, the reactive agent being configured to at least react with pre-transformed material of the three-dimensional printing during the three-dimensional printing. In some embodiments, the seal is arranged between the first piston and the second piston and configured to (e.g., substantially) prevent pre-transformed, debris, or transformed material from a volume between the first piston and the second piston. In some embodiments, the seal comprises a bellow. In some embodiments, the device further comprises a plurality of guide rods arranged about a central axis of the first piston and the second piston, the guide rods being configured to guide the translation of the first piston with respect to the second piston, the translation being vertical. In some embodiments, the device further comprises a build module configured to house the adjusting coupler (e.g., shaft), first piston, second piston and build platform, and wherein the build module is configured to (a) reversibly operatively couple with a processing chamber during the three-dimensional printing, and (b) reversibly decouple from the processing chamber after the three-dimensional printing. In some embodiments, the device is configured to facilitate printing one or more three-dimensional objects in an atmosphere maintained to be different from an ambient atmosphere by at least one characteristic, the ambient atmosphere being external to a build module and to a processing chamber. In some embodiments, the at least one characteristic comprises (i) a pressure above a pressure presiding in the ambient atmosphere, or (ii) a reactive agent being at a concentration lower than its concentration in the ambient atmosphere, the reactive agent being reactive with a starting material of the three-dimensional printing at least during the three-dimensional printing. In some embodiments, the device further comprises temperature adjustment interconnects configured to adjust a temperature of the first piston, the second piston, and/or the build platform. In some embodiments, the temperature adjustment interconnects comprise a manifold. In some embodiments, the temperature adjustment interconnects comprise a channel. In some embodiments, the channel is disposed at least in part within a portion of the build platform and/or second piston. In some embodiments, the temperature adjustment interconnects comprise an internal chamber within a portion of the build platform and/or build platform assembly, e.g., within the second piston thereof. In some embodiments, the temperature adjustment interconnects are configured to receive a flow of a temperature adjustment agent from a source. In some embodiments, the temperature adjustment agent comprises a gas, a fluid, or a semisolid. In some embodiments, the temperature adjustment agent comprises water. In some embodiments, the temperature adjustment agent comprises a coolant. In some embodiments, the temperature adjustment interconnects are configured to reduce a temperature of (i) the build platform, (ii) the first piston, (iii) the second piston, (iv) a material bed and/or three-dimensional objects carried by the build platform during three-dimensional printing, or (v) any combination thereof. In some embodiments, the temperature adjustment interconnects are configured to reduce a temperature at a time comprising: during the three-dimensional printing, or after the three-dimensional printing. In some embodiments, the temperature adjustment interconnects are configured to reduce a temperature at a time comprising: (i) before disengagement of a build module in which a three-dimensional object is disposed during the three-dimensional printing, or (ii) after disengagement of the build module from a processing chamber.

[0020] In another aspect, a method of three-dimensional printing, the method comprises: providing any of the above devices; and using the device during the three-dimensional printing. In some embodiments, the three-dimensional printing comprises connecting a particulate matter. In some embodiments, connecting comprises fusing. In some embodiments, fusing comprises melting. In some embodiments, the adjusting coupler is operatively coupled with an encoder, e.g., an optical or a magnetic encoder. In some embodiments, the adjusting coupler comprises a scissor jack, a lead screw, or gas (e.g., air) bearings. In some embodiments, the method for three-dimensional printing, the method comprises: (a) providing a device comprising: a support, and a build platform assembly comprises a build platform that is configured to carry one or more three-dimensional objects during the three-dimensional printing, the build platform assembly being configured for a reversible engagement and reversible disengagement between the support and the build platform assembly, device being: (I) configured for the reversible engagement and reversible disengagement at least in part by being configured to facilitate reversibly affixing and reversibly releasing at least a portion of the build platform assembly with respect to the support, and/or (II) configured (a) fortranslation of the build platform assembly with respect to the support and (b) for synchronization of the translation with the reversible engagement and reversible disengagement; (b) engaging (i) the build platform with the build platform assembly and (ii) the at least the portion of the build platform assembly with respect to the support; (c) printing a layer of material as part of the one or more three-dimensional objects; and (d) disengaging the at least the portion of the build platform assembly from the support; (d) translating the at least the portion of the build platform assembly in a direction to generate a second layer of material as part of the one or more three-dimensional objects carried by the build platform.

[0021] In another aspect, an apparatus for three-dimensional printing, the apparatus comprises at least one controller configured to (i) operatively couple to any of the above devices; and control, or direct control of, one or more operations associated with the device. In some embodiments, the at least one controller comprises at least one connector configured to connect to a power source. In some embodiments, the at least one controller being configured to operatively couple to a power source at least in part by (I) having a power socket and/or (II) being configured for wireless power transfer using inductive charging. In some embodiments, the at least one controller is included in, or comprises, a hierarchical control system. In some embodiments, the hierarchical control system comprises at least three hierarchical control levels. In some embodiments, the at least one controller is included in a control system configured to control a three-dimensional printer that prints the one or more three-dimensional objects. In some embodiments, the device is a component of a three-dimensional printing system, and wherein the at least one controller is configured to (i) operatively couple to an other component of the three-dimensional printing system and (ii) direct operation of the other component. In some embodiments, the at least one controller is configured to direct operation of the other component at least in part for participation of the other component in three- dimensional printing. In some embodiments, the apparatus for three-dimensional printing, the apparatus comprises: at least one controller configured to: (a) operatively couple to a device comprising: a support, and a build platform assembly comprises a build platform that is configured to carry one or more three-dimensional objects during the three-dimensional printing, the build platform assembly being configured for a reversible engagement and reversible disengagement between the support and the build platform assembly, device being: (I) configured for the reversible engagement and reversible disengagement at least in part by being configured to facilitate reversibly affixing and reversibly releasing at least a portion of the build platform assembly with respect to the support, and/or (II) configured (a) for translation of the build platform assembly with respect to the support and (b) for synchronization of the translation with the reversible engagement and reversible disengagement; (b) direct engagement of (i) the build platform with the build platform assembly and (ii) the at least the portion of the build platform assembly with respect to the support; (c) direct printing a layer of material as part of the one or more three-dimensional objects; (d) direct disengagement of the at least the portion of the build platform assembly from the support; and (d) direct translation of the at least the portion of the build platform assembly in the direction to generate a second layer of material as part of the one or more three-dimensional objects carried by the build platform.

[0022] In another aspect, non-transitory computer readable program instructions for three- dimensional printing, the program instructions, when read by one or more processors operatively coupled with any of the above devices, cause the one or more processors to execute, or direct execution of, one or more operations associated with the device. In some embodiments, the program instructions are inscribed in or more media. In some embodiments, the non-transitory computer readable program instructions for three-dimensional printing, the program instructions, when read by one or more processors operatively coupled with a device, cause the one or more processors to execute operations, the device comprising: a support, and a build platform assembly comprises a build platform that is configured to carry one or more three-dimensional objects during the three-dimensional printing, the build platform assembly being configured for a reversible engagement and reversible disengagement between the support and the build platform assembly, device being: (I) configured for the reversible engagement and reversible disengagement at least in part by being configured to facilitate reversibly affixing and reversibly releasing at least a portion of the build platform assembly with respect to the support, and/or (II) configured (a) fortranslation of the build platform assembly with respect to the support and (b) for synchronization of the translation with the reversible engagement and reversible disengagement; the operations comprise: (a) directing engagement of (i) the build platform with the build platform assembly and (ii) the at least the portion of the build platform assembly with respect to the support; (b) directing printing a layer of material as part of the one or more three-dimensional objects; (c) directing disengagement of the at least the portion of the build platform assembly from the support; and (d) directing translation of the at least the portion of the build platform assembly in the direction to generate a second layer of material as part of the one or more three-dimensional objects carried by the build platform. [0023] In another aspect, a system for three-dimensional printing, the system comprises: any of the above devices configured to perform three-dimensional printing; and an energy beam configured to irradiate a planar layer of powder material to print at least a portion of at least one three-dimensional object at least in part by using three-dimensional printing. In some embodiments, the system further comprises a scanner configured to translate the energy beam along a target surface, wherein the device is operatively coupled with the scanner. In some embodiments, the system further comprises an energy source configured to generate the energy beam, wherein the device is operatively coupled with the energy source. In some embodiments, the system further comprises at least one controller that (i) is operatively coupled with the device and (ii) direct one or more operations associated with the device. In some embodiments, the system is configured to operatively couple to at least one controller configured to (i) operatively couple to the system and (ii) direct one or more operations associated with the system.

[0024] In another aspect, a device for three-dimensional printing, the device comprises: a support; and a piston disposed adjacent to the support and configured for translation relative to the support; an envelope operatively coupled with the piston, the envelope configured to reversibly deform such that reversibly deformation of the envelope causes reversible affixation and release of the piston with respect to the support, the device being: (I) configured for the reversible deformation of the envelope; (I) configured for the reversible engagement and reversible disengagement of the piston with the support at least in part by being configured to facilitate the reversible deformation of the envelope, and/or (II) configured (a) for translation of the piston with respect to the support, (b) for synchronization of the reversible deformation of the envelope and/or (c) for synchronization of the translation with the reversible engagement and reversible disengagement of the piston with respect to the support. In some embodiments, the envelope is configured for reversible deformation with respect to the piston and/or the support. In some embodiments, the piston and the envelope are part of a build platform assembly. In some embodiments, the build platform assembly comprising a build platform configured to carry one or more three-dimensional objects during the three-dimensional printing. In some embodiments, the support comprises a build module body configured to accommodate the build platform assembly. In some embodiments, the at least the portion of the build platform assembly comprises a first piston and a second piston. In some embodiments, the support comprises a wall of a build module body. In some embodiments, the support comprises a surface of a build module body. In some embodiments, the support comprises a ledge, pin, or flat configured to affix a vertical translation of a portion of the build platform assembly when the support is engaged. In some embodiments, the support comprises a plurality of receptacles configured to affix a vertical translation of a portion of the build platform assembly when an engagement mechanism of the build platform assembly is engaged with the plurality of receptacles of the support. In some embodiments, the device further comprises (A) an energy source configured to generate an energy beam to irradiate a pre-transformed material and transform into a transformed material to form the one or more three-dimensional objects, (B) a material extruder configured to extrude material to print the one or more three-dimensional objects, (C) a material dispenser, and/or (D) a laminator configured to deposit layerwise laminated layer to print the one or more three-dimensional objects. In some embodiments, the build platform assembly comprises a piston assembly. In some embodiments, the piston assembly comprises a first piston and a second piston. In some embodiments, the first piston and the second piston are the same in at least one characteristic comprising (i) horizontal circumference shape, (ii) horizontal circumference length, (iii) horizontal cross-section, (iv) horizontal location, (v) material makeup, or (vi) mechanism for affixing to a build module in which the first piston and the second piston are disposed during the three-dimensional printing. In some embodiments, the first piston and the second piston are different by at least one characteristic comprising (i) functionality, (ii) shape, (iii) density, (iv) vertical location, (v) connectivity to one or more components, (vi) material makeup, or (vii) mechanism for affixing to a build module in which the first piston and the second piston are disposed during the three-dimensional printing. In some embodiments, the first piston comprises one or more openings. In some embodiments, the second piston is devoid of one or more openings. In some embodiments, the second piston comprises a cavity for temperature conditioning. In some embodiments, the first piston is devoid of a cavity for temperature conditioning. In some embodiments, the first piston and the second piston have (e.g., substantially) the same shape and/or length of circumference. In some embodiments, the first piston of the build platform assembly is oriented closer to a gravitational center than the second piston of the build platform assembly. In some embodiments, the gravitational center is a gravitational center of the Earth. In some embodiments, the first piston of the build platform assembly is aligned with the second piston of the build platform assembly along a central axis. In some embodiments, the central axis is a vertical axis. In some embodiments, the device further comprises a shaft operatively coupled between the first piston of the build platform assembly and the second piston of the build platform assembly, a length of the adjusting coupler (e.g., shaft) being aligned with the central axis. In some embodiments, the device further comprises an actuator. In some embodiments, the actuator comprises, or is operatively coupled with, a servo motor operatively coupled with the adjusting coupler (e.g., shaft) and configured to facilitate the translation in a vertical direction. In some embodiments, the actuator is operatively coupled with the first piston or to the second piston. In some embodiments, the actuator is coupled with the second piston. In some embodiments, the device further comprises an encoder. In some embodiments, the encoder comprises an optical encoder configured to measure linear motion of the first piston with respect to the second piston. In some embodiments, the device further comprises a sensor. In some embodiments, the sensor comprises a position sensitive device. In some embodiments, the sensor comprises an interferometric detector. In some embodiments, the sensor comprises a fiber-coupled interferometric laser encoder. In some embodiments, the sensor is a component of a metrological detection system configured to measure a position of the first piston. In some embodiments, the metrological detection system further comprises a mirror arranged on a surface of the first piston and configured to reflect an energy beam incident on the mirror to the sensor. In some embodiments, the mirror comprises a retroreflector. In some embodiments, the position of the first piston comprises (i) a vertical position aligned with an axis of vertical translation, (ii) a horizontal position about a plane perpendicular to the axis of the vertical translation, (iii) a pitch with respect to an axis of a first central horizontal axis of the first piston, (iii) a roll with respect to a second central horizontal axis of the first piston, (iv) a yaw or a roll with respect to an axis of the vertical translation. In some embodiments, the first central horizontal axis and the second central horizontal axis are perpendicular to each other. In some embodiments, the device is configured for the reversible engagement and reversible disengagement at least in part by being configured to facilitate (A) reversibly affixing and reversibly releasing a first portion of the build platform assembly with respect to the support, and (B) reversibly releasing and reversibly affixing a second portion of the build platform assembly with respect to the support. In some embodiments, the device is configured for synchronization of the translation of the build platform assembly with the reversible engagement and disengagement at least in part by being configured to synchronize: (i) reversibly affixation of the first portion of the build platform assembly with respect to the support; (ii) release of the second portion of the build platform assembly with respect to the support; and (iii) vertically translation of the second portion of the build platform assembly with respect to the support. In some embodiments, the device is configured to facilitate vertical translation of the second portion of the build platform assembly with respect to the support at least in part being configured to facilitate a plurality of incremental layerwise movements, each layerwise movement comprising less than about 0.05% a total length of travel between the first portion and second portion of the build platform assembly. In some embodiments, the device is configured to facilitate vertical translation of the second portion of the build platform assembly in the plurality of incremental layerwise movements at least in part by being configured to facilitate synchronization of each incremental layerwise movement of the plurality of incremental layerwise movements with one or more other three-dimensional printing processes occurring during a print cycle. In some embodiments, the device is configured to facilitate the three-dimensional printing that comprises

(i) depositing a layer of pre-transformed material on a target surface to generate a material bed,

(ii) directing at least one energy onto the target surface, (iii) a combination thereof. In some embodiments, the material bed generated on the surface of the build platform comprises a fundamental length scale of at least about 300mm, 400mm, 600mm, 1000mm, or 1200 mm. In some embodiments, the material bed formed on the surface of the build platform and supported by the build platform comprises a fundamental length scale of at least about 1000 kg. In some embodiments, the target surface comprises (i) an exposed surface of the material bed or (ii) a surface of the build platform. In some embodiments, the deposition of pre-transformed material on the target surface comprises enlarging a volume of the material bed, wherein an exposed surface of the material is (e.g., substantially) at a same position after deposition of pretransformed material on the target surface. In some embodiments, the deposition of pretransformed material on the target surface comprises layerwise deposition. In some embodiments, the pre-transformed material comprises powder material. In some embodiments, the pre-transformed material comprises elemental metal, metal alloy, ceramic, or an allotrope of carbon. In some embodiments, the device is configured to operate under a positive pressure atmosphere relative to an ambient atmosphere external to the device. In some embodiments, the device is configured to operate under an atmosphere depleted of a reactive agent relative to its concentration in an ambient atmosphere external to the device, the reactive agent being configured to react with a starting material of the three-dimensional printing at least during the three-dimensional printing. In some embodiments, the reactive agent comprises oxygen, water, or hydrogen sulfide. In some embodiments, the device is configured to facilitate synchronization of the translation of the build platform assembly with the reversible engagement and disengagement at least in part by being configured for synchronization of: (I) reversible affixation of the second portion of the build platform assembly with respect to the support; (II) release of the first portion of the build platform assembly with respect to the support; and (III) vertical translation of the first portion of the build platform assembly with respect to the support. In some embodiments, the device is configured to facilitate vertical translation of the first portion of the build platform assembly with respect to the support at least in part by being configured to facilitate a block movement comprising more than at least about 50% of a total length of travel between the first portion and the second portion of the build platform assembly. In some embodiments, the build platform assembly comprises a first engagement mechanism operatively coupled with the first portion of the build platform assembly and configured to reversibly engage and disengage with the support to reversibly affix and release the first portion of the build platform assembly with respect to the support. In some embodiments, the build platform assembly comprises a second engagement mechanism operatively coupled with the second portion of the build platform assembly, the build platform assembly configured for reversible engagement and reversible disengage with the support to facilitate reversible affixation and reversible release of the second portion of the build platform assembly with respect to the support. In some embodiments, the first engagement mechanism and/or second engagement mechanism is configured to hold the portion of the build platform assembly by applying a hold force between the support and the respective first engagement mechanism and/or second engagement mechanism, the hold force being sufficient to hold (i) the build platform, (ii) a material bed formed on the build platform, (iii) the three-dimensional objects formed above the build platform; and (iv) any combination of (i) (ii) and (iii). In some embodiments, the first engagement mechanism and/or second engagement mechanism, comprises a hydraulic locking system. In some embodiments, first engagement mechanism and/or second engagement mechanism comprises a deformation engagement mechanism. In some embodiments, the deformation engagement mechanism comprises a portion configured to reversibly expand and contract. In some embodiments, the deformation engagement mechanism comprises a portion configured to reversibly distort to engage and disengage. In some embodiments, the first engagement mechanism and/or second engagement mechanism comprises a locking system. In some embodiments, the locking system comprises a ring concentrically arranged with respect to a circumference of a selected portion of the build platform assembly and affixed to the selected portion of the build platform assembly. In some embodiments, the ring is arranged with respect to the selected portion of the build platform assembly to define a cavity between a portion of the ring and an outer surface of the selected portion of the build platform assembly. In some embodiments, the cavity is operatively coupled with a channel and configured to be reversibly pressurized and depressurized. In some embodiments, the cavity is configured to be reversibly pressurized by a hydraulic fluid. In some embodiments, the cavity is configured to be reversibly pressurized by at least about 5000 kilopascals. In some embodiments, the cavity is pressurized such that the ring applies at least about 22,000 kilograms of holding force. In some embodiments, the first engagement mechanism and/or second engagement mechanism comprises a fastening engagement mechanism. In some embodiments, the fastening engagement mechanism comprises at least one reversibly moving engagement feature. In some embodiments, the reversibly moving engagement feature includes one or more of a pin, a pad, a flap, a support, or any combination thereof. In some embodiments, the fastening engagement mechanism comprises a plurality of pins. In some embodiments, the plurality of pins is arranged about an outer circumference of the selected portion of the build platform assembly and/or the second portion of the build platform assembly and configured to engage with a plurality of receptacles arranged about an inner circumference of a build module body. In some embodiments, the fastening engagement mechanism further comprises a plurality of seals arranged with respect to the plurality of receptacles and configured to optionally engage with the plurality of receptacles. In some embodiments, the plurality of seals is configured to engage with the plurality of receptacles to (e.g., substantially) prevent pre-transformed or transformed material from an inner volume of the plurality of receptacles. In some embodiments, engaging the plurality of pins comprises supporting, by the plurality of pins, a bottom surface of the first portion and/or the second portion. In some embodiments, the fastening engagement mechanism comprises a plurality of pads. In some embodiments, the fastening engagement mechanism comprises a plurality of pads arranged about (i) an outer circumference of the first portion of the build platform assembly, (ii) an outer circumference of the second portion of the build platform assembly, (iii) an inner circumference of a build module body, or (iv) any combination thereof. In some embodiments, when the fastening engagement mechanism is engaged, the plurality of pads applies a hold force between the first portion of the build platform assembly and/or the second portion of the build platform assembly and a wall of the build module body. In some embodiments, the first engagement mechanism and/or second engagement mechanism comprises a magnetic engagement mechanism. In some embodiments, the magnetic engagement mechanism comprises a plurality of electro-magnets. In some embodiments, the first engagement mechanism comprises, or is operatively coupled with, (i) a first set of engagement features configured to engage with an internal surface of the build module along the first axis, the first portion comprising the first set of engagement features, and (ii) a second set of engagement features configured to engage with an internal surface of the build module along the first axis, the second portion comprising the second set of engagement features. In some embodiments, the build module comprises at least one first alignment feature and a piston assembly comprises respective at least one second alignment feature, the at least one first alignment feature configured to engage with the at least one second alignment feature to, during printing, align the build module with respect to the build platform assembly disposed in the build module, and the piston assembly being the first piston assembly and/or the second piston assembly. In some embodiments, the at least one first alignment feature comprises a protrusion, and where the at least one second alignment feature comprises a depression configured to engage with the protrusion for alignment of the build module with the piston assembly. In some embodiments, the at least one first alignment feature comprises a depression, and where the at least one second alignment feature comprises a protrusion configured to engage with the depression for alignment of the build module with the piston assembly. In some embodiments, engagement features of the first set of engagement features and of the second set of engagement features comprise pads. In some embodiments, the first piston assembly comprises, or is operatively coupled with, (i) a first push-pull actuator operatively coupled with the first set of engagement features, the first push-pull actuator configured to reversibly push and reversibly pull the engagement features along the first axis, and (ii) a second push-pull actuator operatively coupled with the second set of engagement features, the second push-pull actuator configured to reversibly push and reversibly pull the engagement features along the second axis. In some embodiments, each engagement feature is coupled with a pin, the engagement feature being of the first set of engagement features and of the second set of engagement features. In some embodiments, (i) the first push-pull actuator is operatively coupled with the first set of engagement features, each through its respective pin, and/or (ii) the second push-pull actuator is operatively coupled with the second set of engagement features, each through its respective pin. In some embodiments, the first piston assembly is operatively coupled with, or include, push-pull actuators, the push pull actuators comprise the first push-pull actuator and the second push-pull actuator. In some embodiments, each of the push-pull actuators comprise a ring, a secondary piston, a piezoelectric actuator, an eccentric mechanism, a lead screw, or a sliding double wedge mechanism. In some embodiments, the eccentric mechanism comprises the ring or a circle. In some embodiments, the first push-pull actuator and the second push-pull actuator are of the same type. In some embodiments, the first push-pull actuator and the second push-pull actuator are of a different type. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to exert (e.g., substantially) the same force during their respective push operation, and during their respective pull operation. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to cause their respective engagement features to exert (e.g., substantially) the same force onto the build module during their respective push operation, and during their respective pull operation. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate in coordination with each other. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate simultaneously with respect to each other. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate sequentially with respect to each other. In some embodiments, (A) the first set of engagement features comprises a first engagement feature and a second engagement feature, and where the first push-pull actuator is configured to actuate the first engagement feature (e.g., substantially) simultaneously with actuation of the second engagement feature and/or (B) the second set of engagement features comprises a third engagement feature and a fourth engagement feature, and where the second push-pull actuator is configured to actuate the third engagement feature (e.g., substantially) simultaneously with actuation of the fourth engagement feature. In some embodiments, (A) the first set of engagement features comprises a first engagement feature and a second engagement feature, and where the first push-pull actuator is configured to actuate the first engagement feature sequentially to actuation of the second engagement feature and/or (B) the second set of engagement features comprises a third engagement feature and a fourth engagement feature, and where the second push-pull actuator is configured to actuate the third engagement feature sequentially to actuation of the fourth engagement feature. In some embodiments, the build module body comprises a bottom portion (e.g., floor) that is closer to a gravitational center with respect to the build module body. In some embodiments, the bottom portion comprises a plurality of interconnects configured to selectively couple to (i) a gas source, (ii) a gas purge, (iii) a temperature adjustment manifold, (iv) an electrical connection, (v) a hydraulic source, or (vi) any combination of (i), (ii), (iii), (iv), and (v). In some embodiments, the device further comprises a translational mechanism operatively coupled with the first piston, the translational mechanism being operatively coupled with the bottom portion of the build module body. In some embodiments, the vertical translation of the first piston comprises vertical translation by the translational mechanism operatively coupled with the first piston. In some embodiments, the translational mechanism comprises telescopic hydraulic cylinders arranged to extend a length in a vertical direction. In some embodiments, the translational mechanism comprises a hydraulic valve, wherein opening the hydraulic valve allows compression of the translational mechanism and closing the hydraulic value allows extension (e.g., substantially) prevents compression of the translational mechanism. In some embodiments, the build module body further comprises an interlock. In some embodiments, the interlock is a limit switch. In some embodiments, the limit switch limits an extent of travel of the first piston and/or the second piston with respect to the build module body. In some embodiments, the limit switch limits an extent of travel of the translational mechanism. In some embodiments, the limit switch limits an extent of travel of the first piston adjacent to the bottom portion of the build module body. In some embodiments, the limit switch limits an extent of travel of the second piston and/or the build platform adjacent to a top of the build module body with respect to gravitation center. In some embodiments, the build module body further comprises a seal. In some embodiments, the seal is included, or is operatively coupled with a shutter, a lid, a closure, an envelope, or a flap. In some embodiment, the envelope comprises a seal. In some embodiments, the seal is arranged with respect to an upper-most portion of the build module body and vertically opposite a bottom portion of the build module body. In some embodiments, the seal is gas tight. In some embodiments, the seal is a hermetic seal. In some embodiments, the seal is configured to facilitate retaining an internal atmosphere in the build module body for a time period, the internal atmosphere being different from an ambient atmosphere external to the build module. In some embodiments, the seal is configured to facilitate retaining for a time period (i) a positive pressure within the build module body relative to an ambient atmosphere external to the device and/or (ii) a reactive agent at a concentration lower than its concentration in an ambient atmosphere external to the build module, the reactive agent being configured to at least react with pretransformed material of the three-dimensional printing during the three-dimensional printing. In some embodiments, the seal is arranged between the first piston and the second piston and configured to (e.g., substantially) prevent pre-transformed, debris, or transformed material from a volume between the first piston and the second piston. In some embodiments, the seal comprises a bellow. In some embodiments, the device further comprises a plurality of guide rods arranged about a central axis of the first piston and the second piston, the guide rods being configured to guide the translation of the first piston with respect to the second piston, the translation being vertical. In some embodiments, the device further comprises a build module configured to house the adjusting coupler (e.g., shaft), first piston, second piston and build platform, and wherein the build module is configured to (a) reversibly operatively couple with a processing chamber during the three-dimensional printing, and (b) reversibly decouple from the processing chamber after the three-dimensional printing. In some embodiments, the device is configured to facilitate printing one or more three-dimensional objects in an atmosphere maintained to be different from an ambient atmosphere by at least one characteristic, the ambient atmosphere being external to a build module and to a processing chamber. In some embodiments, the at least one characteristic comprises (i) a pressure above a pressure presiding in the ambient atmosphere, or (ii) a reactive agent being at a concentration lower than its concentration in the ambient atmosphere, the reactive agent being reactive with a starting material of the three-dimensional printing at least during the three-dimensional printing. In some embodiments, the device further comprises temperature adjustment interconnects configured to adjust a temperature of the first piston, the second piston, and/or the build platform. In some embodiments, the temperature adjustment interconnects comprise a manifold. In some embodiments, the temperature adjustment interconnects comprise a channel. In some embodiments, the channel is disposed at least in part within a portion of the build platform and/or second piston. In some embodiments, the temperature adjustment interconnects comprise an internal chamber within a portion of the build platform and/or build platform assembly, e.g., within the second piston thereof. In some embodiments, the temperature adjustment interconnects are configured to receive a flow of a temperature adjustment agent from a source. In some embodiments, the temperature adjustment agent comprises a gas, a fluid, or a semisolid. In some embodiments, the temperature adjustment agent comprises water. In some embodiments, the temperature adjustment agent comprises a coolant. In some embodiments, the temperature adjustment interconnects are configured to reduce a temperature of (i) the build platform, (ii) the first piston, (iii) the second piston, (iv) a material bed and/or three-dimensional objects carried by the build platform during three-dimensional printing, or (v) any combination thereof. In some embodiments, the temperature adjustment interconnects are configured to reduce a temperature at a time comprising: during the three-dimensional printing, or after the three-dimensional printing. In some embodiments, the temperature adjustment interconnects are configured to reduce a temperature at a time comprising: (i) before disengagement of a build module in which a three-dimensional object is disposed during the three-dimensional printing, or (ii) after disengagement of the build module from a processing chamber. In some embodiments, the adjusting coupler is operatively coupled with an encoder, e.g., an optical or a magnetic encoder. In some embodiments, the adjusting coupler comprises a scissor jack, a lead screw, or gas (e.g., air) bearings.

[0025] In another aspect, a system for three-dimensional printing, the system comprises: a support; a build platform assembly comprising a build platform that is configured to carry one or more three-dimensional objects during the three-dimensional printing, the build platform assembly being configured for a reversible engagement and reversible disengagement between the support and the build platform assembly, build platform assembly being: (I) configured for the reversible engagement and reversible disengagement at least in part by being configured to facilitate reversibly affixing and reversibly releasing at least a portion of the build platform assembly with respect to the support, and/or (II) configured (a) for translation of the build platform assembly with respect to the support and (b) for synchronization of the translation with the reversible engagement and reversible disengagement; and (A) an energy source configured to generate an energy beam to irradiate a pre-transformed material and transform into a transformed material to form the one or more three-dimensional objects, (B) a material extruder configured to extrude material to print the one or more three-dimensional objects, (C) a material dispenser, and/or (D) a laminator configured to deposit layerwise laminated layer to print the one or more three-dimensional objects.

[0026] In another aspect, a method for three-dimensional printing, the method comprises: deforming an envelope operatively coupled with a piston to alter a circumference of the envelope and engage with a support to affix the piston relative to the support, the envelope being reversibly deformed, the piston being reversibly affixed to the support, the envelope being configured to surround at least a portion of a circumference of the piston; and reversing the deformation of the envelope of the piston to alter the circumference of the envelope to release the envelope from the support, the release facilitating translation of the piston with respect to the support as part of the three-dimensional printing. In some embodiments, the support comprises a build module body configured to accommodate (i) the piston, (ii) the envelope, and (ii) one or more three-dimensional objects during the three-dimensional printing in a printing cycle. In some embodiments, the support comprises a build module body configured to (i) accommodate a build platform and (ii) accommodate the one or more three-dimensional objects carried by the build platform during the three-dimensional printing. In some embodiments, affixation of the piston relative to the support is restrictive of translation of the piston with respect to the support. In some embodiments, the method further comprises translating the piston relative to the support. In some embodiments, the translation comprises a vertical translation. In some embodiments, the piston is configured to operatively couple to a build platform configured to carry one or more three-dimensional objects during the three-dimensional printing.

[0027] In another aspect, an apparatus for three-dimensional printing, the apparatus comprises at least one controller configured to: (A) operatively couple to an envelope that is operatively coupled with a piston, the envelope configured to surround at least a portion of a circumference of the piston, the envelope being configured to reversibly expand and contract a circumference of the envelope; (B) direct deformation of the envelope to alter a circumference of the envelope such that envelope affixes the piston with respect to a support disposed adjacent to the piston, wherein affixation of the piston restricts translation of the piston with respect to the support; and (C) direct reversal of the deformation of the envelope to alter the circumference of the envelope such that the piston is released from its affixation with respect to the support, the release being unrestrictive of the translation of the piston with respect to the support. In some embodiments, the support comprises a build module body configured to accommodate (i) the piston, (ii) the envelope, and (ii) one or more three-dimensional objects during the three- dimensional printing in a printing cycle. In some embodiments, the support comprises a build module body configured to (i) accommodate a build platform and (ii) accommodate one or more three-dimensional objects carried by the build platform during the three-dimensional printing. In some embodiments, the at least one controller is configured to direct affixation of the piston relative to the support such that it is restrictive of translation of the piston with respect to the support. In some embodiments, the at least one controller is configured to direct translation of the piston relative to the support. In some embodiments, the at least one controller is configured to direct translation at least part by being configured to direct a vertical translation. In some embodiments, the piston is configured to operatively couple to a build platform configured to carry one or more three-dimensional objects during the three-dimensional printing.

[0028] In another aspect, non-transitory computer readable program instructions for three- dimensional printing, the program instructions, when read by one or more processors operatively coupled with a device, cause the one or more processors to execute operations, the device comprising: a support; a piston disposed adjacent to the support and configured for translation relative to the support; an envelope operatively coupled with the piston, the envelope configured to reversibly deform such that reversibly deformation of the envelope causes reversible affixation and release of the piston with respect to the support, and being (I) configured for the reversible deformation of the envelope, (II) configured for the reversible engagement and reversible disengagement of the piston with the support at least in part by being configured to facilitate the reversible deformation of the envelope, and/or (III) configured (a) for translation of the piston with respect to the support, (b) for synchronization of the reversible deformation of the envelope and/or (c) for synchronization of the translation with the reversible engagement and reversible disengagement of the piston with respect to the support, the operations comprise: (A) directing deformation of the envelope to alter a circumference of the envelope such that envelope affixes the piston with respect to the support disposed adjacent to the piston, wherein affixation of the piston restricts translation of the piston with respect to the support; and (B) directing reversal of the deformation of the envelope to alter the circumference of the envelope such that the piston is released from its affixation with respect to the support, the release being unrestrictive of the translation of the piston with respect to the support.

[0029] In another aspect, a system for three-dimensional printing, the system comprises: a support; a piston disposed adjacent to the support and configured for translation relative to the support; an envelope operatively coupled with the piston, the envelope configured to reversibly deform such that reversibly deformation of the envelope causes reversible affixation and release of the piston with respect to the support, the system being (I) configured for the reversible deformation of the envelope, (II) configured for the reversible engagement and reversible disengagement of the piston with the support at least in part by being configured to facilitate the reversible deformation of the envelope, and/or (III) configured (a) for translation of the piston with respect to the support, (b) for synchronization of the reversible deformation of the envelope and/or (c) for synchronization of the translation with the reversible engagement and reversible disengagement of the piston with respect to the support; and (A) an energy source configured to generate an energy beam to irradiate a pre-transformed material and transform into a transformed material to form the one or more three-dimensional objects, (B) a material extruder configured to extrude material to print the one or more three-dimensional objects, (C) a material dispenser, and/or (D) a laminator configured to deposit layerwise laminated layer to print the one or more three-dimensional objects.

[0030] In another aspect, a device for three-dimensional printing, the device comprises: a housing of a build module (e.g., a build module body); and a build platform assembly disposed in the housing, the build platform assembly comprises: a first piston assembly comprising a first piston and a first engagement mechanism, the first piston assembly being configured to (I) translate vertically in a direction, and (II) reversibly engage and disengage the first engagement mechanism with the housing; an adjusting coupler configured to facilitate adjustment of a gap, the adjusting coupler being operatively coupled with the first piston assembly; and a second piston assembly comprising a second piston and a second engagement mechanism, the second piston assembly being operatively coupled with the first piston assembly at least in part using the adjusting coupler, the second piston assembly being configured to (i) translate vertically in the direction to facilitate the three-dimensional printing, (ii) engage with a build platform and (Hi) reversibly engage and disengage the second engagement mechanism with the housing, the gap disposed between the first piston assembly and the second piston assembly, the build platform being configured to carry one or more three-dimensional objects during a printing cycle of the three-dimensional printing, and the first piston assembly and the second piston assembly being configured to translate vertically relative to each other to alter the gap, and the first piston assembly and/or the second piston assembly being configured for repetitive translation in the (same) direction, the housing being configured to accommodate (a) the build platform, (b) the first piston assembly, (c) the second piston assembly, (d) the adjusting coupler, and (e) the one or more three-dimensional objects. In some embodiments, the first piston assembly and the second piston assembly are configured to translate vertically relative to each other at least in part using the adjusting coupler. In some embodiments, the first piston and the second piston are configured to vertically translate in a coordinated manner. In some embodiments, the first piston and the second piston are configured to vertically translate in different types of movements. In some embodiments, the different types of movements comprise a fine movement and a coarse (e.g., bulk) movement. In some embodiments, the find movement is incremental to facilitate printing one or more three-dimensional objects in a layerwise manner. In some embodiments, the device is configured to facilitate translation of the build platform in a stepwise manner to facilitate the printing in a layerwise manner. In some embodiments, the device further comprises one or more temperature conditioning channels disposed in, or operatively coupled with (i) the build platform and/or (ii) the second piston assembly. In some embodiments, the first engagement mechanism comprises a first portion and a second portion; and where the second engagement mechanism comprises a third portion and a fourth portion. In some embodiments, (A) the first portion is configured to translate in a first translation type along a first axis disposed in a first plane and (B) the second portion is configured to translate in a second translation type along a second axis disposed in the plane, or in a first parallel plane (e.g., substantially) parallel to the first plane; and where (C) the third portion is configured to translate in a third translation type along a third axis disposed in a second plane and (D) the fourth portion is configured to translate in a fourth translation type along a fourth axis disposed in the second plane, or in a second parallel plane (e.g., substantially) parallel to the second plane. In some embodiments, the first plane and the second plane are (e.g., substantially) parallel to each other. In some embodiments, the first axis and the second axis are (e.g., substantially) normal to each other. In some embodiments, the third axis and the fourth axis are (e.g., substantially) normal to each other. In some embodiments, the first axis and the third axis are (e.g., substantially) parallel to each other. In some embodiments, the second axis and the fourth axis are (e.g., substantially) parallel to each other. In some embodiments, the first plane and the second plane are horizontal planes. In some embodiments, (i) the first portion is configured to translate during the printing in the first translation type along the first axis, (ii) the second portion is configured to translate during the printing in the second translation type along the second axis (iii) the third portion is configured to translate during the printing in the third translation type along the third axis, and (iv) the fourth portion is configured to translate during the printing in the fourth translation type along the fourth axis. In some embodiments, during the printing, the build platform assembly is configured to translate in a third translation type along an axis perpendicular to the first axis and/or to the second axis. In some embodiments, (A) the first axis is (e.g., substantially) normal to the second axis; and/or (B) the third axis is (e.g., substantially) normal to the fourth axis. In some embodiments, (A) the first translation type comprises (a) a first movement in a first direction along the first axis, and (b) a second movement in a second direction along the first axis, the first direction opposing the second direction, (B) the second translation type comprises

(a) a third movement in a third direction along the second axis, and (b) a fourth movement in a fourth direction along the second axis, the third direction opposing the fourth direction, (C) the third translation type comprises (a) a fifth movement in a fifth direction along the third axis, and

(b) a sixth movement in a sixth direction along the third axis, the fifth direction opposing the sixth direction, and/or (D) the fourth translation type comprises (a) a seventh movement in a seventh direction along the fourth axis, and (b) a eighth movement in a eighth direction along the fourth axis, the seventh direction opposing the eighth direction. In some embodiments, the first axis intersects the second axis; and/or where the third axis intersects the fourth axis. In some embodiments, the first axis intersects the second axis, the intersection being in a central vertical axis of the build platform assembly; and/or where the third axis intersects the fourth axis, the intersection being in a central vertical axis of the build platform assembly. In some embodiments, the first engagement mechanism comprises, or is operatively coupled with, (i) a first set of engagement features configured to engage with an internal surface of the build module along the first axis, the first portion comprising the first set of engagement features, and (ii) a second set of engagement features configured to engage with an internal surface of the build module along the first axis, the second portion comprising the second set of engagement features. In some embodiments, the build module comprises at least one first alignment feature and a piston assembly comprises respective at least one second alignment feature, the at least one first alignment feature configured to engage with the at least one second alignment feature to, during printing, align the build module with respect to the build platform assembly disposed in the build module, and the piston assembly being the first piston assembly and/or the second piston assembly. In some embodiments, the at least one first alignment feature comprises a protrusion, and where the at least one second alignment feature comprises a depression configured to engage with the protrusion for alignment of the build module with the piston assembly. In some embodiments, the at least one first alignment feature comprises a depression, and where the at least one second alignment feature comprises a protrusion configured to engage with the depression for alignment of the build module with the piston assembly. In some embodiments, engagement features of the first set of engagement features and of the second set of engagement features comprise pads. In some embodiments, the first piston assembly comprises, or is operatively coupled with, (i) a first push-pull actuator operatively coupled with the first set of engagement features, the first push-pull actuator configured to reversibly push and reversibly pull the engagement features along the first axis, and (ii) a second push-pull actuator operatively coupled with the second set of engagement features, the second push-pull actuator configured to reversibly push and reversibly pull the engagement features along the second axis. In some embodiments, each engagement feature is coupled with a pin, the engagement feature being of the first set of engagement features and of the second set of engagement features. In some embodiments, (i) the first push-pull actuator is operatively coupled with the first set of engagement features, each through its respective pin, and/or (ii) the second push-pull actuator is operatively coupled with the second set of engagement features, each through its respective pin. In some embodiments, the first piston assembly is operatively coupled with, or include, push-pull actuators, the push pull actuators comprise the first push-pull actuator and the second push-pull actuator. In some embodiments, each of the push-pull actuators comprise a ring, a secondary piston, a piezoelectric actuator, an eccentric mechanism, a lead screw, or a sliding double wedge mechanism. In some embodiments, the eccentric mechanism comprises the ring or a circle. In some embodiments, the first push-pull actuator and the second push-pull actuator are of the same type. In some embodiments, the first push-pull actuator and the second push-pull actuator are of a different type. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to exert (e.g., substantially) the same force during their respective push operation, and during their respective pull operation. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to cause their respective engagement features to exert (e.g., substantially) the same force onto the build module during their respective push operation, and during their respective pull operation. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate in coordination with each other. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate simultaneously with respect to each other. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate sequentially with respect to each other. In some embodiments, (A) the first set of engagement features comprises a first engagement feature and a second engagement feature, and where the first push-pull actuator is configured to actuate the first engagement feature (e.g., substantially) simultaneously with actuation of the second engagement feature and/or (B) the second set of engagement features comprises a third engagement feature and a fourth engagement feature, and where the second push-pull actuator is configured to actuate the third engagement feature (e.g., substantially) simultaneously with actuation of the fourth engagement feature. In some embodiments, (A) the first set of engagement features comprises a first engagement feature and a second engagement feature, and where the first push-pull actuator is configured to actuate the first engagement feature sequentially to actuation of the second engagement feature and/or (B) the second set of engagement features comprises a third engagement feature and a fourth engagement feature, and where the second push-pull actuator is configured to actuate the third engagement feature sequentially to actuation of the fourth engagement feature. In some embodiments, the first piston assembly and the second piston are coupled by a seal enclosing the adjusting coupler. In some embodiments, the first piston assembly and the second piston are configured for vertical translation in a sequential movement similar to movement of an inchworm. In some embodiments, the seal is configured to enclose one or more sensors operatively coupled with, or included with, the device. In some embodiments, the seal is configured to hinder printing material from entering an interior of a volume enclosed by the seal, the first piston assembly and the second piston assembly; and where the printing material comprises staring material or of byproduct of the printing. In some embodiments, the seal is configured to be adjustable at least in one direction. In some embodiments, the one direction is a vertical dimension. In some embodiments, the seal comprises at least one bellow. In some embodiments, the device further includes at least one sensor. In some embodiments, the at least one sensor comprises a position sensitive device. In some embodiments, the at least one sensor comprises an interferometric detector. In some embodiments, the at least one sensor comprises a fiber-coupled interferometric laser encoder. In some embodiments, the at least one sensor is a component of a metrological detection system configured to measure a position of the first portion of the build platform. In some embodiments, the metrological detection system further comprises a mirror arranged on a surface of the first portion of the build platform assembly and configured to reflect an energy beam incident on the mirror to the sensor. In some embodiments, (i) the first engagement mechanism is configured to reversibly deform and/or (ii) the second engagement mechanism is configured to reversibly deform. In some embodiments, (i) the first engagement mechanism is configured to reversibly deform at least in part by being configured to reversibly expand and reversibly contract and/or (ii) the second engagement mechanism is configured to reversibly deform at least in part by being configured to reversibly expand and reversibly contract. In some embodiments, deform comprises distort. In some embodiments, (i) the first engagement mechanism is configured to reversibly lock and reversibly unlock and/or (ii) the second engagement mechanism is configured to reversibly lock and reversibly unlock. In some embodiments, an engagement mechanism is of the first engagement mechanism and of the second engagement mechanism, the engagement mechanism comprising a ring concentrically arranged with respect to a horizontal circumference of the build platform assembly and/or with a horizontal circumference of the build module. In some embodiments, the engagement mechanism comprises a fastening engagement mechanism. In some embodiments, the fastening engagement mechanism comprises at least one reversibly moving engagement feature. In some embodiments, the reversibly moving engagement feature includes one or more of a pin, a pad, a flap, a support, or any combination thereof. In some embodiments, the fastening engagement mechanism comprises a plurality of pins. In some embodiments, the plurality of pins is arranged about an outer (e.g., horizontal) circumference of the build platform assembly and configured to engage with a plurality of receptacles arranged about an inner circumference of the build module body. In some embodiments, the fastening engagement mechanism further comprises a plurality of seals arranged with respect to the plurality of receptacles and configured to optionally engage with the plurality of receptacles. In some embodiments, the plurality of seals is configured to engage with the plurality of receptacles to prevent pre-transformed, debris, or transformed material from an inner volume of the plurality of receptacles. In some embodiments, engaging the plurality of pins comprises supporting, by the plurality of pins, a bottom surface of at least one section of the build platform assembly. In some embodiments, the at least one section is at least one piston, respectively. In some embodiments, the fastening engagement mechanism comprises a plurality of pads. In some embodiments, the fastening engagement mechanism comprises a plurality of pads arranged about (i) an outer circumference of at least on section (e.g., piston) of the build platform assembly, (ii) an inner circumference of the build module body, or (Hi) any combination thereof. In some embodiments, the engagement mechanism comprises a magnetic engagement mechanism. In some embodiments, the magnetic engagement mechanism comprises a plurality of electro-magnets. In some embodiments, the first engagement mechanism comprises, or is operatively coupled with, (i) a first set of engagement features configured to engage with an internal surface of the build module along the first axis, the first portion comprising the first set of engagement features, and (ii) a second set of engagement features configured to engage with an internal surface of the build module along the first axis, the second portion comprising the second set of engagement features. In some embodiments, the build module comprises at least one first alignment feature and a piston assembly comprises respective at least one second alignment feature, the at least one first alignment feature configured to engage with the at least one second alignment feature to, during printing, align the build module with respect to the build platform assembly disposed in the build module, and the piston assembly being the first piston assembly and/or the second piston assembly. In some embodiments, the at least one first alignment feature comprises a protrusion, and where the at least one second alignment feature comprises a depression configured to engage with the protrusion for alignment of the build module with the piston assembly. In some embodiments, the at least one first alignment feature comprises a depression, and where the at least one second alignment feature comprises a protrusion configured to engage with the depression for alignment of the build module with the piston assembly. In some embodiments, engagement features of the first set of engagement features and of the second set of engagement features comprise pads. In some embodiments, the first piston assembly comprises, or is operatively coupled with, (i) a first push-pull actuator operatively coupled with the first set of engagement features, the first push-pull actuator configured to reversibly push and reversibly pull the engagement features along the first axis, and (ii) a second push-pull actuator operatively coupled with the second set of engagement features, the second push-pull actuator configured to reversibly push and reversibly pull the engagement features along the second axis. In some embodiments, each engagement feature is coupled with a pin, the engagement feature being of the first set of engagement features and of the second set of engagement features. In some embodiments, (i) the first push-pull actuator is operatively coupled with the first set of engagement features, each through its respective pin, and/or (ii) the second push-pull actuator is operatively coupled with the second set of engagement features, each through its respective pin. In some embodiments, the first piston assembly is operatively coupled with, or include, push-pull actuators, the push pull actuators comprise the first push-pull actuator and the second push-pull actuator. In some embodiments, each of the push-pull actuators comprise a ring, a secondary piston, a piezoelectric actuator, an eccentric mechanism, a lead screw, or a sliding double wedge mechanism. In some embodiments, the eccentric mechanism comprises the ring or a circle. In some embodiments, the first push-pull actuator and the second push-pull actuator are of the same type. In some embodiments, the first push-pull actuator and the second push-pull actuator are of a different type. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to exert (e.g., substantially) the same force during their respective push operation, and during their respective pull operation. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to cause their respective engagement features to exert (e.g., substantially) the same force onto the build module during their respective push operation, and during their respective pull operation. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate in coordination with each other. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate simultaneously with respect to each other. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate sequentially with respect to each other. In some embodiments, (A) the first set of engagement features comprises a first engagement feature and a second engagement feature, and where the first push-pull actuator is configured to actuate the first engagement feature (e.g., substantially) simultaneously with actuation of the second engagement feature and/or (B) the second set of engagement features comprises a third engagement feature and a fourth engagement feature, and where the second push-pull actuator is configured to actuate the third engagement feature (e.g., substantially) simultaneously with actuation of the fourth engagement feature. In some embodiments, (A) the first set of engagement features comprises a first engagement feature and a second engagement feature, and where the first push-pull actuator is configured to actuate the first engagement feature sequentially to actuation of the second engagement feature and/or (B) the second set of engagement features comprises a third engagement feature and a fourth engagement feature, and where the second push-pull actuator is configured to actuate the third engagement feature sequentially to actuation of the fourth engagement feature. In some embodiments, the build module is configured to reversibly operatively coupled with a processing chamber during the three-dimensional printing, and reversibly decouple from the processing chamber after the three-dimensional printing. In some embodiments, the device further comprises (A) an energy source configured to generate an energy beam to irradiate a pretransformed material and transform into a transformed material to form the one or more three- dimensional objects, (B) a material extruder configured to extrude material to print the one or more three-dimensional objects, (C) a material dispenser, and/or (D) a laminator configured to deposit layerwise laminated layer to print the one or more three-dimensional objects. In some embodiments, the housing is configured to maintain in its interior an interior atmosphere different from an ambient atmosphere by the at least one characteristic, the ambient atmosphere being external to the housing. In some embodiments, the at least one characteristic comprises (i) a pressure above a pressure presiding in the ambient atmosphere, or (ii) a reactive agent being at a concentration lower than its concentration in the ambient atmosphere, the reactive agent being reactive with a starting material of the three-dimensional printing at least during the three-dimensional printing. In some embodiments, the housing is configured to maintain in its interior the interior atmosphere at a time comprising during the printing, after the printing, and/or after disengagement from a three-dimensional printer utilized for the printing. In some embodiments, the housing is configured to be closed by a lid configured to maintain in its interior the interior atmosphere at a time comprising after the printing and after the disengagement, when the lid closes the housing. In some embodiments, the device is configured to facilitate printing the one or more three-dimensional objects in an interior atmosphere maintained to be different from an ambient atmosphere by at least one characteristic, the ambient atmosphere being external to the build module and to a processing chamber. In some embodiments, the at least one characteristic comprises (i) a pressure above a pressure presiding in the ambient atmosphere, or (ii) a reactive agent being at a concentration lower than its concentration in the ambient atmosphere, the reactive agent being reactive with a starting material of the three- dimensional printing at least during the three-dimensional printing. In another aspect, a method of three-dimensional printing, the method comprises: providing the device in any of the above devices; and using the device during the three-dimensional printing. In some embodiments, the three-dimensional printing comprises connecting a particulate matter. In some embodiments, connecting comprises fusing. In some embodiments, fusing comprises melting. [0031] In another aspect, a method of three-dimensional printing, the method comprises: providing any of the above devices; and using the device during the three-dimensional printing. In some embodiments, the adjusting coupler may comprise a shaft. In some embodiments the method comprises: (a) providing a device comprising: a build module body; a build platform assembly disposed in the build module body, the build platform assembly comprises: a first piston assembly comprises a first piston and a first engagement mechanism, the first piston assembly being configured to (I) translate vertically in a direction, and (II) reversibly engage and disengage the first engagement mechanism with the build module body; a shaft operatively coupled with the first piston assembly; and a second piston assembly comprises a second piston and a second engagement mechanism, the second piston assembly being operatively coupled with the first piston assembly at least in part using (e.g., through) the adjusting coupler (e.g., shaft), the second piston assembly being configured to (i) translate vertically in the direction to facilitate the three-dimensional printing, (ii) engage with a build platform and (iii) reversibly engage and disengage the second engagement mechanism with the build module body, the build platform configured to carry one or more three-dimensional objects during a printing cycle of the three-dimensional printing, and the first piston assembly and the second piston assembly being configured to translate vertically relative to each other, and the first piston assembly and/or the second piston assembly being configured for repetitive translation in the direction, the build module body being configured to accommodate the build platform, the first piston assembly, the second piston assembly, the adjusting coupler (e.g., shaft), and the one or more three-dimensional object; (b) engaging the build platform with the second piston, and engaging the first engagement mechanism with the build module housing to affix the first piston relative to the build module housing; (c) translating the second piston in the direction to facilitate printing a first layer of transformed material as part of the one or more three-dimensional objects, the second engagement mechanism being disengaged with the build module body; (d) engaging the second engagement mechanism with the build module body to affix the second piston relative to the build module body; (e) disengaging the first engagement mechanism from the build module body; and (f) translating the first piston in the direction to facilitate accurate printing of the second piston to facilitate printing a second layer of transformed material as part of the one or more three-dimensional objects that is carried by the build platform. In some embodiments, the accurate printing comprises accurate measurement of disposition of the second piston. In some embodiments, the adjusting coupler (e.g., shaft) is operatively coupled with an encoder, e.g., an optical or a magnetic encoder.

[0032] In another aspect, an apparatus for three-dimensional printing, the apparatus comprises at least one controller configured to (i) operatively couple to any of any of the above devices; and control, or direct control of, one or more operations associated with the device. In some embodiments, the at least one controller comprises at least one connector configured to connect to a power source. In some embodiments, the at least one controller being configured to operatively couple to a power source at least in part by (I) having a power socket and/or (II) being configured for wireless power transfer using inductive charging. In some embodiments, the at least one controller is included in, or comprises, a hierarchical control system. In some embodiments, the hierarchical control system comprises at least three hierarchical control levels. In some embodiments, the at least one controller is included in a control system configured to control a three-dimensional printer that prints the one or more three-dimensional objects. In some embodiments, the device is a component of a three-dimensional printing system, and wherein the at least one controller is configured to (i) operatively couple to an other component of the three-dimensional printing system and (ii) direct operation of the other component. In some embodiments, the at least one controller is configured to direct operation of the other component at least in part for participation of the other component in three- dimensional printing. In some embodiments, the adjusting coupler may comprise a shaft. In some embodiments, the apparatus comprises: at least one controller configured to: (a) operatively couple to a device comprising: a housing of a build module; a build platform assembly disposed in the housing, the build platform assembly comprises: a first piston assembly comprises a first piston and a first engagement mechanism, the first piston assembly being configured to (I) translate vertically in a direction, and (II) reversibly engage and disengage the first engagement mechanism with the housing; a shaft operatively coupled with the first piston assembly; and a second piston assembly comprises a second piston and a second engagement mechanism, the second piston assembly being operatively coupled with the first piston assembly at least in part using (e.g., through) the adjusting coupler (e.g., shaft), the second piston assembly being configured to (i) translate vertically in the direction to facilitate the three-dimensional printing, (ii) engage with a build platform and (iii) reversibly engage and disengage the second engagement mechanism with the housing, and the first piston assembly and the second piston assembly being configured to translate vertically relative to each other, and the first piston assembly and/or the second piston assembly being configured for repetitive translation in the direction, the housing being configured to accommodate the build platform, the first piston assembly, the second piston assembly, the adjusting coupler (e.g., shaft), and the one or more three-dimensional object, the build platform configured to carry one or more three- dimensional objects during a printing cycle of the three-dimensional printing; (b) direct engagement of the build platform with the second piston, and engaging the first engagement mechanism with the build module housing to affix the first piston relative to the build module housing; (c) direct translation of the second piston in the direction to facilitate printing a first layer of transformed material as part of the one or more three-dimensional objects, the second engagement mechanism being disengaged with the build module body; (d) direct engagement of the second engagement mechanism with the build module body to affix the second piston relative to the build module body; (e) direct disengagement of the first engagement mechanism from the build module body; and (f) direct translation of the first piston in the direction to facilitate accurate printing of the second piston to facilitate printing a second layer of transformed material as part of the one or more three-dimensional objects that is carried by the build platform. In some embodiments, the at least one controller is configured to direct translation of the first piston in the direction to facilitate accurate printing at least in part by facilitating accurate printing that comprises accurate measurement of disposition of the second piston. In some embodiments, the adjusting coupler (e.g., shaft) is operatively coupled with an encoder, e.g., an optical or a magnetic encoder. In some embodiments, the adjusting coupler comprises a scissor jack, a lead screw, or gas (e.g., air) bearings.

[0033] In another aspect, non-transitory computer readable program instructions for three- dimensional printing, the program instructions, when read by one or more processors operatively coupled with any of the above devices, cause the one or more processors to execute, or direct execution of, one or more operations associated with the device. In some embodiments, the program instructions are inscribed in or more media. In some embodiments, the adjusting coupler may comprise a shaft. In some embodiments, the non-transitory computer readable program instructions for three-dimensional printing, the program instructions, when read by one or more processors operatively coupled with a device, cause the one or more processors to execute operations, the device comprising: a housing of a build module; a build platform assembly disposed in the housing, the build platform assembly comprising: a first piston assembly comprises a first piston and a first engagement mechanism, the first piston assembly being configured to (I) translate vertically in a direction, and (II) reversibly engage and disengage the first engagement mechanism with the housing; a shaft operatively coupled with the first piston assembly; and a second piston assembly comprises a second piston and a second engagement mechanism, the second piston assembly being operatively coupled with the first piston assembly at least in part using (e.g., through) the adjusting coupler (e.g., shaft), the second piston assembly being configured to (i) translate vertically in the direction to facilitate the three-dimensional printing, (ii) engage with a build platform and (iii) reversibly engage and disengage the second engagement mechanism with the housing, and the first piston assembly and the second piston assembly being configured to translate vertically relative to each other, the build platform configured to carry one or more three-dimensional objects during a printing cycle of the three-dimensional printing, and the first piston assembly and/or the second piston assembly being configured for repetitive translation in the direction, the housing being configured to accommodate the build platform, the first piston assembly, the second piston assembly, the adjusting coupler (e.g., shaft), and the one or more three-dimensional object; the operations comprising: (a) directing engagement of the build platform with the second piston, and engaging the first engagement mechanism with the build module housing to affix the first piston relative to the build module housing; (b) translating the second piston in the direction to facilitate printing a first layer of transformed material as part of the one or more three- dimensional objects, the second engagement mechanism being disengaged with the build module body; (d) directing engagement of the second engagement mechanism with the build module body to affix the second piston relative to the build module body; (c) directing disengagement of the first engagement mechanism from the build module body; and (d) directing translation of the first piston in the direction to facilitate accurate printing of the second piston to facilitate printing a second layer of transformed material as part of the one or more three-dimensional objects that is carried by the build platform. In some embodiments, the operations comprise directing translation of the first piston in the direction to facilitate accurate printing at least in part by facilitating accurate printing that comprises the accurate printing comprises accurate measurement of disposition of the second piston. In some embodiments, the adjusting coupler is operatively coupled with an encoder, e.g., an optical or a magnetic encoder. In some embodiments, the adjusting coupler comprises a scissor jack, a lead screw, or gas (e.g., air) bearings.

[0034] In another aspect, a system for three-dimensional printing, the system comprises: any of the above devices configured to perform three-dimensional printing; and an energy beam configured to irradiate a planar layer of powder material to print at least a portion of at least one three-dimensional object at least in part by using three-dimensional printing. In some embodiments, the system further comprises a scanner configured to translate the energy beam along a target surface, wherein the device is operatively coupled with the scanner. The system further comprises an energy source configured to generate the energy beam, wherein the device is operatively coupled with the energy source. The system further comprises at least one controller that (i) is operatively coupled with the device and (ii) direct one or more operations associated with the device. In some embodiments, the system is configured to operatively couple to at least one controller configured to (i) operatively couple to the system and (ii) direct one or more operations associated with the system. In some embodiments, the adjusting coupler may comprise a shaft. In some embodiments, the system comprises: a housing of a build module; a build platform assembly disposed in the housing, the build platform assembly comprises: a first piston assembly comprising a first piston and a first engagement mechanism, the first piston assembly being configured to (I) translate vertically in a direction, and (II) reversibly engage and disengage the first engagement mechanism with the housing; a shaft operatively coupled with the first piston assembly; a second piston assembly comprising a second piston and a second engagement mechanism, the second piston assembly being operatively coupled with the first piston assembly at least in part using (e.g., through) the adjusting coupler (e.g., shaft), the second piston assembly being configured to (i) translate vertically in the direction to facilitate the three-dimensional printing, (ii) engage with a build platform and (Hi) reversibly engage and disengage the second engagement mechanism with the housing, the build platform configured to carry one or more three-dimensional objects during a printing cycle of the three-dimensional printing, and the first piston assembly and the second piston assembly being configured to translate vertically relative to each other, and the first piston assembly and/or the second piston assembly being configured for repetitive translation in the direction, the housing being configured to accommodate the build platform, the first piston assembly, the second piston assembly, the adjusting coupler (e.g., shaft), and the one or more three-dimensional object; and (A) an energy source configured to generate an energy beam to irradiate a pre-transformed material and transform into a transformed material to form the one or more three-dimensional objects, (B) a material extruder configured to extrude material to print the one or more three-dimensional objects, (C) a material dispenser, and/or (D) a laminator configured to deposit layerwise laminated layer to print the one or more three-dimensional objects. In some embodiments, the adjusting coupler is operatively coupled with an encoder, e.g., an optical or a magnetic encoder. In some embodiments, the adjusting coupler comprises a scissor jack, a lead screw, or gas (e.g., air) bearings.

[0035] In another aspect, a method for three-dimensional printing, the method comprises: (A) engaging a first engagement mechanism of a first piston assembly, the first piston assembly operatively coupled with a second piston assembly by a shaft, the engagement being restrictive of translation of the first piston assembly with respect to a build module body, the first piston assembly and the second piston assembly being included in a build platform assembly that is supportive of a build platform configured to carry one or more three-dimensional objects during a three-dimensional printing process, the first piston assembly comprises the first engagement mechanism, and the second piston assembly comprises a second engagement mechanism; (B) translating the second piston assembly along the adjusting coupler (e.g., shaft) in a first direction in a plurality of incremental layerwise movements and towards the first piston assembly; (C) engaging the second engagement mechanism of the second piston assembly, the engagement being restrictive of translation of the second piston assembly with respect to the build module body; (D) disengaging the first engagement mechanism of the first piston assembly, the disengagement being unrestrictive of the translation of the first piston assembly with respect to the build module body; and (E) translating the first piston assembly along the adjusting coupler (e.g., shaft) in the first direction in a block movement and away from the second piston assembly. In some embodiments, the method further comprises repeating (A)-(E) until the build platform reaches a requested vertical position with respect to the build module body. In some embodiments, the method further comprises repeating (A)-(E) until the build platform assembly triggers an interlock. In some embodiments, the interlock comprises a limit switch. In some embodiments, the limit switch comprises a lower limit switch of the build module body. In some embodiments, the interlock comprises guide rods and wherein triggering the interlock comprises a portion of the build platform assembly contacting the guide rods. In some embodiments, the limit switch comprises an upper limit switch of the build module body. In some embodiments, the adjusting coupler is operatively coupled with an encoder, e.g., an optical or a magnetic encoder. In some embodiments, the adjusting coupler comprises a scissor jack, a lead screw, or gas (e.g., air) bearings.

[0036] In another aspect, an apparatus for three-dimensional printing, the apparatus comprises at least one controller configured to: (A) operatively couple to a build platform assembly comprises a first piston assembly and a second piston assembly, the first piston assembly operatively coupled with the second piston assembly by a shaft, and the build platform assembly being supportive of a build platform configured to carry one or more three-dimensional objects during a three-dimensional printing process; (B) direct engagement of a first engagement mechanism of the first piston assembly, the engagement being restrictive of translation of the first piston assembly with respect to (i) the second piston assembly and/or (ii) the build module body; (C) direct translation of the second piston assembly along the adjusting coupler (e.g., shaft) in a first direction in a plurality of incremental layerwise movements and towards the first piston assembly; (D) direct the three-dimensional printing of a portion of one or more three-dimensional objects supported by the build platform; (E) direct engagement of a second engagement mechanism of the second piston assembly, the engagement being restrictive of translation of the second piston assembly with respect to the first piston assembly;(F) direct disengagement of the first engagement mechanism of the first piston assembly, the disengagement being unrestrictive of the translation of the first piston assembly with respect to the second piston assembly; and (G) direct translation of the first piston assembly along the adjusting coupler (e.g., shaft) in the first direction in a block movement and away from the second piston assembly. In some embodiments, the adjusting coupler is operatively coupled with an encoder, e.g., an optical or a magnetic encoder. In some embodiments, the adjusting coupler comprises a scissor jack, a lead screw, or gas (e.g., air) bearings.

[0037] In another aspect, non-transitory computer readable program instructions for three- dimensional printing, the program instructions, when read by one or more processors operatively coupled with a device, cause the one or more processors to execute operations, the device comprising: a housing of a build module; a build platform assembly disposed in the housing, the build platform assembly comprises: a first piston assembly comprising a first piston and a first engagement mechanism, the first piston assembly being configured to (I) translate vertically in a direction, and (II) reversibly engage and disengage the first engagement mechanism with the housing; a shaft operatively coupled with the first piston assembly; and a second piston assembly comprising a second piston and a second engagement mechanism, the second piston assembly being operatively coupled with the first piston assembly at least in part using (e.g., through) the adjusting coupler (e.g., shaft), the second piston assembly being configured to (i) translate vertically in the direction to facilitate the three-dimensional printing, (ii) engage with a build platform and (iii) reversibly engage and disengage the second engagement mechanism with the housing, the build platform configured to carry one or more three- dimensional objects during a printing cycle of the three-dimensional printing, and the first piston assembly and the second piston assembly being configured to translate vertically relative to each other, and the first piston assembly and/or the second piston assembly being configured for repetitive translation in the direction, the housing being configured to accommodate the build platform, the first piston assembly, the second piston assembly, the adjusting coupler (e.g., shaft), and the one or more three-dimensional object; the operations comprise: (A) directing engagement of the first engagement mechanism of the first piston assembly; (B) directing translation of the second piston assembly along the adjusting coupler (e.g., shaft) in the direction in a plurality of incremental layerwise movements and towards the first piston assembly; (C) directing engagement of the second engagement mechanism of the second piston assembly, the engagement being restrictive of translation of the second piston assembly with respect to the build module housing; (D) directing disengagement of the first engagement mechanism of the first piston assembly, the disengagement being unrestrictive of the translation of the first piston assembly with respect to the build module housing; and (E) directing translation of the first piston assembly along the adjusting coupler (e.g., shaft) in the first direction in a block movement and away from the second piston assembly. In some embodiments, the adjusting coupler is operatively coupled with an encoder, e.g., an optical or a magnetic encoder. In some embodiments, the adjusting coupler comprises a scissor jack, a lead screw, or gas (e.g., air) bearings.

[0038] In another aspect, a system for three-dimensional printing, the system comprises: a first piston; a second piston being operatively coupled with the first piston, the second piston being configured to (i) translate to facilitate the three-dimensional printing, and (ii) engage with a build platform configured to carry one or more three-dimensional objects during the three- dimensional printing, the first piston being configured to translate, the first piston and the second piston being configured to translate relative to each other, and the first piston and/or the second piston being configured for translation during the three-dimensional printing; and (A) an energy source configured to generate an energy beam to irradiate a pre-transformed material and transform into a transformed material to form the one or more three-dimensional objects, (B) a material extruder configured to extrude material to print the one or more three-dimensional objects, (C) a material dispenser, and/or (D) a laminator configured to deposit layerwise laminated layer to print the one or more three-dimensional objects.

[0039] In another aspect, a device for three-dimensional printing, the device comprises: a piston assembly configured to engage with a build platform being configured to carry one or more three-dimensional objects during their printing; and a translational mechanism configured to alter a vertical extent of an exposed body of the translational mechanism that is operatively coupled with the piston assembly to facilitate additive printing methodology. In some embodiments, the translation mechanism comprises units configured to reversibly (i) nestle consecutively upon contraction, (ii) fold upon contraction, (iii) wrap upon contraction, or (iv) any combination of (i), (ii), and (iii). In some embodiments, the translation mechanism comprises units configured to reversibly contract vertically and reversibly expand vertically. In some embodiments, the translational mechanism comprises a telescopic unit. In some embodiments, the telescopic unit comprises telescopic cylinders. In some embodiments, when the telescopic unit is contracted, the telescopic cylinders are nestled concentrically and/or sequentially within one another. In some embodiments, the translation mechanism utilizes a force comprising an electric, a magnetic, or a hydraulic force. In some embodiments, the translation mechanism comprises a hydraulic telescopic unit. In some embodiments, the device further comprises (A) an energy source configured to generate an energy beam to irradiate a pre-transformed material and transform into a transformed material to form the one or more three-dimensional objects, (B) a material extruder configured to extrude material to print the one or more three-dimensional objects, (C) a material dispenser, and/or (D) a laminator configured to deposit layerwise laminated layer to print the one or more three-dimensional objects. In some embodiments, the translational mechanism is operatively coupled with the piston on a first surface opposing a second surface engaged with the build platform. In some embodiments, altering the vertical extent of the translational mechanism comprises vertically translating the piston assembly by an initiation movement. In some embodiments, the initiation movement positions the build platform at an initiation position with respect to a build module body to initiate the three-dimensional printing.

[0040] In another aspect, a method of three-dimensional printing, the method comprises: providing any of the above devices; and using the device during the three-dimensional printing. In some embodiments, the three-dimensional printing comprises connecting a particulate matter. In some embodiments, connecting comprises fusing. In some embodiments, fusing comprises melting. In some embodiments, the method of three-dimensional printing, the method comprises: (a) providing a device comprising: a piston assembly configured to engage with a build platform being configured to carry one or more three-dimensional objects during their printing; and a translational mechanism configured to alter a vertical extent of an exposed body of the translational mechanism that is operatively coupled with the piston assembly to facilitate additive printing methodology; (b) engaging the piston assembly with the build platform; and (c) translating the piston assembly at least in part by using the translational mechanism to facilitate the three-dimensional printing. An apparatus for three-dimensional printing, the apparatus comprises: at least one controller configured to: (a) operatively couple to a device comprising: a piston assembly configured to engage with a build platform being configured to carry one or more three-dimensional objects during their printing; and a translational mechanism configured to alter a vertical extent of an exposed body of the translational mechanism that is operatively coupled with the piston assembly to facilitate additive printing methodology; (b) direct engagement of the piston assembly with the build platform; and (c) direct translation of the piston assembly at least in part by using the translational mechanism to facilitate the three- dimensional printing.

[0041] In another aspect, an apparatus for three-dimensional printing, the apparatus comprises at least one controller configured to (i) operatively couple to any of the above devices; and control, or direct control of, one or more operations associated with the device. In some embodiments, the at least one controller comprises at least one connector configured to connect to a power source. In some embodiments, the apparatus for three-dimensional printing, the apparatus comprises at least one controller configured to: (A) operatively couple to a piston assembly comprises a build platform, the build platform being configured to carry one or more three-dimensional objects during their printing; and (B) direct translation of a translational mechanism operatively coupled with the piston assembly to translate the piston assembly by altering a vertical extent of the translational mechanism. In some embodiments, the at least one controller is configured to direct the translation at least in part by directing a vertical translation. In some embodiments, the translational mechanism is configured to alter a vertical extent of an exposed body of the translational mechanism that is operatively coupled with the piston assembly.

[0042] In another aspect, non-transitory computer readable program instructions for three- dimensional printing, the program instructions, when read by one or more processors operatively coupled with any of the above devices, cause the one or more processors to execute, or direct execution of, one or more operations associated with the device. The non- transitory computer readable program instructions of any of the above devices, wherein the program instructions are inscribed in or more media. In some embodiments, the non-transitory computer readable program instructions for three-dimensional printing, the program instructions, when read by one or more processors operatively coupled with a device, cause the one or more processors to execute operations, the device comprises: a piston assembly configured to engage with a build platform being configured to carry one or more three-dimensional objects during their printing; and a translational mechanism configured to alter a vertical extent of an exposed body of the translational mechanism that is operatively coupled with the piston assembly to facilitate additive printing methodology; the operations comprise: (a) engaging the piston assembly with the build platform; and (b) translating the piston assembly at least in part by using the translational mechanism to facilitate the three-dimensional printing. A method for three-dimensional printing, the method comprises: engaging a piston assembly with a build platform, the build platform being configured to carry one or more three-dimensional objects during their printing; and translating the piston assembly at least in part by altering a vertical extent of a translational mechanism operatively coupled with the piston assembly. In some embodiments, the translation is a vertical translation. In some embodiments, the translational mechanism is configured to alter the vertical extent of an exposed body of the translational mechanism that is operatively coupled with the piston assembly.

[0043] In another aspect, a system for three-dimensional printing, the system comprises: any of the above devices configured to perform three-dimensional printing; and an energy beam configured to irradiate a planar layer of powder material to print at least a portion of at least one three-dimensional object at least in part by using three-dimensional printing. In some embodiments, the system for three-dimensional printing, the system comprises: a piston assembly configured to engage with a build platform being configured to carry one or more three-dimensional objects during their printing; a translational mechanism configured to alter a vertical extent of an exposed body of the translational mechanism that is operatively coupled with the piston assembly to facilitate additive printing methodology; and (A) an energy source configured to generate an energy beam to irradiate a pre-transformed material and transform into a transformed material to form the one or more three-dimensional objects, (B) a material extruder configured to extrude material to print the one or more three-dimensional objects, (C) a material dispenser, and/or (D) a laminator configured to deposit layerwise laminated layer to print the one or more three-dimensional objects.

[0044] In another aspect, a device for three-dimensional printing, the device comprises: a build platform assembly configured to engage with a build platform configured to carry one or more three-dimensional objects during the three-dimensional printing, the build platform assembly being configured such that (A) a first portion of the build platform assembly is configured to translate in a first translation type along a first axis disposed in a plane and (B) a second portion of the build platform assembly is configured to translate in a second translation type along a second axis disposed in the plane, or in a plane (e.g., substantially) parallel to the plane. In some embodiments, the plane is a horizontal plane. In some embodiments, the first portion of the build platform assembly is configured to translate during the printing in the first translation type along the first axis, and the second portion of the build platform assembly is configured to translate during the printing in the second translation type along the second axis. In some embodiments, during the printing, the build platform assembly is configured to translate in a third translation type along an axis perpendicular to the first axis and/or to the second axis. In some embodiments, the first axis is (e.g., substantially) normal to the second axis. In some embodiments, (A) the first translation type comprises (a) a first movement in a first direction along the first axis, and (b) a second movement in a second direction along the first axis, the first direction opposing the second direction, and (B) the second translation type comprises (a) a third movement in a third direction along the second axis, and (b) a fourth movement in a fourth direction along the second axis, the third direction opposing the fourth direction. In some embodiments, the first direction is (e.g., substantially) normal to the second direction. In some embodiments, the first axis intersects the second axis. In some embodiments, the first axis intersects the second axis, the intersection being in a central vertical axis of the build platform assembly. In some embodiments, the build platform assembly comprises, or is operatively coupled with, (i) a first set of engagement features configured to engage with an internal surface of the build module along the first axis, the first portion comprising the first set of engagement features, and (ii) a second set of engagement features configured to engage with an internal surface of the build module along the first axis, the second portion comprising the second set of engagement features. In some embodiments, the build module comprises at least one first alignment feature and the build platform assembly comprises respective at least one second alignment feature, the at least one first alignment feature configured to engage with the at least one second alignment feature to, during printing, align the build module with respect to the build platform assembly disposed in the build module. In some embodiments, the at least one first alignment feature comprises a protrusion, and where the at least one second alignment feature comprises a depression configured to engage with the protrusion for alignment of the build module with the build platform assembly. In some embodiments, the at least one first alignment feature comprises a depression, and where the at least one second alignment feature comprises a protrusion configured to engage with the depression for alignment of the build module with the build platform assembly. In some embodiments, engagement features of the first set of engagement features and of the second set of engagement features comprise pads. In some embodiments, the build platform assembly comprises, or is operatively coupled with, (i) a first push-pull actuator operatively coupled with the first set of engagement features, the first push- pull actuator configured to reversibly push and reversibly pull the engagement features along the first axis, and (ii) a second push-pull actuator operatively coupled with the second set of engagement features, the second push-pull actuator configured to reversibly push and reversibly pull the engagement features along the second axis. In some embodiments, each engagement feature is coupled with a pin, the engagement feature being of the first set of engagement features and of the second set of engagement features. In some embodiments, (i) the first push-pull actuator is operatively coupled with the first set of engagement features, each through its respective pin, and/or (ii) the second push-pull actuator is operatively coupled with the second set of engagement features, each through its respective pin. In some embodiments, the build platform assembly is operatively coupled with, or include, push-pull actuators, the push pull actuators comprise the first push-pull actuator and the second push-pull actuator. In some embodiments, each of the push-pull actuators comprise a ring, a secondary piston, a piezoelectric actuator, an eccentric mechanism, a lead screw, or a sliding double wedge mechanism. In some embodiments, the eccentric mechanism comprises the ring or a circle. In some embodiments, the first push-pull actuator and the second push-pull actuator are of the same type. In some embodiments, the first push-pull actuator and the second push-pull actuator are of a different type. In some embodiments, the first push-pull actuator and the second push- pull actuator are configured to exert (e.g., substantially) the same force during their respective push operation, and during their respective pull operation. In some embodiments, the first push- pull actuator and the second push-pull actuator are configured to cause their respective engagement features to exert (e.g., substantially) the same force onto the build module during their respective push operation, and during their respective pull operation. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate in coordination with each other. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate simultaneously with respect to each other. In some embodiments, the first push-pull actuator and the second push-pull actuator are configured to operate sequentially with respect to each other. In some embodiments, (A) the first set of engagement features comprises a first engagement feature and a second engagement feature, and where the first push-pull actuator is configured to actuate the first engagement feature (e.g., substantially) simultaneously with actuation of the second engagement feature and/or (B) the second set of engagement features comprises a third engagement feature and a fourth engagement feature, and where the second push-pull actuator is configured to actuate the third engagement feature (e.g., substantially) simultaneously with actuation of the fourth engagement feature. In some embodiments, (A) the first set of engagement features comprises a first engagement feature and a second engagement feature, and where the first push-pull actuator is configured to actuate the first engagement feature sequentially to actuation of the second engagement feature and/or (B) the second set of engagement features comprises a third engagement feature and a fourth engagement feature, and where the second push-pull actuator is configured to actuate the third engagement feature sequentially to actuation of the fourth engagement feature. In some embodiments, the build platform assembly is configured for translation in a direction (e.g., substantially) normal to the first axis and/or to the second axis, e.g., during the printing. In some embodiments, the build platform assembly is configured for disposition in the build module, and where the build platform assembly is configured for translation along a vertical wall of the build module, e.g., during the printing. In some embodiments, the build platform is disposed in the build module, and where the build platform assembly is configured fortranslation is (i) towards a floor of the build module or (ii) away from the floor of the build module. In some embodiments, the build platform is configured for disposition in the build module, and where during the printing, the build platform assembly is configured for translation towards a gravitational environmental center or away from the gravitational environmental center. In some embodiments, the device further comprises (A) an energy source configured to generate an energy beam to irradiate a pre-transformed material and transform into a transformed material to form the one or more three-dimensional objects, (B) a material extruder configured to extrude material to print the one or more three-dimensional objects, (C) a material dispenser, and/or (D) a laminator configured to deposit layerwise laminated layer to print the one or more three-dimensional objects. In some embodiments, the build platform assembly comprises a first piston, and where the first portion and the second portion are part of, or operatively coupled with, the first piston. In some embodiments, the build platform assembly comprises a first piston and a second piston, and where the first portion and the second portion are part of, or operatively coupled with, the first piston; and where the second piston comprises a third portion in a similar arrangement to that of the first portion, and a fourth portion in a similar arrangement to that of the second portion. In some embodiments, the build platform assembly comprises a first piston and a second piston, and where the first portion and the second portion are part of, or operatively coupled with, the first piston; and where the second piston comprises a third portion similar to that of the first portion, and a fourth portion that is similar to the second portion. In some embodiments, the build platform assembly comprises a first piston and a second piston, and where the first portion and the second portion are part of, or operatively coupled with, (i) the first piston or (ii) the second piston. In some embodiments, the first piston and the second piston are the same in at least one characteristic comprising (i) horizontal circumference shape, (ii) horizontal circumference length, (Hi) horizontal crosssection, (iv) horizontal location, (v) material makeup, or (vi) engagement mechanism configured to reversibly engage (e.g., affix) and disengage with the build module in which the first piston and the second piston are disposed during the three-dimensional printing. In some embodiments, the first piston and the second piston are different by at least one characteristic comprising (i) functionality, (ii) shape, (iii) density, (iv) vertical location, (v) connectivity to one or more components, (vi) material makeup, or (vii) mechanism for reversibly engaging with (e.g., affixing to) the build module in which the first piston and the second piston are disposed during the three-dimensional printing. In some embodiments, the first piston comprises one or more openings. In some embodiments, the second piston is devoid of one or more openings. In some embodiments, the second piston comprises a cavity for temperature conditioning. In some embodiments, the first piston is devoid of a cavity for temperature conditioning. In some embodiments, the first piston and the second piston have the same shape and/or length of circumference. In some embodiments, the device is configured to vertically translate translations including the first translation type and the second translation type, the translations selected from at least two members of the group comprising a layerwise translation, a block translation, or an initiation translation. In some embodiments, the device is configured to vertically translate at least two members of the group comprising a first piston assembly, a second piston assembly, or a translational mechanism. In some embodiments, the device where, with respect to the environmental gravitational center, the vertical translation comprises an upward translation or a downward translation. In some embodiments, the first piston is oriented closer to a gravitational center than the second piston. In some embodiments, the gravitational center is a gravitational center of the Earth. In some embodiments, the first piston is aligned with the second piston along a central axis. In some embodiments, the central axis is a vertical axis. In some embodiments, the device further comprises an adjusting coupler configured to facilitate adjustment of a (e.g., vertical) gap between the first piston and the second piston operatively coupled between the first piston and the second piston. In some embodiments, the adjusting coupler comprises a shaft, and where a length of the shaft is aligned with the central axis. In some embodiments, the device further comprises an actuator. In some embodiments, the actuator comprises, or is operatively coupled with a servo motor operatively coupled with the adjusting coupler and configured to facilitate the vertical translation. In some embodiments, the actuator being coupled with the first piston or to the second piston. In some embodiments, the actuator being coupled with the first piston. In some embodiments, the first piston is configured to engaged with the build platform. In some embodiments, the build platform assembly is configured for repetitive vertical translation. In some embodiments, the build platform assembly is configured for repetitive incremental layerwise vertical translation. In some embodiments, the incremental layerwise movement comprises repetitive translation of the second piston relative to (i) the first portion of the build platform assembly and/or (ii) the build module. In some embodiments, further comprises a build module body of the build module, the build module body configured to retain the build platform assembly within an inner volume of the build module body, e.g., during the three-dimensional printing. In some embodiments, the build module body further comprises a seal. In some embodiments, the seal is included, or is operatively coupled with a shutter, a lid, a closure, an envelope, or a flap. In some embodiments, the seal is arranged with respect to an upper-most portion of the build module body and opposite a bottom portion of the build module body. In some embodiments, the seal is gas tight. In some embodiments, the seal is a hermetic seal. In some embodiments, the seal is configured to facilitate retaining an internal atmosphere in the build module body for a time period, the internal atmosphere being different from an ambient atmosphere external to the build module. In some embodiments, the seal is configured to facilitate retaining for a time period (i) a positive pressure within the build module body relative to an ambient atmosphere external to the device and/or (ii) a reactive agent at a concentration lower than its concentration in an ambient atmosphere external to the build module, the reactive agent being configured to at least react with pretransformed material of the three-dimensional printing during the three-dimensional printing. In some embodiments, the seal is arranged between a first piston and a second piston of the build platform assembly, the seal being configured to prevent pre-transformed, debris, or transformed material from a volume between the first piston and the second piston. In some embodiments, the seal comprises a bellow. In some embodiments, (i) the first portion of the build platform assembly comprises a first engagement mechanism and (ii) the second portion of the build platform assembly comprises a second engagement mechanism. In some embodiments, the build platform assembly is configured for disposition in the build module body. In some embodiments, (i) the first engagement mechanism of the first portion of the build platform assembly is configured to reversibly engage and reversibly disengage the first portion with a wall of the build module and (ii) the second engagement mechanism of the second portion of the build platform assembly is configured to reversibly engage and reversibly disengage the second portion with the wall of the build module. In some embodiments, (i) the first portion comprises a first set of engagement features (e.g., first pads) configured to reversibly engage and reversibly disengage the first portion with the wall of the build module and (ii) the second portion comprises a second set of engagement features (e.g., second pads) configured to reversibly engage and reversibly disengage the second portion with the wall of the build module. In some embodiments, engagement with the wall of the build module body of the first engagement mechanism and of the second engagement mechanism is configured to reversibly affix a first section of the build platform assembly with respect to the wall of the build module body, the first engagement mechanism and of the second engagement mechanism being part of, or being operatively coupled with, the first section. In some embodiments, affixing with respect to the fall is at least in part by applying a pressure, or another hold force, on the wall. In some embodiments, the first section comprises a first piston. In some embodiments, the device further comprises (i) a third engagement mechanism of a third portion of the build platform assembly, the third engagement mechanism configured to reversibly engage and reversibly disengage the third portion with the wall of the build module and (ii) a fourth engagement mechanism of a fourth portion of the build platform assembly is configured to reversibly engage and reversibly disengage the fourth portion with the wall of the build module. In some embodiments, (i) the third portion comprises a third set of engagement features (e.g., third pads) configured to reversibly engage and reversibly disengage the third portion with the wall of the build module and (ii) the fourth portion comprises a fourth set of engagement features (e.g., fourth pads) configured to reversibly engage and reversibly disengage the fourth portion with the wall of the build module. In some embodiments, engagement with the wall of the build module body of the third engagement mechanism and of the fourth engagement mechanism is configured to reversibly affix a second section of the build platform assembly with respect to the wall of the build module body, the third engagement mechanism and the fourth engagement mechanism being part of, or being operatively coupled with, the second section. In some embodiments, the second section comprises a second piston. In some embodiments, the build platform comprises a first section and a second section configured to traverse with respect to each other along a third axis (e.g., substantially) perpendicular to the first axis and to the second axis. In some embodiments, the third axis is a vertical axis. In some embodiments, (i) the first engagement mechanism is configured to reversibly deform and/or (ii) the second engagement mechanism is configured to reversibly deform. In some embodiments, (i) the first engagement mechanism is configured to reversibly deform at least in part by being configured to reversibly expand and reversibly contract and/or (ii) the second engagement mechanism is configured to reversibly deform at least in part by being configured to reversibly expand and reversibly contract. In some embodiments, deform comprises distort. In some embodiments, (i) the first engagement mechanism is configured to reversibly lock and reversibly unlock and/or (ii) the second engagement mechanism is configured to reversibly lock and reversibly unlock. In some embodiments, an engagement mechanism is of the first engagement mechanism and of the second engagement mechanism, the engagement mechanism comprising a ring concentrically arranged with respect to a horizontal circumference of the build platform assembly and/or with a horizontal circumference of the build module. In some embodiments, the engagement mechanism comprises a fastening engagement mechanism. In some embodiments, the fastening engagement mechanism comprises at least one reversibly moving engagement feature. In some embodiments, the reversibly moving engagement feature includes one or more of a pin, a pad, a flap, a support, or any combination thereof. In some embodiments, the fastening engagement mechanism comprises a plurality of pins. In some embodiments, the plurality of pins is arranged about an outer (e.g., horizontal) circumference of the build platform assembly and configured to engage with a plurality of receptacles arranged about an inner circumference of the build module body. In some embodiments, the fastening engagement mechanism further comprises a plurality of seals arranged with respect to the plurality of receptacles and configured to optionally engage with the plurality of receptacles. In some embodiments, the plurality of seals is configured to engage with the plurality of receptacles to prevent pre-transformed, debris, or transformed material from an inner volume of the plurality of receptacles. In some embodiments, engaging the plurality of pins comprises supporting, by the plurality of pins, a bottom surface of at least one section of the build platform assembly. In some embodiments, the at least one section is at least one piston, respectively. In some embodiments, the fastening engagement mechanism comprises a plurality of pads. In some embodiments, the fastening engagement mechanism comprises a plurality of pads arranged about (i) an outer circumference of at least on section (e.g., piston) of the build platform assembly, (ii) an inner circumference of the build module body, or (iii) any combination thereof. In some embodiments, the engagement mechanism comprises a magnetic engagement mechanism. In some embodiments, the magnetic engagement mechanism comprises a plurality of electro-magnets. In some embodiments, the device further comprises a sensor. In some embodiments, the sensor comprises a position sensitive device. In some embodiments, the sensor comprises an interferometric detector. In some embodiments, the sensor comprises a fiber-coupled interferometric laser encoder. In some embodiments, the sensor is a component of a metrological detection system configured to measure a position of the first portion of the build platform assembly. In some embodiments, the metrological detection system further comprises a mirror arranged on a surface of the first portion of the build platform assembly and configured to reflect an energy beam incident on the mirror to the sensor. In some embodiments, the device further comprises the build module configured to retain a portion of the build platform assembly. In some embodiments, the build module further comprises an interlock. In some embodiments, the interlock is a limit switch. In some embodiments, the limit switch limits an extent of travel of the build platform assembly with respect to the build module. In some embodiments, the limit switch limits an extent of travel of the build platform assembly, disposed adjacent to a floor of the build module body and between the build platform assembly and the floor of the module body. In some embodiments, the limit switch limits an extent of travel of the build platform assembly adjacent to a top of the build module body with respect to gravitation center. In some embodiments, the three-dimensional printing comprises stepwise translation of the build platform supported by the build platform assembly in a vertical direction, the translation comprising an error in positioning of the stepwise translation less than about 10%, 5%, or 2% in the vertical translation of the build platform. In some embodiments, the three-dimensional printing comprises vertical translation of the build platform assembly relative to the build module body. In some embodiments, translation of the build platform supported by the build platform assembly comprises facilitating translation of the build platform when a material bed is generated on a surface of the build platform and supported by the build platform. In some embodiments, the material bed formed on the surface of the build platform and supported by the build platform comprises a fundamental length scale of at least about 1000 kg. In some embodiments, the material bed comprises at least one fundamental length scale of at least about 300mm, 400mm, 600mm, 1000mm, or 1200 mm. In some embodiments, the build platform comprises a fundamental length scale of at least about 300mm, 400mm, 600mm, 1000mm, or 1200 mm. In some embodiments, the three-dimensional printing comprises facilitating deposition of pre-transformed material on a target surface. In some embodiments, the target surface comprises (i) an exposed surface of a material bed or (ii) a surface of the build platform. In some embodiments, facilitating deposition of pre-transformed material on the target surface comprises enlarging a volume of the material bed, where an exposed surface of the material is at a same position after deposition of pre-transformed material on the target surface. In some embodiments, facilitating deposition of pre-transformed material on the target surface comprises layerwise deposition. In some embodiments, the pre-transformed material comprises powder material. In some embodiments, the pre-transformed material comprises elemental metal, metal alloy, ceramic, or an allotrope of carbon. In some embodiments, the device is configured to operate under a positive pressure atmosphere relative to an ambient atmosphere external to the device. In some embodiments, the device is configured to operate under an atmosphere depleted of a reactive agent relative to its concentration in an ambient atmosphere external to the device, the reactive agent being configured to react with a starting material of the three-dimensional printing at least during the three-dimensional printing. In some embodiments, the reactive agent comprises oxygen, water, or hydrogen sulfide. In some embodiments, the device further comprises temperature adjustment interconnects configured to adjust a temperature of at least one section of the build platform assembly and/or of the build platform. In some embodiments, the temperature adjustment interconnects comprise a manifold. In some embodiments, the temperature adjustment interconnects comprise a channel. In some embodiments, the temperature adjustment interconnects comprise an internal chamber within at least one section of the build platform assembly. In some embodiments, the temperature adjustment interconnects are configured to receive a flow of a temperature adjustment agent from a source. In some embodiments, the temperature adjustment agent comprises a gas, a fluid, or a semisolid. In some embodiments, the temperature adjustment agent comprises water. In some embodiments, the temperature adjustment agent comprises a coolant. In some embodiments, the temperature adjustment interconnects are configured to reduce a temperature of (i) the build platform, (ii) the first portion, (iii) the second portion, (iv) a material bed and/or three-dimensional objects carried by the build platform during three-dimensional printing, or (v) any combination thereof. In some embodiments, the temperature adjustment interconnects are configured to reduce a temperature at a time comprises: during the three-dimensional printing, or after the three-dimensional printing. In some embodiments, the temperature adjustment interconnects are configured to reduce a temperature at a time comprises: (i) before disengagement of the build module in which a three-dimensional object is disposed during the three-dimensional printing, or (ii) after disengagement of the build module from a processing chamber.

[0045] In another aspect, a method of three-dimensional printing, the method comprises: providing any of the above devices; and using the device during the three-dimensional printing. [0046] In another aspect, an apparatus for three-dimensional printing, the apparatus comprising at least one controller configured to (i) operatively couple to any of the above devices; and control, or direct control of, one or more operations associated with the device. [0047] In another aspect, non-transitory computer readable program instructions for three- dimensional printing, the program instructions, when read by one or more processors operatively coupled with any of the above devices to cause the one or more processors to execute, or direct execution of, one or more operations associated with the device. [0048] In another aspect, a system for three-dimensional printing, the system comprises: any of the above devices configured to perform three-dimensional printing; and an energy beam configured to irradiate a planar layer of powder material to print at least a portion of at least one three-dimensional object at least in part by using three-dimensional printing.

[0049] In another aspect, a system for effectuating the methods, operations of an apparatus, and/or operations inscribed by non-transitory computer readable program instructions (e.g., inscribed on a media/medium), disclosed herein.

[0050] In another aspect, a system for effectuating the methods, operations of an apparatus, operation of a device, and/or operations inscribed by non-transitory computer readable program instructions (e.g., inscribed on a media/medium), disclosed herein.

[0051] In another aspect, device(s) (e.g., apparatus) for effectuating the methods, operations of an apparatus, and/or operations inscribed by non-transitory computer readable program instructions (e.g., inscribed on a media/medium).

[0052] In other aspects, systems, apparatuses (e.g., controller(s)), and/or non-transitory computer-readable program instructions (e.g., software) that implement any of the methods disclosed herein. In some embodiments, the program instructions is inscribed on at least one medium (e.g., on a medium or on media).

[0053] In other aspects, methods, systems, apparatuses (e.g., controller(s)), and/or non- transitory computer-readable program instructions (e.g., software) that implement any of the devices disclosed herein and/or any operation of these devices. In some embodiments, the program instructions is inscribed on at least one medium (e.g., on a medium or on media). [0054] In another aspect, an apparatus (e.g., for printing one or more 3D objects) comprises at least one controller that is configured (e.g., programmed) to direct a mechanism used in a 3D printing methodology to implement (e.g., effectuate) any of the method and/or operations disclosed herein, wherein the controller(s) is operatively coupled with the mechanism. In some embodiments, the controller(s) implements any of the methods and/or operations disclosed herein. In some embodiments, the at least one controller comprises, or be operatively coupled with, a hierarchical control system. In some embodiments, the hierarchical control system comprises at least three, four, or five, control levels. In some embodiments, at least two operations are performed, or directed, by the same controller. In some embodiments, at least two operations are each performed, or directed, by a different controller.

[0055] In another aspect, an apparatus (e.g., for printing one or more 3D objects) comprises at least one controller that is configured (e.g., programmed) to implement (e.g., effectuate), or direct implementation of, the method, process, and/or operation disclosed herein. In some embodiments, the at least one controller implements any of the methods, processes, and/or operations disclosed herein.

[0056] In another aspect, non-transitory computer readable program instructions (e.g., for printing one or more 3D objects), when read by one or more processors, are configured to execute, or direct execution of, the method, process, and/or operation disclosed herein. In some embodiments, the at least one controller implements any of the methods, processes, and/or operations disclosed herein. In some embodiments, at least a portion of the one or more processors is part of a 3D printer, outside of the 3D printer, or in a location remote from the 3D printer (e.g., in the cloud).

[0057] In another aspect, a system for printing one or more 3D objects comprises an apparatus (e.g., used in a 3D printing methodology) and at least one controller that is configured (e.g., programmed) to direct operation of the apparatus, wherein the at least one controller is operatively coupled with the apparatus. In some embodiments, the apparatus includes any apparatus or device disclosed herein. In some embodiments, the at least one controller implements, or direct implementation of, any of the methods disclosed herein. In some embodiments, the at least one controller directs any apparatus (or component thereof) disclosed herein.

[0058] In some embodiments, at least two of operations (e.g., instructions) of the apparatus are directed by the same controller. In some embodiments, at least two of operations (e.g., instructions) of the apparatus are directed by different controllers.

[0059] In some embodiments, at least two of operations (e.g., instructions) are carried out by the same processor and/or by the same sub-computer software product. In some embodiments, at least two of operations (e.g., instructions) are carried out (e.g., conducted) by different processors and/or by different sub-computer software products.

[0060] In another aspect, a computer software product, comprising a (e.g., non-transitory) computer-readable medium/media in which program instructions are stored, which instructions, when read by a computer, cause the computer to direct a mechanism used in the 3D printing process to implement (e.g., effectuate) any of the method disclosed herein, wherein the non- transitory computer-readable medium is operatively coupled with the mechanism. In some embodiments, the mechanism comprises an apparatus or an apparatus component.

[0061] In another aspect, a computer system comprising one or more computer processors and non-transitory computer-readable medium/media coupled thereto. In some embodiments, the non-transitory computer-readable medium/media comprises machine-executable code that, upon execution by the one or more computer processors, implements any of the methods and/or operations (e.g., as disclosed herein), and/or effectuates directions of the controller(s) (e.g., as disclosed herein).

[0062] In another aspect, a method for three-dimensional printing, the method comprises executing one or more operations associated with at least one configuration of the device(s) disclosed herein.

[0063] In another aspect, an apparatus for three-dimensional printing, the apparatus comprising at least one controller is configured (i) operatively couple to the device, and (ii) direct executing one or more operations associated with at least one configuration of the device(s) disclosed herein. [0064] In another aspect, at least one controller is associated with the methods, devices, and software disclosed herein. In some embodiments, the at least one controller comprise at least one connector configured to connect to a power source. In some embodiments, the at least one controller being configured to operatively couple to a power source at least in part by (I) having a power socket and/or (II) being configured for wireless power transfer using inductive charging. In some embodiments, the at least one controller is included in, or comprises, a hierarchical control system. In some embodiments, the hierarchical control system comprises at least three hierarchical control levels. In some embodiments, the at least one controller is included in a control system configured to control a three-dimensional printer that prints the one or more three-dimensional objects. In some embodiments, the at least one controller is configured to control at least one other component of a 3D printing system. In some embodiments, the device disclosed herein is a component of a three-dimensional printing system, and wherein the at least one controller is configured to (i) operatively couple to another component of the three- dimensional printing system and (ii) direct operation of the other component. In some embodiments, the at least one controller is configured to direct operation of the other component at least in part for participation of the other component in three-dimensional printing. In some embodiments, the at least one controller is operatively coupled with at least about 900 sensors, or 1000 sensors operatively couple to the three-dimensional printer. In some embodiments, the at least one controller is configured to control a pressure in the three-dimensional printer to be above ambient pressure external to the three-dimensional printer. In some embodiments, the at least one controller is configured to control an internal atmosphere of the three-dimensional printer to be depleted of a reactive agent relative to its concentration in an ambient atmosphere external to the device, the reactive agent being configured to react with a starting material of the three-dimensional printing at least during the three-dimensional printing.

[0065] In another aspect, non-transitory computer readable program instructions for three- dimensional printing, the non-transitory computer readable program instructions, when read by one or more processors operatively couped to the device, cause the one or more processors to direct executing one or more operations associated with at least one configuration of the device(s) disclosed herein.

[0066] In some embodiments, the program instructions are of a computer product.

[0067] In another aspect, a system for three-dimensional printing, the system comprising: the any of the devices above; and an energy beam configured to irradiate powder material (e.g., a planar layer of powder material) to print at least a portion of at least one three-dimensional object at least in part by using three-dimensional printing. In some embodiments, the system further comprising a scanner configured to translate the energy beam along a target surface, wherein the device is operatively coupled with the scanner disposed in an optical system enclosure. In some embodiments, the system further comprises an energy source configured to generate the energy beam, wherein the device is operatively coupled with the energy source. In some embodiments, the energy source comprises a laser source or an electron beam source. In some embodiments, the system further comprises at least one controller that (i) is operatively coupled with the device and (ii) direct one or more operations associated with the device. In some embodiments, the system is configured to operatively couple to at least one controller configured to (i) operatively couple to the system and (ii) direct one or more operations associated with the system.

[0068] The various embodiments in any of the above aspects are combinable (e.g., within an aspect), as appropriate.

[0069] Additional aspects and advantages of the present disclosure will become readily apparent to those skilled in this art from the following detailed description, wherein only illustrative embodiments of the present disclosure are shown and described. As will be realized, the present disclosure is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

INCORPORATION BY REFERENCE

[0070] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF DRAWINGS

[0071] The novel features of the present disclosure are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present disclosure will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the present disclosure are utilized, and the accompanying drawings or figures (also “Fig.” and “Figs.” herein), of which:

[0072] Fig. 1 schematically illustrates a side view of a three-dimensional (3D) printing system and its components;

[0073] Fig. 2 illustrates a path;

[0074] Fig. 3 schematically illustrates a computer system that is programmed or otherwise configured to facilitate the formation of one or more 3D objects;

[0075] Fig. 4 shows a block diagram of a 3D printing system and its components;

[0076] Fig. 5 schematically illustrates a perspective view of a 3D printing system and its components;

[0077] Fig. 6 schematically illustrates side views of a 3D printing system and its components;

[0078] Fig. 7 shows a apportion of a 3D printing system and its components;

[0079] Fig. 8 schematically illustrates a perspective view of a 3D printing system and its components;

[0080] Fig. 9 schematically illustrates various views 3D printing systems and their components;

[0081] Fig. 10 shows schematic views of 3D printing system components; [0082] Fig. 11 shows schematic views of 3D printing system components;

[0083] Fig. 12 shows schematic views of 3D printing system components;

[0084] Fig. 13 shows schematic views of 3D printing system components;

[0085] Fig. 14 shows a schematic view of 3D printing components with two analysis plots;

[0086] Fig. 15 shows schematic views of 3D printing system components;

[0087] Fig. 16 shows schematic views of 3D printing system components;

[0088] Fig. 17 shows schematic views of 3D printing system components;

[0089] Fig. 18 shows schematic views of 3D printing system components;

[0090] Fig. 19 shows a flow diagram of processes relating to 3D printing;

[0091] Fig. 20 shows a flow diagram of processes relating to 3D printing;

[0092] Fig. 21 schematically illustrates various views and vertical cross sections of 3D objects;

[0093] Fig. 22 shows schematic views of 3D printing system components;

[0094] Fig. 23 shows schematic views of 3D printing system components;

[0095] Fig. 24 shows schematic views of 3D printing system components;

[0096] Fig. 25 shows schematic views of 3D printing system components;

[0097] Fig. 26 depicts a projected pattern of a metrological detection system on a physical exposed surface of a material bed;

[0098] Fig. 27 shows schematic views of 3D printing system components;

[0099] Fig. 28 shows a schematic view of 3D printing system components;

[0100] Fig. 29 schematically shows a portion of a 3D printing system and its components;

[0101] Fig. 30 schematically illustrates a perspective view of a 3D printing system and its components;

[0102] Fig. 31 shows schematic perspective views of 3D printing system components;

[0103] Fig. 32 shows a flow diagram of processes relating to 3D printing;

[0104] Fig. 33 shows a flow diagram of processes relating to 3D printing;

[0105] Fig. 34 shows a flow diagram of processes relating to 3D printing;

[0106] Fig. 35 shows schematic views of 3D printing system components;

[0107] Fig. 36 shows schematic views of 3D printing system components;

[0108] Fig. 37 shows schematic views of a build module and associated components; and

[0109] Fig. 38 shows schematic views of a build module and associated components.

[0110] The figures and components therein may not be drawn to scale. Various components of the figures described herein may not be drawn to scale.

DETAILED DESCRIPTION

[0111] While various embodiments of the invention have been shown, and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions may occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein might be employed. The various embodiments disclosed herein are combinable, as appropriate. [0112] Terms such as “a,” “an” and “the” are not intended to refer to only a singular entity but include the general class of which a specific example may be used for illustration. The terminology herein is used to describe specific embodiments in the present disclosure, but their usage does not delimit to the specific embodiments of the present disclosure.

[0113] When ranges are mentioned, the ranges are meant to be inclusive, unless otherwise specified. For example, a range between value 1 and value 2 is meant to be inclusive and include value 1 and value 2. The inclusive range will span any value from about value 1 to about value 2. The term “adjacent” or “adjacent to,” as used herein, includes “next to,” “adjoining,” “in contact with,” and “in proximity to.” When ranges are mentioned (e.g., between, at least, at most, and the like) the endpoint(s) of the range is/are also claimed. For example, when the range is from Xto Y, the values of X and Y are also claimed. For example, when the range is at most Z, the value of Z is also claimed. For example, when the range is at least W, the value of W is also claimed.

[0114] The conjunction “and/or” as used herein in “X and/or Y” - including in the specification and claims - is meant to include the options (i) X, (ii) Y, and (iii) X and Y, as applicable. The conjunction of “and/or” in the phrase “including X, Y, and/or Z” is meant to include any combination and any plurality thereof, as applicable. For example, it is meant to include the following: (1) a single X, (2) a single Y, (3) a single Z, (4) a single X and a single Y, (5) a single X and a single Z, (6) a single Y and a single Z, (7) a single X, a single Y, and a single Z, (8) a plurality of X, (9) a plurality of Y, (10) a plurality of Z, (11) a plurality of X and a single Y, (12) a plurality of X, a single Y and a single Z, (13) a plurality of X and a single Z, (14) a plurality of Y and a single X, (15) a plurality of Y, a single X, and a single Z, (16) a plurality of Y and a single Z, (17) a plurality of Z and a single X, (18) a plurality of Z, a single X, and a single Y (19) a plurality of Z and a single Y, (20) a plurality X and a plurality Y, (21) a plurality X and a plurality Z, (22) a plurality Y and a plurality Z, and (23) a plurality X, a plurality Y, and a plurality Z. The phrase “including X, Y, and/or Z” is meant to have the same meaning as the phrase “comprising X, Y, or Z.”

[0115] The term “operatively coupled” or “operatively connected” refers to a first mechanism that is coupled (or connected) to a second mechanism to allow the intended operation of the second and/or first mechanism. The coupling may comprise physical or non-physical coupling. The non-physical coupling may comprise signal induced coupling (e.g., wireless coupling). [0116] The phrase “is/are structured” or “is/are configured,” when modifying an article, refers to a structure of the article that is able to bring about the referred result.

[0117] Fundamental length scale (abbreviated herein as “FLS”) comprises any suitable scale (e.g., dimension) of an object. For example, an FLS of an object may comprise a length, a width, a height, a diameter, a spherical equivalent diameter, a diameter of a bounding circle, a diameter of a bounding sphere, a radius, a spherical equivalent radius, or a radius of a bounding circle, or a radius of a bounding sphere. [0118] A central tendency as understood herein comprises mean, median, or mode. The mean may comprise a geometric mean.

[0119] Performing a reversible first operation is understood herein to mean performing the first operation and being capable of performing the opposite of that first operation (e.g., which is a second operation). For example, when a controller directs reversible opening of a shutter, that shutter can also close, and the controller can optionally direct a closure of that shutter. For example, when a recoater reversibly translates in a first direction, that recoater can also translate in a second direction opposite to the first direction. For example, when a controller directs reversibly translating a recoater in a first direction, that recoater can translate in the first direction and can also translate in a second direction opposite to the first direction, e.g., when the controller directs the recoater to translate in the second direction.

[0120] In an aspect provided herein is a system for generating a 3D object comprising: an enclosure for accommodating a material bed comprising pre-transformed material (e.g., starting material such as powder); an energy beam capable of transforming the pre-transformed material to form a transformed material; and a controller that directs the energy to impinge on and exposed surface of the material bed and translate along a path (e.g., as described herein). The transformed material may be capable of hardening to form at least a portion of a 3D object. The system may comprise an energy source generating the energy beam, a guiding system that guides the energy beam along the exposed surface such as an optical system (e.g., comprising a scanner), a control system, a layer dispensing mechanism comprising a recoater, gas source(s), pump(s), nozzle(s), valve(s), sensor(s), display(s), chamber(s), processor(s) comprising or software (e.g., comprising algorithm(s)) inscribed on a computer readable media/medium. The control system may be configured to control temperature, pressure, gas flow, optics, actuator(s), energy source(s), energy beam(s), and/or atmosphere(s). The control system may comprise processor(s). The enclosure may comprise a processing chamber and/or a build module. The base may be referred to herein as the “build plate” or “build platform." The substrate may comprise a piston. The system for generating at least one 3D object (e g., in a printing cycle) and its components may be any 3D printing system. Examples of 3D printers, their components, and associated methods, software, systems, devices, and apparatuses, can be found in International Patent Application Serial No. PCT/US17/60035, filed November 3, 2017; and in International Patent Application Serial No. PCT/US22/16550, filed February 26, 2022; each of which is entirely incorporated herein by reference.

[0121] Where suitable, one or more of the features shown in a figure comprising a 3D printer and/or components thereof can be combined with one or more of the various features of other 3D printers and/or components thereof described herein. A figure shown herein may not show certain features of a 3D printer and/or components thereof described herein. It should be understood that any such features can be incorporated within the 3D printer as requested and where suitable. [0122] The present disclosure provides three-dimensional (3D) printing apparatuses, systems, software, and methods for forming a 3D object. For example, a 3D object may be formed by sequential addition of material or joining of starting material (e.g., pre-transformed material or source material) to form a structure in a controlled manner (e.g., under manual or automated control).

[0123] Transformed material, as understood herein, is a material that underwent a physical change. The physical change can comprise a phase change. The physical change can comprise fusing (e.g., melting or sintering), connecting, or bonding (e.g., physical, or chemical bond). The physical change can be a phase transformation such as from a solid to a partially liquid, or to a liquid, phase.

[0124] The 3D printing process may comprise printing one or more layers of hardened material in a building cycle, e.g., in a printing cycle. A building cycle (e.g., printing cycle), as understood herein, comprises printing the (e.g., hardened, or solid) material layers of a print job (e.g., all, or substantially all, the layers of a printing job), which may comprise printing one or more 3D objects above a platform (e.g., in a single material bed). The one or more 3D object(s) may or may not be physically anchored to the platform (e.g., a build platform) above which it/they are printed.

[0125] Pre-transformed material (also referred to herein as “starting material”), as understood herein, is a material before it has been transformed (e.g., once transformed) by an energy beam during an upcoming 3D printing process, e.g., it is a starting material for an upcoming 3D printing process. The pre-transformed material may be a material that was, or was not, transformed prior to its use in the upcoming 3D printing process. The pre-transformed material may be a material that was partially transformed prior to its use in the upcoming 3D printing process. The pre-transformed material may be a starting material for the upcoming 3D printing process. The pre-transformed material may be liquid, solid, or semi-solid (e.g., gel). The pretransformed material may be a particulate material. For example, the particulate material may be a powder material. The powder material may comprise solid particles of material(s). The particulate material may comprise vesicles (e.g., containing liquid or semi-solid material). The particulate material may comprise solid or semi-solid material particles. The pre-transformed material may have been transformed by a 3D printer process prior to the upcoming 3D printing process. For example, in a first 3D printing process (having a first build cycle), powder material was used to form a 3D object. A remainder of the powder material of the first 3D printing process may become a pre-transformed material for an upcoming second 3D printing process (having a second build cycle). Thus, even though the remainder powder of the first 3D printing process may comprise transformed material (e.g., bits of sintered powder), it is still considered a pre-transformed material relative to the second 3D printing process. The remainder can be filtered and otherwise recycled for use as a pre-transformed material in the second 3D printing process. [0126] In some embodiments, in a 3D printing process, the deposited pre-transformed material may be fused (e.g., sintered or melted), bound, or otherwise connected to form at least a portion of the requested 3D object. Fusing, binding, or otherwise connecting the material is collectively referred to herein as “transforming” the material. Fusing the material may refer to melting, smelting, or sintering a pre-transformed material.

[0127] In some embodiments, melting may comprise liquefying the material (i.e., transforming to a liquefied state). A liquefied state refers to a state in which at least a portion of a transformed material is in a liquid state. Melting may comprise liquidizing the material (i.e., transforming to a liquidus state). A liquidus state refers to a state in which an entire transformed material is in a liquid state. The apparatuses, methods, software, and/or systems provided herein are not limited to the generation of a single 3D object but may be utilized to generate one or more 3D objects simultaneously (e.g., in parallel) or separately (e.g., sequentially). The multiplicity of 3D object may be formed in one or more material beds (e.g., powder bed). In some embodiments, a plurality of 3D objects is formed in one material bed.

[0128] In some examples, 3D printing methodologies comprise extrusion, wire, granular, laminated, light polymerization, or powder bed and inkjet head 3D printing. Extrusion 3D printing can comprise robo-casting, fused deposition modeling (FDM) or fused filament fabrication (FFF). Wire 3D printing can comprise electron beam freeform fabrication (EBF3). Granular 3D printing can comprise direct metal laser sintering (DMLS), electron beam melting (EBM), selective laser melting (SLM), selective heat sintering (SHS), or selective laser sintering (SLS). Powder bed and inkjet head 3D printing can comprise plaster-based 3D printing (PP). Laminated 3D printing can comprise laminated object manufacturing (LOM). Light polymerized 3D printing can comprise stereo-lithography (SLA), digital light processing (DLP), or laminated object manufacturing (LOM). 3D printing methodologies can comprise Direct Material Deposition (DMD). The Direct Material Deposition may comprise, Laser Metal Deposition (LMD, also known as, Laser deposition welding). 3D printing methodologies can comprise powder feed, or wire deposition.

[0129] In some examples, 3D printing methodologies differ from methods traditionally used in semiconductor device fabrication (e.g., vapor deposition, etching, annealing, masking, or molecular beam epitaxy). In some instances, 3D printing may further comprise one or more printing methodologies that are traditionally used in semiconductor device fabrication. 3D printing methodologies can differ from vapor deposition methods such as chemical vapor deposition, physical vapor deposition, or electrochemical deposition. In some instances, 3D printing may further include vapor deposition methods.

[0130] In an aspect provided herein is a system for generating a 3D object comprising: an enclosure for accommodating at least one layer of pre-transformed material (e.g., powder); an energy (e.g., energy beam) capable of transforming the pre-transformed material to form a transformed material; and a controller that directs the energy to impinge on the exposed surface of the layer of pre-transformed material and translate along a path (e.g., as described herein). The transformed material may be capable of hardening to form at least a portion of a 3D object. The system may comprise an energy source generating the energy beam, an optical system, a control system, a layer dispensing mechanism such as a recoater, gas source(s), pump(s), nozzle(s), valve(s), sensor(s), display(s), chamber(s), processor(s) comprising or software (e.g., comprising algorithm(s)) inscribed on a computer readable media/medium. The control system may be configured to control temperature, pressure, gas flow, optics, actuator(s), energy source(s), energy beam(s), and/or atmosphere(s). The chamber may comprise a base (e.g., building platform) and a substrate. The substrate may comprise a piston. The system for generating at least one 3D object (e.g., in a printing cycle) and its components may be any 3D printing system. Examples of 3D printers, their components, and associated methods, software, systems, devices, and apparatuses, can be found in International Patent Application Serial No. PCT/US17/60035, filed November s, 2017; and in International Patent Application Serial No. PCT/US22/16550, filed February 26, 2022; each of which is entirely incorporated herein by reference.

[0131] In some embodiments, the deposited pre-transformed material within the enclosure is a liquid material, semi-solid material (e.g., gel), or a solid material (e.g., powder). The deposited pre-transformed material within the enclosure can be in the form of a powder, wires, sheets, or droplets. The material (e.g., pre-transformed, transformed, and/or hardened) may comprise elemental metal, metal alloy, ceramics, or an allotrope of elemental carbon. The allotrope of elemental carbon may comprise amorphous carbon, graphite, graphene, diamond, or fullerene. The fullerene may be selected from the group comprising a spherical, elliptical, linear, or tubular fullerene. The fullerene may comprise a buckyball, or a carbon nanotube. The ceramic material may comprise cement. The ceramic material may comprise alumina, zirconia, or carbide (e.g., silicon carbide, or tungsten carbide). The ceramic material may include high performance material (HPM). The ceramic material may include a nitride (e.g., boron nitride or aluminum nitride). The material may comprise sand, glass, or stone. In some embodiments, the material may comprise an organic material, for example, a polymer or a resin (e.g., 114 W resin). The organic material may comprise a hydrocarbon. The polymer may comprise styrene or nylon (e.g., nylon 11). The polymer may comprise a thermoplast. The organic material may comprise carbon and hydrogen atoms. The organic material may comprise carbon and oxygen atoms. The organic material may comprise carbon and nitrogen atoms. The organic material may comprise carbon and sulfur atoms. In some embodiments, the material may exclude an organic material. The material may comprise a solid or a liquid. In some embodiments, the material may comprise a silicon-based material, for example, silicon-based polymer or a resin. The material may comprise an organosilicon-based material. The material may comprise silicon and hydrogen atoms. The material may comprise silicon and carbon atoms. In some embodiments, the material may exclude a silicon-based material. The powder material may be coated by a coating (e.g., organic coating such as the organic material (e.g., plastic coating)). The material may be devoid of organic material. The liquid material may be compartmentalized into reactors, vesicles, or droplets. The compartmentalized material may be compartmentalized in one or more layers. The material may be a composite material comprising a secondary material. The secondary material can be a reinforcing material (e g., a material that forms a fiber). The reinforcing material may comprise a carbon fiber, Kevlar®, Twaron®, ultra-high-molecular- weight polyethylene, or glass fiber. The material can comprise powder (e.g., granular material) and/or wires. The bound material can comprise chemical bonding. Transforming can comprise chemical bonding. Chemical bonding can comprise covalent bonding. The pre-transformed material may be pulverous. The printed 3D object can be made of a single material (e.g., single material type) or multiple materials (e.g., multiple material types). Sometimes one portion of the 3D object and/or of the material bed may comprise one material, and another portion may comprise a second material different from the first material. The material may be a single material type (e.g., a single alloy or a single elemental metal). The material may comprise one or more material types. For example, the material may comprise two alloys, an alloy and an elemental metal, an alloy and a ceramic, or an alloy and an elemental carbon. The material may comprise an alloy and alloying elements (e.g., for inoculation). The material may comprise blends of material types. The material may comprise blends with elemental metal or with metal alloy. The material may comprise blends excluding (e.g., without) elemental metal or including (e.g., with) metal alloy. The material may comprise a stainless steel. The material may comprise a titanium alloy, aluminum alloy, and/or nickel alloy.

[0132] In some cases, a layer within the 3D object comprises a single type of material. In some examples, a layer of the 3D object may comprise a single elemental metal type, or a single alloy type. In some examples, a layer within the 3D object may comprise several types of material (e.g., an elemental metal and an alloy, an alloy and a ceramic, an alloy, and an elemental carbon). In certain embodiments, each type of material comprises only a single member of that type. For example: a single member of elemental metal (e.g., iron), a single member of metal alloy (e.g., stainless steel), a single member of ceramic material (e.g., silicon carbide or tungsten carbide), or a single member of elemental carbon (e.g, graphite). In some cases, a layer of the 3D object comprises more than one type of material. In some cases, a layer of the 3D object comprises more than member of a type of material.

[0133] In some examples, the material bed, and/or 3D printing system (or any component thereof such as a build platform) may comprise any material disclosed herein. The material may comprise a material type which constituents (e.g., atoms) readily lose their outer shell electrons, resulting in a free-flowing cloud of electrons within their otherwise solid arrangement. The material bed may comprise a particulate material (e.g., powder). In some examples the material (e.g., powder, and/or 3D printer component) may comprise a material characterized in having high electrical conductivity, low electrical resistivity, high thermal conductivity, or high density. [0134] In some embodiments, the elemental metal is an alkali metal, an alkaline earth metal, a transition metal, a rare-earth element metal, a precious metal, or another metal. The elemental metal may comprise Titanium, Copper, Platinum, Gold, or Silver. [0135] In some embodiments, the metal alloy comprises iron-based alloy, nickel-based alloy, cobalt-based alloy, chrome-based alloy, cobalt chrome-based alloy, titanium-based alloy, magnesium-based alloy, or copper-based alloy. The alloy may comprise an oxidation or corrosion resistant alloy. The alloy may comprise a super alloy (e.g., Inconel, In718, Ti64, F357, Haynes282, GRCop-42, C22, CA6NM, Hastelloy-X). The alloy may comprise an alloy used for aerospace applications, automotive application, surgical application, or implant applications. The metal may include a metal used for aerospace applications, automotive application, surgical application, or implant applications.

[0136] In some embodiments, the metal alloys are refractory alloys. The refractory metals and alloys may be used for heat coils, heat exchangers, furnace components, or welding electrodes. The refractory alloys may comprise a high melting points, low coefficient of expansion, mechanically strong, low vapor pressure at elevated temperatures, high thermal conductivity, or high electrical conductivity.

[0137] In some embodiments, the material (e.g., alloy or elemental) comprises a material used for applications in industries comprising aerospace (e.g., aerospace super alloys), jet engine, missile, automotive, marine, locomotive, satellite, defense, oil & gas, energy generation, semiconductor, fashion, construction, agriculture, printing, or medical. The material may comprise an alloy used for products comprising, devices, medical devices (human & veterinary), machinery, cell phones, semiconductor equipment, generators, engines, pistons, electronics (e.g., circuits), electronic equipment, agriculture equipment, motor, gear, transmission, communication equipment, computing equipment (e.g., laptop, cell phone, tablet), air conditioning, generators, furniture, musical equipment, art, jewelry, cooking equipment, or sport gear. The material may comprise an alloy used for products for human or veterinary applications comprising implants, or prosthetics. The metal alloy may comprise an alloy used for applications in the fields comprising human or veterinary surgery, implants (e.g, dental), or prosthetics.

[0138] In some embodiments, the alloy includes a high-performance alloy. The alloy may include an alloy exhibiting at least one of excellent mechanical strength, resistance to thermal creep deformation, good surface stability, resistance to corrosion, and resistance to oxidation. The alloy may include a face-centered cubic austenitic crystal structure. The alloy can be a single crystal alloy. Examples of materials, 3D printers, and associated methods, software, systems, devices, materials (e.g., alloys), and apparatuses, can be found in International Patent Application Serial No. PCT/US17/60035, filed November s, 2017; and in International Patent Application Serial No. PCT/US22/16550, filed February 26, 2022; each of which is entirely incorporated herein by reference.

[0139] In some embodiments, the elemental carbon comprises graphite, Graphene, diamond, amorphous carbon, carbon fiber, carbon nanotube, or fullerene.

[0140] In some embodiments, the material comprises powder material (also referred to herein as a “pulverous material”). The powder material may comprise a solid comprising fine particles. The powder may be a granular material. The powder can be composed of individual particles. At least some of the particles can be spherical, oval, prismatic, cubic, or irregularly shaped. At least some of the particles can have a fundamental length scale (e.g., diameter, spherical equivalent diameter, length, width, depth, or diameter of a bounding sphere). The central tendency of the fundamental length scale (abbreviated herein as “FLS”) of the particles can be from about 5 micrometers (pm) to about 100 pm, from about 10 pm to about 70 pm, or from about 50 pm to about 100 pm. The particles can have central tendency of the FLS of at most about 75 pm, 65 pm, 50 pm, 30 pm, 25 pm or less. The particles can have a central tendency of the FLS of at least 10 pm, 25 pm, 30 pm, 50 pm, 70 pm, or more. A central tendency of the distribution of an FLS of the particles (e.g., range of an FLS of the particles between largest particles and smallest particles) can be about at least about 5 pm, 10 pm, 20 pm, 30 pm, 40 pm, 53 pm, 60 pm, or 75 pm. The particles can have a central tendency of the FLS of at most about 65 pm. In some cases, the powder particles may have central tendency of the FLS between any of the aforementioned FLSs.

[0141] In some embodiments, the powder comprises a particle mixture, which particle comprises a shape. The powder can be composed of a homogenously shaped particle mixture such that all the particles have (e.g., substantially) the same shape and FLS magnitude within at most about 1%, 5%, 8%, 10%, 15%, 20%, 25%, 30%, 35%, or 40% distribution of FLS.

[0142] In some embodiments, the 3D object(s) are printed from a material bed. The FLS (e.g., width, depth, and/or height) of the material bed can be at least about 50 millimeters (mm), 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 200 mm, 250 mm, 280 mm, 400 mm, 500 mm, 600mm, 800 mm, 900 mm, 1 meter (m), 2 m or 5 m. The FLS (e.g., width, depth, and/or height) of the material bed can be at most about 50 millimeters (mm), 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 200 mm, 250 mm, 280 mm, 400 mm, 500 mm, 600mm, 800 mm, 900 mm, 1 meter (m), 2 m, or 5 m. The FLS of the material bed can be between any of the afore-mentioned values (e.g., from about 50 mm to about 5m, from about 250 mm to about 500 mm, from about 280 mm to about 1m, or from about 500mm to about 5m). In some embodiments, the FLS of the material bed is in the direction of the gas flow.

[0143] In some examples, the 3D printing system requires operation of maximum a single standard daily work shift. The 3D printing system may require operation by a human operator working at most of about 8 hours (h), 7h, 6h, 5h, 4h, 3h, 2h, 1 h, or 0.5h a day. The 3D printing system may require operation by a human operator working between any of the aforementioned time frames (e.g., from about 8h to about 0.5h, from about 8h to about 4h, from about 6h to about 3h, from about 3h to about 0.5h, or from about 2h to about 0.5h a day).

[0144] In some embodiments, the enclosure and/or processing chamber of the 3D printing system may be opened to the ambient environment sparingly. In some embodiments, the enclosure and/or processing chamber of the 3D printing system may be opened by an operator (e.g., human) sparingly. Sparing opening may be at most once in at most every 1 , 2, 3, 4, or 5 weeks. The weeks may comprise weeks of standard operation of the 3D printer. In some embodiments, the 3D printer has a capacity of 1 , 2, 3, 4, or 5 full prints in terms of pre- transformed material (e.g., starting material such as powder) reservoir capacity. The 3D printer may have the capacity to print a plurality of 3D objects in parallel, e.g., in one material bed. For example, the 3D printer may be able to print at least 2, 3, 4, 5, 6, 7, 8, 9, or 103D objects in parallel.

[0145] Ambient refers to a condition to which people are (generally) accustomed to. For example, ambient pressure may be about 1 atmosphere. Ambient temperature may be a typical temperature to which humans are (generally) accustomed to. For example, from about 15 °C to about 30 °C, from about -30 °C to about 60 °C, from about -20 °C to about 50 °C, from 16 °C to about 26 °C, from about 20 °C to about 25 °C. “Room temperature” may be measured in a confined or in a non-confined space. For example, “room temperature” can be measured in a room, an office, a factory, a vehicle, a container, or outdoors. The vehicle may be a car, a truck, a bus, an airplane, a space shuttle, a spaceship, a ship, a boat, or any other vehicle. Room temperature may represent the small range of temperatures at which the atmosphere feels neither hot nor cold, approximately 24 °C. it may denote 20 °C, 25 °C, or any value from about 20 °C to about 25 °C.

[0146] In some embodiments, the 3D printer has a capacity to complete at least 1 , 2, 3, 4, or 5 printing cycles before requiring human intervention. Human intervention may be required for refilling the pre-transformed (e.g., powder) material, unloading the build modules, unpacking the 3D object, removing the debris byproduct of the 3D printing, or any combination thereof. The 3D printer operator may condition the 3D printer at any time during operation of the 3D printing system (e.g., during the 3D printing process). Conditioning of the 3D printer may comprise refilling the pre-transformed material that is used by the 3D printer, replacing gas source, or replacing filters. The conditioning may be with or without interrupting the 3D printing system. For example, refilling and unloading from the 3D printer can be done at any time during the 3D printing process without interrupting the 3D printing process. Conditioning may comprise refreshing the 3D printer.

[0147] In some embodiments, a time lapse between the end of printing in a first material bed, and the beginning of printing in a second material bed is at most about 60 minutes (min), 40 min, 30 min, 20 min, 15 min, 10 min, or 5 min. The time lapse between the end of printing in a first material bed, and the beginning of printing in a second material bed may be between any of the afore-mentioned times (e.g., from about 60 min to about 5 min, from about 60 min to about 30 min, from about 30 min to about 5 min, from about 20 min to about 5 min, from about 20 'min to about 10 min, or from about 15 min to about 5min). Examples of the speed during which the 3D printing process proceeds, 3D printing systems, apparatuses, devices, and components, controllers, software, and 3D printing processes can be found in International Patent Application Serial No. PCT/US15/36802 that is incorporated herein in its entirety.

[0148] In some embodiments, the at least one 3D object is removed from the material bed after the completion of the 3D printing process. For example, the 3D object(s) may be removed from the material bed when the transformed material that formed the 3D object hardens. For example, the 3D object may be removed from the material bed when the transformed material that formed the 3D object is no longer susceptible to deformation under standard handling operation (e.g., human and/or machine handling). At times, the generated 3D object requires very little, or no further processing after its retrieval. Further processing may be post printing processing. Further processing may comprise trimming, annealing, curing, or polishing, e.g., as disclosed herein. Further processing may comprise polishing such as sanding. In some cases, the generated 3D object can be retrieved and finalized without removal of transformed material and/or auxiliary support features.

[0149] In some examples, the generated 3D object adheres (e.g., substantially) to a requested model of the 3D object. The 3D object (e.g., solidified material) that is generated can have an average deviation value from the intended dimensions (e.g., of a requested 3D object) of at most about 0.5 microns (pm), 1 pm, 3 pm, 10 pm, 30 pm, 100 pm, 300 pm or less from a requested model of the 3D object. The deviation can be any value between the afore-mentioned values. The average deviation can be from about 0.5 pm to about 300 pm, from about 10 pm to about 50 pm, from about 15 pm to about 85 pm, from about 5 pm to about 45 pm, or from about 15 pm to about 35 pm. The 3D object can have a deviation from the intended dimensions in a specific direction, according to the formula D _v + — , wherein D _v is a deviation value, L is the

^K dv length of the 3D object in a specific direction, and K _dv is a constant. D _v can have a value of at most about 300 pm, 200 pm, 100 pm, 50 pm, 40 pm, 30 pm, 20 pm, 10 pm, 5 pm, 1 pm, or 0.5 pm. D _v can have a value of at least about 0.5 pm, 1 pm, 3 pm, 5 pm, 10 pm, 20 pm, 30 pm, 50 pm, 70 pm, 100 pm, 300 pm or less. D _v can have any value between the afore-mentioned values. For example, D _v can have a value that is from about 0.5 pm to about 300 pm, from about 10 pm to about 50 pm, from about 15 pm to about 85 pm, from about 5 pm to about 45 pm, or from about 15 pm to about 35 pm. K _dv can have a value of at most about 3000, 2500, 2000, 1500, 1000, or 500. C _dl? can have a value of at least about 500, 1000, 1500, 2000, 2500, or 3000. K _dv can have any value between the afore-mentioned values. For example, K _dv can have a value that is from about 3000 to about 500, from about 1000 to about 2500, from about 500 to about 2000, from about 1000 to about 3000, or from about 1000 to about 2500.

[0150] At times, the generated 3D object (i.e., the printed 3D object) does not require further processing following its generation by a method described herein. The printed 3D object may require reduced amount of processing after its generation by a method described herein. For example, the printed 3D object may not require removal of auxiliary support (e.g., since the printed 3D object was generated as a 3D object devoid of auxiliary support). The printed 3D object may not require smoothing, flattening, polishing, or leveling. The printed 3D object may not require further machining. In some examples, the printed 3D object may require one or more treatment operations following its generation (e.g., post generation treatment, or post printing treatment). The further treatment step(s) may comprise surface scraping, machining, polishing, grinding, blasting (e.g., sand blasting, bead blasting, shot blasting, or dry ice blasting), annealing, or chemical treatment. Examples of 3D printing systems, apparatuses, devices, and components, controllers, software, and 3D printing processes (e.g., post-processing, postgeneration treatment, and post-printing treatment) can be found in International Patent Application Serial No. PCT/US22/52588, filed December 12, 2022, which is entirely incorporated herein by reference.

[0151] At times, the methods described herein are performed in the enclosure (e.g., container, processing chamber, and/or build module). One or more 3D objects can be formed (e.g., generated, and/or printed) in the enclosure (e.g., simultaneously, and/or sequentially). The enclosure may have a predetermined and/or controlled (e.g., maintained) pressure. The enclosure may have a predetermined and/or controlled atmosphere. The control may be manual or via a control system.

[0152] In some embodiments, the 3D printer comprises a chamber having an interior space. The chamber may be referred to herein as a “processing chamber.” The processing chamber may facilitate ingress of an energy beam. The energy beam may be directed towards a target surface, e.g., an exposed surface of a material bed. The 3D printer may comprise one or more modules, e.g., build modules. At times, at least one build module may be situated in the enclosure and coupled with the processing chamber. At times, at least one build module engages with the processing chamber to expand an interior volume of the processing chamber. [0153] In some embodiments, the 3D printer comprises a layer dispensing mechanism. The pre-transformed material may be deposited in the enclosure by a layer dispensing mechanism (also referred to herein as a “layer dispenser,” or “layer forming apparatus). In some embodiments, the layer dispensing mechanism includes one or more material dispensers (also referred to herein as “dispensers” and “material dispensing mechanism”), and/or at least one powder removal mechanism (also referred to herein as material “remover” or “material remover”) to form a layer of pre-transformed material (e.g., starting material) within the enclosure. In some embodiments, the layer dispensing mechanism includes a leveler to planarize (e.g., smooth, such as substantially planarize) an exposed surface of a material bed within the enclosure. The deposited starting material may be leveled by a leveling operation. The leveling operation may comprise using a powder removal mechanism that does not contact the exposed surface of the material bed. The material (e.g., powder) dispensing mechanism may comprise one or more dispensers. The material dispensing mechanism may comprise at least one material (e.g., bulk) reservoir. The layer dispensing mechanism and energy beam can translate and form the 3D object adjacent to the build platform, while the build platform gradually lowers its vertical position to facilitate layer-wise formation of the 3D object. The layer dispensing mechanism and energy beam can translate and form the 3D object within the material bed (e.g., as described herein), while the build platform gradually lowers its vertical position to facilitate layer-wise formation of the 3D object. The layer dispensing mechanism can be used to form at least a portion of the material bed. The layer dispensing mechanism can dispense material, remove material, and/or shape the material bed, e.g., shape an exposed surface of a layer of material of the material bed. The material can comprise a pre-transformed material or a debris. Shaping the material bed may comprise altering a shape of the exposed surface of the material bed, e.g., planarizing the exposed surface of the material bed. The layer dispensing mechanism can be in a layer forming mode when dispensing the material and/or shaping the material bed. The layer dispensing mechanism can be in a parked mode when the layer dispensing mechanism is in an idle position such as a parked position. The material dispensing mechanism (e.g., the dispenser) can comprise a reservoir configured to retain a volume of pre-transformed material. The volume of pre-transformed material may be equivalent to about the volume of pre-transformed material sufficient for at least one or more dispensed layers above the build platform. Examples of 3D printing systems, apparatuses, devices, and components (e.g., material dispensing mechanisms and material removal mechanisms), controllers, software, and 3D printing processes can be found in Patent Application serial number PCT/US 15/36802 filed on June 19, 2015; in Provisional Patent Application serial number 62/317,070 filed April 1 , 2016; in International Patent Application serial number PCT/US16/66000 filed on December 9, 2016; in International Patent Application serial number 62/265,817, filed December 10, 2015; or in Provisional Patent Application serial number 63/357,901 , filed on July 1 , 2022; each of which is incorporated herein in its entirety.

[0154] In some embodiments, the 3D printing system comprises a build module. The build module may be mobile or stationary. The build module may comprise an elevation mechanism, e.g., comprising a build platform assembly. The build module may comprise a platform that may be coupled with the build platform assembly. The platform may be situated within the build module. The base (e.g., build platform) may reside adjacent to the substrate, e.g., above the substrate relative to a gravitational center of the environment (e.g., Earth). For example, the base may (e.g., reversibly) connect to the substrate. The elevation mechanism may be reversibly connected to (and disconnected from) at least a portion of the base. The elevation mechanism may comprise a portion that vertically translates the build platform with respect to a gravitational center (e.g., a gravitational center of the Earth). The base may be disposed on the substrate. A material bed may be disposed above base. The build platform may comprise, or be configured to operatively couple to, an engagement mechanism. The substrate may comprise, or be configured to operatively couple to, an engagement mechanism. The engagement mechanism may facilitate engagement and/or dis-engagement between the base (e.g., of the build platform) and the substrate. The engagement mechanism may facilitate sequential and/or continuous movement of the base (e.g., of the build platform) relative to the substrate. The engagement mechanism may comprise one or more mechanical engagement features comprising a ring, pins, or pads. The engagement mechanism may comprise at least one actuator. Each piston assembly may comprise an engagement mechanism. Each piston assembly may comprise at least one engagement mechanism. The build platform may be configured to support one or more layers of pre-transformed material (e.g., as part of the material bed). The build platform may be configured to support at least a portion of the 3D object (e.g., during forming of the 3D object). The substrate and/or the base (e.g., build platform) may be removable or non-removable (e.g., from the 3D printing system and/or relative to each other). The substrate and/or base may be fastened (I) to the build module and/or (II) to each other. The build platform and/or substrate may be translatable. The translation of the build platform may be controlled and/or regulated by at least one controller (e.g., by a control system). The translation of the substrate may be controlled and/or regulated by at least one controller (e.g., by a control system). The build platform and/or substrate may be translatable horizontally, vertically, or at an angle (e.g., planar or compound angle). The control system may be any control system disclosed herein, e.g., a control system of the 3D printer such as the one controlling an energy beam. The substrate may comprise a piston. At times, the 3D printing system may comprise more than one substrate. At times, the 3D printing system may comprise more than one piston. The disclosure herein relating to the substrate may apply to the substrates.

[0155] In some embodiments, the build module, processing chamber, and/or enclosure comprises one or more seals. The seal may be a sliding seal or a stationary (e.g., top) seal. For example, the build module and/or processing chamber may comprise a sliding seal that meets with the exterior of the build module upon engagement of the build module with the processing chamber. At least a portion of the 3D printing process, the atmospheres of the build module and processing chamber may be separate. For example, the processing chamber may comprise a top seal that faces the build module and is pushed upon engagement of the processing chamber with the build module. For example, the build module may comprise a top seal that faces the processing chamber and is pushed upon engagement of the processing chamber with the build module. The seal may be a face seal, or compression seal. The seal may comprise an O-ring. For example, the build module and the processing chamber may be separated by a load lock. The build platform and/or substrate may be separated from one or more walls (e.g., side walls) of the build module by a seal. The seal may be impermeable or (e.g., substantially) impermeable to gas. The seal may be permeable to gas. The seal may be impermeable to the pretransformed (e.g., and to the transformed) material. The seal may be flexible. The seal may be elastic. The seal may be bendable. The seal may be compressible. The seal may include a material comprising rubber (e.g., latex), Teflon, plastic, or silicon. The seal may comprise a mesh, membrane, sieve, paper (e.g., filter paper), cloth such as felt (e.g., Aramid felt, or another high temperature felt or fiber), or a brush. The mesh, membrane, paper and/or cloth may comprise randomly or non-randomly arranged fibers. The paper may comprise a HEPA filter. The seal may be permeable to at least one gas. The seal may be impermeable to the pretransformed (e.g., and to the transformed) material. The seal may not allow a pre-transformed (e.g., and to the transformed) material to pass through.

[0156] In some embodiments, the substrate (e.g., piston) is separated from the base (e.g., build platform) assembly by a seal. The base and/or the substrate may be separated from the internal surface of the build module by one or more seals. The seal may be attached to the moving build platform and/or substrate (e.g., while the walls of the build module are devoid of a seal). The seal may be attached to the (e.g., vertical) walls of the build module (e.g., while the build platform and/or substrate is devoid of a seal). In some embodiments, both the build platform and/or substrate and the walls of the build module comprise a seal. The seal may be placed laterally (e.g., horizontally) between one or more walls (e.g., side walls) of the build module. The seal may be connected to a bottom plane of the build platform and/or substrate. The seal may be connected to a side (e.g., circumference) of the build platform and/or substrate. The seal may be permeable to gas. The seal may be impermeable to particulate material (e.g., powder). The seal may not allow permeation of particulate material into the build platform assembly and/or piston assembly. The build platform assembly may comprise a piston and a build platform. The piston assembly may comprise a piston. The seal may be flexible. The seal may be elastic. The seal may be bendable. The seal may be compressible. The seal may include a material comprising a polymeric material (e.g., nylon, polyurethane), Teflon, plastic, rubber (e.g., latex), or silicon. The seal may comprise a mesh, membrane, sieve, paper (e.g., filter paper), cloth (e.g., felt, or wool), or brush. The mesh, membrane, paper and/or cloth may comprise randomly and/or non-randomly arranged fibers. The paper may comprise a HEPA filter.

[0157] In some embodiments, the build platform is translated, e.g., before, during, and/or after printing one or more 3D objects in a print cycle. The translation may be in both directions (e.g., back and forth such as up and down relative to a gravitational vector). The translation may be vertical. The translation may be effectuated by a build platform assembly and/or an actuator (e.g., controlled by a control system). The build platform assembly may be configured to provide a high precision platform for building one or more 3D objects in a printing cycle with high fidelity. The build module may accommodate a material bed having at least one (e.g., two or more) FLS (e.g., diameter, width, and/or height) of at most about 200mm, 250 mm, 300mm, 350 mm, 400mm, 450 mm, 500mm, 550 mm, 600 mm, 650 mm, 700mm, 800mm, 900mm, 1000mm, 1200mm, 1500 mm, 2000 mm, 2500 mm, 3000 mm, 3500 mm, 4000mm, or 4500 mm. The FLS of the material bed accommodated by the build module may have a FLS value between any of the aforementioned values (e.g., from about 100mm to about 4500mm, from about 100mm to about 2000mm, from about 100mm to about 700mm, or from about 300mm to about 4000 mm). In addition to the material bed, the build module may be configured to accommodate a base (e.g., build platform) and at least one substrate (e.g., piston). The build module may accommodate a build platform having an FLS (e.g., diameter or width) of at least about 100 millimeters (mm), 200mm, 300mm, 400mm, 500mm, 600 mm, 700mm, 800mm, 900mm, 1000mm, 1500mm, or 2000mm, 2500 mm, 3000 mm, 3500 mm, or 4000 mm. The build module may accommodate a build platform having at least one FLS (e.g., diameter, height and/or width), the FLS being of at most about 200mm, 250 mm, 300mm, 350 mm, 400mm, 450 mm, 500mm, 550 mm, 600 mm, 650 mm, 700mm, 800mm, 900mm, 1000mm, 1200mm, 1500 mm, 2000 mm, 4000mm, or 4500mm. The FLS of the build platform accommodated by the build module may have a FLS value between any of the aforementioned values (e.g., from about 100mm to about 4500mm, from about 100mm to about 1200mm, from about 100mm to about 1500mm, or from about 300mm to about 2000 mm). The build platform assembly may be able to translate in a continuous and/or discrete manner. The build platform assembly may be able to translate in discrete increments of at most about 5 micrometers (pm), 20pm, 30pm, 40pm, 50pm, 60pm, 70pm, or 80pm. The build platform assembly may be able to translate in discrete increments having a value between any of the aforementioned values (e.g., from about 5pm to about 80pm, from about 10pm to about 60pm, or from about 40pm to about 80pm). The build platform assembly may have a precision (e.g., error +/-) of at most about 0.25pm, 0.5pm, 1 pm, 1.5pm, 2pm, 2.5pm, 3pm, 4pm, or 5pm. The build platform assembly may have a precision value between any of the aforementioned precision value (e.g., from about 0.25pm to about 5pm, from about 0.25pm to about 2.5pm, or from about 1 ,5pm to about 5pm). The build platform assembly may have a precision (e.g., error +/-) of at most about 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 8% or 10% of its incremental movement. The build platform assembly may have a precision value between any of the aforementioned precision value relative to its incremental movement (e.g., from about 0.5% to about 10%, from about 0.5% to about 5%, or from about 1% to about 10%). The weight of the material bed (e.g., including any printed 3D object therein) may be at least about 300 Kilograms (Kg), 500 Kg, 800Kg, 1000Kg, 1200Kg, 1500Kg, 1800Kg, 2000Kg, 2500Kg, or 3000Kg. The weight of the material bed (e.g., including any printed 3D object therein) may be between any of the aforementioned values (e.g., from about 300Kg to about 3000Kg, from about 300Kg to about 1500Kg, or from about 1000Kg to about 3000Kg). The build platform assembly may be configured to translate the build module at a speed of at most 3 millimeters per second (mm/sec), 5 mm/sec, 10 mm/sec, 20 mm/sec, 30 mm/sec, or 50 mm/sec. The build platform assembly may be configured to translate the build module at a speed of at least 1 mm/sec, 3 mm/sec, 5 mm/sec, 10 mm/sec, 20 mm/sec, 30 mm/sec, or 40 mm/sec. The build platform assembly may be configured to translate the build module at a speed between any of the aforementioned speeds (e.g., from about 1 mm/sec to about 50 mm/sec, from about 1 mm/sec to about 20 mm/sec, or from about 5 mm/sec to about 50 mm/sec). The build platform assembly may be configured to translate the build module at a speed of at most 1 millimeter per second squared (mm/sec ² ), 2.5 mm/sec ² , 5 mm/sec ² , 7.5 mm/sec ² , 10 mm/sec ² , or 20 mm/sec ² . The build platform assembly may be configured to translate the build module at an acceleration Of at least 0.5 mm/sec ² , 1 mm/sec ² , 2 mm/sec ² , 3 mm/sec ² , 5 mm/sec ² , 10 mm/sec ² , or 15 mm/sec ² . The build platform assembly may be configured to translate the build module at a speed between any of the aforementioned speeds (e.g., from about 0.5 mm/sec ² to about 20 mm/sec ² , from about 0.5 mm/sec ² to about 10 mm/sec ² , or from about 4 mm/sec ² to about 20 mm/sec ² ). The build platform assembly may be configured such that a time to complete a translation of a first portion of the build platform assembly relative to a second portion of the build platform assembly (e.g., to perform a block movement) is at most about 120 seconds (sec), 60 sec, 50 sec, 45 sec, 40 sec, 35 sec, 30 sec, 25 sec, 20 sec, 15 sec, or less. The build platform assembly may be configured such that a time to complete a translation of a first portion of the build platform assembly relative to a second portion of the build platform assembly is any value between the aforementioned values, for example, between about 120 sec and 40 sec, between about 60 sec and 25 sec, or between about 35 sec and 15 sec. The first piston assembly and/or the second piston assembly may translate in three degrees of freedom, e.g., om z and in theta phi axes. Movement of one piston assembly may be configured to be coordinated angularly (e.g., rotationally) with respect to movement of the other piston assembly, e.g., align angularly, curb (e.g., hinder) unwanted movement, and/or cancel out unwanted drifts; the build platform assembly comprising the one piston assembly and the other piston assembly. The one piston assembly may have a (e.g., finite) rigidity with respect to the other piston assembly, e.g., due to existence of surrounding shafts (e.g., posts) and/or aligning features, e.g., depression and corresponding protrusion such as disclosed herein such as in relation to Fig. 36.

[0158] In some embodiments, the pre-transformed material (e.g., starting material for the 3D printing) is deposited in an enclosure to form a material bed. The enclosure may comprise a build module. The build module can contain the pre-transformed material (e.g., without spillage). Material may be placed in or inserted (e.g., deposited) to the build module. The material may be deposited in, pushed to, sucked into, or lifted to the build module. The material may be layered (e.g., spread) in the enclosure such as by using a layer dispensing mechanism. The pretransformed material may be deposited by a layer dispensing mechanism. The platform may be configured to support one or more layers of pre-transformed material (e.g., as part of the material bed). The platform may be configured to support at least a portion of the 3D object (e.g., during forming of the 3D object). The pre-transformed material may be layer-wise deposited adjacent to a side of the build module, e.g., above and/or on the bottom of the build module. The pre-transformed material may be layered adjacent to the substrate and/or adjacent to the base. Adjacent to may be above. Adjacent to may be directly above, or directly on. The pre-transformed material may be layered on a target surface, e.g., on an exposed surface of a material or on a surface of the build platform. The deposited layer of pre-transformed material may be (e.g., substantially) planar. For example, the deposited layer may have a central tendency of planarity (e.g., a surface roughness R _a ) that is from about 15% to about 65% of a second central tendency of thickness of the deposited layer. The second central tendency of thickness of the deposited layer may be about equal to a discrete increment of vertical translation of the platform. The second central tendency of thickness of the deposited layer may be about equal to any discrete increment of vertical translation of the build platform assembly, e.g., as disclosed herein. The incremental movement may be effectuated using an actuator. The actuator may be operatively coupled to a mechanism configured to perform a precise movement. The mechanism may comprise a piezoelectric actuator, an eccentric mechanism, a lead screw, or a sliding (e.g., double) wedge mechanism. The mechanism may comprise a (e.g., piezoelectric) locking ring. The eccentric mechanism may comprise a ring or circle. The precise movement may be in the micrometer scale. The mechanism may have a precision value between any of the aforementioned precision value (e.g., from about 0.25pm to about 5pm, from about 0.25pm to about 2.5pm, or from about 1 ,5pm to about 5pm). The mechanism may have a precision (e.g., error +/-) of at most about 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 8% or 10% of its movement span (e.g., amplitude). The mechanism may have a precision value between any of the aforementioned precision value relative to its movement span (e.g., from about 0.5% to about 10%, from about 0.5% to about 5%, or from about 1% to about 10%). The (e.g., horizontal and/or planar) movement span may be from the external surface of the engagement mechanism in its fully contracted state (towards the interior of the build platform assembly) to the internal surface of the build module body. The movement span may comprise the interstitial space between the build platform assembly and the internal surface of the build module body wall(s). In some embodiments, the interstitial space may have a horizontal span that is at most about 0.5, 1 , 2, 5, or 10 FLS of a central tendency of the starting material utilized for the printing, e.g., particulate matter such as powder, cross section of filaments, or cross section of strings.

[0159] In some embodiments, the 3D printer comprises an energy source that generates an energy beam. The energy beam may project energy to the material bed. The apparatuses, systems, and/or methods described herein can comprise at least one energy beam. In some cases, the 3D printing system can comprise at least two, three, four, five, eight, twelve, sixteen, twenty-four, thirty-two, or more energy beams. The energy beam may include radiation comprising electromagnetic, electron, positron, proton, plasma, or ionic radiation. The electromagnetic beam may comprise microwave, infrared, ultraviolet or visible radiation. The ion beam may include a cation or an anion. The electromagnetic beam may comprise a laser beam. The energy beam may derive from a laser source, in some embodiments, the energy source is an energy beam source. The energy source (e.g., Fig. 1 , 121) may be a laser source. The laser may comprise a fiber laser, a solid-state laser, or a diode laser (e.g., diode pumped fiber laser). [0160] In some embodiments, the energy source is a laser source. The laser source may comprise a Nd: YAG, Neodymium (e.g., neodymium-glass), or an Ytterbium laser. The laser beam may comprise a corona laser beam, e.g., a laser beam having a footprint similar to a doughnut shape or a ring shape. The laser may comprise a carbon dioxide laser (CO ₂ laser). The laser may be a fiber laser. The laser may be a solid-state laser. The laser can be a diode laser. The energy source may comprise a diode array. The energy source may comprise a diode array laser. The laser may be a laser used for micro laser sintering. Examples of 3D printing systems, apparatuses, devices, components (e.g., energy beams), controllers, software, and 3D printing processes can be found in International Patent Application Serial No. PCT/US17/60035, filed November 3, 2017; and in International Patent Application Serial No. PCT/US22/16550, filed February 26, 2022; each of which is entirely incorporated herein by reference.

[0161] In some embodiments, the energy beam (e.g., transforming energy beam) comprises a Gaussian energy beam. The energy beam may have any cross-sectional shape comprising an ellipse (e.g., circle), or a polygon (e.g., as disclosed herein). The energy beam may be continuous or non-continuous (e.g., pulsing). The energy beam may be modulated before and/or during the formation of a transformed material as part of the 3D object. The energy beam may be modulated before and/or during the 3D printing process. In some embodiments, the energy beam (e.g., laser) has a power of at least about 150Watt (W), 200W, 250W, 350W, 500W, 750W, 1000W, or 1500W. The energy source may have a power between any of the aforementioned energy beam power values (e.g., from about from about 150Wto about 1000W, or from about 1000Wto about 1500W). The energy beam may derive from an electron gun.

[0162] In some embodiments, the 3D printer includes a plurality of energy beam, e.g., laser beams. The 3D printer may comprise at least 2, 4, 6, 8, 10, 12, 16, 20, 24, 32, 36, 64, or more energy beams. Each of the energy beam may be coupled with its own optical window. At times, at least two energy beams may shine through the same optical window. At times, at least two energy beams may shine through different optical windows.

[0163] In some embodiments, the energy beam (e.g., transforming energy beam) comprises a Gaussian energy beam. The energy beam may have any cross-sectional shape comprising an ellipse (e.g., circle), or a polygon (e.g., as disclosed herein). The energy beam may be continuous or non-continuous (e.g., pulsing). The energy beam may be modulated before and/or during the formation of a transformed material as part of the 3D object. The energy beam may be modulated before and/or during the 3D printing process.

[0164] In some embodiments, the beam profile of the energy beam is altered, e.g., during printing. Any of the 3D printing methodologies disclosed herein can include altering the beam profile. Alteration of the beam profile can be using a physical component and/or a computational scheme (e.g., algorithm). Alteration of the beam profile can comprise manual and/or automatic methods. The automatic methods may comprise usage of at least one controller directing the beam profile alteration. The beam profile may be altered during the 3D printing, e.g., during printing of a layer of transformed material that forms at least a portion of the 3D object.

Alteration of the beam profile can comprise alteration of a type of an energy profile utilized. The type of the beam profile comprises: a gaussian beam profile, a top hat beam profile, or a ring (e.g., corona or doughnut) beam profile. For example, the energy beam may print a first portion of the 3D object using a gaussian beam profile, and then print a second portion of the 3D object using a ring shaped beam profile.

[0165] In some embodiments, the beam profile of the energy beam is altered, e.g., during printing. Any of the 3D printing methodologies disclosed herein can include altering the beam profile. Alteration of the beam profile can be using a physical component and/or a computational scheme. Alteration of the beam profile can comprise manual and/or automatic methods. The automatic methods may comprise usage of at least one controller directing the beam profile alteration. The beam profile may be altered during the 3D printing, e.g., during printing of a layer of transformed material that forms at least a portion of the 3D object. Alteration of the beam profile can comprise alteration of a type of an energy profile utilized. The type of the beam profile comprises: a gaussian beam profile, a top hat beam profile, or a doughnut (e.g., corona) beam profile. For example, the energy beam may print a first portion of the 3D object using a gaussian beam profile, and then print a second portion of the 3D object using a doughnut shaped beam profile.

[0166] In some embodiments, the energy beam(s) is/are utilized for the 3D printing. The energy beam(s) can translate vertically, horizontally, or in an angle (e.g., planar or compound angle). The energy beam(s) can be modulated. The energy beam(s) emitted by the energy source(s) can be modulated.

[0167] In some embodiments, the energy beam is moveable with respect to a material bed and/or 3D printing system. The energy beam can be moveable such that it can translate relative to the material bed. The energy beam can be moved by an optical system (e.g., comprising a scanner). The movement of the energy beam can comprise utilization of a scanner. In some embodiments, the energy source is stationary. In some embodiments, the energy beam (e.g., laser beam) impinges onto an exposed surface of a material bed to generate at least a portion of a 3D object. The energy beam may be a focused beam. The energy beam may be a dispersed beam. The energy beam may be an aligned beam. The apparatus and/or systems described herein may comprise a focusing coil, a deflection coil, or an energy beam power supply. The optical system may be configured to direct at least one energy beam from the at least one energy source to a position on a target surface such as an exposed surface of a material bed within the enclosure, e.g., to a predetermined position on the target surface. The 3D printing system may comprise a processor (e.g., a central processing unit). The processor can be programmed to control a trajectory of the at least one energy beam and/or energy source with the aid of the optical system. The systems and/or the apparatus described herein can comprise a control system in communication with the at least one energy source and/or energy beam. The control system can regulate a supply of energy from the at least one energy source to the material in the container. The control system may control the various components of the optical system. The various components of the optical system may include optical components comprising a mirror(s), a lens (e.g., concave, or convex), a fiber, a beam guide, a rotating polygon, or a prism.

[0168] In some embodiments, the 3D printer comprises a power supply. The power supply to any of the components described herein can be supplied by a grid, generator, local, or any combination thereof. The power supply can be from renewable or non-renewable sources. The renewable sources may comprise solar, wind, hydroelectric, or biofuel. The power supply can comprise rechargeable batteries.

[0169] In some cases, the 3D printing system can comprise two, three, four, five, eight, ten, sixteen, eighteen, twenty, twenty-four, thirty-two, or more energy sources that each generates an energy beam (e.g., laser beam). An energy source can be a source configured to deliver energy to an area (e.g., a confined area). An energy source can deliver energy to the confined area through radiative heat transfer. The energy source may comprise a laser source or an electron beam source. [0170] In some embodiments, the 3D printing system comprises one or more sensors. The 3D printing system includes at least one enclosure. In some embodiments, the 3D printing system (e.g., its enclosure) comprises one or more sensors (alternatively referred to herein as one or more sensors). The enclosure described herein may comprise at least one sensor. The enclosure may comprise, or be operatively coupled with, the build module, the filtering mechanism, gas recycling system, the processing chamber, or the ancillary chamber. The sensor may be connected and/or controlled by the control system (e.g., computer control system, or controller(s)). The control system may be able to receive signals from the at least one sensor. The control system, e.g., through a control scheme, may act upon at least one signal received from the at least one sensor. The control scheme may comprise a feedback and/or feed forward control scheme, e.g., that has been pre-programmed. The feedback and/or feed forward control may rely on input from at least one sensor that is connected to the controller(s). [0171] In some embodiments, the 3D printing system comprises one or more sensors. The one or more sensors can comprise a pressure sensor, a temperature sensor, a gas flow sensor, or an optical density sensor. The pressure sensor may measure the pressure of the chamber (e.g., pressure of the chamber atmosphere). The pressure sensor can be coupled with the control system. The pressure can be electronically and/or manually controlled. The controller may regulate the pressure (e.g., with the aid of one or more vacuum pumps) according to input from at least one pressure sensor. The sensor may comprise light sensor, image sensor, acoustic sensor, vibration sensor, chemical sensor, electrical sensor, magnetic sensor, fluidity sensor, movement sensor, speed sensor, position sensor, pressure sensor, force sensor, density sensor, metrology sensor, sonic sensor (e.g., ultrasonic sensor), or proximity sensor. The metrology sensor may comprise measurement sensor (e.g., height, length, width, depth, angle, and/or volume). The metrology sensor may comprise a magnetic, acceleration, orientation, or optical sensor. The optical sensor may comprise a camera. The metrology sensor may measure the gap. The metrology sensor may measure at least a portion of the layer of material (e.g, pre-transformed, transformed, and/or hardened). The layer of material may be a pre-transformed material (e.g., powder), transformed material, or hardened material. The metrology sensor may measure at least a portion of the 3D object. The sensor may comprise a temperature sensor, weight sensor, powder level sensor, gas sensor, or humidity sensor. The gas sensor may sense any gas enumerated herein. The temperature sensor may measure the temperature without contacting the material bed (e.g., non-contact measurements). The weight of the enclosure (e.g., container), or any components within the enclosure can be monitored by at least one weight sensor in or adjacent to the material. One or more position sensors (e.g., height sensors) can measure the height of the material bed relative to the substrate. The position sensors can be optical sensors. The position sensors can determine a distance between one or more energy sources and a surface of the material bed. The surface of the material bed can be the upper surface of the material bed relative to a gravitational center of the environment. Examples of 3D printing systems, apparatuses, devices, and components (e.g., sensors), controllers, software, and 3D printing processes can be found in International Patent Application Serial No. PCT/US17/60035, filed November s, 2017; and in International Patent Application Serial No. PCT/US22/16550, filed February 26, 2022; each of which is entirely incorporated herein by reference.

[0172] In some embodiments, the 3D printer comprises one or more valves. The methods, systems and/or the apparatus described herein may comprise at least one valve. The valve may be shut or opened according to an input from the at least one sensor, or manually. The degree of valve opening or shutting may be regulated by the control system, for example, according to at least one input from at least one sensor. The systems and/or the apparatus described herein can include one or more valves, such as throttle valves. The valve may or may not comprise a sensor sensing the open/shut position of the valve. The valve may be a component of a gas flow mechanism, e.g., operable to control a flow of gas of the gas flow mechanism. A valve may be a component of gas flow assembly, e.g., operable to control a flow of gas of the gas flow assembly.

[0173] In some embodiments, the 3D printer comprises one or more actuators such as motors. The motor may be controlled by the controller(s) (e.g., by the control system) and/or manually. The motor may alter (e.g., the position of) the substrate and/or to the base. The motor may alter (e.g., the position of) the build platform assembly. The actuator may facilitate translation (e.g., propagation) of the layer dispenser, e.g., the actuator may facilitate reversible translation of the layer dispenser. The motor may alter an opening of the enclosure (e.g., its opening or closure). The motor may be a step motor or a servomotor. The actuator (e.g., motor) may alter (e.g., a position of) one or more optical components, e.g., mirrors, lenses, prisms, and the like. The servomotors may comprise actuated linear lead screw drive motors. The motors may comprise belt drive motors. The motors may comprise rotary encoders. The encoder may comprise an absolute encoder. The encoder may comprise an incremental encoder. The apparatuses and/or systems may comprise switches. The switches may comprise homing or limit switches. The motors may comprise actuators. The motors may comprise linear actuators. The motors may comprise belt driven actuators. The motors may comprise lead screw driven actuators. The actuators may comprise linear actuators.

[0174] In some embodiments, the 3D printer (e.g., its components) comprises one or more nozzles. The systems and/or the apparatus described herein may comprise at least one nozzle. For example, the material remover may comprise a nozzle. The nozzle may be regulated according to at least one input from at least one sensor. The nozzle may be controlled automatically or manually. The controller(s) may control the nozzle. The controller(s) may any controller(s) disclosed herein, e.g., as part of the control system of the 3D printer. The nozzle may include jet (e.g., gas jet) nozzle, high velocity nozzle, propelling nozzle, magnetic nozzle, spray nozzle, vacuum nozzle, or shaping nozzle (e.g., a die). The nozzle can be a convergent or a divergent nozzle. The spray nozzle may comprise an atomizer nozzle, an air-aspirating nozzle, or a swirl nozzle. The material dispenser can comprise a nozzle, e.g., through which material is removed from the material bed. The gas flow system may comprise a nozzle, e.g., that facilitates adjustment to the gas flow. The optical window may be supported by a nozzle that directs debris away from the optical window, e.g., at towards the material bed. The nozzle may comprise a venturi nozzle.

[0175] In some embodiments, the 3D printer comprises one or more pumps. The systems and/or the apparatus described herein may comprise at least one pump. The pump may be regulated according to at least one input from at least one sensor. The pump may be controlled automatically or manually. The controller may control the pump. The one or more pumps may comprise a positive displacement pump. The positive displacement pump may comprise rotarytype positive displacement pump, reciprocating-type positive displacement pump, or linear-type positive displacement pump.

[0176] In some embodiments, the 3D printer comprises a communication technology. The communication may comprise wired or wireless communication. For example, the systems, apparatuses, and/or parts thereof may comprise Bluetooth, wi-fi, global positioning system (GPS), or radio-frequency (RF) technology. The RF technology may comprise ultrawideband (UWB) technology. Systems, apparatuses, and/or parts thereof may comprise a communication port. The communication port may be a serial port or a parallel port. The communication port may be a Universal Serial Bus port (USB). The systems, apparatuses, and/or parts thereof may comprise USB ports. The USB can be micro or mini-USB. The surface identification mechanism may comprise a plug and/or a socket (e.g., electrical, AC power, DC power). The systems, apparatuses, and/or parts thereof may comprise an electrical adapter (e.g., AC and/or DC power adapter). The systems, apparatuses, and/or parts thereof may comprise a power connector. The power connector can be an electrical power connector. The power connector may comprise a magnetically attached power connector. The power connector can be a dock connector. The connector can be a data and power connector. The connector may comprise pins. The connector may comprise at least about 10, 15, 18, 20, 22, 24, 26, 28, 30, 40, 42, 45, 50, 55, 80, or 100 pins.

[0177] In some embodiments, the 3D printer comprises a controller. The controller may monitor and/or direct (e.g., physical) alteration of the operating conditions of the apparatuses, software, and/or methods described herein. The controller may be a manual or a non-manual controller. The controller may be an automatic controller. The controller may operate upon request. The controller may be a programmable controller. The controller may be programed. The controller may comprise a processing unit (e.g., CPU or GPU). The controller may receive an input (e.g., from a sensor). The controller may deliver an output. The controller may be part of a control system comprising multiple controllers. The controller may receive multiple inputs. The controller may generate multiple outputs. The controller may be a single input single output controller (SISO) or a multiple input multiple output controller (MIMO). The controller may interpret the input signal received. The controller may acquire data from the one or more sensors. Acquire may comprise receive or extract. The data may comprise measurement, estimation, determination, generation, or any combination thereof. The controller may comprise feedback control. The controller may comprise feed-forward control. The control may comprise on-off control, proportional control, proportional-integral (PI) control, or proportional-integral- derivative (PID) control. The control may comprise open loop control, or closed loop control. The controller may comprise closed loop control. The controller may comprise open loop control. The controller may utilize one or more wired and/or wireless networks for communication, e.g., with other controllers or devices, apparatuses, or systems of the 3D printing system and its components. For example, wired ethernet technologies, e.g., a local area networks (LAN). For example, wireless communication technologies, e.g., a wireless local area network (WLAN). The controller may utilize one or more control protocols for communication, for example, with other controller(s) or one or more devices, apparatuses, or systems of the 3D printing system or any of its components. Control protocols can comprise one or more protocols of an internet protocol suite, e.g., transmission control protocol (TCP) or transmission control protocol/internet protocol (TCP/IP). Control protocols can comprise one or more serial communication protocols. Control protocols can comprise one or more of controller area networks or another message-based protocol, e.g., for communication with microcontrollers and devices. Control protocols can interface with one or more serial bus interfaces for communication with the 3D printing system and its components. The controller may comprise a user interface. The user interface may comprise a keyboard, keypad, mouse, touch screen, microphone, speech recognition package, camera, imaging system, or any combination thereof. The outputs may include a display (e.g., screen), speaker, or printer. Examples of controller, control protocols, control systems, 3D printing systems, apparatuses, devices, and any of their components, and 3D printing processes can be found in International Patent Application Serial No. PCT/US17/18191 , filed February 16, 2017, titled “ACCURATE THREE-DIMENSIONAL PRINTING,” which is incorporated herein by reference in their entirety.

[0178] Control may comprise regulate, modulate, adjust, maintain, alter, change, govern, manage, restrain, restrict, direct, guide, oversee, manage, preserve, sustain, restrain, temper, or vary.

[0179] In some embodiments, the methods, systems, device, software and/or the apparatuses described herein comprise a control system. The control system can be in communication with one or more energy sources, optical systems, gas flow system, material flow systems, energy (e.g., energy beams), build platform assembly, and/or with any other component of the 3D printing system.

[0180] In some embodiments, the 3D printer comprises at least one filter. The filter may be a ventilation filter. The ventilation filter may capture fine powder from the 3D printing system. The filter may comprise a paper filter such as a high-efficiency particulate air (HEPA) filter (a.k.a., high-efficiency particulate arresting filter). The ventilation filter may capture debris comprising soot, splatter, or spatter. The debris may result from the 3D printing process. The ventilator may direct the debris in a requested direction (e.g., by using positive or negative gas pressure). For example, the ventilator may use vacuum. For example, the ventilator may use gas flow. Fig. 1 shows an example of a 3D printing system 100 having a processing chamber 107 coupled with a build module 123. The build module comprises an elevation mechanism 105 (e.g., as part of a build platform assembly) that vertically translate a substrate (e.g., piston) 109 along arrow 112. A base 102 is disposed on substrate (e.g., piston) 109. Material bed 104 is disposed above base 102 (e.g., also referred herein as “build platform,” or “build plate”). The 3D printing system 100 comprises a guidance system 120 for energy beam 101 such as an optical guidance system (e.g., a galvanometer scanner). Energy source (e.g., laser source) 121 generates energy beam 101 that traverses through the guidance system 120 (e.g., comprising a scanner) and through an optical window 115 into processing chamber 107 enclosing interior space 126 that can include an atmosphere. The optical window 115 is configured to allow the energy beam to pass through without (e.g., substantial) energetic loss. Processing chamber 107 can include an optional temperature adjustment device (e.g., cooling plate), not shown. Seal 103 encircles the substrate and/or base, e.g., to deter (e.g., prevent) migration of material of the material bed from reaching elevation mechanism 105. Energy beam 101 impinges upon an exposed surface 119 of material bed 104, to form at least a portion of a 3D object 106. Fig. 1 shows an example of a build module 123. Build module 123 can contain the pre-transformed (e.g., starting) material in a material bed 104. As depicted in Fig. 1 , the 3D printer comprises a layer dispensing mechanism 122. The layer dispensing mechanism 122 includes a material dispenser 116 and a powder removal mechanism 118 to form a layer of pre-transformed material (e.g., starting material) within the enclosure. Layer dispensing mechanism 122 includes a leveler 117. The material may be layered (e.g., spread) in the enclosure such as by using the layer dispensing mechanism 122. Build module 123 is configured to enclose a substrate 109 and arranged adjacent to a bottom 111 of build module 123. Bottom 111 is defined relative to the gravitational field along gravitational vector 199 pointing towards gravitational center G, or relative to the position of the footprint of the energy beam 101 on the layer of pre-transformed material as part of a material bed 104. Build module 123 comprises a build platform 102. The substrate is coupled with one or more seals 103 that enclose the material in a selected area within the build module to form material bed 104.

[0181] In some embodiments, the formation of the 3D object includes transforming (e.g., fusing, binding and/or connecting) the pre-transformed material (e.g., 3D printing starting material such as a powder material) using an energy beam. The energy beam may be projected on to the starting material (e.g., disposed in the material bed), thus causing the pre-transformed material to transform (e.g., fuse). The energy beam may cause at least a portion of the pretransformed material to transform from its present state of matter to a different state of matter. For example, the pre-transformed material may transform at least in part (e.g., completely) from a solid to a liquid state. The energy beam may cause at least a portion of the pre-transformed material to chemically transform. For example, the energy beam may cause chemical bonds to form or break. The chemical transformation may be an isomeric transformation. The transformation may comprise a magnetic transformation or an electronic transformation. The transformation may comprise coagulation of the material, cohesion of the material, or accumulation of the material. Transformation of the material may comprise connecting disconnected starting materials. For example, connecting various powder particles. The connection may comprise phase transfer, or chemical bonding. The connection may comprise fusing the starting material, e.g., sintering or melting the starting material.

[0182] In some embodiments, the methods described herein comprise repeating the operations of material deposition and material transformation operations to produce (e.g., print) a 3D object (or a portion thereof) by at least one 3D printing (e.g., additive manufacturing) method. For example, the methods described herein may comprise repeating the operations of depositing a layer of pre-transformed material and transforming at least a portion of the pretransformed material to connect to the previously formed 3D object portion (e.g., repeating the 3D printing cycle), thus forming at least a portion of a 3D object. The transforming operation may comprise utilizing energy beam(s) to transform the material. In some instances, the energy beam is utilized to transform at least a portion of the material bed.

[0183] In some embodiments, the term “auxiliary support,” as used herein, generally refers to at least one feature that is a part of a printed 3D object, but not part of the requested, intended, designed, ordered, and/or final 3D object. Auxiliary support may provide structural support during and/or after the formation of the 3D object. The auxiliary support may be anchored to the enclosure. For example, an auxiliary support may be anchored to the build platform (e.g., build platform such as a build plate), to the side walls of the material bed, to a wall of the enclosure, to an object (e.g., stationary, or semi-stationary) within the enclosure, or any combination thereof. The auxiliary support may be the build platform or the bottom of the enclosure. The auxiliary support may enable the removal of energy from the 3D object (e.g., or a portion thereof) that is being formed. The removal of energy (e.g., heat) may be during and/or after the formation of the 3D object. Examples of auxiliary support comprise a fin (e.g., heat fin), anchor, handle, pillar, column, frame, footing, wall, build platform, or another stabilization feature. In some instances, the auxiliary support may be mounted, clamped, or situated on the build platform. The auxiliary support can be anchored to the build platform, to the sides (e.g., walls) of the build platform, to the enclosure, to an object (stationary or semi-stationary) within the enclosure, or any combination thereof.

[0184] In some examples, the generated 3D object(s) can be printed without auxiliary support in a material bed in which it/they are formed. In some examples, low hanging overhanging feature an/or hollow cavities of the generated 3D object can be printed without (e.g., without any) auxiliary support. The low overhanging features may be shallow overhanging features with respect to an exposed surface of the material bed. The low overhanging features may form an angle of at most about 40 degrees (°), 35 °, or 25 ° with the exposed surface of the material bed (or a plane parallel thereto). The printed 3D object can be devoid of auxiliary supports. The printed 3D object may be suspended (e.g., float anchorlessly) in the material bed (e.g., powder bed). The term “anchorlessly,” as used herein, generally refers to without, or in the absence of, an auxiliary anchor. In some examples, an object is suspended in a material bed anchorlessly without attachment to a support. For example, the object floats in the material bed. A portion of the printed 3D object can be devoid of auxiliary supports. The portion of the 3D object may be suspended over a volume of the material bed. For example, a portion of the object defines an enclosed cavity which may be temporarily filled with powder material during a build process. The generated 3D object may be suspended in the layer of pre-transformed material (e.g., powder material). The pre-transformed material can offer support to the printed 3D object (or the object during its generation). Sometimes, the generated 3D object may comprise one or more auxiliary supports. The auxiliary support may be suspended in the pre-transformed material (e.g., powder material). The auxiliary support may provide weight or stabilizer. The auxiliary support can be suspended in the material bed such as within the layer of pre-transformed material in which the 3D object (or a portion thereof) has been formed. The auxiliary support may touch the build platform. The auxiliary support may be suspended in the material bed and not touch (e.g., contact) the build platform. The auxiliary support may be anchored to the build platform.

[0185] In some examples, the at least 3D object may be generated above a build platform, which at least one 3D object comprises auxiliary supports. In some examples, the auxiliary support(s) adhere to the upper surface of the build platform. In some examples, the auxiliary supports of the printed 3D object may touch the build platform (e.g., the bottom of the enclosure, the substrate, or the base). Sometimes, the auxiliary support may adhere to the build platform. In some embodiments, the auxiliary supports are an integral part of the build platform. At times, auxiliary support(s) of the printed 3D object, do not touch the build platform. In any of the methods described herein, the printed 3D object may be supported only by the pre-transformed material within the material bed. Any auxiliary support(s) of the printed 3D object, if present, may be suspended adjacent to the build platform. Occasionally, the build platform may have a prehardened (e.g., pre-solidified) amount of material. Such pre-solidified material may provide support to the printed 3D object. At times, the build platform may provide adherence to the material. At times, the build platform does not provide adherence to the material. The build platform may comprise elemental metal, metal alloy, elemental carbon, or ceramic. The build platform may comprise a composite material (e.g., as disclosed herein). The build platform may comprise glass, stone, zeolite, or a polymeric material. The polymeric material may include a hydrocarbon or fluorocarbon. The build platform (e.g., base) may include Teflon. The build platform may include compartments for printing small objects. Small may be relative to the size of the enclosure. The compartments may form a smaller compartment within the enclosure, which may accommodate a layer of pre-transformed material.

[0186] In some examples, when the energy source is in operation, the material bed reaches a certain (e.g., average) temperature. The average temperature of the material bed can be an ambient temperature or “room temperature.” The average temperature of the material bed can have an average temperature during the operation of the energy (e.g., beam(s)). The average temperature of the material bed can be an average temperature during the formation of the transformed material, the formation of the hardened material, or the generation of the 3D object. The average temperature can be below or just below the transforming temperature of the material. Just below can refer to a temperature that is by at most about 1 °C, 2 °C, 3 °C, 4 °C, 5 °C, 6 °C, 7 °C, 8 °C, 9 °C, 10 C, 15 °C, or 20 °C below the transforming temperature. The average temperature of the material bed (e.g., pre-transformed material) can be by at most about 25 °C (degrees Celsius), 50 °C, 100 °C, 150 °C, 200 °C, 250 °C, 300 °C, 400 °C, 500 °C, 600 °C, 700 °C, 800 °C, 900 °C, 1000 °C, 1200 °C, 1400 °C, 1600 °C, 1800 °C, or 2000 °C. The average temperature of the material bed (e.g., pre-transformed material) can be at least about 20 °C, 25 °C, 50 °C, 100 °C, 150 °C, 200 °C, 250 °C, 300 °C, 400 °C, 500 °C, 600 °C, 700 °C, 800 °C, 900 °C, 1000 °C, 1200 °C, 1400 °C, 1600 °C, or 1800 °C. The average temperature of the material bed (e.g., of the pre-transformed material therein) can be any temperature between the afore-mentioned material average temperatures. The temperature of the material bed can be conditioned (e.g., heated or cooled) before, during, or after forming (e.g., printing) the 3D object (e.g., hardened material). The material bed temperature can be controller (e.g., substantially maintained) at a predetermined value. The temperature of the material bed can be monitored. The material temperature can be controlled manually and/or by a control system (e.g., such as any control system disclosed herein).

[0187] At times, the energy beam follows a path. The path of the energy beam may be a vector. The path of the energy beam may comprise a raster, a vector, or any combination thereof. The path of the energy beam may comprise an oscillating pattern. The path of the energy beam may comprise a zigzag, wave (e.g., curved, triangular, or square), or curve pattern. The curved wave may comprise a sine or cosine wave. The path of the energy beam may comprise a sub-pattern. The path of the energy beam may comprise an oscillating (e.g., zigzag), wave (e.g, curved, triangular, or square), and/or curved sub-pattern. The curved wave may comprise a sine or cosine wave.

[0188] At times, the energy (e.g., energy beam) travels in a path. The path may comprise a hatch, e.g., path 201 of Fig. 2. The path of the energy beam may comprise repeating a path. For example, the first energy may repeat its own path. The second energy may repeat its own path, or the path of the first energy. The repetition may comprise a repetition of 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10 times or more. The energy may follow a path comprising parallel lines. The lines may be hatch lines. The distance between each of the parallel lines or hatch lines, may be at least about 1 pm, 5 pm, 10 pm, 20 pm, 30 pm, 40 pm, 50 pm, 60 pm, 70 pm, 80 pm, 90 pm, or more. The distance between each of the parallel lines or hatch lines, may be at most about 1 pm, 5 pm, 10 pm, 20 pm, 30 pm, 40 pm, 50 pm, 60 pm, 70 pm, 80 pm, 90 pm, or less. The distance between each of the parallel lines or hatch lines may be any value between any of the afore-mentioned distance values (e.g., from about 1 pm to about 90 pm, from about 1 pm to about 50 pm, or from about 40 pm to about 90 pm). The distance between the parallel or parallel lines or hatch lines may be (e.g., substantially) the same in every layer (e.g., plane) of transformed material. The distance between the parallel lines or hatch lines in one layer (e.g., plane) of transformed material may be different than the distance between the parallel lines or hatch lines respectively in another layer (e.g., plane) of transformed material within the 3D object. The distance between the parallel lines or hatch lines portions within a layer (e.g., plane) of transformed material may be (e.g., substantially) constant. The distance between the parallel lines or hatch lines within a layer (e.g., plane) of transformed material may be varied. The distance between a first pair of parallel lines or hatch lines within a layer (e.g., plane) of transformed material may be different than the distance between a second pair of parallel lines or hatch lines within a layer (e.g., plane) of transformed material, respectively. The first energy beam may follow a path comprising two hatch lines or paths that cross in at least one point. Fig. 2 shows an example of a path 201 of an energy beam comprising a zigzag sub-pattern (e.g., energy beam 202 shown as an expansion (e.g., blow-up) of a portion of the path 201). The sub-path of the energy beam may comprise a wave (e.g., sine or cosine wave) pattern. The sub-path may be a small path that forms the large path. The sub-path may be a component (e.g., a portion) of the large path. The path that the energy beam follows may be a predetermined path. A model may predetermine the path by utilizing a controller or an individual (e.g., human). The controller may comprise a processor. The processor may comprise a computer, computer program, drawing or drawing data, statue or statue data, or any combination thereof. The hatch lines or paths may be straight or curved. The hatch lines or paths may be winding. At times, the path comprises successive lines. The successive lines may touch each other. The successive lines may overlap each other in at least one point. The successive lines may (e.g., substantially) overlap each other. The successive lines may be spaced by a first distance (e.g., hatch spacing). Examples of 3D printing systems, apparatuses, devices, and any component thereof; controllers, software, and 3D printing processes (e.g., hatch spacings) can be found in International Patent Application Serial No PCT/US 16/34857 filed on May 27, 2016, titled “THREE-DIMENSIONAL PRINTING AND THREE-DIMENSIONAL OBJECTS FORMED USING THE SAME” that is entirely incorporated herein by reference.

[0189] In some embodiments, the 3D printing system comprises a processor. The processor may be a processing unit. The controller may comprise a processing unit. The processing unit may be central. The processing unit may comprise a central processing unit (herein “CPU”). The controllers or control mechanisms (e.g., comprising a computer system) may be programmed to implement methods of the disclosure. The processor (e.g., 3D printer processor) may be programmed to implement methods of the disclosure. The controller may control at least one component of the systems and/or apparatuses disclosed herein. Fig. 3 is a schematic example of a computer system 300 that is programmed or otherwise configured to facilitate the formation of a 3D object according to the methods provided herein. The computer system 300 can control (e.g., direct, monitor, and/or regulate) various features of printing methods, apparatuses and systems of the present disclosure, such as, for example, control force, translation, heating, cooling and/or maintaining the temperature of a powder bed, process parameters (e.g., chamber pressure), scanning rate (e.g., of the energy beam and/or the platform), scanning route of the energy source, position and/or temperature of the cooling member(s), application of the amount of energy emitted to a selected location, or any combination thereof. The computer system 301 can be part of, or be in communication with, a 3D printing system or apparatus. The computer may be coupled with one or more mechanisms disclosed herein, and/or any parts thereof. For example, the computer may be coupled with one or more sensors, valves, switches, motors, pumps, scanners, optical components, or any combination thereof. The computer system 300 can include a processing unit 306 (also “processor,” “computer” and “computer processor” used herein). The computer system may include memory or memory location 302 (e.g., randomaccess memory, read-only memory, flash memory), electronic storage unit 304 (e.g., hard disk), communication interface 303 (e.g., network adapter) for communicating with one or more other systems, and peripheral devices 305, such as cache, other memory, data storage and/or electronic display adapters. The memory 302, storage unit 304, interface 303, and peripheral devices 305 are in communication with the processing unit 306 through a communication bus (solid lines), such as a motherboard. The storage unit can be a data storage unit (or data repository) for storing data. The computer system can be operatively coupled with a computer network (“network”) 301 with the aid of the communication interface. The network can be the Internet, an internet and/or extranet, or an intranet and/or extranet that is in communication with the Internet. In some cases, the network is a telecommunication and/or data network. The network can include one or more computer servers, which can enable distributed computing, such as cloud computing. The network, in some cases with the aid of the computer system, can implement a peer-to-peer network, which may enable devices coupled with the computer system to behave as a client or a server. The processing unit can execute a sequence of machine- readable instructions, which can be embodied in a program or software. The instructions may be stored in a memory location, such as the memory 302. The instructions can be directed to the processing unit, which can subsequently program or otherwise configure the processing unit to implement methods of the present disclosure. Examples of operations performed by the processing unit can include fetch, decode, execute, and write back. The processing unit may interpret and/or execute instructions. The processor may include a microprocessor, a data processor, a central processing unit (CPU), a graphical processing unit (GPU), a system-on-chip (SOC), a co-processor, a network processor, an application specific integrated circuit (ASIC), an application specific instruction-set processor (ASIPs), a controller, a programmable logic device (PLD), a chipset, a field programmable gate array (FPGA), or any combination thereof. The processing unit can be part of a circuit, such as an integrated circuit. One or more other components of the system 300 can be included in the circuit.

[0190] In some embodiments, the storage unit 304 stores files, such as drivers, libraries, and saved programs. The storage unit can store user data (e.g., user preferences and user programs). In some cases, the computer system can include one or more additional data storage units that are external to the computer system, such as located on a remote server that is in communication with the computer system through an intranet or the Internet. The processor may be configured to process control protocols, e.g., communicate with one or more components of the 3D printer system using the control protocols. Control protocols can be one or more of the internet protocol suite, e.g., transmission control protocol (TCP) or transmission control protocol/internet protocol (TCP/IP). Control protocols can be one or more of serial communication protocols. Control protocols can be one or more of controller area networks or another message-based protocol, e.g., for communication with microcontrollers and devices. Control protocols can interface with one or more serial bus interfaces for communication with the 3D printing system and its components. The control protocol can be any control protocol disclosed herein.

[0191] In some embodiments, the 3D printer comprises communicating through a network. The computer system can communicate with one or more remote computer systems through a network. For instance, the computer system can communicate with a remote computer system of a user (e.g., operator). Examples of remote computer systems include personal computers (e.g., portable PC), slate or tablet PC’s (e.g., Apple® iPad, Samsung® Galaxy Tab), telephones, Smart phones (e.g., Apple® iPhone, Android-enabled device, Blackberry®), or personal digital assistants. A user (e.g., client) can access the computer system via the network.

[0192] In some embodiments, the computer system utilizes program instructions to execute, or direct execution of, operation(s). The program instructions can be inscribed in a machine executable code. Methods as described herein can be implemented by way of machine (e.g., computer processor) executable code stored on an electronic storage location of the computer system, such as, for example, on the memory 302 or electronic storage unit 304. The machine executable or machine-readable code can be provided in the form of software. During use, the processor 306 can execute the code. In some cases, the code can be retrieved from the storage unit and stored on the memory for ready access by the processor. In some situations, the electronic storage unit can be precluded, and machine-executable instructions are stored on memory. The code can be pre-compiled and configured for use with a machine have a processer adapted to execute the code or can be compiled during runtime. The code can be supplied in a programming language that can be selected to enable the code to execute in a pre-compiled or as-compiled fashion.

[0193] In some embodiments, the 3D printer comprises a gas flow mechanism. The gas flow mechanism may be in fluidic contact with one or more enclosures of the 3D printer. For example, the gas flow mechanism may be in fluidic contact with (i) a processing chamber, (ii) a build module, (iii) an optical enclosure, or (iv) any combination thereof. The gas flow mechanism may be in fluidic contact with a processing chamber and/or a build module. The gas flow mechanism may be in fluid communication with the optical enclosure.

[0194] In some examples, the enclosure comprises an atmosphere having an ambient pressure (e.g., 1 atmosphere), or positive pressure. The atmosphere may have a negative pressure (i.e., vacuum). Different portions of the enclosure may have different atmospheres. The different atmospheres may comprise different gas compositions. The different atmospheres may comprise different atmosphere temperatures. The different atmospheres may comprise ambient pressure (e.g., 1 atmosphere), negative pressure (i.e., vacuum) or positive pressure. The different portions of the enclosure may comprise the processing chamber, build module, or enclosure volume excluding the processing chamber and/or build module. The vacuum may comprise pressure below 1 bar, or below 1 atmosphere. The positively pressurized environment may comprise pressure above 1 bar or above 1 atmosphere. In some cases, the chamber pressure can be standard atmospheric pressure. The pressure may be measured at an ambient temperature (e.g., room temperature such as 20 °C, or 25 °C).

[0195] In some embodiments, the enclosure includes an atmosphere. The enclosure may comprise a (e.g., substantially) inert atmosphere. The atmosphere in the enclosure may be (e.g., substantially) depleted by one or more gases present in the ambient atmosphere. The atmosphere in the enclosure may include a reduced level of one or more gases relative to the ambient atmosphere. For example, the atmosphere may be substantially depleted, or have reduced levels of water (i.e., humidity), oxygen, nitrogen, carbon dioxide, hydrogen sulfide, or any combination thereof. The level of the depleted or reduced level gas may be at most about 0.1 parts per million (ppm), 1 ppm, 3 ppm, 10 ppm, 50 ppm, 100 ppm, 500 ppm, 1000 ppm, 3000 ppm, or 5000 ppm volume by volume (v/v). The level of the depleted or reduced level gas may be at least about 1 ppm, 10 ppm, 50 ppm, 100 ppm, 500 ppm, 1000 ppm, or 5000 ppm (v/v). The level of the oxygen gas may be at most about 1 ppm, 10 ppm, 50 ppm, 100 ppm, 500 ppm, 1000 ppm, or 2000 ppm (v/v). The level of the water vapor may be at most about 1 ppm, 10 ppm, 50 ppm, 100 ppm, 500 ppm, 700 ppm, 800 ppm, 900 ppm, or 1000 ppm, (v/v). The level of the gas (e.g., depleted, or reduced level gas, oxygen, or water) may be between any of the afore-mentioned levels of gas. The atmosphere may comprise air. The atmosphere may be inert. The atmosphere in the enclosure (e.g, processing chamber) may have reduced reactivity (e.g., be non-reactive) as compared to the ambient atmosphere external to the processing chamber and/or external to the printing system. The atmosphere may have reduced reactivity with the material (e.g., the pre-transformed material deposited in the layer of material (e.g., powder) or with the material comprising the 3D object), which reduced reactivity is compared to the reactivity of the ambient atmosphere. The atmosphere may hinder (e.g., prevent) oxidation of the generated 3D object, e.g., as compared to the oxidation by an ambient atmosphere external to the 3D printer and/or processing chamber. The atmosphere may hinder (e.g., prevent) oxidation of the pre-transformed material within the layer of pre-transformed material before its transformation, during its transformation, after its transformation, before its hardening, after its hardening, or any combination thereof. The atmosphere may comprise an inert gas. For example, the atmosphere may comprise argon or nitrogen gas. The atmosphere may comprise a Nobel gas. The atmosphere can comprise a gas selected from the group comprising argon, nitrogen, helium, neon, krypton, xenon, hydrogen, carbon monoxide, or carbon dioxide. The atmosphere may comprise hydrogen gas. The atmosphere may comprise a safe amount of hydrogen gas. The atmosphere may comprise a v/v percent of hydrogen gas of at least about 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, or 5%, at ambient pressure (e.g., and ambient temperature). The atmosphere may comprise a v/v percent of hydrogen gas of at most about 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, or 5%, at ambient pressure (e.g., and ambient temperature). The atmosphere may comprise any percent of hydrogen between the afore-mentioned percentages of hydrogen gas. The atmosphere may comprise a v/v hydrogen gas percent that is at least able to react with the material (e.g., at ambient temperature and/or at ambient pressure), and at most adhere to the prevalent work-safety standards in the jurisdiction (e.g., hydrogen codes and standards). The material may be the material within the layer of pre-transformed material (e.g., powder), the transformed material, the hardened material, or the material within the 3D object. Ambient refers to a condition to which people are generally accustomed. For example, ambient pressure may be about one (1) atmosphere.

[0196] In some embodiments, material utilized in the 3D printing undergoes passivation, e.g., using a passivation systems. A passivation system may comprise (A) an in-situ passivation system, (B) an ex-situ passivation system, or (C) a combination thereof. The passivation system may control a level of the oxidizing agent below a threshold. The oxidizing agent in the oxidizing mixture (e.g., oxygen) may be kept below a threshold (e.g., below 2000 ppm), e.g., by using one or more controllers such as the control system disclosed herein.

[0197] In some embodiments, humidity levels and/or oxygen levels in at least a portion of the enclosure, (e.g., processing chamber, ancillary chamber, and/or build module) can be regulated such that an oxygenation and/or humidification of powder in the powder conveyance system is controlled. For example, oxygenation and/or humidification levels of recycled pre-transformed material (e.g., recycled powder material) can be about 5 parts per million (ppm) to about 1500 ppm. For example, oxygenation and/or humidification levels of recycled pre-transformed material can be at most about 1500 ppm, 1200 ppm, 1000 ppm, 500 ppm, 250 ppm, or less. For example, oxygenation and/or humidification levels of pre-transformed material can be about zero ppm. For example, oxygen content in pre-transformed material can be about 0 weight percent (wt %), 0.1 wt %, 0.25 wt %, 0.3 wt %, 0.5 wt %, 0.75 wt %, 1 .0 wt %, or more. At times, atmospheric conditions can, in part, influence a flowability of pre-transformed material (e.g., powder material) from the layer dispensing mechanism. A dew point of an internal atmosphere of an enclosure (e.g., of the processing chamber) can be (I) below a level in which the powder particles absorb water such that they become reactive under condition of 3D printing Process(es) and/or sufficient to cause measurable defects in a 3D object printed from the powder particles and (II) above a level of humidity below which the powder agglomerates, (e.g., electrostatically). In some embodiments, conditions (I) and/or (II) may depend in part on a type of powder material and/or on processing condition(s) of the 3D printing process(es). For example, a dew point of an internal atmosphere of the enclosure (e.g., of the processing chamber) can be from about -80 °C to about -30 °C, from about -65 °C to about -40 °C, or from about -55 °C to about -45 °C, at an atmospheric pressure of at least about 10 kilo-Pascals (kPa), about 12 kPa, about 14 kPa, about 16 kPa, about 18 kPa, about 20 kPa above ambient pressure external to the enclosure. For example, a dew point of an internal atmosphere of the enclosure can be any value within or including the afore-mentioned values. The 3D printing system may comprise an in-situ passivation system, e.g., to passivate filtered debris and/or any other gas borne material before their disposal. Examples of gas conveyance system and components (including control components), in-situ passivation systems, controlled oxidation methods and systems, 3D printing systems, control systems, software, and related processes, can be found in International Patent Applications Serial Nos. PCT/US17/60035 and PCT/US21/35350, each of which is incorporated herein by reference in its entirety.

[0198] In some embodiments, the enclosure includes an atmosphere that is greater than (e.g., at a positive pressure with respect to) an ambient atmosphere external to the enclosure. The atmosphere within the enclosure may comprise a positive pressure of at least about 20 Kilo Pascal (KPa), 18 KPa, 16 KPa, 14 KPa, 12 KPa, 10KPa, or 5KPa above ambient atmospheric pressure, e.g., above 101 KPa. The pressure in the enclosure can be at a range between any of the afore-mentioned pressure values above atmospheric pressure, e.g., from about 5 KPa to about 20KPa, the values representing a pressure difference above atmospheric pressure, e.g., above 101 KPa. The pressure can be measured by a pressure gauge. The pressure can be measured at ambient temperature (e.g., room temperature (R.T.)). In some cases, the chamber pressure can be standard atmospheric pressure. The pressure may be measured at an ambient temperature (e.g., room temperature such as about 20°C, or about 25°C). The composition of the atmosphere within the enclosure may comprise any one or more of the gases described herein, for example, clean dry air (CDA), argon, and/or nitrogen. The gas may comprise a reactive agent (e.g., comprising oxygen or humidity). The atmosphere may comprise a v/v percent of the reactive agent (gas) of at most about 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, or 5%, at ambient pressure (e.g., and ambient temperature). The atmosphere may comprise any percent of the reactive agent (gas) between the aforementioned percentages of hydrogen gas. The enclosure may comprise a gas flow, e.g., before, after, and/or during three-dimensional printing. The gas flow within the enclosure may comprise at least about 150 liters per minute (LPM), 200 LPM, 250 LPM, 300 LPM, 350 LPM, 400 LPM, 450 LPM, 500 LPM, 550 LPM, 600 LPM, 650 LPM, 700 LPM, 750 LPM, 800 LPM, 900 LPM, 1000 LPM, or 1200 LPM. The gas flow within the enclosure may comprise any value between the aforementioned values, for example, from about 150 LPM to about 500 LPM, from about 450 LPM to about 750 LPM, or from about 700 LPM to about 1200 LPM.

[0199] In some embodiments, a 3D printing system includes, or is operationally couple to, one or more gas recycling systems. The gas recycling system can be at least a portion of the gas flow mechanism. The processing chamber may include gas inlet(s) and gas outlet(s). The gas recycling system can be configured to recirculate the flow of gas from gas outlet(s) back into processing chamber via the gas inlet(s). Gas flow through a channel exiting a gas outlet can include solid and/or gaseous contaminants such as debris (e.g., soot). A filtration system can be configured to filter out at least some of the solid and/or gaseous contaminants, thereby providing a clean gas (e.g., cleaner than gas flow through channel exiting the gas outlet). The filtration system can include one or more filters. The filters may comprise physical filters or chemical filters. The clean gas exiting the filtering mechanism (also herein “filtration system”) can be under lower pressure relative to the incoming gas pressure into the filtering mechanism. The lower pressure and the pressure of the incoming gas pressure may be above ambient pressure external to the 3D printing system. The clean gas can be directed through a pump to regulate (e.g., increase) its relative pressure prior to entry to the processing chamber. Clean gas with a regulated pressure that exits the pump can be directed through one or more sensors. The one or more sensors may comprise a flow meter, which can measure the flow (e.g., pressure) of the pressurized clean gas. The one or more sensors may comprise temperature, humidity, oxygen sensors, or any other sensor disclosed herein. In some cases, the clean gas can have an ambient pressure or higher. The higher pressure may provide a positive pressure within processing chamber (see example values of positive pressure described herein). A first portion of the clean gas can be directed through at least one inlet of a gas inlet portion of the enclosure, while a second portion of the clean gas can be directed to first and/or second window holders that provide gas purging of optical window areas, as described herein. That is, the gas recycling system can provide clean gas to provide a primary gas flow for the 3D printing system, as well as a secondary gas flow (e.g., window purging). In some embodiments, the pressurized clean gas is further filtered through a filter prior to reaching one or both of the window holders. In some embodiments, the one or more filters (e.g., as part of one or more filters and/or a filtration system) are configured to filter out particles having nanometer-scale (e.g., about 10 nm to about 500 nm) diameters. In some embodiments, the gas recycling system may provide clean gas to a recessed portion of the enclosure. In some embodiments, gas flow from the recessed portion of the enclosure can be directed through the gas recycling system. In some embodiments, gas flow from the recessed portion can be directed through one or more filters of a filtration system. In some embodiments, the gas recycling system provides clean gas directed to first and/or second window holders.

[0200] Fig. 4 shows a schematic side view of an example 3D printing system 400 that is coupled with a gas recycling system 403 in accordance with some embodiments. 3D printing system 400 includes processing chamber 402, which includes gas inlets 404 and gas outlet 405. The gas recycling system 403 is configured to recirculate the flow of gas from gas outlet 405 back into processing chamber 402 via the gas inlets 404. Filtration system 408 is configured to filter out at least some of the solid and/or gaseous contaminants, thereby providing a clean gas 409 (e.g., cleaner than gas flow through channel 406). The clean gas 409 exiting the filtering mechanism (also herein “filtration system") can be under lower pressure relative to the incoming gas pressure into the filtering mechanism. The clean gas is directed through a pump 410 to regulate (e.g., increase) its relative pressure prior to entry to the processing chamber. Clean gas 411 with a regulated pressure that exits the pump is directed through one or more sensors 412, e g., a flow meter, temperature sensors, humidity sensors, oxygen sensors, or any other sensor disclosed herein. A first portion of the clean gas is directed through at least one inlet(s) 404 of a gas inlet portion of the enclosure, while a second portion of the clean gas is directed to first and/or second window holders 414 and 416 that provide gas purging of optical window areas, as described herein. In some embodiments, the pressurized clean gas is further filtered through a filter e.g., 417 prior to reaching one or both of the window holders. In some embodiments, the one or more filters 417 and/or filtration system 408 are configured to filter out particles having nanometer-scale (e.g., about 10 nm to about 500 nm) diameters. In some embodiments, the gas recycling system provides clean gas to a recessed portion 418 of the enclosure. In some embodiments, gas flow 450a and 450b from the recessed portion 418 of the enclosure is directed through the gas recycling system 403. In some embodiments, gas flow from the recessed portion is directed through one or more filters of a filtration system. In some embodiments, the gas recycling system provides clean gas directed to first and/or second window holders 414 and 416.

[0201] In some embodiments, 3D printing system comprises a pre-transformed material (e.g., starting material such as powder) conveyor system (e.g., also referred to as “conveyance system” or “powder conveyance system”). The pre-transformed material conveyor system may be coupled with a processing chamber having a layer dispensing mechanism (e.g., recoater). Pre-transformed material (e.g., powder) from a reservoir (e.g., hopper) can be introduced into the layer dispensing mechanism disposed in the processing chamber. Once the layer dispensing mechanism dispenses a layer of pre-transformed material to layerwise form a material bed utilized for the three-dimensional printing, excess pre-transformed material may be attracted away from the material bed. In this process, excess pre-transformed material may be attracted away from the material bed using layer dispensing mechanism and introduced into separator (e.g., cyclone), and optionally to an overflow separator (e.g., cyclone). The pretransformed material may undergo separation (e.g., cyclonic separation) in separator(s), and may be introduced into sieve(s), followed by gravitational flow into a lower reservoir (e.g., hopper). The separated and sieved pre-transformed material can be then delivered into separator(s), and into a reservoir that can deliver the pre-transformed material back into the layer dispensing mechanism. The separator may be coupled with sieve(s) instead of to the reservoir. The pre-transformed conveyor system may comprise pumps (e.g., displacement pump and/or compressor pumps), and a temperature regulator (e.g., heater or radiator such as a radiant plane). The pre-transformed conveyor system may comprise a venturi nozzle, for example, to facilitate suction of the pre-transformed material from the reservoir into separator(s). The conveyance system can include a condensed gas source (e.g., a blower or a cylinder of condensed gas). The conveyance system may include a heat exchanger. The conveyance system may include one or more filters. The conveyance system may operate at a positive pressure above ambient pressure external to the conveyance system (e.g., above about one atmosphere). The gas circulating system may be configured to circulate (e.g., and recirculate) gas also in the processing chamber. The gas circulating system may sweep debris (e.g., soot) away from the process area in which the 3D object is being printed. At times, a pressure differential is required to convey pre-transformed material from one compartment of the 3D printer to another. The pressure differential may be established via pressurizing or vacuuming one or more compartments. For example, pre-transformed material from the layer dispensing system to the recycling system (e.g., including the separator(s), sieve(s), and/or reservoirs) may be conveyed using (a) induced pressure differential among components, (b) pressure isolation of the components, and (c) induced pressure equilibration of components.

[0202] Fig. 5 shows a perspective view example of a portion of a 3D printing system including a processing chamber having a roof 501 in which optical windows 580 are disposed to facilitate penetration of an energy beam into the processing chamber interior space, side wall 511 having a gas exit port covering 505 coupled thereto. The processing chamber has two gas entrance port coverings 502a and 502b coupled with an opposing wall to side wall 511 . The opposing wall is coupled with an actuator 503 configured to facilitate translation of a layer dispensing mechanism mounted on a framing 504 above a base disposed adjacent to a floor of the processing chamber, which framing is configured to translate back and forth in the processing chamber along railings. The processing chamber floor has slots through which remainder material can flow downwards towards gravitational center G along gravitational vector 590. The slots are coupled with funnels such as 506 that are connected by channels (e.g., pipes) such as 507 to material reservoir such as 509. The processing chamber is coupled with a build module 521 that comprises a substrate to which the base is attached, which substrate is configured to vertically translate with the aid of actuator 522 coupled with an elevator motion stage (e.g., supporting plate) 523 via a bent arm. The elevator motion stage and coupled components are supported by framing 508, (e.g., depicted in Fig. 5 missing a beam that may be removed for installation and/or maintenance). Atmosphere (e.g., content and/or pressure) may be equilibrated between the material reservoirs and the processing chamber via schematic channel (e.g., pipe) portions 533a-c. Remainder material in the material reservoirs may be conveyed via schematic channels (e.g., pipes) 543a-b to a material recycling system, e.g., for future use in printing. The components of the 3D printing system are disposed relative to gravitational vector 590 pointing to gravitational center G.

[0203] Fig. 6 shows in example 600 a front side example of a portion of a 3D printing system comprising a material reservoir 601 configured to feed pre-transformed material to a layer dispensing mechanism, an enclosure 609 configured to enclosure, e.g., scanner(s) and/or director(s) (e.g., optical system) of at least one energy beam (e.g., laser beam) configured to transform the pre-transformed material into a transformed material to print one or more 3D object in a printing cycle. Example 600 of Fig. 6 shows a build module 602 having a door with three circular viewing windows. The windows may be any window disclosed herein. The viewing window may be a single or a double pane window. The window may be an insulated glass unit (IGU), the window may be configured to withstand positive pressure within the processing chamber, e.g., during printing. The positive pressure is above ambient pressure external to the build module, e.g., the ambient pressure may be about one atmosphere. Example 600 show a material reservoir 604 configured to accumulate recycled remainder starting material (e.g., pretransformed material) from the layer dispensing process to form a material bed and/or a remainder of the material bed that did not form one or more 3D objects during a printing cycle, post 605 as part of a build platform assembly of build module 608; two material reservoirs 607 for accumulating a remainder of the material bed that did not form the 3D object, and actuator 603 configured to translate the layer dispensing mechanism to dispense a layer of pretransformed material as part of a material bed. Supports 606 are planarly stationed in a first horizontal plane, which supports 606 and associated framing support one section of the 3D printing system portion 600 and framing 610 is disposed on a second horizontal plane higher than the first horizontal plane. Fig. 6 shows in 650 an example side view example of a portion of the 3D printing system shown in example 600, which side view comprises a material reservoir 651 configured to feed pre-transformed material to a layer dispensing mechanism, an enclosure

659 enclosing, e.g., scanners and/or directors (e.g., optical system) of at least one energy beam (e.g., laser beam) configured to transform the pre-transformed material into a transformed material to print one or more 3D object in a printing cycle. Example 650 of Fig. 6 shows an example of a build module 652 having a door comprising handle 669 (as part of a handle assembly). Example 600 show a material reservoir 654 configured to accumulate recycled remainder from the layer dispensing process to form a material bed and/or a remainder of the material bed that did not form one or more 3D objects during a printing cycle, a portion of the material conveyance system 668 configured to convey the material to reservoir 654. The material conveyed to reservoir 654 may be separated (e.g., sieved) before reaching reservoir 654. The example shown in 650 shows post 655 as part of a build platform assembly of build module 658; two material reservoirs 657 for accumulating a remainder of the material bed that did not form the 3D object, and actuator 653 configured to translate the layer dispensing mechanism to dispense a layer of pre-transformed material as part of a material bed, e.g., along railing 667 in processing chamber and into garage 666 in a reversible (e.g., back and forth) movement. Supports 656 are planarly stationed in a first horizontal plane, which supports 606 and associated framing support one section of the 3D printing system portion 650 and framing

660 is disposed on a second horizontal plane higher than the first horizontal plane. In the example shown in Fig. 6, the 3D printing system components may be aligned with respect to gravitational vector 690 pointing towards gravitational center G.

[0204] In some embodiments, the build module is included as part of the 3D printing system. In some embodiments, the build module is separate from the 3D printing system. The build module may be independent (e.g., operate independently) from the 3D printing system. For example, the build module may comprise its own controller, motor, elevator, build platform, valve, channel, or shutter. [0205] In some embodiments, the 3D printing system comprises a load-lock mechanism.

The load lock may comprise an intermediate chamber for atmospheric exchange. The load lock may comprise an intermediate chamber for (I) transferring from ambient atmospheric conditions into another atmospheric conditions or (II) transferring from the other atmospheric conditions to ambient atmospheric conditions. The load-lock mechanism may be operatively coupled with the processing chamber and/or a build module. For example, the load lock may comprise an intermediate chamber for (I) transferring the build module from ambient atmospheric conditions into an atmospheric conditions of the processing chamber or (II) transferring the build module from the processing chamber atmospheric conditions to ambient atmospheric conditions. In some embodiments, as a part of the load-lock mechanism or separate from the load lock mechanism, the build module may comprise a shutter. In some embodiments, as a part of the load-lock mechanism or separate from the load lock mechanism, the processing chamber may comprise a shutter. The shutter may be reversibly openable and shut-able (e.g., by the build module controller, the processing chamber controller, or the load lock controller). The shutter may be reversibly removable and engageable (e.g., by the build module controller, the processing chamber controller, or the load lock controller). The removal of the shutter may comprise manual and/or automatic removal. The build module shutter may be opened and/or shut while being connected to the build module. The processing chamber shutter may be opened and/or shut while being connected to the processing chamber (e.g., through connector(s)). The shutter connector may comprise a hinge, chain, or a rail. In an example, the shutter may be opened in a manner similar to opening a door or a window. The shutter may be opened by swiveling (e.g., similar to opening a door or a window held on a hinge). The shutter may be opened by removing the shutter from the opening which it blocks (e.g., which it shuts). [0206] In some embodiments, the build module comprises a build platform and/or piston(s) that is translatable, e.g., relative to the build module. The build platform and/or piston(s) may be vertically translatable, e.g., using at least one actuator. The platform may be translatable using an elevation mechanism, e.g., comprised in a build platform assembly. The build platform assembly may include at least one translation mechanism comprising (i) a lead screw (e.g., with a nut), (ii) a scissor jack, (iii) a piston assembly, (iv) a telescopic (e.g., hydraulic, or pneumatic) cylinder, or (v) any combination thereof. The build platform assembly may include one or more supportive structures, e.g., guide rods, shafts, rails, or the like. The lead screw may comprise a nut. The nut may be coupled with a shaft or guide rod. A turning of the lead screws and/or nut may allow the shaft (or guide rod) to travel (e.g., vertically). The shaft may comprise the lead screw, e.g., may be the lead screw. The lead screw can be coupled with an actuator (e.g., a motor). The build platform assembly may comprise high torque and low inertia actuator(s). The build platform assembly may comprise, or be operatively coupled with, a hydraulic, magnetic, or electronic force source. The build platform assembly may comprise a sensor utilized in a feedback control scheme (e.g., a feedback sensor). The feedback sensor may be disposed (e.g., directly) on any component of the build platform assembly. The feedback sensor may facilitate precise angular position sensing. The build platform assembly may comprise an optical location sensor. The build platform assembly may comprise an encoder. For example, the build platform is coupled with an encoder. The encoder may be a vertical encoder. The encoder may comprise a rotary encoder, a shaft encoder, an electro-mechanical encoder, an optical encoder, a magnetic encoder, a capacitive encoder, a gray encoder, or an electrical encoder. The actuator may comprise a servo motor. The encoder may comprise a sensor (e.g., a position sensor, a thermal sensor, a motion sensor, or a weight sensor). Each side of the encoder may be coupled with an end point of a length of translation of an aspect of the build module, e.g., a distance of translation of a piston assembly. For example, one side of the encoder may be coupled with a bottom surface of the platform, and an opposite side of the encoder may be coupled with a bottom plate of the build module. For example, one side of the encoder may be coupled with a first piston assembly (e.g., to a first piston thereof) and an opposite side of the encoder may be coupled with a second piston assembly (e.g., to a second piston thereof). In some embodiments, the build platform assembly is devoid of an encoder.

[0207] In some embodiments, the build platform assembly includes, or is coupled with, a sensor. The sensor may be any sensor disclosed herein. The sensor may sense a weight on the platform. The sensor may sense a position (e.g., absolute, or relative position) of the build platform assembly, e.g., of the platform. The sensor may sense a motion of the build platform assembly, e.g., of the platform. The sensed measurement may be received by the encoder. The encoder may direct a controller (e.g., an actuator) to adjust the measurement (e.g., before, during and/or after the 3D printing).

[0208] In some embodiments, an encoder is coupled with the build module. The bottom of the build module may be coupled with one or more encoders and/or other positional sensor(s). The bottom encoders may be any encoder disclosed herein. The positional sensor may be any positional sensor disclosed herein, e.g., comprising an optical sensor. The bottom encoders may communicate with a controller. The bottom encoders may communicate with the same controller as the vertical encoder. The bottom encoders may be controlled by the same controller as the vertical encoder. The bottom encoders may be controlled by a separate controller (e.g., microcontroller). The bottom encoders may adjust a position of the build platform assembly, compensate for weight on the platform, and/or compensate for thermal expansion/contraction. [0209] In some embodiments, the build module is operatively coupled with at least one controller. The controller may be its own controller. The controller may comprise a control circuit, e.g., an electrical circuit. The controller may have a connection to power, e.g., electrical power. The controller may comprise programmable control code. The controller may be different than, or the same as, the controller controlling the 3D printing process and/or the processing chamber. The controller controlling the 3D printing process and/or the processing chamber may comprise a different control circuit than the control circuit of, or the same control circuit as, the build module controller. The controller controlling the 3D printing process and/or the processing chamber may comprise a different programmable control code than, or the same control code as, the programmable control code of the build module controller. The build module controller may communicate the engagement of the build module to the processing chamber.

Communicating may comprise emitting signals to the processing chamber controller. The communication may cause initialization of the 3D printing. The communication may cause one or more load lock shutters to alter their position (e.g., to open). The build module controller may monitor sensors (e.g., position, motion, optical, thermal, spatial, gas, gas composition or location) associated with the build module. The build module controller may control (e.g., adjust) the active elements (e.g., actuator, atmosphere, elevator mechanism, valves, opening/closing ports, seals) associated with the build module, e.g., based at least in part on the sensed measurements.

[0210] In some embodiments, the 3D printing system comprises an alignment system configured to translate the build platform vertically, e.g., during the printing process. The build platform assembly may comprise one or more shafts. There may be a plurality of shafts (e.g., peripheral shafts) that encircle a central shaft. The plurality of shafts (e.g., peripheral shafts) may comprise at least 3, 4, 5, or 6 shafts (e.g., linear shafts). At least two of the plurality of peripheral shafts (e.g., all of the peripheral shafts) have the same, or substantially the same, FLS (e.g., dimensions). The central shaft may have the same, or substantially the same, length as a peripheral shaft. The central shaft may have the same diameter and/or cross section as a peripheral shaft. The central shaft may have a larger dimension than the peripheral shaft. The central shaft may comprise a scale configured to be read by an encoder (e.g., a linear absolute encoder). The central shaft may be coupled with an encoder, e.g., a servo motor. The encoder can provide feedback to controller(s) (e.g., to the control system) on the position of the substrate (e.g., piston). The peripheral shafts may be guiding shafts. The peripheral shafts are concentrically arranged with the central shaft. The central shaft may be configured to facilitate fluid communication of a heat exchange system that is operatively coupled with the build platform, e.g, and exchanges heat with the build platform. For example, the central shaft may be hollow and the fluid communication of the heat exchange system takes place at least in part through an interior of the central shaft. The heat exchange system may be a cooling system. The fluid communication may comprise gas, liquid, or semi-solid (e.g., gel) fluid communication. [0211] In some embodiments, the build module, processing chamber, and/or enclosure comprises a gas equilibration channel. The gas (e.g., pressure and/or content) may equilibrate between at least two of the build module, processing chamber, and enclosure through the gas equilibration channel. The gas equilibration channel (e.g., Fig. 7, 745) may comprise a valve and/or a gas opening port. The valve may allow at least one gas to travel through. The gas may enter or exit through the valve. For example, the gas may enter or exit the build module, processing chamber, and/or enclosure through the valve.

[0212] In some embodiments, the build module comprises multiple (e.g., two or more) chambers. The multiple chambers may be isolated from each other. Isolated may comprise gas tight, hermetically sealed, can hold positive pressure over time, physically separated, reduced contamination, or the like. Over time may be at least about a length of a printing cycle. Over time may comprise a length of at least about 1 , 2, 5, 10, or 20 printing cycles. The chambers may comprise an internal chamber and an external chamber. At times, at least one of the chambers (e.g., the internal chamber) may comprise at least one seal. The seal may allow a gas to pass through. The seal may be permeable to a gas, but not to a pre-transformed or a transformed material. The seal may be any seal disclosed herein. For example, the seal may be permeable to a gas, but not to a particulate material. The seal may be placed laterally (e.g., horizontally) between one or more walls (e.g., side walls) of the internal chamber. The seal may allow a gas to circulate and/or equilibrate between the internal chamber and external chamber. The seal may hinder passage of pre-transformed or transformed material from the first chamber to the second chamber (e.g., comprising one or more bearings and/or motors). The seal may be connected to the bottom plane of the internal chamber. The seal may be placed beneath the platform. Beneath may be closer to the gravitational center. The seal may not allow permeation of pre-transformed (e.g., particulate) material into the build platform assembly. The seal may (e.g., substantially) hold the atmosphere of the build module inert. Substantially may be relative to its effect on the 3D printing. Substantially may be imposing a negligible effect on the 3D printing. The seal may vary in size, e.g., may be expandable and/or contractible. The variation in size may be control using temperature, magnetism, electricity, or pneumatically. The seal may be elastic. The seal may be compressible (e.g., on pressure, or as a result of the elevator operation), e.g., reversibly compressible. The seal may be extensible, e.g., reversibly extendable. The seal may return to its original shape and/or size when released (e.g., from pressure, or vacuum). The seal may compress and/or expand relative (e.g., proportionally) to the amount of translation of the build platform assembly (e.g., the one or more piston assemblies). The seal may compress and/or expand relative to the amount of pressure applied (e.g., within the build module). The seal may reduce (e.g., prevent) permeation of pretransformed (e.g., particulate) material from one side of the seal to the opposing side of the seal. The seal may facilitate protection of the build platform assembly (e.g., comprising a guide, rail, bearing, or actuator (e.g., motor)), by reducing (e.g., blocking) permeation of the pretransformed material through the seal. The seal may comprise a bellow. The bellow may comprise formed (e.g., cold formed, or hydroformed), welded (e.g., edge-welded, or diaphragm) or electroformed bellow. The bellow may be a mechanical bellow. The bellow can comprise any material disclosed herein (e.g., comprising stainless steel, titanium, nickel, or copper). For example, the material of the bellow may comprise a metal, rubber, polymeric, plastic, latex, silicon, composite material, or fiberglass. The material may have high plastic elongation characteristic, high-strength, and/or be resistant to corrosion. The seal may comprise a flexible element (e.g., a spring, wire, tube, or diaphragm). The seal may be (e.g., controllably) expandable and/or contractible. The seal may reduce the amount of (e.g., prevent) permeation of particulate material from one side of the seal to its opposite side. The seal may protect the actuator(s), by blocking permeation of the particulate material to the area where the actuators reside. The seal may comprise bellow(s). The seal (e.g., envelope such as a bellow) may enclose at least a portion of the build platform assembly to form an internal chamber with respect to the build module. The seal may encircle at least a portion of the piston assemblies. The seal may protect an expandable volume between the first piston assembly and the second piston assembly, e.g., reduce (e.g., prevent) contamination of the internal volume with pretransformed or transformed material. The seal may enclose a portion of the build platform assembly and a bottom region of the build module. The seal may enclose a volume between the first (e.g., lower) piston assembly and a floor of the build module body. The seal may enclose a volume of the build platform assembly including optical components. The build platform assembly may comprise a first piston and a second piston. The first piston and second piston differ in their respective location, in their functionality, and/or in their shape. For example, the first (e.g., lower) piston may comprise one or more opening (e.g., holes). The one or more openings may accommodate the shaft and/or the guide rods, e.g., to facilitate contraction of the volume between the first piston and the second piston. The first piston may translate with respect to the guide rods and/or shaft coupling the first piston to the second piston. A seal may be disposed between the opening and the guide rod and/or the shaft. The seal may facilitate the relative movement between the first piston and the guide rod and/or shaft. The seal may (e.g., substantially) facilitate in maintenance of the atmosphere of the build module such at the atmospheres in the various sub-environments of the build module. The microenvironments of the build module may include (i) a volume between the floor of the build module and the first piston assembly, (ii) a volume between the first piston assembly and the second piston assembly, (iii) a volume between the first piston assembly and the top of the build module opposing its floor, (iv) a volume between the build platform assembly and the body of the build module, or (v) any combination of (i), (ii), (iii), and (iv). The top of the build module may be closed by a lid, e.g., a shutter. The top of the build module may engage with the processing chamber. The coupling of the build module with the processing chamber may be through a load lock having an intermediate volume including a controlled environment, the load lock is configured to reduce potential for contamination in the process chamber and/or build module during engagement and disengagement of the build module with the processing chamber. A material of the seal may be any material for a seal disclosed herein. The build module and/or processing chamber may comprise a reversible openable shutter, e.g., as disclosed herein. For example, the build module and processing chamber may each comprise a separate reversibly openable shutter, e.g., a controllable shutter. The internal chamber may comprise one or more openings. The openings may allow the shaft(s), guide rod(s), and/or sensor (e.g., encoder) to pass through. The openings may allow a line of sight of a beam path of a metrology detector to pass through into the inner chamber. The beam may be an electromagnetic beam. The opening for the electromagnetic beam may or may not be equipped (e.g., closed) by an optical window. [0213] FIG. 7 shows an example of a 3D printing system, according to some embodiments. The 3D printer includes a build module 701. The build module 701 comprises an internal chamber 706 and an external chamber 707, where the internal chamber is enclosed by the external chamber. The build module includes a build platform assembly comprising one or more lead screw(s) 711 , and nuts coupled with a shaft 709 (e.g., guide rods). Turning the lead screws and/or nut can allow the shaft to travel vertically, e.g., vertical translation 712. The lead screw is coupled with an actuator, e.g., motor 710. The build module comprises an encoder 723 configured to facilitate controlling (e.g., monitoring) a vertical position of the platform (e.g., a relative position). The encoder can be coupled with an external engagement mechanism 740 configured to externally engage with the processing chamber and enclose the build module. The bottom plane of the internal chamber comprises a seal 725. The seal 725 can prevent the permeation of pre-transformed or transformed material into the build platform assembly, e.g., into a motor 710 or screw 711. Internal chamber 706 includes multiple openings that can allow an encoder 723 and shafts 709 to pass through. The shafts 709 are coupled with a platform comprising a base 702. (e.g., a build platform). A material bed 704 is formed on the platform, where a seal, e.g., seal 705 prevents pre-transformed (and transformed) material from traveling through to the internal chamber 706. Fig. 7 shows an example of a gas equilibration channel 745 that allows a gas to pass through into the inner chamber 706. The gas equilibration channel 745 has an opening port 754 disposed between the processing chamber having a wall and the build module 701 having a wall. A valve 750 is disposed along the gas equilibration channel 745, to optionally allow least one gas to travel through. The gas may enter or exit through the valve. The gas equilibration channel 745 has an opening port 752 connected to the build module, and an opening port 754 connected to the processing chamber. Energy beam 770 impinges upon an exposed surface 772 of material bed 704, to print at least a portion of a 3D object 776.

[0214] In some embodiments (e.g., Fig. 7) a height of the build module accommodates (i) a vertical translation range of the build plate and (ii) a vertical height requirement of supportive structures (e.g, guide rails and encoder) of the build platform assembly. At times, an orientation and dimensionality of a requested three-dimensional object(s) to be printed and confined in a build module of a three-dimensional (3D) printing system necessitates a dimension along a vertical axis (e.g., along a z-axis) that challenges accommodation of the 3D printing system in a facility, e.g., due to its large size.

[0215] Fig. 8 shows an example of a 3D printing system 800 disposed in relation to gravitational vector 890 directed towards gravitational center G. The 3D printing system comprises processing chamber 801 coupled with an ancillary chamber (e.g., garage) 802 configured to accommodate a layer dispensing mechanism (e.g., recoater), e.g., in its resting (e.g., idle) position. The processing chamber is coupled with a build module 803 that extends 804 under a plane (e.g., floor) at which user 805 stands on (e.g., can extend under-grounds). The processing chamber may comprise a door (not shown) facing user 805. 3D printing system 800 comprises enclosure 806 that can comprise an energy beam alignment system (e.g., an optical system) and/or an energy beam directing system (e.g., scanner) - not shown. A layer dispensing mechanism (not shown) may be coupled with a framing 807 as part of a movement system that facilitate movement of the layer dispensing mechanism along the material bed and garage (e.g., in a reversible back-and-forth movement). The movement system comprises a translation inducer system (e.g., comprising a belt or a chain 808). 3D printing system 800 comprises a filter unit 809, heat exchangers 810a and 810b, pre-transformed material reservoir 811 , and gas flow mechanism (e.g., comprising gas inlets and gas inlet portions) disposed in enclosure 813. The filtering system may filter gas and/or pre-transformed (e.g., powder) material. The filtering system may be configured to filter debris (e.g., comprising byproduct(s) of the 3D printing). As depicted in Fig. 8, in order to extend a capability of a 3D printing system in a vertical direction (e.g., along a z-axis), a plane at which the user 805 stands would have to be raised in the vertical direction (e.g., which may exceed an available ceiling height of a facility housing the 3D printer), or the build module would need to be extended under-grounds (e.g., which may require excavating a trench into a floor of the facility).

[0216] In some embodiments, the 3D printing system comprises a build module, where a height (e.g., vertical height) of the build module accommodates a vertical translation of the build platform that is at least greater than a height requirement of the supportive structures (e.g., guide rails and encoder) of the build platform assembly. The build module may comprise a housing, e.g., a build module body. The build module body may comprise an FLS (e.g., a length) that is at least about 100 millimeters (mm), 200 mm, 300 mm, 400 mm, 500 mm, 550 mm, 600 mm, 650 mm, 700 mm, 800 mm, 900 mm, 1000 mm, 1100 mm, 1200 mm, 1400 mm, 1600 mm, 1800 mm, 2000 mm, or more. The build module body may comprise an FLS that is any value between the aforementioned values, e.g., between about 100 mm and 1400 mm, between about 500 mm and 1200 mm, or between about 500 mm and 2000 mm. The build module may comprise interconnects, e.g., to couple the build module to one or more components of the 3D printing system. Interconnects may comprise, for example, electrical interconnects, hydraulic interconnects, pneumatic interconnects, temperature adjustment manifold interconnects, gas connections, magnetic interconnects, or the like. The build module may comprise one or more of a valve, nozzle, flow meter, and regulator. Electrical interconnects may comprise power connection, power regulator, power stabilization system (e.g., an uninterrupted power supply (UPS)). The build module may comprise a power supply configured to provide power to components of the build module, e.g., to a build platform assembly. The build module may comprise an (e.g., electrical) interconnect to receive power from a power supply of the 3D printing system. Hydraulic interconnects may couple one or more hydraulic components of the build module to a hydraulic source. Temperature adjustment interconnects (e.g., comprising a manifold) may comprise coolant lines to connect one or more components of the build module to a coolant source, e.g., to a water circulation source or a gas source. The temperature adjustment interconnects may be part of a temperature conditioning system such as a cooler. Gas interconnects may comprise gas connects to a gas source, e.g., to an argon source, clean dry air (CDA) source, a nitrogen source, air, or the like. Gas interconnects may connect a gas source to gas purge manifold and/or a temperature adjustment manifold. The build module may comprise a prismatic volume. The build module body may enclose a cylindrical volume. The build module body may enclose a rectangular volume. The build module body may comprise an opaque or a transparent material. The build module body may comprise an elemental metal, metal alloy, a ceramic, or an allotrope of elemental carbon. The build module body may comprise a composite material. The build module body may include a material comprising aluminum, stainless steel, or any material disclosed herein. The build module body may be formed from (e.g., machined, extruded) a single unit. The build module body may comprise segments connected together to define the build module body. The build module body may comprise a window or a door. The build module may comprise an external engagement mechanism, e.g., to facilitate transporting the build module. For example, the external engagement mechanism may be utilized to reversibly engage the build module with the 3D printer. Transporting may be by a transporter comprising a vehicle, or an aircraft. The transported can be fully or partially automatic. The transporter can be manually operated at least in part.

[0217] Fig. 9 depicts schematic views of example 3D printing systems. 3D printing system 900 includes a processing chamber 902 and build module 904. Build module 904 is aligned with the 3D printing system by frame 906 and can be reversibly engaged/disengaged with the processing chamber 902. Frame 906 includes lifting arms 908 that are arranged and configured to engage with a kinematic mounting platform 910 of the build module 904. The lifting arms may be coupled with an actuator, e.g., a motor. Lifting arms 908 are coupled with frame 906 by shafts 912, e.g., any shafts disclosed herein. For example, shafts 912 can include linear bearings and rods. Shafts 912 can engage with the kinematic mounting platform 910 of the build module 904 to adjust a position of the build module 904 relative to the frame 906. An alignment of the build module with respect to the 3D printing system, e.g., about XYZ axes, may be adjusted in part using shafts 912. An alignment may be adjusted to align a center axis of the build module with a center axis of a receiving opening in a portion of the processing chamber 902. Build module 904 may be translated, e.g., vertically translated, horizontally translated (with respect to a gravitational vector 990 pointing towards gravitational center G) to engage the build module with the processing chamber 902. At times, e.g., when the build module is engaged with the frame 906, the build module 904 may be translated vertically to engage a portion of the build module 904 with the processing chamber 902. Build module 904 includes a window 914, e.g., to allow for a user to view into a portion of the build module 904. The window may facilitate maintenance and/or inspection. Build module 904 includes interconnects 916, e.g., any interconnect disclosed herein. Interconnects 916 can be connected to the 3D printing system 900 during an engagement process of the build module 904 with the 3D printing system 900. At times, a build module supported by frame 906 may include a gap 918 between a base 920 of the build module and a supportive surface 922. At times, a build module supported by frame 906 and disengaged from the processing chamber 902 may include a gap 924 between a surface 926 of the build module 904 and a bottom surface 928 (e.g., an engagement surface) of the processing chamber 902. As depicted in Fig. 9, a build module 954 can engage with a 3D printing system 950. The build module 954 is engaged with processing chamber 956 to extend an internal volume of the processing chamber into the build module 954. As aligned, the build module aligns with optical windows 958 of the processing chamber 956 along a central axis 960. [0218] In some embodiments, the build module comprises a build platform assembly. The build platform assembly may comprise at least one structures (e.g., shafts) supportive of a build platform and/or substrate. The build platform assembly may comprise one or more sensors. The build platform assembly may comprise one or more supportive structures, e.g., guide rods, shafts, rails, or the like. The build platform assembly may comprise at least one piston assembly. The piston assembly may comprise at least one piston. The build platform assembly may comprise two or more piston assemblies. The build platform assembly may comprise at least two piston assemblies, or at least three piston assemblies. The build platform assembly may comprise a first piston assembly and a second piston assembly (e.g., a lower piston and an upper piston with respect to the gravitational center G). At times, the build platform assembly provides a range of linear translation (e.g., precision linear translation) between the first piston assembly and second piston assembly. The first piston assembly and the second piston assembly may be coupled by at least one shaft. The shaft may be operatively coupled with an encoder, e.g., any encoder recited herein. The shaft may comprise a lead screw (e.g., with a nut).

[0219] At times, the build platform assembly is translated. Translation of the build platform assembly may comprise translation of one or more components of the build platform assembly. For example, translation of the build platform assembly comprises translation of at least one piston assembly, e.g., of one or more piston assemblies of the build platform assembly. For example, translation of the build platform assembly comprises translation of a build platform coupled (e.g., supported by) a piston assembly. Translation of the build platform assembly may comprise vertical translation. Vertical translation can be relative to a gravitational vector pointing to the gravitational center of the environment (e.g., of Earth). Vertical translation can be reversible, e.g., in an up and down movement. Vertical translation may comprise different types of vertical translation, e.g., a first type of vertical translation, a second type of vertical translation, and a third type of vertical translation. Different types of vertical translation can be utilized during the three-dimensional printing of three-dimensional objects, e.g., to facilitate additive printing methodology.

[0220] In some embodiments, the 3D printing process may comprise translating the build platform assembly in a first type of vertical translation, e.g., in an upward direction. The upward direction may be against the gravitational vector pointing the environmental gravitational center, and/or in a vertical direction extending from the floor of the build platform to the build module’s opening that accommodates the build platform. The first type of vertical translation may comprise an initiation translation. The initiation translation may bring the build platform to its topmost position from which the 3D printing initiates, e.g., from which the material bed starts being generated. The initiation translation may be referred to as “build start” translation. The initiation translation may comprise a large increment translational pushup. An initiation increment may span at least about 50%, 60%, 75%, 80%, 90%, 95%, 99%, or 100% of a full vertical length of travel of the build platform, e.g., from adjacent to a bottom (e.g., a floor) of the build module body to its top position of the build module body, the top opposition the build module body’s floor. The initiation increment (e.g., initiation translation) may comprise any aforementioned percentage of the full vertical length of travel of the build platform assembly, for example, between about 50% and 100%, between about 65% and 99%, or between about 75% and 95%. Initiation translation may comprise a vertical translation of at least about 100 millimeters (mm), 200mm, 250mm, 500 mm, 1000 mm, 110 centimeters (cm), 120 cm, 140 cm, 150 cm, 200 cm, 250 cm, 300 cm, 350 cm, 400 cm, 1 meter (m), 2m, 3m, 4m or more.

[0221] In some embodiments, the 3D printing process may comprise translating a portion of the build platform assembly in a second type of vertical translation, e.g., in a downward direction. The downward direction may be along the gravitational vector pointing the environmental gravitational center, and/or in a vertical direction extending from the build module’s opening that accommodates the build platform to the floor of the build platform. The second type of vertical translation may comprise a block translation (also herein “sectional” translation). The block translation may move the portion of the build platform assembly downwards to reset a detection mechanism that facilitates accurate detection and/or control of a layerwise movement of another portion of the build platform assembly. For example, the build platform assembly may comprise a first piston assembly and a second piston assembly. For example, the block translation may move the first piston assembly downwards to reset a detection mechanism that facilitates accurate detection and/or control of a layerwise movement of the second piston assembly. The detection mechanism may comprise an optical detection mechanism. The detection mechanism may comprise an encoder. For example, the block translation may comprise an incremental value comprising at least about 50%, 60%, 75%, 80%, 90%, 95%, 99%, or 100% of a length of the shaft coupling the first piston assembly with the second piston assembly. The block translation may comprise values of at least about 1 millimeter (mm), 5 mm, 10 mm, 20 mm, 50 mm, 100 mm, 150 mm, 200 mm, 250 mm, 400 mm, 600 mm, 1000 mm, or more. The block translation may comprise any value between the aforementioned values, for example, between about 1 mm and 100 mm, between about 20 mm and 250 mm, or between about 200 mm and 1000 mm.

[0222] In some embodiments, the 3D printing process may comprise translating a portion of the build platform assembly in a third type of vertical translation, e.g., in a downward direction. The downward direction may be along the gravitational vector pointing the environmental gravitational center, and/or in a vertical direction extending from the build module’s opening that accommodates the build platform to the floor of the build platform. The third type of vertical translation may comprise layerwise translation (also herein “layer-height” translation). The layerwise translation may move the portion of the build platform assembly downwards layerwise to facilitate generation of a layer of starting material as part of the material bed. The portion of the build platform assembly may comprise the second piston assembly, the second piston assembly may comprise, or may be operatively (e.g., physically) coupled with a build platform. The second piston assembly may comprise a second piston. The second piston may be operatively (e.g., physically) coupled with the build platform. At least one energy beam may impinge on the exposed surface of the layer of starting material to form at least one layer of a 3D object that is formed layerwise. An extent of the layerwise translation may correspond and/or be controlled at least in part using an input from the detection mechanism, e.g., as disclosed herein. The layerwise translation may comprise values of at most about 1 millimeter (mm), 750 microns (pm), 500 pm, 250 pm, 200 pm, 150 pm, 100 pm, 50 pm, 25 pm, 10 pm, 5 pm, or smaller. The layerwise translation may comprise any value between the aforementioned values, for example, between about 1 mm and 25 pm, between about 500 pm and 100 pm, or between about 100 pm and 5 pm. The block translation and/or the layerwise translation may comprise a precision error, e.g., an error in position along the z-axis. A precision error can be, for example, any error value described herein. For example, a precision (e.g., error +/-) of at most about 0.25pm, 0.5pm, 1 pm, 1 ,5pm, 2pm, 2.5pm, 3pm, 4pm, or 5pm. The precision value may be between any of the aforementioned precision value (e.g., from about 0.25pm to about 5pm, from about 0.25pm to about 2.5pm, or from about 1 ,5pm to about 5pm). The precision value may be (e.g., error +/-) at most about 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 8% or 10% of the vertical translation.

[0223] In some embodiments, the 3D printing process may comprise translating the build platform assembly and/or any portion thereof in a first, second, and third type of vertical translation. The types of translation may differ in their span and/or frequency of their occurrence during a 3D printing cycle. At least one translation type utilizes a different translation mechanism that at least one other translation type. For example, the initiation translation utilizes a translation mechanism, whereas the piston assembly (e.g., first and/or second) utilizes an external engagement mechanism. At least one of the translation (e.g., all translations) may be discrete. At least one of the translation may be continuous. In some embodiments, all three translations are discrete translations. At least one of the three translation types may be in a direction opposing at least one other of the three translation types. At least two of the three translation types may be in opposing directions to one another. At least two of the three translation types may be along the (e.g., substantially) same direction. For example, the initiation translation may be in a direction (e.g., translating up) opposing the direction of the bulk translation (e.g., translating down). For example, the initiation translation may be in a direction (e.g., translating up) opposing the direction of the layerwise translation (e.g., translating down). For example, the layerwise translation may be in the (e.g., substantially) same direction (e.g., translating down) as the direction of the bulk translation (e.g., translating down). At least two of the translational types (e.g., all three translational types) may differ in their translational span. The first type of translational movement (e.g., initiation movement) may be larger in span than the second type of translational movement (e.g, block movement), which may be larger than a third type of translational movement (e.g., layerwise movement). The initiation translation may be the largest span translation. The layerwise translation may be the smallest span translation. The block translation may have a translational span that is smaller than the initiation translational span and larger than the layerwise translational span. The different types of translations occur at different frequency during a 3D printing process. For example, the initiation translation occurs at the beginning of a 3D printing process. For example, the block translation of the first piston assembly occurs a first number of times during a 3D printing process. For example, for every block translation, the layerwise translation of the second piston assembly occurs multiple times. The layerwise translational span may be at least about 1 , 2, 3, 4, or 5 orders of magnitude smaller as compared to the block translational span. The block translational span may be at least about 2, 3, 4, or 5 times smaller as compared to the initiation translational span. For example, the layerwise translation may be a few tenths of a micron, the block translation can be in the order of hundreds of millimeters, and the initiation translation can be in the order of thousands of millimeters.

[0224] In some embodiments, the build platform assembly translates in an initiation translation. Initiation translation of the build platform assembly may comprise vertical translation by an optional translation mechanism such as any translation mechanism disclosed herein. The translation mechanism may be configured to (A) push the build platform assembly quickly upwards (e.g., to an initiation position) and/or (B) act as (e.g., function as) a safety cushion to slow down (e.g., and halt or stop) an unplanned fall of the build platform assembly falls downward towards the floor of the build module body. Push quickly may be with respect to movement of the first piston assembly and/or second build platform assembly, e.g., as compared to the build and/or to the incremental movements thereof. For example, a translation mechanism coupled with the build platform assembly. The translation mechanism can be any translation mechanism disclosed herein, e.g., at least one translation mechanism comprising (i) a lead screw, (ii) a scissor jack, (iii) a piston assembly, or (iv) a telescopic unit. For example, initiation translation comprises altering a vertical extent of the translation mechanism (e.g., telescopic unit) that is coupled with the at least one piston assembly. The telescopic unit may comprise telescopic cylinders, e.g., telescopic hydraulic cylinders or telescopic pneumatic cylinders. Altering a vertical extent of the translation mechanism (e.g., telescopic unit) may comprise translating the build platform (e.g., by translating at least one of the piston assemblies) from first position relative to the build module body to a second position relative to the build module body. The second position may be located above the first position relative to the gravitational vector pointing towards gravitational center G of the environment. The second position may be at a fully extended position of the translation mechanism. The second position may be at a top-most position of the build platform assembly relative to the build module body. The first position may be at a bottom-most position of the build platform assembly relative to the build module body. The first and/or second position may be dictated (limited) by a position of a limit switch located on the build module. The first and/or second position may be dictated (limited) by a position of a hard stop, e.g., guide rods, shafts, rails, or the like, of the build module body. Translation of the build platform assembly may comprise vertical translation(s) of one or more piston assemblies, e.g., incremental translation. Each of the one or more piston assemblies may have an associated vertical translation type, e.g., different incremental translation types. The different incremental translation types of the first piston assembly may be relative to the second piston assembly and vice versa. For example, the different incremental translation types may correspond to the respective piston assembly’s position with respect to the shaft (e.g., and encoder) coupled with the piston assembly and/or to another piston assembly also coupled with the shaft. For example, a first type of incremental translation of a piston assembly of the build platform assembly (e.g., of a first piston assembly) comprises a block translation (e.g., a reset movement, section movement). A block translation can reset a length of travel between piston assemblies, e.g., between a first piston assembly and a second piston assembly. The length of travel can be reset to a full extent of travel possible between a first piston assembly and a second piston assembly along a shaft coupled with the first piston assembly and the second piston assembly. The block translation of the piston assembly can reset a height position of an encoder (e.g., an optical encoder, a laser encoder) that dictates a vertical translation of one piston assembly with respect to another piston assembly, e.g., a vertical translation of the second piston assembly with respect to the first piston assembly. For example, a second type of incremental translation of a piston assembly of the build platform assembly (e.g., of a second piston assembly) comprises a layerwise translation (e.g., a layerheight movement). The layerwise translation of the piston assembly, e.g., with respect to another piston assembly, can relate to a layer height of pre-transformed material deposited on an exposed surface of the material bed or build platform or relate (e.g., correspond) to a layer height of a 3D object supported by the material bed. For example, layerwise translation can be a movement of the second piston assembly with respect to the first piston assembly. Sequential layerwise incremental movements can be utilized during a 3D printing process, e.g., each layerwise movement corresponding to a sequentially deposited layer of pre-transformed material. Block translation and/or layerwise translation of a piston assembly can be in any increment disclosed herein. Block translation and/or layerwise translation of a piston assembly may comprise linear translation of the piston assembly along a direction (e.g., and along a shaft disposed along that direction). Block translation and/or layerwise translation may comprise incremental translation, e.g., including two or more increments. The layerwise translation may comprise translational values that are smaller than the first type of incremental translation, e.g., smaller than the block translation.

[0225] In some embodiments, the build platform assembly comprises at least one piston assembly. A piston assembly may comprise a piston. The piston assembly may comprise at least one engagement mechanism, e.g., an internal engagement mechanism configured to be disposed in the build module body during operation. The (internal) engagement mechanism may facilitate reversible engagement and disengagement of the piston assembly with a build platform. The engagement mechanism may facilitate reversible engagement and disengagement of the piston assembly with a support, e.g., a build module body. The build platform assembly may comprise a first piston assembly and a second piston assembly. The first piston assembly may be arranged below the second piston assembly with respect to the bottom of the build module, the first piston assembly being disposed closer to the bottom (e.g., a floor) of the build module relative to the second piston assembly. The first piston assembly may be arranged below the second piston assembly with respect to a gravitational vector pointing towards a gravitational center. The first piston assembly comprises a first piston. The second piston assembly comprises a second piston. The first piston may be disposed (e.g., substantially) parallel to the second piston. The first piston may be disposed (e.g., substantially) concentric with the second piston. The circumference of the first piston and the second piston may be aligned. The first piston and the second piston may relate to each other by symmetry operations comprising an inversion point, a C ₂ symmetry axis, or a mirror symmetry plane. The inversion point, symmetry axis, and/or mirror symmetry plane may be disposed between the first piston and the second piston. The first piston assembly may be arranged directly below (e.g., without another intervening piston) the second piston assembly where a central axis of the first piston assembly is aligned with a central axis of the second piston assembly. The first piston assembly and the second piston assembly may have a (e.g., substantially) same FLS, e.g., diameter. The first piston assembly and the second piston assembly may have an FLS, e.g., diameter, that is (e.g., about) equal to an FLS of a build platform configured to engage with the build platform assembly. The first piston assembly and the second piston assembly may have an FLS (e.g., diameter) that is (e.g., about) equal or less than an FLS of the build module body, e.g, an inner diameter of the build module body. The first piston assembly (e.g., lower piston assembly that is closer to the floor of the build module housing) may have a surface that is substantially parallel to a surface of the second piston assembly. The surface may be perpendicular to the vertical axis. The surface may be perpendicular to the gravitational vector pointing towards gravitational center G of the environment. The second piston assembly may be configured to engage with a build platform. Engage with the build platform may comprise couple with, affixed to, supportive of, retain, or the like. For example, the second piston assembly (e.g., top piston assembly) may comprise an engagement mechanism to retain the build platform. The first piston assembly and/or the second piston assembly may (e.g., each) comprise a seal. The seal may be arranged about an outer diameter of the piston assemblies. The seal may be arranged between the piston assemblies and an inner surface of the build module body. The seal may be a gas tight seal. The seal may (e.g., substantially) prevent pre-transformed (and transformed) material from accessing a volume below the piston assemblies. The seal may be any seal disclosed herein. [0226] In some embodiments, the build platform assembly comprises one or more shafts, e g., as disclosed herein. One or more piston assemblies of the build platform assembly may be coupled with at least one shaft, e.g., operationally coupled such as physically coupled. A first piston assembly may be coupled with at least one shaft. A second piston assembly may be coupled with at least one shaft. The first piston assembly may be operationally coupled with the second piston assembly via the at least one shaft. A shaft may arranged and coupled concentrically along a direction (e.g., vertical axis) relative to the first piston assembly and with second piston assembly, e.g., the shaft may be a central shaft. One or more shafts may be arranged about a periphery of the first piston assembly and second piston assembly and along the direction, e.g., parallel to a vertical axis (e.g., along a gravitational vector). The shaft may comprise peripheral guide rods. For example, the shaft may be a central shaft, and the peripheral guide rods may be peripheral shafts. The guide rods may be any guide rods disclosed herein, e.g., a linear-bearing guide rod. The shaft may be any shaft disclosed herein. The shaft may comprise a translation mechanism such as a ball-screw jack or any other translation mechanism such as the ones disclosed herein. The shaft may comprise, or be operatively coupled with, an encoder, e.g., a servo motor. The shaft may comprise a precision right-angle gear box. The shaft may facilitate vertical and/or linear translation between the first piston assembly and the second piston assembly.

[0227] In some embodiments, the base (e.g., also referred to herein as “build platform” or “build plate”) and/or substrate (e.g., piston) is temperature adjusted (e.g., cooled). Temperature adjustment may be performed utilizing a temperature adjustment interconnects (e.g., a manifold, a heat sink, or a curved channel). Temperature adjustment interconnects may comprise a temperature adjustment agent such as a coolant. The coolant may be passive or active. A passive temperature adjuster (e.g., temperature adjustment agent) may comprise temperature conductive material, e.g., comprising copper, aluminum, or silver. The passive temperature adjuster may comprise a metallic rod or slab. The passive temperature adjuster may comprise a heat sink. The active temperature adjuster may comprise flowing gas, liquid, or semi-solid (e.g., gel). The active temperature adjuster may comprise flowing a coolant such as water. An active temperature adjuster may comprise flowing a material having a high heat capacity (e.g., water). Temperature adjustment interconnects may comprise one or more channels. Temperature adjustment interconnects may comprise a portion internal to one or more structures of the build platform assembly (e.g., internal volume of shaft(s), piston(s), or the like). Temperature adjustment interconnects may comprise a temperature adjustment chamber (e.g., cavity) that is a part of a piston assembly. For example, a temperature adjustment chamber that is a part of the substrate (e.g., piston). Temperature adjustment interconnects may comprise one or more passageways (e.g., channels) internal to the build platform assembly. For example, the one or more passageways may be internal to a portion of a piston assembly. For example, the one or more passageways may be internal to a portion of a build platform (e.g., build plate). The one or more passageways may comprise a serpentine passageway, spiral passageway, concentric passageways, or the like. The temperature adjustment interconnects may comprise one or more ports. The temperature adjustment interconnect may comprise one or more sensors (e.g., temperature sensor and/or pressure sensor). At times, one or more of a central shaft or peripheral shaft(s) are hollow. The peripheral shafts may be hollow. The central shaft may be hollow. One or more of the central shaft and/or peripheral shafts may be configured to accommodate one or more temperature adjusters such as channels. The coolant may flow in the channel(s) or be stationary. The coolant may be configured for high heat conductivity and/or capacity. For example, the coolant comprises water. The coolant may comprise gas. The gas may be the same or different than the gas in the build module and/or processing chamber. [0228] In some embodiments, the build platform assembly comprises a translation mechanism such as a telescopic unit. The telescopic unit may comprise telescopic cylinders, e.g., telescopic hydraulic cylinders. The telescopic unit may comprise a set of nested components configured to extend along an axis, e.g., in a vertical direction. Nested components may comprise rails. Nested components may comprise cylinders. The telescopic unit may comprise an actuator. The telescopic unit may have a first, retracted (compressed) state and a second, extended (uncompressed) state. An FLS of the retracted state (e.g., a length) may be less than about half the FLS of the extended state (e.g., the length). The FLS of the retracted state may be less than about 45%, 35%, 30%, 25%, 20%, 15%, or less of the extended state of the telescopic unit. The telescopic unit may be coupled with the build platform assembly, e.g., affixed to, supportive of, or otherwise operationally coupled with. The telescopic unit may be coupled with a base of the build module body. The telescopic unit may be coupled with a piston assembly of the build platform assembly. The telescopic unit may be coupled with a first piston assembly, e.g., a bottom piston assembly relative to a gravitational vector. The telescopic unit may be coupled with a surface of the first piston assembly and configured to vertically translate the first piston assembly by extending a length of the telescopic unit. The telescopic unit may be configured to adjust a vertical position of the build platform assembly with respect to the build module body, e.g., by extending/retracting a length of the telescopic unit. A range of travel of the telescopic unit (e.g., a range of vertical travel of the build platform assembly) may be limited by one or more sensors, e.g., limit switches. For example, sensor(s) located at a vertical top-most portion and/or a vertical bottom-most portion of the build module body (relative to a gravitational vector) may limit a travel of the telescopic unit. A range of travel of the telescopic unit (e.g., a range of vertical travel of the build platform assembly) may be limited by one or more physical stoppers. For example, physical stoppers located at a vertical top-most portion and/or a vertical bottom-most portion of the build module body (relative to a gravitational vector) may limit a travel of the telescopic unit. At times, the telescopic unit comprises telescopic hydraulic cylinders. The telescopic hydraulic cylinders may comprise two or more cylindrical components that are extendable/retractable along an axis, e.g., along the z-axis. The telescopic hydraulic cylinders may comprise an uncompressible liquid, e.g., oil, water, gel, or another uncompressible liquid. In some embodiments, the build platform assembly is devoid of a translation mechanism that is a telescopic unit.

[0229] In some embodiments, the build platform assembly may comprise a guide mechanism. The guide mechanism may comprise one or more guide rods (e.g., one or more rails, shafts, or the like). The guide rods may be vertical guide rods. At least one of the guide rods may (e.g., each) have, or are operatively coupled with, an encoder. At least one of the guide rods may facilitate control of the magnitude, direction and/or angle of elevation of the platform. At least one of the guide rods may be dense. In some embodiments, the guide rod may be hollow. At least one of the guide rods may comprise a channel. The channel may allow electricity, communication, and/or temperature adjuster to run through. The channel may allow electrical and/or communication cables to run through. The guide rods may comprise, or be coupled with, a nut. The guide mechanism may comprise one or more (e.g., linear) bearings, columns, or scissor guides. The guide mechanism may comprise any translational mechanism disclosed herein. The guide mechanism may comprise, or be operatively coupled with, a linear motor. The guide rod may be coupled (e.g., connected) to the substrate (e.g., piston) and/or bottom of the build platform. The guide mechanism may comprise, or be operatively coupled with, an actuator such as a motor. The guide mechanism may comprise, or be operatively coupled with, a screw. The actuator may be operatively coupled with (e.g., connected to) the screw. The actuator may be controlled by one or more controllers, e.g., any controller disclosed herein. The build platform assembly may comprise, or be operatively coupled with, an encoder. The encoder may facilitate controlling (e.g., monitoring) the (e.g., relative) vertical position of the platform. The encoder may span the (e.g., allowed) motion region of the build platform assembly or any components thereof. For example, the encoder may span the motion region of the second (e.g., upper) piston assembly. In some embodiments, the actuator causes a translation. The actuator may cause a vertical translation such as an incremental vertical translation. The vertical translation may comprise the initiation, block, or layerwise translation, e.g., as disclosed herein. The build platform assembly may comprise one or more vertical actuators.

[0230] In some embodiments, the build module comprises a build platform assembly. The build platform assembly may be supportive of a platform, e.g., a build platform and/or substrate. The build platform assembly may comprise one or more sensors. The build platform assembly may comprise one or more supportive structures, e.g., guide rods, shafts, rails, or the like. The build platform assembly may comprise at least one piston assembly. The piston assembly may comprise at least one piston. The build platform assembly may comprise two or more piston assemblies. The build platform assembly may comprise at least two piston assemblies, or at least three piston assemblies. The build platform assembly may comprise a first piston assembly and a second piston assembly (e.g., a lower piston assembly and an upper piston assembly). At times, the build platform assembly provides a range of linear translation (e.g., precision linear translation) between the first piston assembly and second piston assembly. The first piston assembly and the second piston assembly may be coupled by a shaft. The shaft may comprise an encoder, e.g., any encoder recited herein. The shaft may comprise a lead screw (e.g., with a nut).

[0231] In some embodiments, the build platform assembly comprises a first piston and a second piston. The pistons may be disposed parallel and concentrically relative to each other. The pistons may be similar by at least one characteristic. The pistons may be different by at least one characteristic. The piston characteristic may include horizontal location, vertical location, circumference, material, functionality, rigidity, or shape. For example, the first piston and the second piston may have the same horizontal location, the same circumference, be parallel to each other, and be concentrically aligned. For example, the first piston and the second piston may differ from each other in their vertical location, their shape, their functionality, and their interconnectivity. For example, the first piston may facilitate coupling to a build platform, and optionally facilitate temperature conditioning of the build platform. For example, the coupling between the first piston and the build platform may enclosure a cavity disposed therebetween that is utilized for temperature conditioning. The cavity may be in the second piston, in the build plate, or in both the second piston and the build plate. For example, the first piston may comprise one or more openings, e.g., to facilitate movement of guide rods and shaft therethrough, to facilitate a sensing beam therethrough, or any combination thereof. For example, the first piston may be operatively (e.g., physically) coupled with an encoder and/or to an actuator. For example, the second piston may be operatively coupled with a detector. The first piston and/or the second piston may be coupled with, or include, a rigidity enhancing structure to enhance the rigidity of the respective piston, e.g., during operation.

[0232] Fig. 10 depicts schematic views of 3D printing system components. As depicted in Fig. 10, a build platform assembly 1000 includes a first piston assembly 1002 and a second piston assembly 1004. First piston assembly (e.g., also referred to herein as a “lower” piston assembly) is arranged closer to a gravitational center along gravitational vector 1090 than the second piston assembly (e.g., also referred to herein as an “upper" piston assembly). First piston assembly 1002 and second pistons assembly 1004 each include a respective piston 1006, 1008. First piston assembly 1002 and second pistons assembly 1004 each include respective (internal) engagement mechanisms 1010 and 1012. The engagement mechanisms 1010 and 1012 may be any engagement mechanism disclosed herein configured for disposing in the build module during operation. As depicted in Fig. 10, any of the engagement mechanisms 1010 and 1012 can comprise an engagement mechanism using force comprising a hydraulic, a pneumatic, an electric, a thermal, or a magnetic, force. In an example, the engagement mechanism comprises a pneumatic engagement mechanism. In an example, the engagement mechanism comprises a hydraulic engagement mechanism. The engagement mechanism may be configured to engage the piston assembly with a support such as an internal surface of a build module body. Build platform assembly 1000 includes a central shaft, e.g., a ball-screw-jack 1014, coupled between the first piston assembly 1002 and second piston assembly 1004. The ball-screw-jack comprises a drive screw 1015 and a nut 1017, where an actuator 1018 (e g., a servo motor) turns the nut 1017 with respect to the screw 1015 to translate the drive screw 1015 vertically. The first piston of the first piston assembly comprises openings 1082 and 1081 a-c that facilitated movement of shaft 1014 and guide rods 1022a-c therethrough respectively, e.g., as the second piston assembly progresses downwards in a layerwise movement. A seal may be disposed between the guide rod (e.g., 1022a) and its respective opening at the first piston assembly (e.g., 1081a). A seal may be disposed between central shaft 1014 and its respective opening 1082 at the first piston assembly 1002 that is analogous to first piston assembly 1052. The actuator 1018 comprises, or is operatively coupled with, an encoder 1016. Encoder can be any encoder disclosed herein. For example, encoder is an optical encoder. The encoder is coupled with an actuator 1018. Actuator 1018 can be any actuator disclosed herein. For example, actuator 1018 can be a servo motor. The actuator 1018 is coupled with the ball-screw-jack by a gear box 1020, e.g., by a coupler. Gear box can be, for example, a precision 1 :1 right angle gear box. Build platform assembly 1000 includes guide rods 1022 (also referred to herein as “guideposts”). Guide rods 1022a, 1022b, and 1022c can be any guide rods disclosed herein. Any of guide rods 1022a-c may be hollow, e.g., to facilitate circulation of a temperature adjuster (e.g., coolant) through a temperature adjustment interconnect including an internal portion of the build platform assembly. Any of guide rods 1022a-c may be dense (e.g., not hollow). Guide rod 1022s included a port 1024, e.g., to facilitate circulation of a temperature adjuster (e.g., a coolant) through an internal portion of the temperature adjustment interconnect such as to circulate water or gas. At times, build platform assembly comprises or is coupled with a build platform 1026, e.g., a build plate. Build platform can be supported by (e.g., engaged with) the second piston assembly 1004. First piston assembly 1002 and second piston assembly 1004 can translate, e.g., translate vertically, with respect to each other, e.g., along a length of the drive screw 1015 of the ball-screw-jack 1014. [0233] As depicted in the example shown in Fig. 10, a build platform assembly 1050 includes a first piston assembly 1052 and a second piston assembly 1054 having openings 1081 a-c, and opening 1082. First piston assembly 1052 includes openings 1056, 1057 through a body of the first piston 1058 of first piston assembly 1052. Any of the openings 1056 and 1057 may be equipped with an optical window. Second piston assembly 1054 includes at least one metrological detector 1060, e.g., any metrological detector disclosed herein. The metrological detector 1060 (e.g., optical detector) may be arranged on a surface 1062 of a second piston 1064 of the second piston assembly 1054 such that the metrological detector is disposed to and facing an opening 1056 of the first piston assembly 1052. Metrological detector 1060 and opening 1056 are aligned along a z-axis (e.g., along gravitational vector 1090). Build platform assembly 1050 includes ports 1068a-b, and 1070a-b coupled with one or guide rods 1072a-b, respectively. The ports may be utilized to facilitate circulation of the temperature adjuster (e.g., temperature adjustment agent) through an internal portion of a temperature adjustment interconnect. At times, some of the ports are coupled with a first passageway (e.g., channel) for a first temperature adjuster (e.g., water circulation), and other ports are coupled with a second passageway for a second temperature adjuster (e.g., gas circulation). Any of the piston may have a rigidity enhancing structure, e.g., that deters deformation (e.g., bending or buckling) of the piston such as during operation of the piston. Fig. 10 shows an example of rigidity enhancing structure 1085 that can be coupled with, or be part of, second piston 1064.

[0234] Fig. 11 depicts a schematic view of example 3D printing system components. A build module 1100 comprises a build platform assembly 1102. Build module 1100 includes a build module body 1104 having a housing 1106 and a bottom portion 1108 (e.g., floor of the build module body). Housing 1106 includes an inner wall 1110. Build platform assembly 1102 can be retained within housing 1106 and reversibly contact the inner wall 1110 of the housing 1106, e.g., using engagement mechanisms 1112, 1114. Bottom portion 1108 includes a plurality of interconnects 1116, e.g., any interconnect disclosed herein. The plurality of interconnects 1116 may comprise, or be operatively coupled with, one or more controllers (not shown). The one or more controllers may be operable to control operations of one or more components of the build module, e.g., interconnects, build platform assembly (or any component thereof), metrological detection systems (e.g., encoders), valves, motors, and the like. The one or more controllers may be operable to control processes of the build module, as described herein. The one or more controllers may be any controller described herein. Bottom portion 1108 includes guide-posts 1118 configured to limit an extent of travel of the build platform assembly 1102 with respect to the bottom portion 1108. For example, to prevent the build platform assembly 1102 from colliding components of the build platform assembly 1102 with bottom portion 1108. Bottom portion 1108 includes components 1120 of a metrology detection system, e.g., an energy source, detectors, optical components, or the like. Bottom portion 1108 comprises, or is operationally coupled with, a translational mechanism that includes a telescopic unit 1124. Telescopic unit 1124 is arranged to extend along a central axis (e.g., z-axis) 1128 of the build module 1100, e.g., aligned with gravitational vector 1190. Telescopic unit 1124 is coupled with a surface 1126 of build platform assembly 1102 and aligned with a central axis 1128 of the build platform assembly. The telescopic unit may be actuated by a force comprising a hydraulic, pneumatic, electric, or magnetic force. In an example, the telescopic unit is actuated using a hydraulic force. Build module 1100 comprises a kinematic mounting platform 1130. Kinematic mounting platform 1130 includes support channels 1132, e.g., to assist with supporting the build module 1100. Build platform assembly 1102 comprises a first piston assembly 1134 and a second piston assembly 1136. A volume (e.g., intermediate space) between the first piston assembly 1134 and second piston assembly 1136 may comprise a bellows 1138 configured to protect from (e.g., prevent) contamination within the volume. Build platform assembly 1102 can comprise, or be operatively coupled with, a build platform 1140. The telescopic unit is an optional unit. The build platform assembly may be configured to translate without the telescopic unit, e.g., with or without a substitute (e.g., an equivalent mechanism) to the telescopic unit. [0235] Fig. 12 depicts example views of 3D printing system components. A build module 1200 comprises a build platform assembly 1202. The build platform assembly 1202 is arranged within a build module body 1204. As depicted in Fig. 12, build platform assembly 1202 is located adjacent to a bottom portion 1206 (e.g., floor) of the build module body 1204. The build platform assembly 1202 is located at a bottom-most point of travel, with respect to a gravitational center (e.g., aligned with gravitational vector 1290 pointing towards gravitational center G) such that a build platform 1228 engaged with the build platform assembly is located at a position 1222. When the build platform 1228 is located at position 1222, the build platform assembly 1202 contacts guideposts 1208 that limit an extent of vertical translation of the build platform assembly 1202. A bottom portion limit switch (not shown) may limit the extent of vertical translation of the build platform assembly 1202 adjacent to the bottom portion 1206 of the build module body 1204. Bottom portion 1206 includes interconnects 1207, e.g., any interconnect disclosed herein. Bottom portion 1206 includes, or is operatively coupled with, one or more controllers (not shown) that may be operable to direct operations of one or more components of the build module 1200. Build platform assembly 1202 includes a first piston assembly 1216 and a second piston assembly 1214. Build platform assembly 1202 includes a bellows 1205. The second piston assembly 1214 is arranged with respect to the first piston assembly 1216 and can translate with respect to the first piston assembly 1216 by a vertical distance 1220. The vertical distance 1220 can correspond to a full length of travel of the second piston with respect to the first piston along a shaft coupled between the first and second pistons. The build module 1200 includes an optional translation mechanism that is a telescopic unit 1226. The telescopic unit 1226 is configured in a non-extended state (e.g., compressed state). When the telescopic unit 1226 in a non-extended state, a distance 1230 between the bottom portion 1206 of the build module body 1204 and a bottom surface of the first piston assembly 1216 may correspond to a bottom-most point of travel of the build platform assembly 1202. As depicted in Fig. 12, a build module 1250 includes a telescopic unit 1252 telescopic unit 1226 that is configured in an extended state. The telescopic unit is coupled with a build platform assembly 1254, e.g., coupled with a bottom surface of a first piston assembly 1262. The extended state corresponds to a distance 1253 between a bottom portion 1251 of the build module body 1256 and the bottom surface of a first piston assembly 1262. A limit switch (not shown) located at a top-most point (e.g., with respect to a gravitational center) of travel of the build platform assembly 1254 along the build module body 1256, can limit the travel of the build platform assembly 1254. After the initiation translation to a second position 1258, an engagement mechanism 1260 of the first piston assembly 1262 may be reversibly engaged (e.g., engaged and disengaged) with respect to the build module body 1256. Optionally, a second piston assembly 1264 is translated (e.g., in a layerwise translation) relative to the build module body 1256 to align a build platform 1266 engaged with the build platform assembly 1254 to an initiation position for the 3D printing process. At times, an initiation position corresponds to second position 1258.

[0236] In some embodiments, the build platform assembly comprises at least one engagement mechanism, (e.g., also referred to herein as a “locking mechanism”). The engagement mechanism may be configured to stabilize a position of a piston assembly relative to a build module body, relative to a build platform assembly, or a combination thereof. The build platform assembly may comprise (e g., at least one) engagement mechanism to affix a position of the build platform assembly with respect to a support of the build module. The support of the build module may comprise a wall (e.g., an inner surface of the wall) of the build module body. The build platform assembly may translate along an axis (e.g., along a z-axis) with respect to the build module body. The axis may be a vertical axis, the axis may be along the gravitational vector pointing to gravitational center G of the environment. Translation with respect to the build module body may comprise reversibly engaging and disengaging an engagement mechanism of the build platform assembly. The engagement mechanism may be reversibly engaged with the support. For example, the engagement mechanism reversibly engage and disengage with (I) a surface of the support, (II) indentations in the support, (III) protrusions in the support, (IV) railing in the support, or (V) guides (e.g., screw guides) in the support. The support may comprise a body of the build module. For example, the engagement mechanism reversibly engage and disengage with (I) an inner wall surface of the build module body, (II) indentations in the inner wall of the build module, or (III) protrusions in the inner wall of the build module. The engagement mechanism may comprise a holding force between the engagement mechanism and the support. The holding force may depend, at least in part, on a material of the engagement mechanism and of the support. The holding force requested between the engagement mechanism and the support may depend at least in part on a geometry between the engagement mechanism and the support. For example, a surface of the support may have one geometry and the engagement mechanism may have a second geometry complementary to the one geometry. The complementary geometry may facilitate pressing the engagement mechanism onto the support by a (e.g., substantially) even force along the engagement mechanism and/or the contacting support portion. For example, an inner surface of the build module body may have a first geometry and the engagement mechanism may have a second geometry complementary to the first geometry. The complementary geometry may facilitate pressing the engagement mechanism onto the inner surface by a (e.g., substantially) even force along the engagement mechanism and/or the contacting portion of the inner surface of the build module. An (e.g., substantially) even force may refer to a (e.g., substantially) homogenous force. For example, the geometry may comprise a cylindrical inner wall of the build module body and a cylindrical engagement mechanism. The various points on the cylindrical engagement mechanism may exert a (e.g., substantially) homogenous force on the inner wall of the build module portion which it contacts. The holding force requested between the engagement mechanism and the support may depend in part on a weight of a material bed and/or 3D object(s) supported by the build platform engaged with the build platform assembly. The engagement mechanism may comprise a holding force of at least about 2200 kilograms (kg), 2500 kg, 2700 kg, 3200 kg, 3800 kg, 4500 kg, 9000 kg, 13,000 kg, 16,000 kg, 18,000 kg, 20,000 kg, 22,000 kg, 23,000 kg, or 25,000 kg. or more between the engagement mechanism and a support, e.g., the inner wall of the build module body. The holding force may comprise any value between the aforementioned values, for example, between about 2200 kg and 20000 kg, between about 2500 kg and 23,000 kg, or between about 2700 kg and 25,000 kg. The engagement mechanism may comprise a coefficient of friction between the engagement mechanism and the support that may depend, in part, on a material of the engagement mechanism and of the support. The engagement mechanism may comprise a coefficient of friction of at least about 0.25, 0.35, 0.5, 0.6, 0.75, 0.9, 1.0, 1.15, 1 .25, 1 .35, 1 .5 or more between the engagement mechanism and a support, e.g., the inner wall of the build module body. The coefficient of friction may be any value between the aforementioned values, for example, between about 0.35 and 0.75, between about 0.25 and 1.35, or between about 0.6 and 1.5. The engagement mechanism may reversibly restrict, affix, hold, halt, stop, deter, or otherwise (e.g., substantially) prevent a movement of at least a portion of the build platform assembly. Disengagement of the engagement mechanism may release, un-restrict, or otherwise allow a movement of at least a portion of the build platform assembly. Disengagement of the engagement mechanism may comprise allowing a (e.g., substantially) uninhibited translation of the build platform assembly relative to the build module body. At times, the engagement mechanism may cause a translation of at least portion of the build platform assembly during or after engagement or disengagement of the engagement mechanism. The engagement mechanism may cause a translational error of a piston assembly of the build platform assembly during, or after, engagement/disengagement of the engagement mechanism. A translation error may be a shift about an XY plane of the build platform assembly (e.g., about a plane perpendicular to a gravitational vector). A translation error may be a rotational shift about a central vertical axis of the build platform assembly (e.g., relative to an axis parallel to a gravitational vector). A translation error may a vertical shift of the build platform assembly (e.g., along an axis parallel to the gravitational vector). A translation error may be a pitch, yaw, and/or roll shift of the build platform assembly, e.g., of the build platform engagement with the build platform assembly, relative to an XY plane perpendicular to the gravitational vector. The translational error may comprise an error in the X axis, Y axis, and/or Z axis, with XYZ designating a Cartesian coordinate system. An amount of translation error may depend, in part, on a type of engagement mechanism utilized. The engagement mechanism may comprise a magnetic, electric, electrostatic, hydraulic, pneumatic, thermal, or mechanical force. The engagement mechanism may comprise a deformation engagement mechanism that may reversibly distort (e.g., expand and contract) to apply a force such as a force on side wall(s) of the build module body. The engagement mechanism may comprise a fastening engagement mechanism that may comprise reversibly engageable moving parts to apply a force. The moving parts may be fasteners. The moving parts may reversibly move in and out of receptacles (e.g., crevices, holes, or indentations) such as to facilitate the reversible engagement and disengagement, respectively. For example, a fastening engagement mechanism may comprise (i) pins and respective holes, or (ii) a hydraulic deformation engagement mechanism and respective surface. The translation error due to engagement/disengagement of the engagement mechanism can be at most about 0.075 millimeters (mm), 0.05 mm, 0.025 mm, 0.02 mm, 0.01 mm, 0.005 mm, 0.0025 mm, 0.002 mm, 0.001 mm, or less. The translation error may be a vertical translational error. The translation error may be a horizontal translational error. The translation error may comprise a vertical or a horizontal translational error. The build platform assembly may comprise at least one engagement mechanism. The build platform assembly may comprise two or more engagement mechanisms. The engagement mechanisms may be a same type or a different type. Each piston assembly of the build platform assembly may comprise a respective engagement mechanism. The build module body may comprise an engagement mechanism configured to reversibly engage and disengage with the build platform assembly. Engagement and/or disengagement of the engagement mechanisms of the piston assemblies may be coordinated. The coordination may be in action, and/or in time. For example, the engagement and/or disengagement of the first piston assembly and of the second piston assembly may be coordinated. For example, the initiation movement may be coordinated (i) with the layerwise movement and/or (ii) with the block movement. For example, the block movement and the layerwise movement may be coordinated. The engagement mechanism may comprise (A) a deformation engagement mechanism, (B) a fastening engagement mechanism, (C) a magnetic engagement mechanism, or (E) any combination thereof.

[0237] In some embodiments, the engagement mechanism comprises a deformation engagement mechanism. The deformation mechanism may comprise a locking ring configured to lock a piston mechanism with respect to a surface, e.g., internal surface of vertical wall(s) of the build module body. The locking ring of the engagement mechanism may reversibly deform such as reversibly expand and contract. When the locking mechanism expands against the surface, the locking mechanisms may be affixed to the surface; and when the locking mechanism contracts, the locking mechanisms may be released from the surface. The (reversible) expansion and (reversible) contraction may utilize any force disclosed herein, e.g, comprising electric, pneumatic, hydraulic, or magnetic force. For example, a force bringing about thermal, electric (e.g., piezoelectric), pneumatic or hydraulic deformation. The deformation engagement mechanism may comprise a locking system, e.g., a locking ring. In an example, the locking system comprises a hydraulic locking system, e.g., a hydraulic locking ring. In an example, the locking system comprises a thermal locking system, e.g., a thermal locking ring. In an example, the locking system comprises a piezoelectric system (e.g., using a reverse piezoelectric effect), e.g., a piezoelectric locking ring. At times, each piston assembly of the build platform assembly comprises a respective (e.g., hydraulic) deformation engagement mechanism. The deformation engagement mechanisms may be separately engaged and disengaged reversibly. The deformation engagement mechanism may be (e.g., substantially) simultaneously engaged and disengaged reversibly. Engaging the deformation engagement mechanism may comprise pressurizing or depressurizing a component of the deformation engagement mechanism. Disengaging the deformation engagement mechanism may comprise pressurizing or depressurizing a component of the deformation engagement mechanism. A pressure, e.g., hydraulic pressure, may comprise at most about 17,500 kilo-Pascals (kPa), 15,000 kPa, 10,000 kPa, 7500 kPa, 5000 kPa, 2500 kPa, 1750 kPa, or less. The pressure may be any value within the aforementioned values, for example, from about 17,500 kPa to about 2500 kPa, from aboutl 5,000 kPa to about 1750 kPa, or from about 15,000 kPa to about 2500 kPa. The (e.g., hydraulic) deformation engagement mechanism may comprise a component configured to reversibly expand and contract when the engagement mechanism is engaged and disengaged. For example, when the component is expanded, the deformation engagement mechanism is engaged with the support (e.g., inner surface of the build module). For example, when the component is contracted, the deformation engagement mechanism is disengaged from the support (e.g., inner surface of the build module). At times, when a force (e.g., pressure, electricity, or temperature) is applied to the deformation engagement mechanism, a component of the deformation engagement mechanism expands to apply pressure against a support, e.g., apply a holding force against a surface of an inner wall of the build module body. When a force is applied to the deformation engagement mechanism, a component of the deformation engagement mechanism contracts to release the force (e.g., pressure and/or friction) between the piston assembly and the support, e.g., remove a holding force from an inner wall of the build module body such that the piston assembly is no longer affixed to the support. For example, when a pressure is applied to the deformation engagement mechanism, a component of the deformation engagement mechanism contracts to release a pressure between the piston assembly and the support, e.g., remove a holding force from an inner wall of the build module body. For example, a component of the (e.g., hydraulic) deformation engagement mechanism may form an envelope surrounding a circumference of a piston assembly such that applying/removing a pressure to the engagement mechanism causes the envelope to reversibly expand/contract with respect to the piston assembly and the inner wall of the build module body. When the piston is disk shape (e.g., has a circular horizontal cross section), the envelope may adopt the shape of a cylinder wall or a ring. The envelope may be referred to herein as the “locking ring.” The (e.g., hydraulic) engagement mechanism may or may not comprise a same material as the support, e.g., a same or a different material as that of the build module body.

The engagement mechanism may comprise a material having a coefficient of thermal expansion that is (substantially) similar or the same as a material of the support, e.g., of the build module body. For example, the engagement mechanism may comprise steel, stainless steel, aluminum, ceramic, or any other material recited herein.

[0238] In some embodiments, the disclosure regarding the deformation engagement mechanism is adapted to other forces, e.g., as disclosed herein. For example, a thermal engagement mechanism. For example, an electrical engagement mechanism. For example, any force that may (e.g., reliably, and reproducibly) induce reversible expansion and contraction of a material configured as disclosed herein. The reversible engagement and disengagement of the engagement mechanism may be controlled manually and/or automatically, e.g., using a control system such as disclosed herein. [0239] In some embodiments, the deformation engagement mechanism comprises a locking system, e.g., locking ring(s). The locking system may comprise a ring having a band width and a machined cavity into a thickness of a wall of the band, where the ring may be affixed (e.g., welded) about an outer surface of a piston housing of a piston assembly. The locking system may comprise a ring having a diameter that is at least the same or greater size than an outer diameter of a piston of the piston assembly. The ring may have an FLS, e.g., a band width, thickness, diameter, or the like, that is about 1.25 millimeters (mm), 2 mm, 2.5 mm, 6 mm, 12 mm, 25 mm, 50 mm, 100 mm, 200 mm, 250 mm, 300 mm, 350 mm, 400 mm, 500 mm, 550 mm, 600 mm, 700 mm, 750 mm, 900 mm, or 1025 mm. The ring may have an FLS that is any value between the aforementioned values, for example, between aboutl .25 mm and 35 mm, between about 50 mm and 300 mm, or between about 500 mm and 1025 mm. The deformation engagement mechanism may be hydraulic. Hydraulic fluid may be introduced (e.g., pumped) into a cavity defined between the machined cavity in the wall of the ring band and the outer surface of the piston housing. The introduction of hydraulic fluid into the cavity may cause a portion of the ring to deform, e.g., a portion of the band of the ring. For example, the introduction of hydraulic fluid into the cavity may cause a portion of the ring to expand and contact an inner wall of the build module body. A portion of the ring surface in contact with the inner wall of the build module body may be at least about 40%, 45%, 50%, 55%, 60%, 75%, 90%, or more. For example, the portion of the ring surface in contact with the inner wall of the build module body may be any value between the aforementioned values, e.g., from about 40% to about 75%, from about 50% to about 90%, or from about 45% to about 60%. A deformation of the band of the ring may comprise a deflection of a portion of the band of the ring. The deflection of the band of the ring may be sufficient for the portion of the band of the ring to make physical contact with the inner wall of the cylinder. The deflection can be any value described herein related to an FLS of the engagement mechanism, for example, at least about 0.005 inches (“), 0.010”, 0.015”, 0.02”, or more. An amount of surface area of the ring in contact with the inner wall of the build module body may dictate, in part, an amount of force (e.g., hydraulic pressure) applied by the engagement mechanism on the inner wall of the build module body. In some embodiments, an amount of pressure induced may be selected to minimize a pressure/stress on the ring while maximizing a deformation of the portion of the ring without (substantially) exceeding a yield stress of the ring material. For example, in the case of a hydraulic deformation engagement mechanism, the pressure induced may be by introducing hydraulic fluid into the cavity. The pressure induced, such as by introducing hydraulic fluid into the cavity, can be about any pressure value disclosed herein.

[0240] In some embodiments, an engagement mechanism comprises a fastening engagement mechanism, e.g., comprising mechanical pad(s). A fastening engagement mechanism may comprise a plurality of engagement features such as pads; e.g., break pads. A plurality of engagement features may comprise at least about 2 engagement features, 3 engagement features, 4 engagement features, 5 engagement features, 6 engagement features, 8 engagement features, 10 engagement features, 12 engagement features, or more. The plurality of engagement features may comprise brake pads. Each piston assembly may comprise a plurality of fastening engagement mechanism. The plurality fastening engagement mechanisms may work sequentially and synchronously with each other. A (e.g., vertical and/or horizontal) cross-sectional shape of the engagement feature may comprise a rectangular, circular, polygonal, a geometric shape, a regular shape, or an irregular shape (e.g., 3D shape). A surface of the engagement feature configured to engage with the interior surface of the build module body (e.g., wall thereof), may have a complementary shape to the build module body surface. A surface of the engagement feature configured to engage with the interior surface of the build module body (e.g., wall thereof), may have a shape sufficient to hold the piston assembly in place while the piston supports the printed 3D object and/or starting material used to print the 3D object, e.g., without slippage. The build module body surface may have a smooth (e.g., polished) internal surface. The build module may or may not have structural features configured to align the build platform assembly with respect to the build module body during operation. The structural features may comprise depressions (e.g., indentations) or protrusions. The build module body may have a surface having an Ra (arithmetic average of profile height deviations from the mean line) of at most about 10 micrometers (pm), 20pm, 50pm, or 100pm, the surface excluding these structural features. The surface of the engagement feature configured to couple with the internal surface of the build module may have an Ra value of at most about 10 micrometers (pm), 20pm, 50pm, or 100pm. An FLS of the engagement feature may be at least about 25 millimeters (mm), 50 mm, 75 mm, 100 mm, 110 mm, 115 mm, 120 mm, 130 mm, 145 mm, or more. An FLS of the engagement feature may be any value between the aforementioned values, for example, between about 25 mm and about 120 mm, between about 50 mm and about 130 mm, between about 100 mm and about 145 mm, where the term “between” is inclusive. The plurality of engagement features may be distributed (e.g., substantially) about a circumference of a housing of a piston of the piston assembly. The distribution may be an even distribution, e.g., equidistance distribution of the engagement features along the circumference. The plurality of engagement features may be distributed unevenly about an outer circumference of the housing of the piston of the piston assembly. At times, the plurality of engagement features may be distributed about an inner circumference of the build module body. The plurality of engagement features may be distributed (e.g., substantially) evenly about the inner circumference of the build module body. The plurality of engagement features may be distributed unevenly about the inner circumference of the build module body. The plurality of engagement features may be distributed along a length of the build module body, e.g., each engagement feature set being of an other piston of the build module assembly pistons. The plurality of engagement features may be distributed on an inner wall of the build module body along two horizontal sections, each horizontal section associated with another piston of the build platform assembly. The plurality of engagement features may be distributed along an external surface of the build platform assembly to facilitate (e.g., reversible) engagement and disengagement with an inner surface of the build module body, e.g., and enable the build platform assembly to move vertically along the build module wall(s) in a motion such as a stepwise motion. The plurality of engagement features may reversibly engage and disengage with a support, e.g., with an inner wall of the build module body. The plurality of engagement features may reversibly engage and disengage with the support by applying a holding force (e.g., substantially) perpendicular to a gravitational vector of the 3D printing system. The reversible engagement and disengagement of the engagement features may be controlled by a control system, e.g., such as disclosed herein. The (fastening) engagement mechanism of the engagement features may comprise an actuator. An actuator may be any actuator disclosed herein. For example, an actuator may be a motor, e.g., a servomotor. The actuator may be operatively coupled, or may comprise, a gear. For example, an actuator may be a pneumatic actuator. The actuator may comprise a hydraulic actuator, a hydraulic actuator, a magnetic actuator, or an electric actuator. The engagement mechanism may compromise a (e.g., pivotable) ring (e.g., wheel), an engagement piston, or a lead screw. The engagement piston is a secondary piston different from the first piston and second piston. The engagement mechanism may be configured to press at least two of the engagement features (e.g., substantially) simultaneously to engage a piston of the build platform assembly (e.g., of the first piston and second piston) with vertical wall(s) of the build module body. The engagement mechanism may be configured to retract at least two of the engagement features (e.g., substantially) simultaneously to disengage a piston from the vertical wall(s) of the build module body. The actuator may rely on any force disclosed herein, e.g., utilized by the engagement mechanism. (Reversibly) engaging the plurality of engagement features with the inner wall of the build module body may comprise contacting (e.g., physically contacting) respective surfaces and/or receptacles of the plurality of engagement features with the inner wall of the build module body or (II) separating (e.g., physically separating) respective surfaces and/or receptacles of the plurality of engagement features from the inner wall of the build module body. (Reversibly) disengaging the plurality of engagement features with the inner wall of the build module body may comprise separating (e.g., physically separating) respective surfaces and/or receptacles of the plurality of engagement features from the inner wall of the build module body. (Reversibly) engaging the plurality of engagement features with the inner wall of the build module body may comprise applying a holding force by the plurality of engagement features on the inner wall of the build module body. (Reversibly) disengaging the plurality of engagement features from the inner wall of the build module body may comprise retracting a holding force by the plurality of engagement features from being applied on the inner wall of the build module body. A surface area of the plurality of engagement features may reversibly contact a support (e.g., an inner wall of a build module body and/or a surface of a piston of the build platform assembly) to apply the holding force, e.g., as described herein. A surface area of the plurality of engagement features may reversibly separate from the support (e.g., an inner wall of a build module body and/or a surface of a piston of the build platform assembly) to release the holding force, e.g., as described herein. A value of the holding force may be any value of a holding force described herein. A material of the plurality of engagement features may be any material described herein. The material of the plurality of engagement features may be (e.g., substantially) the same material as a material of the build module body. In an example, the material of the plurality of engagement features comprises aluminum, steel, ceramic, or the like. The engagement feature may or may not comprise a brake pad. The engagement feature may comprise a plate, a claw, or a jaw. The engagement feature may be a planar piece having a thickness (e.g., substantially) smaller than the FLS of the planar cross section. A engagement feature (e.g., each engagement feature) may move about an axis, e.g., to facilitate reversible engagement and disengagement. The axis may be located unsymmetrically with respect to the engagement feature. The engagement feature may be operatively coupled with at least one controller, e.g., to the control system. The movement of the engagement feature may comprise a linear motion, e.g., pushed by a pin operatively coupled with the engagement feature. The movement of the engagement feature may comprise swiveling or rotation motion. The motion of the engagement feature may be controlled, e.g., by at least one controller such as using the control system disclosed herein. The movement of the engagement feature may be into a receptacle or out of a receptacle. The movement of the engagement feature (e.g., pad) may be to compress and retract from an internal surface of the build module body.

[0241] In some embodiments, an engagement mechanism comprises a fastening engagement mechanism, e.g., comprising mechanical pin(s). A fastening engagement mechanism may comprise a plurality of engagement features. Engagement features may comprise, for example, pads, pins, posts, flanks, supports, or the like. Engagement features may be reversibly retractable and expandable, to engage and disengage the engagement mechanism with the support. The build platform assembly may comprise a plurality of engagement features, e.g., a plurality of pins. A cross-section of the engagement features may comprise circular, ellipsoid, rectangular, polygonal, a geometric shape, a regular shape, or an irregular shape (e.g., 3D shape). The build module body may comprise a plurality of engagement features, e.g., a plurality of pins. At least two of the engagement features (e.g., pins) may be operatively (e.g., physically) coupled directly or indirectly with an actuator. Indirect coupling of the engagement features may be through a lead screw, an engagement piston, or a (e.g., pivotable) ring (e.g., wheel). Indirect coupling of the engagement features may be through a (e.g., pivotable) ring, e.g., a wheel. The engagement mechanism may be configured to reversibly extend and contract the engagement features (directly or indirectly) coupled with it. The ring may be pivotable about a central axis of the build module and/or of the build platform assembly. At times, the build platform assembly comprises a plurality of engagement features. The engagement features may comprise, or may be operatively coupled with, flat supports (e.g., pads) where a portion of the build platform assembly is resting at least in part on the flat support(s). The flat support(s) may be located such that a bottom portion of the piston assembly (relative to a gravitational vector), rests on the flat supports. The engagement features may reversibly engage and disengage with corresponding receptacles, e.g., holes, crevices, slots, or the like. The receptacles may restrict movement of the engagement mechanism about an internal space of the receptacle. Engaging an engagement feature may comprise sliding (inserting) an engagement feature into a corresponding receptacle. For example, sliding a pin into a hole or a slot. Disengaging the engagement feature may comprise removing the engagement feature from the corresponding receptacle, or reversing the movement with respect to the receptacle. For example, removing the pin from the hole. For example, moving the hole in a reverse direction with respect to the pin. Engaging an engagement feature may comprise rotating, swinging, pivoting, or the like, into or with respect to an engaged (e.g., supportive, restricting) position with respect to a receptacle. For example, engaging a flat support comprises rotating the flat support into a corresponding receptacle (e.g., a beveled feature, a slotted feature, or the like). The movement of the engagement features may be manually and/or automatically controlled, e.g., by at least one controller such as the control system disclosed herein. A plurality of receptacles may be located along the engagement feature, e.g., along the (e.g., pivotable) ring such as along the wheel.

[0242] In some embodiments, the build module may comprise a seal. In some embodiments, the build platform assembly may comprise a seal. The seal may be configured to reduce contamination of the engagement features and/or receptacles with pre-transformed and transformed material, e.g., during operation. At times, the fastening engagement mechanism may comprise a plurality of seals configured to reduce contamination of the engagement features and/or receptacles with pre-transformed and transformed material. The plurality of seals may comprise shutters, covers, stoppers, flaps, pins, bellows, or the like. The seals may comprise any seal disclosed herein. The plurality of seals can be configured to be engaged and disengaged to expose one or more of the engagement features and/or receptacles, e.g., to selectively expose one or more of the engagement features and/or receptacles. The fastening engagement mechanism may comprise an actuator. The actuator may be any actuator disclosed herein, e.g., control by at least one controller such as the control system. The actuator may be coupled with one or more of the plurality of engagement features, receptacles, and/or seals. The actuator may be operable to sequentially engage and disengage one or more of the engagement features, receptacles and/or seals to facilitate a translation, e.g., vertical translation, of the build platform assembly with respect to the build module body. Engaging and disengaging the plurality of engagement features with corresponding receptacles, may comprise a holding force between the engagement features and corresponding receptacles. A value of the holding force may be any value of a holding force described herein. A material of the plurality of engagement features and seals may be any material described herein. The material of the plurality of engagement features may be a same or a different material as a material of the build module body. The material of the plurality of engagement features and/or seals may be a same material or a different material as that of the material surrounding (e.g., enclosing) the receptacles. For example, the material of the plurality of engagement features and/or seals may be aluminum, steel, ceramic, or the like.

[0243] In some embodiments, the engagement features are arranged along the inner surface of the build module body and (reversibly) press and release into pistons of the build platform assembly such that they enable the build platform assembly to move vertically along the build module wall(s) in a motion such as a stepwise motion. The plurality of engagement features may be distributed along a length of the build module body, e.g., each engagement feature set being of another piston of the build platform assembly. The plurality of engagement features distributed on an inner wall of the build module body may (e.g., reversibly) engage and disengage with an outer surface of the piston housing of the piston assembly. The movement of the engagement feature may be to compress and retract from an external side surface of the pistons, respectively. A plurality of receptacles may be located on the build module body, e.g., a plurality of holes distributed on the build module body. The plurality of receptacles may be distributed along a length of the build module body, e.g., distributed (e.g., substantially) periodically and/or at equidistance along the length of the build module body. A periodicity of the spacing of the plurality of receptacles may be selected by a length of travel of a first piston assembly with respect to a second piston assembly. For example, a periodicity of the spacing may enable engagement of a plurality of pins of an engagement mechanism of the first piston and/or of the second piston as the build platform assembly translates vertically with respect to the support (e.g., build module body).

[0244] In some embodiments the engagement features are distributed. The engagement features may be distributed along a circumference of a piston assembly, or along a circumference of a support (e.g., build module wall). For example, the engagement features may couple to the piston assembly and reversibly protrude therefrom, and the support having complementary receptacles with which the engagement features may couple. For example, the engagement features may couple to the support and reversibly protrude therefrom, and the piston assembly may have complementary receptacles with which the engagement features may couple. The distribution of the engagement features or their complementary holes along a circumference of the piston assembly may form a symmetric structure, e.g., that is concentric with the piston assembly and/or with the support (e.g., build module body). The distribution of the engagement features or their complementary holes along a circumference of the support assembly may form a symmetric structure, e.g., that is concentric with the piston assembly and/or with the support (e.g., build module body). The engagement features may be distributed in an equidistant or in a non-equidistant manner. Force exerted on each the engagement features corresponding to a piston assembly upon its engagement with the support, may be (e.g., substantially) similar (e.g., the same), the piston assembly being of the build platform assembly.

[0245] In some embodiments, an engagement mechanism comprises a magnetic mechanism (e.g., an electro-magnetic mechanism). The magnetic mechanism may comprise a plurality of magnets (e g., electro-magnets). The magnets that may be reversibly engaged and disengaged (e.g., selectively powered) with at least a portion of the build platform assembly from a support, e.g., from an inner wall of the build module body. The plurality of magnets may be arranged on an outer circumference of housing of a piston assembly. The plurality of magnets may be arranged on an inner circumference of the build module body. Two or more of the magnets may be engaged (e.g., substantially) simultaneously. The plurality of magnets may comprise at least about 2 electro-magnets, 3 electro-magnets, 4 electromagnets, 5 electromagnets, 6 electromagnets, 8 electromagnets, or more. The electro-magnetic mechanism may comprise an actuator, e.g., any actuator disclosed herein. The actuator may be coupled with the plurality of electro-magnets to change a state of the electro-magnets (e.g., turn the electro-magnets “ON” or “OFF”). A material of the support (e.g., build module body) and/or piston housing may be selected in part to engage with the electro-magnets, e.g., may comprise steel. The disclosure above relating to the engagement features and/or complementary receptacles may correspond to the magnets. For example, their control by a controller(s), their distribution along a circumference of the piston assembly, their distribution along the support (e.g., build module body).

[0246] Fig. 13 depicts schematic views of example 3D printing system components. Fig. 13 depicts a partial cross-sectional view 1301 and expanded view 1303 of a piston assembly 1300. Piston assembly 1300 includes a piston 1302 and a (e.g., hydraulic) locking system 1304. The (e.g., hydraulic) locking system includes a (e.g., reversibly expandable, and reversibly contractable) ring 1306 having a band width 1308 and a thickness 1310. Ring 1306 may be affixed to the piston 1302 at fixture points 1312, 1314. Fixture points may be welding points. Ring 1306 is arranged with respect to an outer surface 1316 of piston 1302 to define a cavity 1318 between the ring 1306 and the outer surface 1316 of the piston 1302. The cavity 1318 is coupled with a channel 1320, to allow flow of (e.g., hydraulic) fluid reversibly into/out of the cavity 1318. Fig. 13 depicts a schematic view 1350 and expanded view 1370 of a portion of a wall 1352 of a build module body and an outer surface of a portion of a ring 1356 of a (e.g., hydraulic) locking system 1354. At minimal (e.g., zero) added (e.g., hydraulic) pressure to the (e.g., hydraulic) locking system 1354, a gap 1360 is established between the wall 1352 of the build module body and ring 1356 of the (e.g., hydraulic) locking system of the piston assembly. Gap 1360 facilitates a smooth translation of the piston with respect to a build module body. An FLS of the gap 1360 can include an FLS of a tolerance 1362 for the wall of the build module body and an FLS of a tolerance 1364 for the ring of the (e.g., hydraulic) locking system. A design clearance 1366 within gap 1360 can compensate for variation in applied (e.g., hydraulic) pressure during engagement or disengagement of the (e.g., hydraulic) locking system with a build module body.

[0247] Fig. 14 depicts example finite element analysis (FEA) plots of 3D printing system components. The finite element analysis (FEA) plots 1400, 1402 depict cross-sectional views of FEA for a cross-section of a (e.g., reversibly expandable, and reversibly contractable) ring by (e.g., hydraulic) pressure introduced into a cavity of a (e.g., hydraulic) locking system, e.g., ring 1306 of a (e.g., hydraulic) locking system 1304 of a build platform assembly. Plot 1400 depicts an FEA of the ring with (e.g., hydraulic) pressure applied within the cavity of the (e.g., hydraulic) locking system until a yield strength of the ring is approached. Plot 1402 depicts an FEA of a ring with a minimal (e.g., hydraulic) pressure applied within the cavity to achieve a deflection (e.g., expansion) of an outer diameter of the ring sufficient to contact an inner surface of the build module body. Fig. 14 depicts an example 1420 of a ring 1422 for a (e.g., hydraulic) locking system. As depicted, ring 1422 includes vertical channels 1424 to allow pre-transformed or transformed material to pass through the vertical channels 1424 of the ring 1422.

[0248] Fig. 15 depicts schematic views of example 3D printing system components including build platform assembly 1500 in which fastening engagement features (e.g., pads) are configured to reversibly press upon an internal surface of the build module wall(s) and reversibly release from the internal surface of the build module wall(s), the engagement features distributed along a circumference of each piston assembly. The build module may or may not have structural features configured to align the build platform assembly with respect to the build module body during operation. In the example shown of build platform assembly 1500 is show with respect to gravitational vector 1590 pointing towards the gravitational center of the ambient environment. As depicted in Fig. 15, a build platform assembly 1500 includes fastening engagement mechanisms, e.g., engagement features such as mechanical (e.g., breaking) pads as part of piston assemblies 1502, 1503. Piston assemblies 1502, 1503 include two sets of a plurality of (mechanical) pads such a first pad set including pads1504, and a second pad set including pads 1510. The pads such as 1504, 1510 are arranged with respect to the build platform assembly 1500 such that during operation, engaging pads such as 1504, 1510 apply a horizontal holding force on the internal surface of the build module wall(s) such as along holding vector 1522 that is (e.g., substantially) perpendicular to (vertical) axis 1520 along the central shaft. Axis 1520 can lie during operation (e.g., substantially) parallel to gravitational vector 1590. Vector 1522 can lie upon operation (e.g., substantially) perpendicular to gravitational vector 1590. A first set of plurality of pads such as pads 1504 are distributed about an outer circumference of the housing 1506 of the first piston assembly 1503. A second set of plurality of pads such as pads 1510 includes pads that are distributed about an outer circumference of the housing 1512 of the second piston assembly 1502 having upper surface 1514. Piston assembly 1502 can include, or can be operatively coupled with, an actuator (not shown). First piston assembly 1503 comprises a (e.g., pneumatic) secondary piston 1540 operatively coupled with (e.g., pivotable) ring (e.g., wheel) 1541 configured to cause the pistons such as 1504 to reversibly push out and retract, e.g., depending on the pivot direction of the (e.g., pivotable) ring, as the ring pivots about central axis 1520, the pivoting is confined by the extent of port (e.g., hole) such as 1542. Central axis 1520 can comprise a lead screw (now shown) rotated by actuator (e.g., motor) 1543, that causes gear 1544 to rotate, the gear being coupled (e.g., indirectly) to the lead screw. [0249] Fig. 15 depicts schematic views of example 3D printing system components including build platform assembly 1550 in which fastening engagement features (e.g., pins) are configured to reversibly be inserted into receptacles of an internal surface of the build module wall(s) and reversibly release from the receptacles of the build module wall(s), the engagement features distributed along a circumference of each piston assembly. Fig. 15 shows in example 1550, a build platform assembly including pistons 1558 and 1556 with respect to gravitational vector 1599 pointing towards the gravitational center of the ambient environment. As depicted in Fig. 15, a build platform assembly includes fastening engagement mechanisms, e.g., mechanical mechanism 1552 and 1554, each comprising pins. The build platform assembly in example 1550 includes a first piston 1556 and a second piston 1558, e.g., components of a first piston assembly and a second piston assembly, respectively. Each of first piston 1556 and second piston 1558 is coupled with a respective engagement mechanism 1552 and 1554. Each engagement mechanism 1552 and 1554 includes set of respective pins such as pins 1560 and 1562. Engagement mechanism 1552 includes set of pins such as pin 1560. Engagement mechanism 1554 includes set of pins such as pin 1562. The pins 1560 and 1562 are (e.g., aligned and) configured to engage with receptacles 1564a-b located on the build module body 1566. Pin 1560 is (e.g., aligned and) configured to engage with receptacle 1564a. Pin 1562 is (e.g., aligned and) configured to engage with receptacle 1564b. As depicted Fig. 15, the pins of the first engagement mechanism 1552 such as pin 1560, are engaged with (e.g., inserted into) receptacles 1564a. Engaged pins 1560 hold (e.g., restrict) translation of the first piston 1556 with respect to build module body 1566. Pins of the second engagement mechanism 1554 such as pin 1562, are disengaged to allow translation of the second piston 1558 with respect the build module body 1566. Build module body 1566 comprises seals 1568 (e.g., covers) configured to reversibly engage and disengage with receptacles 1564 e.g., when the pins 1562 are not engaged with the receptacles 1564. During operation, movement of platform 1558 with respect to platform 1556 is configured to alter distance d between the platforms. The build module body 1566 comprises floor 1580 and stoppers such as 1582 that can cushion (e.g., and stop) an accidental collapse of the build platform assembly onto floor 1580.

[0250] In some embodiments, the build platform assembly comprises a translation stage. A translation stage may comprise a multi-axis translation stage. A translation stage may be a manual and/or automatic translation stage, e.g., control by at least one controller such as the ones disclosed herein. A translation stage may be a semi-automated or automated stage. A translation stage may translate in at least one degree of freedom. A translation stage may translate in a plurality of degrees of freedom (e.g., at least 2, 3, 4, 5, or 6 degrees of freedom). A translation stage may be configured to provide XY translation. A translation stage may be configured to provide XYZ translation. A translation stage may be configured to provide linear translation, e.g., translation about an XY plane, XYZ multi-axis translation. A translation stage may be configured to provide rotational translation, e.g., 360° rotation about an axis such as a central axis. At times, the translation stage comprises a rotational stage. At times, the translation stage comprises a theta/phi goniometer. The translation stage may comprise an actuator. An actuator can be any actuator disclosed herein, e.g., controlled by the at least one controller. The translation stage may comprise an encoder such as any encoder disclosed herein. The translation stage may comprise continuous, or a discrete, translation. The translation stage may comprise incremental translation. The translation stage may be operatively coupled with the build platform assembly. The translation stage may be coupled with a build platform, e.g., base. The translation stage may be coupled with a second piston assembly, e.g., coupled with an upper piston assembly relative to the gravitational vector. The translation stage may be coupled with the build module body. The translation stage may be arranged with respect to a surface of the build platform and configured to adjust an orientation of the build platform about one or more axis. The translation stage may be configured to adjust an orientation of a surface of the build platform configured to carry a material bed and/or 3D objects during a 3D printing process. The translation stage may be configured to adjust an orientation of the surface of the build platform about an XY plane, e.g., relative to a gravitational vector directed towards the gravitational center of the environment. The translation stage may be configured to adjust an orientation of the surface of the build platform about a rotational axis, e.g., about a z-axis of the build platform aligned with the gravitational vector. The translation stage may be configured to adjust an orientation of the surface of the build platform about two or more axes, e.g., about theta and phi relative to an XY plane perpendicular to the gravitational vector.

[0251] In another aspect, building the 3D object comprises at least three types of movements. The first movement is an initiation movement facilitating translating (e.g., pushing) the build platform assembly to the top of the build module body such that the build platform is at its topmost position. The top of the build module is in a direction opposing to a floor of the build module (e.g., opposing a floor of the build module body). The top-most position can be (i) a position at which the build platform is ready to receive a first layer of starting material to generate the material bed, or (i) a position that after one layerwise translation will be ready to receive the first layer of starting material (e.g., pre-transformed material). Once the build platform assembly reaches its top-most position, the first piston assembly becomes affixed to the build module, with the first piston assembly being the lower most piston assembly closer to the floor of the build module. Once the first piston assembly is affixed to the build module, the second piston assembly initiates a layerwise movement towards the first piston assembly. The second piston assembly is the upper most piston assembly that includes a piston to which the build platform is coupled. Once the layerwise movement is executed, the second piston assembly affixes itself to the build module, and a layer of starting material is spread on the build platform. Energy beam(s) transform some of the starting material to a transformed material as part of the 3D object, thus generating a layer of the 3D object. Then the second piston assembly disengages itself from the build module, and performs another layerwise movement towards the first piston assembly. A vertical distance of the layerwise translation may correspond (e.g., correlate) to a height of a deposited (e.g., planarized) layer of pre-transformed material on an exposed surface of the material bed or build platform. A vertical distance of the layerwise vertical translation may correspond (e.g., correlate) to a height of a layer of hardened material as part of the layerwise printed 3D object. The successive layerwise movements of the second piston assembly (and of the build platform) towards the first piston assembly may repeat until the 3D object is layerwise generated or until the second piston reaches a threshold distance from the first piston at which the second piston can no longer perform layerwise translations. When the 3D object is not complete and the second piston assembly reaches the threshold distance from the first piston assembly, a block movement is executed. The build platform assembly may translate towards the floor of build module body in a block increment that is a larger increment than the layerwise increment. To accomplish the larger incremental block movement while retaining the accuracy of the layerwise deposition, the second piston assembly is affixed to the build module while the first piston assembly is released from build module body and translates in the block increment towards the floor of build module body, thus extending the distance between the second piston assembly and the first piston assembly. During the block incremental movement of the first piston assembly towards the floor of the build module body, the position of the build platform is affixed, e.g., by affixing the second piston assembly to the build module body. Once the block incremental movement is complete and the distance between the first piston assembly and the second piston assembly is fully extended, the first piston assembly affixes itself to the build module body. Then the second piston assembly initiates its successive layerwise incremental movements, between each a layer of transformed material is generated as part of the 3D object. The successive layerwise movements and fine movements are repeated until the 3D object is complete. This may or may not correspond to the first piston assembly reaching its bottom most position relative to the build module body. Once the 3D object has completed its printing the 3D object may be released from the build module. The release from the build module may be in the 3D printing system, e.g., by pushing the 3D object disposed in the material bed upwards using the translation mechanism that performs an initiation movement. By the initiation movement, the build platform and the 3D object disposed above it in the material bed, are pushed up and become fully exposed in the processing chamber to which the build module is coupled with. The release from the build module may be outside the 3D printing system, e.g., in an unpacking stations. The 3D object may disengage from the processing chamber, and transferred to an unpacking stations. In the unpacking stations, the 3D object disposed in the material bed may be pushed upwards using the translation mechanism that performs an initiation movement. By the initiation movement, the build platform and the 3D object disposed above it in the material bed, are pushed up and become fully exposed in the unpacking stations to which the build module is coupled with. While this disclosure centers on the build module body as being the support, other supports may be utilized to facilitate a similar outcome.

[0252] In some embodiments, the build platform assembly is configured to translate vertically. The build platform assembly may be translated at least in part by utilizing a combination of operations. The combination of operations may comprise initiation translation, block translation, and layerwise translation operations. The combination of operations may comprise a set of initiation operations, e.g., to set up or initiate a 3D printing process. The combination of operations may comprise a set of build operations, e.g., to facilitate a 3D printing process. The combination of operations may include (i) translation a first piston assembly of a build platform assembly in larger increments (e.g., leaps such as block increments disclosed herein), and (ii) within each of the large increments, translating a second piston assembly of the build platform assembly in smaller increments (e.g., layerwise increments disclosed herein). The first piston assembly and the second piston assembly can each engage with a build module body to hold their positions, respectively. The first piston assembly and the second piston assembly can be coupled by a shaft, where a length of travel (e.g., an extent of the large increments) can be set by a vertical extent of the shaft.

[0253] At times, the build platform assembly is configured to perform operations comprising a set of initiation operations, e.g., to set up or initiate a 3D printing process. The set of initiation operations may comprise positioning the build platform assembly with respect to the build module body in a requested position, e.g., by translating the build platform assembly in an initiation translation such as is disclosed herein. The request position may comprise an initiation position, e.g., a first position for a 3D printing process. Positioning the build platform assembly may comprise positioning the build platform assembly such that a portion of the build platform assembly is aligned with a top (e.g., relative to a gravitational vector) of the build module body. Positioning the build platform assembly may comprise adjusting a position of a first piston engaged with a build platform such that the build platform is aligned with an initiation position. For example, such that the build platform is level with a top portion of the build module body. For example, such that a surface of the build platform is level with a top edge of the build module body. At times, aligning the build platform assembly in the initiation position comprises engaging an interlock (e.g., limit switch) located at a vertical limit of travel of the build platform assembly with respect to the build module body. The set of initiation operations may comprise vertically translating the build platform assembly from a first position to a second position with respect to the build module body. The first position may comprise a lower position with respect to a second position relative to a gravitational vector. The first position may be defined based at least in part on an interlock (e.g., limit switch or physical supports). The first position may be a lowest position of travel for the build platform assembly relative to a gravitational vector. The set of initiation operations may comprise vertically translating a first portion of the build platform assembly relative to a second portion of the build platform assembly. The set of initiation operations may comprise vertically translating the second portion of the build platform assembly relative to the first portion of the build platform assembly. The first portion may comprise a first piston assembly. The second portion may comprise a second piston assembly. Vertically translating the second piston assembly relative to the first piston assembly may comprise translating the second piston assembly along a shaft coupled with the second piston assembly and the first piston assembly. The set of initiation operations may comprise (A) extending the second piston assembly with respect to the first piston assembly (e.g., in a block increment), (B) translating the build platform assembly from a first position to a second position (e.g., in an initiation or large increment), (C) engaging an engagement mechanism of the first piston assembly with respect to the build module body, and (optionally) (D) translating the second piston assembly relative to the build module body to align the build platform engaged with the build platform assembly to an initiation position for the 3D printing process, e.g., using layerwise increments. At times, (A) extending the second piston assembly with respect to the first piston assembly comprises a translation of the second piston assembly along a shaft coupled with the second piston assembly and the first piston assembly (e.g., between the second piston assembly and the first piston assembly). Extending the second piston assembly with respect to the first piston assembly may comprise translating the second piston assembly a full range of translation available between the first piston assembly and second piston assembly, e.g., a block translation. Extending the second piston assembly with respect to the first piston assembly may comprise engaging an engagement mechanism of the first piston assembly to hold (e.g., affix) a position of the first piston assembly with respect to the build module body. At times (B) translating the build platform assembly from the first position to the second position comprises an initiation translation movement. Initiation translation of the build platform assembly may comprise vertical translation by a translational mechanism, e.g., a telescopic unit, coupled with the build platform assembly. The first position may comprise a lowest-most position of the build platform assembly with respect to the build module body (e.g., relative to a gravitational vector). The second position may comprise an upper-most position of the build platform assembly with respect to the build module body (e.g., relative to the gravitational vector). Initiation translation of the build platform assembly may comprise disengaging one or more engagement mechanisms of the build platform assembly prior to initiation translation. The second position may comprise an initiation position. At times, (C) engaging the engagement mechanism of the first piston assembly comprises reversibly restricting (e.g., halting) movement of the first piston assembly relative to the build module body. At times, (D) translating the second piston assembly relative to the build module body to align the build platform engaged with the build platform assembly to an initiation position for the 3D printing process comprises a layerwise translation of the second piston to align the build platform with the initiation position.

[0254] At times, the build platform assembly is configured to perform operations comprising a set of build operations, e.g., to facilitate 3D printing processes. The set of build operations may comprise positioning the build platform assembly with respect to the build module body in a plurality of requested positions to facilitate a 3D printing process. The requested position(s) may comprise a series of positions along a vertical axis of the build module body corresponding to respective layers of a 3D printing process. The requested positions may be (substantially) evenly spaced. The set of build operations may be performed simultaneously and/or sequentially to additional 3D printing processes, e.g., comprising dispensing of pre-transformed material, connecting (e.g., fusing such as sintering and/or solidifying) pre-transformed material to form transformed material as part of 3D object(s), or purging an atmosphere of an enclosure. The set of build operations may comprise performing operations by at least one piston assembly of the build platform assembly. The set of build operations may comprise performing operations by two or more piston assemblies of the build platform assembly. The set of build operations may comprise initiation translation, block translation, or layerwise translation. The build operations may comprise a multi-incremental translation that includes different types of translations. The set of build operations may include a first type of incremental translation (e.g., block movement) and/or a second type of incremental translation (e.g., layerwise movement). For every block translation, there may be multi-incremental layerwise translations. For every initiation translation, there may be multi-incremental block translations. The set of build operations may comprise reversibly engaging and disengaging at least one engagement mechanism of the build platform assembly. The engagement mechanism may be any engagement mechanism disclosed herein. The set of build operations may comprise reversibly engaging and disengaging a respective engagement mechanism of one or more piston assemblies. The set of build operations may comprise adjusting a position of one or more translation stages (e.g., XY stage, XYZ stage, rotational stage, theta/phi goniometer). The set of build operations may comprise translating (e.g., vertically translating) at least one piston assembly at a given time. The set of build operations may comprise translating two or more piston assemblies at a given time. The set of build operations may comprise engaging an engagement mechanism for a piston assembly while another piston assembly is translating with respect to the piston assembly. The set of build operations may comprise reversibly engaging and disengaging a translation mechanism such as a telescopic unit, e.g., telescopic (e.g., hydraulic) cylinders, coupled with the build platform assembly. The translation mechanism may be engaged, for example, when an engagement mechanism of the second piston assembly (e.g., a lower piston assembly) is engaged. The translation mechanism may be disengaged, for example, when an engagement mechanism of the second piston assembly is disengaged and/or when the second piston assembly is translating vertically (e.g., along the gravitational vector). Engaging the translation mechanism may comprise adjusting a position of a (e.g., hydraulic) valve (e.g., open) to allow (e.g., hydraulic) fluid to pressurize the translation mechanism such that the translation mechanism is (substantially) incompressible. Disengaging the translation mechanism may comprise adjusting the position of the (e.g., hydraulic) value (e.g., close) to allow the translation mechanism to be compressible by the translation of the second piston assembly. The set of build operations may be repeated sequentially until the build platform assembly reaches a requested position (e.g., a 3D printing process of a 3D object is completed). The set of build operations may comprise operations including: (E) the second piston assembly engages with the support and holds (e.g., affixes) a position, (F) the first piston assembly is disengaged, or disengages, from the support and then translates in a larger increment (e.g., block increment), (G) the first piston assembly engages with the support and holds (e.g., affixes) a position , (H) the second piston assembly is disengaged, or disengages, from the support and then translates sequentially in smaller increments (e.g., layerwise increments) towards the first piston assembly until a minimal gap distance is reached between the first piston assembly and the second piston assembly, and (I) optionally repeat operations (E) to (H) until the second piston assembly reaches a requested position. The support may be the build module body. Between each of the layerwise incremental movements of the second piston assembly, a layer of pre-transformed material is deposited, and at least one energy beam transforms a portion of the layer of pre-transformed material to a transformed material as part of a layerwise printed 3D object. A vertical distance of the layerwise operation may correspond to a height of a layer of hardened material as part of the layerwise printed 3D object. At times, (E) engagement of the second piston assembly with the build module body includes reversibly engaging an engagement mechanism of the second piston assembly and/or an engagement mechanism of the build module body. The engagement mechanism may comprise any engagement mechanism disclosed herein. At times, (F) the first piston assembly is disengaged, or disengages, from the build module body comprises reversibly disengaging an engagement mechanism of the first piston assembly and/or an engagement mechanism of the build module body. The engagement mechanism may comprise any engagement mechanism disclosed herein. At times, translating in the larger increment comprises a block translation movement, as disclosed herein. At times, (G) the first piston assembly engages with the build module body comprises reversibly engaging the engagement mechanism of the first piston assembly and/or an engagement mechanism of the build module body. At times, (H) the smaller increments towards the first piston assembly comprise layerwise translation movement, as disclosed herein. The minimal gap distance between the first piston assembly and the second piston assembly may comprise a physical contact between a surface of the first piston assembly and a surface of the second piston assembly. The minimal gap distance may comprise a gap defined by one or more support structures (e.g., hard stops) between the first piston assembly and the second piston assembly. At times, (I) the requested position corresponds to about a full extent of vertical translation available for the build platform assembly within the build module body. At times, a requested position corresponds to a vertical extent of a 3D object carried by the build platform assembly.

[0255] In some embodiments, translation of the build platform to its start position comprises movement of at least one movement mechanism type. For example, translation of the build platform to its start position comprises may comprise utilizing the translation mechanism (e.g., telescopic unit) that facilitates the initiation movement in an upward direction against the gravitational vector directed to the environmental gravitational center. Translation of the build platform to its start position may or may not comprise utilizing the engagement mechanism that facilitates the block movement, moving in the upward direction. For example, translation of the build platform to its start position may or may not comprise utilizing the engagement mechanism that facilitates the layerwise movement, moving in the upward direction. At times, one or two types of movements in the upward direction are utilized to translate the build platform to its start position with respect to generating the material bed. The start position of the build platform may include the build platform being flush with the floor of the processing chamber. The start position of the build platform may include the build platform deviating downward from the floor of the processing chamber towards the floor of the build module by a height corresponding to a layer of starting material of the material bed. Translating the build platform to its start position may comprise using the translation mechanism (e.g., telescopic shaft) to elevate the build platform to its start position, e.g., without use of block translation or layerwise translation. Translating the build platform to its start position may comprise using the translation mechanism (e.g., telescopic shaft) to elevate the build platform upward, and adjusting position of the build platform downward using the layerwise translation to bring the build platform to its start position to accommodates a layer of starting material, e.g., without use of block. Translating the build platform to its start position may comprise expanding the distance between the first piston assembly and the second piston assembly using a block translation in an upward movement, and then using the translation mechanism (e.g., telescopic shaft) to elevate the build platform to its start position, e.g., without use of layerwise translation. Translating the build platform to its start position may comprise expanding the distance between the first piston assembly and the second piston assembly using a block translation in the upward direction, and then using the translation mechanism (e.g., telescopic shaft) to elevate the build platform to its start position, and adjusting position of the build platform downward using the layerwise translation to bring the build platform to its start position to accommodates a layer of starting material. Once the build platform is at its start position, the distance between the first piston and second piston - if not fully expanded - may be expanded to its full span. Once the build platform is at its start position, the build platform may translate layerwise downward - if not already in that position - by using the layerwise movement in a downward direction. Upward and downward are relative to a floor of the build module and/or the gravitational vector pointing to environmental center G. During an upwards expansion of the distance between the first piston assembly and the second piston assembly, the first (e.g., lower) piston is affixed to the support (e.g., to the build module body). During a downward expansion of the distance between the first piston assembly and the second piston assembly, the second (e.g., upper) piston is affixed to the support (e.g., to the build module body). Expanding the distance between the first piston assembly and the second piston assembly may utilize the same actuator, e.g., that is couple to the central shaft.

[0256] Fig. 16 depicts schematic examples of initiation operations for a build platform assembly 1602. Fig. 16 shows an example of translating the build platform to its start position by (i) expanding the distance between the first piston assembly and the second piston assembly using a block translation in an upward movement, and then (ii) using the translation mechanism (e.g., telescopic shaft) to elevate the build platform to its start position. In the example shown in Fig. 16, two types of movements in the upward direction are utilized to translate the build platform to its start position, the initiation movement and the block movement in the upward direction. As depicted, an initial position 1600 of the build platform assembly 1602 with respect to the build module body 1604 includes the build platform assembly 1602 located adjacent to a bottom portion 1606 of the build module body 1604. The build platform assembly 1602 is in contact with guide rods 1608 that limit an extent of vertical translation of the build platform assembly 1602. A base limit switch (not shown) may limit the extent of vertical translation of the build platform assembly 1602 adjacent to the bottom portion 1606 of the build module body 1604. A set of initiation operations 1610, 1612 include a first operation 1610 that includes extending a second piston assembly 1614 with respect to the first piston assembly 1616 by a block translation in an upwards direction opposing to gravitational vector 1690 pointing to gravitational environmental center G. In the upward block movement, the second piston is translated vertically to a full extent of block travel along a shaft coupled between the first piston assembly 1616 and second piston assembly 1614. During the translation of the second piston assembly 1614 with respect to the first piston assembly 1616, an engagement mechanism 1618 (e.g., a hydraulic engagement mechanism) of the first piston assembly 1616 is engaged, holding (e.g., affixing) the first piston assembly 1616 with respect to the build module body 1602. The second piston assembly 1614 can translate with respect to the first piston assembly 1616 by a vertical distance 1620, e.g., in a block incremental movement. The vertical distance 1620 can correspond to a full length of travel of the second piston with respect to the first piston along a shaft coupled between the first and second pistons (e.g., a full length of the shaft - shaft not shown), e.g., using an actuator 1630. A second operation 1612 includes translating the build platform assembly from a first position (e.g., position 1622 depicted in first operation 1610) to a second position 1624, e.g., the start position for the 3D printing. Translating the build platform assembly 1602 to second position 1624 can be performed by a translation mechanism such as a telescopic unit 1626. At the second position 1624, the build platform 1628 may be ready to accept a layer of starting material as part of the material bed. In the initial orientation 1600, the telescopic unit 1626 is in a non-extended state (e.g., compressed state). In the second operation 1612, the telescopic unit 1626 is in a fully extended state (e.g., after executing an initiation translation). Prior to translating the build platform assembly 1602 to second position 1624, the engagement mechanism 1618 of second piston assembly 1614 is disengaged. Translating the build platform assembly 1602 to second position 1624 can translate a build platform 1628 to an initiation position for a 3D printing process. A limit switch (not shown) located at a top-most point (e.g., with respect to a gravitational center G) of travel of the build platform assembly 1602 along the build module body 1604 can limit the travel of the build platform assembly 1602. After the initiation translation to the second position assembly 1614, the engagement mechanism 1618 of the first piston assembly is engaged with respect to the build module body 1604. Optionally, the second piston assembly 1614 is translated (e.g., in layerwise translation) relative to the build module body 1604 to align the build platform 1628 engaged with the build platform assembly 1602 to the initiation position for the 3D printing process. Once the build platform assembly 1602 is aligned with the initiation position (second position 1624), the 3D printing process can be initiated.

[0257] Fig. 17 depicts schematic examples of build operations for a build platform assembly. These operations may be utilized in the layerwise extension of a material bed, e.g., as part of a layerwise 3D printing process using a material bed. These operations may be utilized in the layerwise extension of a 3D object, e.g., as part of a layerwise 3D printing process. The 3D printing may or may not utilize a material bed. For example, the 3D printing may utilize layerwise extrusion. The components shown in Fig. 17 may be depicted relative to Gravitational vector 1790 directed towards environmental gravitational center G. The build operations depicted in Fig. 17 may coincide (e.g., sequentially, or simultaneously) with one or more 3D printing processes as described herein. For example, one or more processes may include depositing pre-transformed material on an exposed surface of a material bed or the build platform, directing one or more energy beams to form (e.g., sinter or fuse) a portion of the material bed to form layer(s) of a 3D object, purging an atmosphere of the enclosure, or the like. The set of build operations 1700, 1702, 1704, 1706 includes a build operation 1700 including engaging a second piston assembly 1708 of a build platform assembly 1710 with a build module body 1712 and holding (e.g., affixes) a position 1715 of a build platform 1724 engaged with the second piston assembly 1708 with respect to the build module body 1712. The build module assembly includes the translation mechanism 1731. However for drawing simplicity, it is depicted as including the first piston assembly, the second piston assembly, and their associated mechanisms (e.g., central shaft 1732, guide rods 1733a and 1733b, and actuator1730). The mechanism between the first piston assembly and second piston assembly may be protected using a cover or a seal, e.g., a bellow (not shown). While two guide rods are shown in the example in Fig. 17, there may be more guide rods such as three guide rods, e.g., arranged in a triangular manner, with the third guide rod disposed behind the shaft 1732. Optionally, build operation 1700 includes disengaging a first piston assembly 1714 from the build module body 1712, or using a disengaged first piston assembly 1714, and translating the first piston in a block increment, a vertical distance 1716 downwards towards the bottom portion of the build module body 1712, e.g., along gravitational vector 1790. Optionally, the first piston assembly is extended with respect to the second piston assembly during an initiation operation, e.g., operation 1610 in Fig. 16. A build operation 1702 includes engaging the first piston assembly 1714 with the build module body 1712 and holding (e.g., affixing) a position 1718 of the first piston assembly 1714 with respect to the build module body 1712. Build operation 1702 includes disengaging the second piston assembly 1708 from the build module body 1712 and then translating in successive layerwise increments towards the first piston assembly 1714 until a minimal gap distance 1720, as depicted in 1704, is reached between the first piston assembly 1714 and the second piston assembly 1708. The block increment is larger than the layerwise increments. Between each increment of the layerwise movements of 1702, 1704, a layer of starting material can be added to expand the material bed, e.g., when a material bed is utilized for the 3D printing. Between each increment of the layerwise movements of 1702, 1704, a layer of transformed material can be added to the layerwise printed 3D object disposed above build platform 1724 as part of a 3D printing process. A distance of the layerwise increment may correspond to (e.g., relate to) a height of the layer of transformed material as part of the layerwise printed 3D object. To facilitate addition of layers to the printed 3D object, optionally, build operation 1706 depicts a repetition of build operation 1700, where the build platform 1724 of the build platform assembly 1710 is located at a second position 1722 after an additional layerwise incremental movement towards the floor 1750 of build module body 1712. Optionally, the build operations described with respect to 1700, 1702, and 1704 may be repeated until a build platform 1724 engaged with the build platform assembly 1710 reaches a requested position. The build platform assembly 1710 may translate towards the bottom portion (e.g., floor) 1750 of build module body 1712 in a block increment) To accomplish the block implemental movement while retaining the accuracy of the layerwise deposition: while the second piston assembly 1708 is engaged with the build module body 1712, the first piston assembly 1714 could be released from build module body 1712 and extended in the larger increment towards the floor 1750 of build module body 1712.

[0258] Fig. 18 depicts schematic views of example 3D printing system components including a build platform assembly in which fastening engagement features (e.g., pins) are configured to reversibly be inserted into receptacles of an internal surface of the build module wall(s) and reversibly release from the receptacles of the build module wall(s). The engagement features (e.g., pins) are distributed along a circumference of each piston assembly. The engagement features are configured to engage with corresponding receptacles disposed in wall of the internal portion of the build module body. The receptacles are disposed in horizontal sets at equidistance along a height of the wall. The receptacles in each horizontal set are disposed equidistant from each other along an inner circumference of the build module wall. Vertical distance between sets of receptacles may correspond to a height of (i) a layer of powder dispensed on a build plate supported by the build module assembly disposed in the build module and/or (ii) a layer of a 3D object supported by the build plate during printing of the 3D object. In the examples shown in Fig. 18 the build platform assembly is show with respect to gravitational vector 1890 pointing towards the gravitational center of the ambient environment. Fig. 18 depicts schematic examples of operations of the engagement mechanism. As depicted in Fig. 18, build platform assembly 1804 comprises first piston 1820, second piston 1824. Each piston is coupled with respective engagement mechanisms1802 and 1806. Each of the engagement mechanisms may be selectively (e.g., and sequentially) engaged with a build module body 1808, e.g., using pins engaged with corresponding receptacles. The engagement may be to facilitate movement of the build platform assembly with respect to the build module body 1808. Each of the engagement mechanisms may be selectively disengaged with a build module body 1808, e.g., using pins disengaged from their corresponding receptacles. Examples 1810, 1812, 1814, 1816, and 1818 of Fig. 18 schematically depict such engagement and disengagement operations. Operations 1810, 1812, 1814, 1816, and 1818 can each optionally correspond to a respective build operations, e.g., similar to the ones described with reference to Fig. 17. The components of Fig. 18 may be depicted relative to a gravitational vector 1890 pointing toward the environmental gravitational center G.

[0259] Operation 1810 depicts a first piston 1820 and a second piston 1824, e.g., components of a first piston assembly and a second piston assembly, respectively. The first piston 1820 is coupled with engagement mechanism 1802 and second piston 1824 is coupled with engagement mechanism 1806. Each engagement mechanism includes set of respective fasteners (e.g., pins) configured to reversibly emerge from, and be reversibly retracted to, a circumference of a piston mechanism; such as pins, e.g., 1826 of the first engagement mechanism 1802, and pin 1828 of the second engagement mechanism 1806. The pins such as 1826, 1828 are each configured to engage with receptacles such as receptacles 1830 (e.g., crevices, intrusions, or holes) located along wall(s) of build module body 1808. As depicted in operation 1810, pins 1826 and 1828 are engaged with (e.g., inserted into) receptacles 1830. Engaged pins 1826 and 1828 with receptacles 1830 is configured to hold (e.g., restrict) translation of the first piston 1820 and second piston 1824 with respect to the build module body 1808, and place the pistons at distance d1 between first piston 1820 and second piston 1824. Piston 1820 is held with pins of the first piston assembly, such as pin 1826, at a distance d11 from floor 1811 of the build module body. Build module body 1808 comprises seals such as 1834 (e.g., covers) configured to (e.g., reversibly) engage with receptacles 1830 e.g., when the corresponding pins 1826 and/or 1828 are not engaged with the receptacles 1830. Operation 1810 depicts a set of seals 1834 engaged with the receptacles 1832.

[0260] Operation 1812 depicts second piston 1824 engaged by the engagement mechanism 1806 with respect to the build module body 1808 by pins such as pin 1828 engaged with receptacles 1830 in a similar manner to example 1810, and first piston 1820 disengaged from the build module body 1808 such that pins such as pin 1826 of engagement mechanism 1802 are not engaged with their corresponding receptacles, e.g., disengaged from their corresponding receptacles. Operation 1812 depicts an operation where the first piston 1820 can vertically translate (e.g., downwards) with respect to the second piston 1824 and enlarge distance d1 shown in example 1810, to distance d2 shown in example 1812, the distance being between first piston 1820 and second piston 1824. Piston 1820 is disposed at a distance d12 from floor 1811 , distance d12 being smaller than distance d11 .

[0261] Operation 1814 depicts the first piston 1820 and second piston 1824 held with respect to the build module body 1808 by respective engagement mechanisms 1802 and 1806 at least in part by each of their respective pins being engaged with their respective receptacles, thus enlarging distance d2 shown in example 1812, to d3 shown in example 1814, the distance between first piston 1820 and second piston 1824; and shorten distance d13 from floor 1811 to the first piston, distance d13 being smaller than distance d12. [0262] Operation 1816 depicts first piston 1820 engaged with build module body 1808 at least in part by engagement mechanism 1802 and second piston 1824 engaged with build module body 1808 least in part by engaging engagement mechanism 1806 at a lower position as compared to that depicted in operation 1814, allowing second piston 1824 to engage with a receptacle at a position closer to piston 1820 to generate distance d4 between first piston 1820 and second piston 1824, e.g., to allow the second piston to vertically translate with respect to the build module body 1808 to shorten distance d3 shown in example 1814, to d4 shown in example 1816. Piston 1820 is held with pins of the first piston assembly at a distance d14 from floor 1811 , distance d14 being (e.g., substantially) the same as distance d13. Piston 1820 is held with pins of the first piston assembly, such as by engaging pins thereof with the corresponding receptables of engagement mechanism 1802.

[0263] Operation 1818 depicts first piston 1820 engaged with build module body 1808 at least in part by engagement mechanism 1802, and second piston 1824 engaged with build module body 1808 least in part by disengaging engagement mechanism 1806 at a lower position as compared to that depicted in operation 1814, thus allowing second piston 1824 to engage with a receptacle at a position closer to piston 1820 to generate distance d5 between first piston 1820 and second piston 1824, e.g., to allow the second piston to vertically translate with respect to the build module body 1808 to shorten distance d4 shown in example 1816, to d5 shown in example 1818. Piston 1820 is held with pins of the first piston assembly at a distance d15 from floor 1811 , distance d15 being (e.g., substantially) the same as distance d14. The movement of piston 1821 in the direction 1850 facilitates exposure of a portion 1851 of the internal surface of build module 1808, showing additional receptacles embedded therein such as receptacle 1852.

[0264] Fig. 19 depicts a flow diagram of a process 1900 relating to 3D printing. The process comprises: in block 1901 , providing a housing of a build module (e.g, a build module body); and a build platform assembly disposed in the housing, the build platform assembly comprises: a first piston assembly comprising a first piston and a first engagement mechanism, the first piston assembly being configured to (I) translate vertically in a direction, and (II) reversibly engage and disengage the first engagement mechanism with the housing; an adjusting coupler (e.g., shaft) configured to facilitate adjustment of a gap, the adjusting coupler being operatively coupled with the first piston assembly; and a second piston assembly comprising a second piston and a second engagement mechanism, the second piston assembly being operatively coupled with the first piston assembly at least in part using the adjusting coupler, the second piston assembly being configured to (i) translate vertically in the direction to facilitate the three-dimensional printing, (ii) engage with a build platform and (iii) reversibly engage and disengage the second engagement mechanism with the housing, the gap disposed between the first piston assembly and the second piston assembly, the build platform configured to carry one or more three- dimensional objects during a printing cycle of the three-dimensional printing, and the first piston assembly and the second piston assembly being configured to translate vertically relative to each other to alter the gap, and the first piston assembly and/or the second piston assembly being configured for repetitive translation in the (e.g., substantially) same direction, the housing being configured to accommodate (a) the build platform, (b) the first piston assembly, (c) the second piston assembly, (d) the adjusting coupler, and (e) the one or more three-dimensional objects; in block 1902, the build platform with the second piston and engaging the first engagement mechanism with the build module housing to affix the first piston relative to the housing of the build module; in block 1903, translating the second piston in the direction to facilitate printing a first layer of transformed material as part of the one or more three- dimensional objects, the second engagement mechanism being disengaged with the housing of the build module; in block 1904, engaging the second engagement mechanism with the housing of the build module to affix the second piston relative to the housing (e.g., body) of the build module; in block 1905, disengaging the first engagement mechanism from the housing of the build module; and in block 1906, translating the first piston in the direction to facilitate accurate printing of the second piston to facilitate printing a second layer of transformed material as part of the one or more three-dimensional objects that is carried by the build platform. The accurate printing can comprise accurate measurement of disposition of the second piston.

[0265] Fig. 20 depicts a flow diagram of process 2000 relating to 3D printing. The process comprises: in block 2001 , providing a device comprising: (A) a first piston, and (B) a second piston being operatively coupled with the first piston, the second piston being configured to (i) translate to facilitate the three-dimensional printing, and (ii) engage with a build platform configured to carry one or more three-dimensional objects during the three-dimensional printing, the first piston being configured to translate, the first piston and the second piston being configured to translate relative to each other, and the first piston and/or the second piston being configured for translation during the three-dimensional printing; in block 2002, affixing the first piston; in block 2003, translating the second piston to facilitate printing a first layer of transformed material as part of the one or more three-dimensional objects; in block 2004, affixing the second piston; in block 2005, detaching the first piston; and in block 2006, translating the first piston to facilitate accurate printing the second piston to facilitate printing a second layer of transformed material as part of the one or more three-dimensional objects that is carried by the build platform.

[0266] At times, the generated 3D object (e.g., the hardened cover) is substantially smooth. The generated 3D object may have a deviation from an ideal planar surface (e.g., atomically flat or molecularly flat) of at most about 1 .5 nanometers (nm), 2 nm, 3 nm, 4 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 100 nm, 300 nm, 500 nm, 1 micrometer (pm), 1.5 pm, 2 pm, 3 pm, 4 pm, 5 pm, 10 pm, 15 pm, 20 pm, 25 pm, 30 pm, 35 pm, 100 pm, 300 pm, 500 pm, or less. The generated 3D object may have a deviation from an ideal planar surface of at least about 1.5 nanometers (nm), 2 nm, 3 nm, 4 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 100 nm, 300 nm, 500 nm, 1 micrometer (pm), 1.5 pm, 2 pm, 3 pm, 4 pm, 5 pm, 10 pm, 15 pm, 20 pm, 25 pm, 30 pm, 35 pm, 100 pm, 300 pm, 500 pm, or more. The generated 3D object may have a deviation from an ideal planar surface between any of the afore-mentioned deviation values. The generated 3D object may comprise a pore. The generated 3D object may comprise pores. The pores may be of an average FLS (diameter or diameter equivalent in case the pores are not spherical) of at most about 1.5 nanometers (nm), 2nm, 3nm, 4nm, 5 nm, 10nm, 15nm, 20nm, 25nm, 30nm 35nm, 100nm, 300nm, 500nm, 1 micrometer (pm), 1 .5 pm, 2 pm, 3 pm, 4 pm, 5 pm, 10 pm, 15 pm, or 20 pm. The pores may be of an average FLS of at least about 1.5 nanometers (nm), 2nm, 3nm, 4nm, 5 nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 100nm, 300nm, 500nm, 1 micrometer (pm), 1 .5 pm, 2 pm, 3 pm, 4 pm, 5 pm, 10 pm, 15 pm, or 20 pm. The pores may be of an average FLS between any of the afore-mentioned FLS values (e.g., from about 1 nm to about 20 pm). The 3D object (or at least a layer thereof) may have a porosity of at most about 0.05 percent (%), 0.1% 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1 %, 2 %, 3 %, 4 %, 5 %, 6 %, 7 %, 8 %, 9%, 10 %, 20%, 30%, 40%, 50%, 60%, 70%, or 80%. The 3D object (or at least a layer thereof) may have a porosity of at least about 0.05 %, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1 %, 2 %, 3 %, 4 %, 5 %, 6 %, 7 %, 8 %, 9%, 10 %, 20%, 30%, 40%, 50%, 60%, 70%, or 80%. The 3D object (or at least a layer thereof) may have porosity between any of the afore-mentioned porosity percentages (e.g., from about 0.05% to about 80%, from about 0.05% to about 40%, from about 10% to about 40%, or from about 40% to about 90%). In some instances, a pore may traverse the generated 3D object. For example, the pore may start at a face of the 3D object and end at the opposing face of the 3D object. The pore may comprise a passageway extending from one face of the 3D object and ending on the opposing face of that 3D object. In some instances, the pore may not traverse the generated 3D object. The pore may form a cavity in the generated 3D object. The pore may form a cavity on a face of the generated 3D object. For example, pore may start on a face of the plane and not extend to the opposing face of that 3D object.

[0267] The resolution of the printed 3D object may be at least about 1 micrometer, 1 .3 micrometers (pm), 1 .5 pm, 1.8 pm, 1 .9 pm, 2.0 pm, 2.2 pm, 2.4 pm, 2.5 pm, 2.6 pm, 2.7 pm, 3 pm, 4 pm, 5 pm, 10 pm, 20 pm, 30 pm, 40 pm, 50 pm, 60 pm, 70 pm, 80 pm, 90 pm, 100 pm, 200 pm, or more. The resolution of the printed 3D object may be at most about 1 micrometer, 1.3 micrometers (pm), 1.5 pm, 1.8 pm, 1.9 pm, 2.0 pm, 2.2 pm, 2.4 pm, 2.5 pm, 2.6 pm, 2.7 pm, 3 pm, 4 pm, 5 pm, 10 pm, 20 pm, 30 pm, 40 pm, 50 pm, 60 pm, 70 pm, 80 pm, 90 pm, 100 pm, 200 pm, or less. The resolution of the printed 3D object may be any value between the above- mentioned resolution values. At times, the 3D object may have a material density of at least about 99.9%, 99.8%, 99.7%, 99.6%, 99.5%, 99.4%, 99.3%, 99.2% 99.1%, 99%, 98%, 96%, 95%, 94%, 93%, 92%, 91%, 90%, 8%, or 70%. At times, the 3D object may have a material density of at most about 99.5%, 99%, 98%, 96%, 95%, 94%, 93%, 92%, 91%, 90%, 8%, or 70%. At times, the 3D object may have a material density between the afore-mentioned material densities. The resolution of the 3D object may be at least about 100 dots per inch (dpi), 300dpi, 600dpi, 1200dpi, 2400dpi, 3600dpi, or 4800dpi. The resolution of the 3D object may be at most about 100 dpi, 300dpi, 600dpi, 1200dpi, 2400dpi, 3600dpi, or 4800dip. The resolution of the 3D object may be any value between the afore-mentioned values (e g., from 100dpi to 4800dpi, from 300dpi to 2400dpi, or from 600dpi to 4800dpi). The height uniformity (e.g., deviation from average surface height) of a planar surface of the 3D object may be at least about 100 pm, 90 pm, 80 pm, 70 pm, 60 pm, 50 pm, 40 pm, 30 pm, 20 pm, 10 pm, or 5 pm. The height uniformity of the planar surface may be at most about 100 pm, 90 pm, 80 pm, 70 pm, 60 pm, 50 pm, 40 pm, 30 pm, 20 pm, 10 pm, or 5 pm. The height uniformity of the planar surface of the 3D object may be any value between the afore-mentioned height deviation values (e.g., from about 100 pm to about 5 pm, from about 50 pm to about 5 pm, from about 30 pm to about 5 pm, or from about 20 pm to about 5 pm). The height uniformity may comprise high precision uniformity. [0268] At times, a 3D printing process, e.g., 3D printing processes described herein, may result in a physical signature in a 3D object such as a material signature. A physical signature may comprise a detectable deviation on a surface of the 3D object. At times, a portion of a 3D object may comprise a plurality of physical signatures comprising a plurality of deviations. The physical signature may occur systematically and/or repeatedly along a surface of the 3D object. For example, the physical signature may indicate occurrence of a block incremental movement. The physical signature may occur along the surface in vertical increments that correspond to an integer multiplier of the block movement span (vertical distance). The physical signature may be characteristic to the block movement span, e.g., the type of signature and/or in its location along the 3D object. At times, fewer than every layer of a 3D object comprises a physical signature. At times, at most about 10%, 5%, 2%, 1%, 0.5%, 0.1%, 0.025%, 0.01%, 0.005%, 0.001%, or fewer of the layers of the 3D object comprise a physical signature. A percentage of layers of the 3D object comprising a physical signature may be between any of the aforementioned values, for example, between about 10% and 0.1%, between about 0.1% and 0.005%, or between about 0.025% and 0.001%. A physical signature may comprise a deviation in an internal volume of the 3D object. A physical signature may comprise a microstructural characteristic. A physical signature may comprise a macrostructural characteristic. A physical signature may comprise a dimension about equal to an FLS of a layer (e.g., a thickness) of the 3D printing process. A physical signature may comprise a dimension about equal to an FLS of two or more layers (e.g., a thickness) of the 3D printing process. A physical signature may comprise a dimension (substantially) oriented along an XY plane, e.g., perpendicular to the gravitational vector. An FLS of the physical signature may comprise at most about 300 microns (pm), 250 pm, 200 pm, 150 pm, 100 pm, 75 pm, 50 pm, 25 pm, or less. An FLS of the physical signature may comprise any value between the aforementioned values, for example, between about 300 pm and 100 pm, between about 200 pm and 50 pm, or between about 150 pm and 25 pm. A physical signature may comprise a divot, indent, gap, hole, perforation, slot, ledge, flank, or other feature that intrudes into an external surface of the 3D object. A physical signature may comprise a post, ledge, bump, tag, or other feature that extrudes from an external surface of the 3D object. A physical signature may comprise an offset in a requested overlap of a first layer with respect to a second layer of the 3D object. A physical signature may comprise a deviation in a curvature, line, surface, or another feature from a requested dimension. For example, the deviation may comprise bowing (outward or inward) of a surface of the 3D object with respect to a requested surface characteristic. The plurality of physical signatures may be periodic, e.g., periodically spaced along a vertical direction with respect to a gravitational vector. The plurality of physical signature may be non-periodic, e.g., non-periodically spaced along a vertical direction with respect to a gravitational vector. A physical signature may correspond to deviations in 3D printing processes. For example, an extended dwell time before, during, or after pre-transformed material is deposited on a target surface. For example, an extended dwell time before, during, or after a melting/sintering process forming transformed material (e.g., a portion of the 3D object). Extended dwell time may comprise a dwell time that is greater than a nominal dwell time of a 3D printing process. For example, a dwell time that is at least about 5%, 10%, 15%, 20%, 25%, 40%, 50%, 60%, 100%, 150%, or greater than a nominal dwell time of a 3D printing process. At times, an extended dwell time may correspond to when at least a portion of the build platform assembly is translating with respect to the build module body. For example, when a second piston assembly is translating with respect to a first piston assembly. At times, a physical signature may correspond to a shifting of a target surface between, during, or after a 3D printing process. For example, engagement and/or disengaging an engagement mechanism of a build platform assembly may cause a shift in the target surface (e.g., due to a shift in the build platform), e.g., an XY position, rotation (e.g., pitch, yaw, and/or roll), height along a z-axis, or any combination thereof. For example, physical signatures may occur in layers corresponding to engagement of an engagement mechanism of a second piston after the second piston translates vertically in the block movement or “large leap.” In instances where the block movements by the build platform assembly are (e.g., substantially) of equal value, the physical signatures may appear periodically on a surface of the 3D object, or in an integer multiplier of that periodicity. In instances where the block movements by the build platform assembly are of non-equal value, physical signatures may appear non-periodic on a surface of the 3D object. There may be a characteristic physical signature that may be attributed to the block movement. The signature may be caused, for example, due to mechanical tolerances of the build platform, engagement mechanism, build module body, actuator, or the like. The shift may be caused by contamination between components of the 3D printing system, e.g., between a seal and a build module body, between a seal and a build platform, between a seal and a piston assembly, or any combination thereof.

[0269] In some embodiments, the 3D object is generated using a block movement and a layerwise movement. The layers of hardened material that constitute the printed 3D object may all have (e.g., substantially) the same height. The layerwise movements may (e.g., all) span (e.g., substantially) the same distance. The block movements may or may not be equal in distance. For example, the 3D object may be generated using equidistant block movements, e.g., forming a periodic block movement. For example, the 3D object may be generate using block movements of various distances (e.g., spans, or extents), e.g., forming a non-periodic block movement. In the non-periodic block movement, at least one of the block movements may be of a different distance than at least one other block movement in a printing cycle. For example, in a non-periodic block movement in a printing cycle, two block movements may span a vertical distance “A” and another block movement may span a vertical distance “B.” For example, in a non-periodic block movement in a printing cycle, one block movements may span a vertical distance “A,” a second block movement may span a vertical distance “B,” and a third block movement may span a vertical distance “C,” with “A,” “B,” and “C” spanning different vertical distances. The block movement may or may not have a visible physical signature, e.g., on a surface of the printed 3D object. The physical signature may or may not (e.g., measurably) appear as a consequence of a block movement. For example, one or more block movements during generation of the 3D object may not imprint a physical signature. For example, one or more block movements during generation of the 3D object may imprint a physical signature, e.g., consecutively, or non-consecutively. If the block movement may imprint a unique signature characteristic of the block movement, it may be detected regardless of the periodicity of the block movement. If the block movement may imprint a signature that is not a unique signature characteristic to the block movement, it may be detected due to its periodicity if the block movement is periodic, e.g., by detecting a repetition of the physical signature every distance corresponding to the block movement span, or an integer multiplier thereof.

[0270] At times, it is advantageous to utilize block movements having different spans (e.g., extent). For example, when a physical signature is imprinted during a block movement, certain portions of the 3D object may be less or more tolerant to such physical signature. The vertical extend of the block signature may be controlled (e.g., tailored, determined, or synchronized) to minimize imprint of the physical signature in portions of the 3D object that are less tolerant to the physical signature. For example, when it is requested to curb the extend of the material bed to the size of the 3D object, and this size requires less than the full extent of a block movement, a block movement may be utilized having an extent smaller that the full extent (e.g., a partial block movement).

[0271] Fig. 21 depicts schematic example of various physical signatures in various portions of 3D objects. Physical signatures 2102a-c depict example deviations in surfaces 2104a-c of portions of 3D objects. A physical signature 2102a comprises (A) an intrusion 2106 into surface 2104a and (B) a deviation of curvature 2108 of the surface 2104a from a requested curvature 2110. A physical signature 2102b comprises (A) an intrusion 2112 into surface 2104b and (B) a deviation of curvature 2114 of the surface 2104b from a requested curvature 2116. A physical signature 2102c comprises (A) an intrusion 2118 into surface 2104a. As depicted in Fig. 21 , a curvature 2120 of surface 2104c is (substantially) aligned with a requested curvature 2122. The deviation in a 3D object can be any of the deviations 2104a-c. The deviation in a 3D object can be any of the deviation portions 2108, 2106, 2116, 2115, 2118. At times, surface 2130 of a portion of a 3D object includes a plurality of physical signatures 2132. The plurality of physical signatures may have periodic spacing or non-periodic spacing with respect to a build axis, e.g., along a z-axis. The periodic spacing may correspond to an integer number times that a block translation is performed, e.g., the block translation being performed by a first piston. As depicted in the example shown in Fig. 21 , surface 2130 (e.g., viewed from a XZ plane) includes a plurality of physical signatures 2132 that are (i) spaced apart by a vertical distance “A,” thus forming a periodically occurring physical signature along portion 2134 of surface 2130 having the vertical periodicity “A”; and (ii) spaced apart by two different vertical distances “A” and “B” along portion 2136 of surface 2130, thus forming a non-periodic repetition of the physical signature along surface 2130. The physical signatures 2132 appear as divots on the surface 2130, corresponding to one or more layers of the 3D object including the physical signatures. In fig.

21 , the vertical axis extends along the z-axis. Surfaces 2130, and 2104a-c are viewed along the XZ plane. Fig. 21 depicts an example of a 3D object generated using a block movements having different vertical spans (e.g., height): “A,” “B,” and “C.” Fig. 21 depicts an example of a vertical cross-section in a 3D object 2140 as viewed from a YZ plane, including a plurality of physical signatures 2142 having periodic vertical spacing in surface portion 2144, the physical signature being spaced apart by a periodicity distance “A”; and non-periodic spacing in portion 2146 that includes spacing “A,” “B,” and “C;” the arrangement of the physical signatures and distances is with respect to the vertical axis, here the z-axis. 3D object 2140 comprises a plurality of layers (not shown) printed using a 3D printing process that includes a block translation and layerwise translation. A vertical span (e.g., extent) of the block translation corresponds to vertical distance “A” such as in portion 2143. The 3D object comprises a plurality of layers having respective surfaces oriented along the XY plane. The layers of the block 2143 are printed using the layerwise translation. The printed layers substantially overlap, and have minimal (e.g., zero) physical signatures, e.g., a non-detectable, a negligible, or an insubstantial physical signature. The physical signatures 2142 may occur due to the block translation. Such physical signature appears as deviations (e.g., horizontal lines along the YX plane) on the surface of 3D object 2140, corresponding to the physical signatures. Physical signatures 2142 can be imprinted due to bowing (e.g., inward deviation, and outward deviation) from a requested surface 2147, e.g., depicted as a dashed line. The bowing may or may not propagate over several layers of hardened material. In the example shown in 2140, the bowing propagates over a plurality of subsequent layers in a block. Each block movement taking place during the printing of 3D object 2140 is schematically separated by dotted line such as 2148. For example, 3D object 2140 is printed using three block movements spanning a vertical distance corresponding to “A,” one block movements spanning a vertical distance corresponding to “B,” and one block movements spanning a vertical distance corresponding to “C.” 3D object 2140 is printed using a non-periodic block movement. Fig. 21 shows an example of 3D object 2150 shown as a vertical cross section. 3D object 2150 is printed using a periodic block movement spanning vertical distance “A.” Each block movement taking place during the printing of 3D object 2150 is schematically separated by dotted line such as 2158. 3D object 2150 includes physical signatures 2152, and 2154. Physical signature 2152 is generated by an offset in a requested overlap of a first layer in block 2156 with respect to its immediately adjacent second layer in block 2158, the offset being in direction 2161. Physical signature 2154 is generated by an offset in a requested overlap of a third layer in block 2162 and its immediately adjacent fourth layer in block 2164 of the 3D object 2150, the offset being in a direction 2160 opposing direction 2161. Two layers that are immediately adjacent are devoid of an intervening layer therebetween. 3D object 2150 thus depicts two physical signatures that indicate (i) a block movement spanning vertical distance, “A;” and (ii) two block movements spanning accumulated vertical distance “2A” that is an integer multiplier of the periodic block movement spanning vertical distance “A.”

[0272] In some embodiments, the build platform assembly comprises temperature conditioning, e.g., as disclosed herein. A temperature adjustment interconnect may condition a temperature of at least a portion of the build platform assembly such as of the build platform, at a time comprising before, during, or after forming (e.g., printing) the 3D object. Conditioning a temperature of at least the portion of the build platform assembly may comprise adjusting a temperature of the portion of the build platform assembly and a region surrounding the portion of the build platform assembly. Conditioning the temperature may comprise adjusting a temperature (e.g., raising or lowering a temperature) of the portion of the build platform assembly by any temperature value disclosed herein. For example, conditioning the temperature may be reducing or raising a temperature of the portion of the build platform assembly by at least about 1500°C, 1000°C, 500°C, 250°C, 200°C, 100°C, or 50°C

[0273] In some embodiments, temperature conditioning occurs before, during and/or after the printing. The temperature conditioning may be controlled manually and/or automatically, e.g., using at least one controller such as the one disclosed herein. Fig. 22 depicts schematic views of an example of 3D printer component. Build platform assembly 2200 includes a first piston 2202 and a second piston 2204. Build platform assembly 2200 includes a temperature adjustment component 2206 comprising one or more channels (e.g., pipes). The temperature adjustment component may or may not be a manifold. The temperature adjustment component 2206 may be operatively coupled with a temperature adjustment source (not shown), for example, a gas source and/or a water circulation source. The temperature adjustment source may comprise a coolant, e.g., as disclosed herein. Temperature adjustment component 2206 includes channel(s) 2208. Temperature adjustment component includes an internal portion including a channel extending to shafts 2210, 2212. Shafts 2210, 2212 include a respective inlet 2214 and outlet 2216 that can allow flow of an active temperature adjustment agent (e.g., water or gas) into an internal portion of the build platform assembly 2200 via the inlet 2214 and a flow of temperature adjustment agent out of the internal portion of the build platform via the outlet 2216. The temperature adjustment component includes passageway(s) (e.g., channel such as pipe) 2218 internal to the build platform assembly 2200. Passageway(s) 2218 can be utilized to adjust a temperature of build platform 2220 engaged with the build platform assembly 2200. The passageway(s) 2218 can be adjacent to a surface of the build platform 2220 or within a portion of the build platform 2220. As depicted in Fig. 22, passageway(s) 2218 include serpentine passageway(s). In some embodiments, the cavity below the build platform is devoid of passageway(s), and may accommodate flowing temperature adjustment agent that is not directed. In some embodiments, the cavity below the build platform comprises a passive temperature adjustment, e.g., a passive heatsink, or a slab of temperature conductive material such as the one disclosed herein.

[0274] In some embodiments, the 3D printing system comprises a controller. The controller may include one or more components. The controller may comprise a processor. The controller may comprise a specialized hardware (e.g., electronic circuit). The controller may be a proportional-integral-derivative controller (PID controller). The control may comprise dynamic control (e.g., in real time during the 3D printing process). For example, the control of the (e.g., transforming) energy beam may be a dynamic control (e.g., during the 3D printing process). The PID controller may comprise a PID tuning software. The PID control may comprise constant and/or dynamic PID control parameters. The PID parameters may relate a variable to the required power needed to maintain and/or achieve a setpoint of the variable at any given time. The calculation may comprise calculating a process value. The process value may be the value of the variable to be controlled at a given moment in time. For example, the process controller may control a height of at least one portion of the layer of hardened material that deviates from the average surface of the target surface (e.g., exposed surface of the material bed) by altering the power of the energy source and/or power density of the energy beam, wherein the height measurement is the variable, and the power of the energy source and/or power density of the energy beam are the process value(s). The variable may comprise a temperature or metrological value. The parameters may be obtained and/or calculated using a historical (e.g., past) 3D printing process. The parameters may be obtained in real time, during a 3D printing process. During a 3D printing process, may comprise during the formation of a 3D object, during the formation of a layer of hardened material, or during the formation of a portion of a layer of hardened material. The calculation output may be a relative distance (e.g., height) of the material bed (e.g., from a cooling mechanism, bottom of the enclosure, optical window, energy source, or any combination thereof).

[0275] In some embodiments, a controller of a 3D printing system comprises a metrological detection system. The metrological detection system may be used in the control of 3D printing processes of the 3D printing system. The metrological detection system may be configured to detect distance variations such as vertical distance variations, e.g., height variations. The metrological detection system may be configured to detect height variations in a planar surface, e.g., a planar exposed surface of a material bed. The metrological detection system may comprise a height mapper system. The metrological detection system may comprise an interferometric optical system. The metrological detection system may comprise a position sensitive device system. The metrological detection system may comprise an optical detector. The metrological detection system may include, or be operatively coupled with, an image processor. The metrological detection system may comprise an imaging detector to monitor irregularities. The image detector may comprise a camera such as a charged coupled device (CCD) camera. The image detector may comprise detecting a location or an area of the printed 3D object and convert it to a pixel in the X-Y (e.g., horizontal) plane. The image detector may comprise detecting an interference pattern generated by an interferometric beam path. The image detector may comprise detecting position of a beam incident on the image detector relative to an imaging region of the image detector. The controller may comprise one or more computational schemes to convert data (e.g., measurement data) from the metrological detection system to generate a result. The one or more computational schemes may be utilized to determine one or more aspects of the build platform assembly and/or of the target surface, e.g., the exposed surface of the material bed or the build platform surface. The one or more aspects may comprise positional aspects, or localization aspects. The one or more aspects may be absolute or relative. For example, an aspect can include a physical orientation of a moving component of the build module, the moving component comprising a base, substrate, build platform assembly, or piston assembly, where the piston assembly comprises the substrate (also herein, “piston”) and the build module assembly comprises the base (also herein “build platform”). The physical orientation may comprise a relative orientation (e.g., relative to a requested orientation) or an absolute orientation (e.g., relative to a coordinate axis). For example, an aspect may comprise a relative orientation of the target surface with respect to requested orientation, e.g., characterizing offset value(s) of the target surface from requested value(s). For example, an aspect may include (a) a height (e.g., along a z-axis) of the target surface, (b) an XY position(c) a rotation of the target surface, or (d) any combination of (a), (b), and (c). The rotation of the target surface may include (A) pitch or roll (e.g., due to movement around the horizontal axis) of the target surface, (B) yaw (e.g., due to movement around the vertical axis) of the target surface, or (C) any combination of (A) and (B). The XY position may be (i) of the target surface and/or (ii) of a 3D object carried by the build platform. The controller may utilize one or more computational schemes to measure a height (e.g., along a z-axis) of the target surface (e.g, a phase shift computational scheme). The computational scheme may comprise an algorithm. The controller may utilize a computational scheme comprising a (e.g., digital) modulation scheme that conveys data by changing (e.g., modulating) the phase of a reference signal (e.g., carrier wave).

[0276] In some embodiments, to facilitate a 3D printing process, a metrological detection system measures an aspect of a moving component of the build module, the moving component comprising a base, substrate, build platform assembly, or piston assembly, where the piston assembly comprises the substrate (also herein, “piston”) and the build module assembly comprises the base (also herein “build platform”). The aspect may be measured before, during, and/or after any 3D printing process described herein. For example, the aspect may be measured in real time during the 3D printing process. For example, the aspect may be measured before, during, and/or after a translation of the build platform assembly. For example, the aspect may be measured before, during, and/or after a layer of pre-transformed material is deposited on a target surface. For example, the aspect may be measured before, during, and/or after a lasing process to form transformed material. The aspect may be measured and processed before, during, and/or after any 3D printing process described herein. For example, the aspect may be measured and processed in real time during the 3D printing process. For example, the aspect may be measured and processed before, during, and/or after a translation of the build platform assembly. For example, the aspect may be measured and processed before, during, and/or after a layer of pre-transformed material is deposited on a target surface. For example, the aspect may be measured and processed before, during, and/or after a lasing process to form transformed material. An aspect of the moving component of the build module may comprise (i) an orientation about an XY plane (e.g., perpendicular to a gravitational vector), (ii) an orientation along a z-axis (e.g., parallel to the gravitational vector), (iii) a rotation about a z-axis (e.g., with respect to the gravitational vector), or (v) a combination thereof. The rotation may comprise a pitch, a roll, or a yaw, e.g., with respect to the gravitational vector. For example, a position sensitive detector system may measure an orientation of the moving component of the build module assembly about the XY plane. For example, an interferometric detection system may measure an orientation along the z-axis, a rotation of the moving component of the build module, the rotation comprising a pitch, a roll, or a yaw. For example, a height mapper system may measure (A) an orientation of the moving component of the build module about the XY plane and/or (B) an orientation along the z-axis of the moving component of the build module, respectively. At times, the metrological detection system may measure a positional deviation (e.g., error, offset, deflection) in an aspect of the moving component of the build module. For example, a positional deviation in the aspect may be an offset from a request position. A positional deviation in an aspect of the moving component of the build module, may occur due to variations in 3D printing processes. For example, introduction of a contaminant (e.g., pre-transformed material, transformed material, and/or debris) between the moving component of the build module and an inner surface of the build module body may result in a positional deviation in an aspect, e.g., a position of the moving component of the build module relative to a requestion position. For example, positioning errors due to encoder, actuators, or the like may result in a deviation in an aspect of the moving component of the build module. Measurements collected by the metrological detection system may be utilized by one or more controllers, for example, to provide feedback controls to one or more control systems. For example, the one or more controllers may process, or direct processing, the measurements at a time including before, after and/or during the 3D printing process (e.g., in real time). The one or more controllers may be integrated in a control system that controls the 3D printing process (e.g., the recoater, gas flow system, and/or energy beam(s)). The control system may be a hierarchical control system. The control system may comprise a least three hierarchical control levels.

[0277] In some embodiments, a metrological detection system comprises an interferometric detection system. An interferometric detection system may comprise a plurality of optical components. The plurality of optical components may comprise mirrors, lenses, prisms, fibers, or another optical component disclosed herein. The interferometric detection system may comprise at least one energy source, e.g., a laser source. The interferometric detection system may comprise a plurality of energy sources, e.g., three or more energy sources. Each energy source may generate an energy beam along a respective beam path. At times, the interferometric detection system is configured to divide (e.g., split) an energy beam from an energy source into a plurality of beam paths, e.g., two beam paths, three beam paths, or more. The interferometric detection system may comprise a beam splitter to divide the energy beam from the energy source into the two or more beam paths. The interferometric detection system may comprise an encoder. The encoder may comprise any encoder disclosed herein. The encoder may comprise a laser encoder, e.g., a fiber optic interferometric laser encoder. The encoder may be mounted on a bottom portion (e.g., floor) of the build module, e.g., affixed to a floor of the build module body. The encoder may be arranged facing (e.g., directed towards) a surface of the build platform assembly. For example, the encoder may be arranged facing a bottom surface of the first piston assembly, wherein bottom is with respect to a gravitational vector. At times, the interferometric detection system comprises a mirror, for example, a retroreflector. The retroreflector may be mounted on the bottom surface of the first piston assembly and opposite the encoder along a vertical axis (e.g., with respect to the gravitational vector). The interferometric detection system may comprise a plurality of beam paths, e.g., two beam paths, three beam paths, four beam paths, or more. The interferometric detection system may comprise a beam path. Each beam path may traverse from a respective encoder arranged at a base of the build module body to a retroreflector arranged on a bottom surface of the first piston assembly. Beam path(s) may traverse through opening(s) (e.g., a window) defined in the body of the second piston assembly (e.g., a lower piston assembly with respect to a gravitational center). The beam paths may be distributed about a circumference of the build platform assembly, e.g., about a rotational axis of the build platform assembly. The beam paths may be distributed (substantially) equidistant from each other beam path. The beam paths may reflect from respective retroreflectors arranged on the bottom surface of the first piston assembly and traverse back through the respective openings defined in the second piston assembly and be incident on the respective encoders. The original beam path and the reflected beam path may be incident on a detector. An interference pattern generated between an original beam path and the reflected beam path may be detected by the fiber optic laser encoder. The interference pattern may comprise information related to a height of the bottom surface of the first piston assembly with respect to a floor of the build module body. The height may be along a z-axis, along a vertical axis, and/or along a gravitational vector. Interference patterns generated by respective beam paths may comprise information related to a pitch, a roll, and/or a yaw of the bottom surface of the first piston assembly with respect to the floor of the build module body. One or more controllers may utilize the information from the interference patterns to determine a pitch, roll, yaw, and/or height along a z-axis of the moving build module component. At times, the interferometric detection system may comprise a resolution of at most about 2 microns (pm), 1.5 pm, 1 pm, 0.75 pm, 0.5 pm, or less.

[0278] Fig. 23 depicts schematic views of example various metrological detection systems. As depicted in Fig. 23 build module 2300 includes an interferometric detection system 2302. The interferometric detection system 2302 includes beam paths 2304 distributed about a circumference of the build module 2300. Interferometric detection system 2302 includes at least one energy beam from an energy source (not shown), e.g., a fiber-coupled laser source. At times, one energy source 2306 can be divided into two or more energy beams along respective beam paths, e.g., by a beam splitter (not shown). Each energy beam is coupled with a respective encoder 2308, e.g., a fiber coupled laser encoder. Interferometric detection system 2302 includes mirrors 2310, e.g., retroreflectors. Encoder 2308 (e.g., or a fiber-coupled laser encoder) can be located on a surface 2312 of a bottom portion (e.g., floor) 2314 of the build module 2300. The beam paths 2304 can be aligned with windows 2316 of a first piston 2318 of the build platform assembly 2320 such that an energy beam passes through the windows 2316 (substantially) unattenuated. Energy beams along beam paths 2304 can be incident on the mirrors 2310 located opposite the encoders 2308 on a surface 2322 of a second piston 2324 of the build platform assembly 2320. The reflected energy beams can propagate along the same respective beam paths 2304 through the windows 2316 and be incident on respective encoders 2308. A distance 2326 between the surface 2322 of the second piston 2324 and the surface 2312 of bottom portion 2314 along a z-axis, e.g., aligned with gravitational vector 2390, can be determined based in part of an interference pattern formed at the encoder 2308 between an original energy beam and a reflect energy beam for a beam path 2304. Two or more beam paths 2304 can each be utilized to generate respective measurements of distance 2326, e.g., to yield information about a pitch, roll, yaw of the second piston 2324 of the build platform assembly 2320. Information about pitch, roll, yaw, and height along the z-axis of the second piston 2324 can be utilized, e.g., by a controller, to determine positional orientation of a build platform engaged with the build platform assembly 2320. As depicted in Fig. 23, a portion of a build module 2350 includes a build platform assembly 2352. A portion of a metrology detector (e.g., an encoder) 2354 located on a surface 2356 of a bottom portion 2358 of the build module 2350 can align with a retroreflector (not shown) on a surface 2360 of a second piston 2362 of the build platform assembly 2352. An energy beam can propagate along beam path 2364 and pass through a window 2366 in a first piston 2368 of the build platform assembly 2352 to be incident on the retroreflector. A reflected energy beam can propagate on a beam path through the window 2366 and be incident on the portion of the metrology detector (e.g., encoder) 2354. [0279] In some embodiments, a metrological detection system comprises a position sensitive detector (PSD) system. The PSD system may comprise an energy source, e.g., a fiber coupled laser source. The PSD may comprise a plurality of energy sources, e.g., two energy sources, three energy sources, four energy sources, or more. The PSD may comprise an energy source and a beam-splitter configured to split (e.g., divide) an energy beam from the energy source into two or more beam paths, e.g., three beam paths, four beam paths, or more. The beam paths may be arranged to launch into free space from a bottom of the build module body (e.g., with respect to a gravitational center) and arranged to traverse vertically along a z-axis of the build module body. The PSD system may comprise a position sensitive detector (PSD). The PSD system may comprise a plurality of PSDs, e.g., two PSDs, three PSDs, four PSDs, or more. The PSDs may be arranged on a bottom surface of the first piston (e.g., an upper piston with respect to a gravitational center) opposite a respective beam path and configured to receive the respective beam path within a detection region of the PSD. Each beam path may traverse through a respective opening (e.g., an optical window) defined in the body of the second piston assembly (e.g., a lower piston assembly with respect to a gravitational center). The beam paths may be distributed about a circumference of the build platform assembly, e.g., about a rotational axis of the build platform assembly. The beam paths may be distributed (substantially) equidistant from each other beam path. A location of incidence of the energy beam within a detection region of the PSD may comprise information related to an orientation of the bottom surface of the first piston assembly with respect to an XY plane perpendicular to the gravitational vector. A location of incidence of the energy beam within a detection region of the PSD may comprise information related to a rotational orientation of the bottom surface of the first piston assembly with respect to central axis oriented along the gravitational vector. One or more controllers may utilize the information from the PSDs to determine an offset of the build platform about the XY plane and/or a rotational offset of the build platform engaged with the build platform assembly and/or of a target surface with respect to a requested orientation.

[0280] Fig. 24 depicts schematic views of example metrological detection systems. As depicted in Fig. 24 build module 2400 includes a position sensitive detector (PSD) system 2402. The PSD system 2402 includes beam paths 2404 distributed about a circumference of the build module 2400. The PSD system 2402 includes an energy beam from an energy source 2406 e.g., a fiber-coupled laser source. At times, one energy source 2406 can be divided into two or more energy beams along respective beam paths, e.g., by a beam splitter (not shown). PSD system 2402 includes detectors 2410, e.g., positive sensitive detectors. Energy source 2406 can be located on a surface 2412 of a bottom portion (e.g., floor) 2414 of the build module 2400. Energy beams can propagate along beam paths 2404 through windows 2416 of a first piston 2418 of the build platform assembly 2420. Energy beams propagating on beam paths 2404 can be incident on the detectors 2410 located opposite the energy source 2406 on a surface 2422 of a second piston 2424 of the build platform assembly 2420. A location of incidence of the energy beam within a detection region of the detector 2410 may comprise information related to a rotational orientation and/or XY offset (e.g., perpendicular to gravitational vector 2490) of the bottom surface of the second piston 2424 with respect to axis 2426 oriented along the gravitational vector 2490. Two or more beam paths 2404 can each be utilized to provide a measurement. Information about rotational orientation and/or XY offset of the second piston 2424 can be utilized, e.g., by a controller, to determine positional orientation of a build platform engaged with the build platform assembly 2420. As depicted in Fig. 24, a portion of a build module 2450 includes a build platform assembly 2452. An energy source 2454 (e.g., of a metrology detector such as an interferometer) located on a surface 2456 of a bottom portion 2458 of the build module 2450 can align with a detector 2451 (e.g., position sensitive device), orientated on a surface 2460 of a second piston 2462 of the build platform assembly 2452. A beam path 2464 can pass through a window 2466 in a first piston 2468 of the build platform assembly 2452.

[0281] In some embodiments, a metrological detection system comprises a height mapper system. The height mapper system may comprise one or more detectors (e.g., cameras), and an optical image generator. The one or more detectors may comprise a metrological detector. The optical image generator may comprise a projector or a laser. The optical image generator may generate a detectable oscillating (e.g., fluctuating) optical image, e.g., as disclosed herein. The optical image generator may project an oscillating image having areas of detectable different optical intensity. The height mapper system may include (1) one or more optical detectors, and (2) one or more projectors. The height mapper system may comprise, or be operatively coupled with, one or more processors configured to process the detected image. The one or more processors may be operatively coupled with, or part of, one or more controllers. The one or more controllers (e.g., control system) may be the control may be configured to control the 3D printing of one or more 3D objects. The control system may be a hierarchical control system (e.g., comprising three or more hierarchical levels of control). At times, the height mapper system may comprise a first detector and an additional detector distant from the first detector. The additional detector can be disposed distant from the first optical image generator that is configured to project the image on the exposed surface from another angle. The location of the additional detector can alleviate detection issues, e.g., due to specular reflection, by projecting an image on the exposed surface that will not cause saturation of the detector. At times, the height mapper system may comprise a first projector and an additional projector distant from the first projector. The additional projector can be disposed distant from the detector that is configured to detect the image on the exposed surface. The location of the additional projector can alleviate detection issues, e.g., due to specular reflection, by projecting an image on the exposed surface that will not cause saturation of the detector.

[0282] In some embodiments, the height mapper system projects an image, e.g., a light pattern, onto a target surface (e.g., exposed surface of a material bed). The target surface may comprise a protruding object such as a marker object, or at least a portion of the 3D object. The target surface may include a protruding object. The projected image may be a projected pattern. The projected image may be an oscillatory (e.g., fluctuating) pattern. The height mapper system may operate during at least a portion of the 3D printing. For example, the height mapper system can project an image before, after, and/or during the operation of the transforming energy beam. The projected image may comprise a shape. The shape may be a geometrical shape. The shape may be a rectangular shape. The shape may comprise a line. The shape may scan the target surface (e g., exposed surface of the material bed) laterally, for example, from one side of the target surface to its opposing side. The shape may scan at least a portion of the target surface (e.g., in a lateral scan). The scan may be along the length of the exposed surface. The projected shape may span (e.g., occupy) at least a portion of the width of the target surface. For example, the shape may span a portion of the width of the target surface, the width of the target surface, or exceed the width of the target surface. The shape may scan the at least a portion of the target surface before, after and/or during the 3D printing. The scan may be controlled manually and/or automatically (e.g., by a controller). The projected shape may be of an electromagnetic radiation (e.g., visible light). The projected shape may be detectable. The projected shape may scan the target surface at a frequency of at least about 0.1 Hertz (Hz), 0.2Hz, 0.5Hz, 0.7Hz, 1Hz, 1.5Hz, 2Hz, 3Hz, 4Hz, 5Hz, 6 Hz, 7 Hz, 8 Hz, 10 Hz, 20 Hz, 50 Hz, 100 Hz, 200Hz, 300Hz, 400Hz, or 500Hz. The projected shape may scan the target surface at a frequency between any of the afore-mentioned frequencies (e.g., from about 0.1 Hz to about 500 Hz, from about 1 Hz to about 500 Hz, from about 1 Hz to about 100 Hz, from about 0.1 Hz to about 100 Hz, from about 0.1 Hz, to about 1 Hz, from about 0.5Hz to about 8 Hz, or from about 1Hz to about 8Hz). The image may comprise (e.g., alternating) stripes. The distance between the stripes may be constant. The distance between the stripes may be variable. The distance between the stripes may be varied (e.g., manually or by a controller) in real time. Real time may be when performing metrological detection. Real time may be when building (e.g., printing) the 3D object. The deviation from the regularity (e.g., linearity) of the stripes may reveal a height deviation from the average (or mean) exposed surface (e.g., of the material bed) height. The shape of the deviation from regularity (e.g., linearity) may reveal a shape characteristic of the buried 3D object portion (that is buried in the material bed). The deviated (e.g., curved) lines above a 3D object may relate to a warping of the 3D object that is (immediately) underneath. The regularity (e.g, linearity) of the lines detected above the 3D object may relate to the planarity of the top surface of the 3D object that is (immediately) underneath. For example, lines above the 3D object (whether buried in the material bed, or exposed) that match the regularity of the projected image, may reveal a planar top surface of a 3D object. For example, a deviation from the regularity of the projected image above the 3D object (whether buried in the material bed, or exposed), may reveal a deformation in the top surface of a 3D object. For example, linear lines above the 3D object may reveal a planar top surface of a 3D object, when the metrology projector projects stripes. For example, non-linear (e.g., curved) lines above the 3D object may reveal a non-planar (e.g., curved) top surface of a 3D object, when the metrology projector projects stripes. The reflectivity of the target surface may indicate the planar uniformity of the exposed surface. At times, a fluctuating pattern may be apparent on at least a portion of the target surface. In some embodiments the fluctuating pattern is detectable (e.g., may appear) on at least a portion of the target surface, wherein fluctuating intensity pattern is presented as a function of location (e.g., of at least a portion of the target surface). [0283] At times, the height mapper system detects a planar target surface that deviates from its horizontal placement. The target surface may or may not have protruding 3D objects therefrom. The deviation from planarity may cause a deviation (e.g., deformation) in the projected image apparent on the planar surface that is horizontally oriented as compared to the original image utilized for the projection. For example, the projected image includes parallel rectangular shapes. When this image is projected on the target surface that is horizontally oriented, the shapes will be detected as parallel and rectangular. When this image is projected on the target surface that deviates from its horizontal placement (e.g., on a slanted surface), the image detected may include trapezoid shapes instead of the rectangular shapes. The degree of deviation between the rectangular shape to the trapezoid shape may be indicative on the degree and direction of deviation from planarity of the target surface. The size of the features (e.g., shapes) of the image as projected onto the target surface, may facilitate determination of the vertical distance of the target surface from the detector and/or projector. This distance may correlate to a distance from the floor of the build module.

[0284] Fig. 25 illustrates an example of a device comprising a plurality of window holders 251 Oa-f disposed in two manifolds. Each of holders 2510a-d is supporting each of windows 2504a-d, respectively. The windows are similar to the optical windows depicted in Fig. 9, 958. Each of holders 2510e-h is supporting each of windows 2504e-h, respectively. The device comprising the optical windows 2504a-h is configured for disposition at a ceiling of a processing chamber in which one or more 3D object can be printed. Each of the windows 2504a-h is configured to facilitate passage of a transforming energy beam into the processing chamber. The device in figure 25 comprises two components 2501 and 2502 of a first type, and component 2503 of a different type. The first type can be a detector (e.g., a camera), and the second type can be a projector configured to project an image. The second type can be a detector (e.g, a metrological detector), and the first type can be a projector configured to project an image. Examples of gas flow system, 3D printers, related control system, related methods, apparatuses, systems, and program instructions (e g., software), can be found in International Patent Application Serial No. PCT/US22/16550 filed February 16, 2022; and U.S. Patent Application Serial No. 17/986,814 filed November 14, 2022, which are each incorporated herein by reference in their entirety.

[0285] Fig. 26 shows an example of a metrological detector (e.g., included in a height mapper system) which projects a striped image on the exposed surface of a material bed (e.g., powder bed), which image comprises darker stripes 2601 and lighter stripes 2602. The material bed in the example of Fig. 26 is an Inconel 718 powder bed. In the example shown in Fig. 26, a 3D object 2605 is partially buried in the material bed and lifts a portion of the pre-transformed material (e.g., powder) of the material bed such that a deviation from the linearity of the stripes is visible. A portion 2603 of the 3D object 2605 is reflective, whereas the material bed is substantially less reflective. The deviated (e.g., curved) lines above a 3D object may relate to a warping of the 3D object (e.g., 2605) that is (immediately) underneath. The shape of the deviation from regularity (e.g., linearity) may reveal a shape characteristic of the buried 3D object portion (that is buried in the material bed). For example, the lines above the exposed surface 2604 of the 3D object are (e.g., substantially) linear, whereas the lines above the 3D object 2605 curve. The deviated (e.g., curved) lines above a 3D object may relate to a warping of the 3D object that is (immediately) underneath. The regularity (e.g., linearity) of the lines detected above the 3D object may relate to the planarity of the top surface 2604 of the 3D object 2605 that is (immediately) underneath.

[0286] In some embodiments, the 3D printing system comprises a control system. The control system may comprise one or more controllers. The control system may comprise, or be operatively coupled with, one or more devices, apparatuses, and/or systems of the 3D printing system, including any component of the device(s), apparatuses(s), and/or system(s). The controller(s) may comprise, or be operatively coupled with, a hierarchical control system. The hierarchical control system may comprise at least three, four, or five, control levels. In some embodiments, at least two operations are performed, or directed, by the same controller. In some embodiments, at least two operations are each performed, or directed, by a different controller. A control system may comprise a build module control system. A control system may comprise a laser control system. The controller may comprise a feedback control scheme. The feedback control scheme may comprise an open feedback loop control scheme. The feedback loop control scheme may comprise a closed feedback loop control scheme. Feedback control scheme may comprise hardware compensation. Feedback control scheme may comprise software compensation. The control system may comprise, or be operatively coupled with, a metrological detection system and configured to receive measurement data from the metrological detection system. The control system may be configured to generate control signals responsive to the measurement data collected by the metrological detection system. [0287] In some embodiments, the control system comprises a build module control system. The build module control system may comprise, or be operatively coupled with, one or more components of the build module, e.g., the build platform assembly, one or more interconnects, actuators, encoders, seals, shutters, or the like. At times, the build module control system is operable to control operations comprising translational movement (e.g., vertical translational movement) of the build platform assembly. The build module control system may be operable to control operations comprise translational movement of the one or more piston assemblies. The build module control system may be operable to control operations comprise translational movement of the telescopic unit. The build module control system may be operable to control operations related to the one or more engagement mechanisms of the build platform assembly (e.g., engaging/disengaging the engagement mechanisms). The build module control system may be operable to control operations comprising positioning of one or more translation stages, for example, any translation stage disclosed herein (e.g., of a theta/phi goniometer, rotational stage, XY stage, or XYZ stage). [0288] At times, the build module control system comprises, or is operatively coupled with, a build platform assembly. The build module control system may comprise, or be operatively coupled with, one or more piston assemblies of the build platform assembly. The build module control system may comprise, or be operatively coupled with, engagement mechanism(s) of the build platform assembly. The build module control system may comprise a feedback loop configured to adjust a position of the build platform assembly, e.g., one or more components of the build platform assembly. For example, to adjust a vertical position relative to a gravitational vector of the piston assembly. For example, to adjust a rotational orientation relative to a central axis of the build module body. The build module control system may be configured to receive, from a metrological detection system, data comprising information related to an aspect of the piston assembly, e.g., positional deviation from a requested position. The positional deviation may comprise any positional deviation disclosed herein. The build module control system may generate a control signal to adjust the aspect, e.g., to adjust the position of the piston assembly. The control signal may be provided to an actuator of the piston assembly, e.g., a servo motor or any other actuator disclosed herein. The control signal may be provided to an actuator of the piston assembly or build platform assembly that causes the actuator to perform an operation, e.g., to adjust a vertical position of the piston assembly. The control signal may be provided to an actuator (e.g., a stepper motor or servo motor) of a translation stage that causes the actuator to perform an operation, e.g., to adjust a position of the translation stage coupled with the piston assembly and/or build platform. The build module control system may comprise plurality of feedback controls (e.g., control schemes) for respective translation movements. For example, a first feedback control for an initiation translation movement, a second feedback control for block translation movement, and a third feedback control for layerwise translation movement. An initiation translation movement feedback control may correspond to a position of the build platform assembly with respect to the build module body, e.g., by the telescopic unit. A block translation movement feedback control and/or a layerwise translation movement feedback control may correspond to a relative position of a first piston assembly with respect to a second piston assembly.

[0289] In some embodiments the control system comprises a laser control system. The laser control system may comprise, or be operatively coupled with, a laser system (e.g., optical system) of the 3D printing system, e.g., energy sources, optical components, motors, encoders, or the like. At times, the laser control system is operable to control operations of the optical system(s) of the 3D printing system. The laser control system may be operable to adjust operations the optical systems in response to a measured positional deviation of one or more aspects of the build module. The laser control system may be operable to adjust (e.g., calibrate) one or more characteristics of the irradiating energy (e.g., the energy beam) incident on the target surface, e.g., the exposed surface of the material bed. Adjusting one or more characteristics of the irradiating energy beam may comprise a software adjustment (e.g., calibration). Adjusting one or more characteristics of the irradiating energy beam may comprise a hardware adjustment (e.g., calibration).

[0290] In some embodiments, the laser control system is configured to calibrate one or more characteristics of the irradiating energy (e.g., energy beam) in response to a positional deviation of the target surface, build platform assembly, build platform, or piston assembly, from a requested position. For example, the laser control system may be configured to calibrate one or more characteristics of the irradiating energy in response to a positional deviation of the target surface about an XY plane and/or about a rotational axis of the target surface (e.g., rotation about a central axis). For example, the laser control system may calibrate (i) the position at which the irradiating energy contacts a surface (e.g., the target surface), (ii) the shape of the footprint of the energy beam at the (e.g., target) surface, (iii) the XY offset of a first energy beam position at the (e.g., target) surface with respect to a second energy beam position at the (e.g., target) surface, and/or (iv) the XY offset of the energy beam with respect to the (e.g., target) surface. The position at which the energy beam contacts the surface is the position at which the energy beam impinges on the surface.

[0291] In some embodiments, the laser control system is configured to calibrate one or more characteristics of the irradiating energy (e.g., energy beam). A calibration may include a comparison of a commanded (e.g., instructed) energy beam position (e.g., at the target surface) compared with an actual (e.g., measured) energy beam position at the target surface. The characteristics of the energy beam may be calibrated along a field of view of the optical system (e.g., and/or detector). The laser control system may calibrate characteristics of a processing cone of the energy (e.g., laser beam). The calibration of the focus mechanism may achieve a requested spot or footprint size for various locations in the field of view of the irradiating energy (e.g., intersection of the processing cone with the target surface and/or calibration structure surface). The power density distribution measure may be calibrated (e.g, substantially) identically, or differently, along the field of view of the irradiating energy. In some embodiments, different positions in the field of view may require different focus offsets and/or or footprint size. Processing cone coverage of the material bed can depend in part on dimensions of one or more of the mirrors of a scanner, e.g., galvanometric scanner, utilized to direct a path of the energy beam about the target surface. Laser control systems, control systems, controllers and operation thereof, 3D printing systems and processes, apparatus, methods, computer programs, are disclosed in International Patent Application Serial No. PCT/US19/14635 filed January 22, 2019, titled “CALIBRATION IN THREE-DIMENSIONAL PRINTING;” and U.S. Provisional Patent Application Serial No. 63/290,878 filed on December 17, 2021 , titled “MANIPULATION AND ALIGNMENT OF ENERGY BEAMS IN THREE-DIMENSIONAL PRINTING;” each of which is incorporated herein by reference in its entirety.

[0292] At times, a calibration comprises generated a compensation for one or more characteristics of the laser system. A compensation may be effectuated at least in part by a (e.g., energy beam) calibration. At times, an energy beam calibration comprises formation of one or more (e.g., physically printed or optically projected) alignment markers using at least one energy beam directed at a target surface. The one or more alignment markers may form an arrangement (e.g., a pattern). The position(s) of the marker(s) may be according to a requested (e.g., pre-determined) arrangement (e.g., a reference pattern). Requested may be according to a commanded arrangement as directed by commands to a guidance system for directing the energy beam(s). The arrangement (e.g., position(s)) of the one or more alignment markers may be detected by a detection system. The detected position(s) (e.g., measured position(s)) of the alignment marker(s) may be compared to commanded (e.g., requested) position(s). The energy beam calibration may comprise correction (e.g., compensation) of any deviation of the detected position(s) from the commanded position(s). The deviation of the detected position(s) from the commanded position(s) may be caused in part by (a) thermal effects on the energy beam and/or optical components, (b) position deviation of the target surface, (c) a non-uniformity of layer deposition, or (d) a combination thereof. Following application of the (e.g., initial) compensation to the energy beam (e.g., to the guidance system directing the energy beam), further (e.g., additional) calibration may be performed. Further calibration may (e.g., iteratively) improve the compensation of the any deviation between the detected position(s) from the commanded position(s) of the energy beam at the target surface. The deviation may depend on the nature and/or geometry of one or more optical elements of the optical system. The calibration may comprise altering the one or more elements (e.g., position thereof) of the optical system. The calibration may comprise altering a command to one or more elements of the optical system and/or to the energy source.

[0293] In some embodiments, the control system utilizes data from a metrological detection system. The control system may use the data to control one or more parameters of the 3D printing. For example, the control system may use the metrology data to control one or more parameters of the layer dispensing mechanism (e.g., the material dispenser, the leveling mechanism, and/or the material removal mechanism). For example, the metrological measurement(s) may facilitate determination and/or subsequent compensation for a roughness and/or inclination of the exposed surface of the material bed with respect to the platform and/or horizon. The inclination may comprise leaning, slanting, or skewing. The inclination may be in two or three dimensional. The inclinations may be in the X, Y, and/or Z axis in a Cartesian coordinate system. The inclination may comprise deviating from a planar surface that is parallel to the platform and/or horizon. The roughness may comprise random, or systematic deviation. The systematic deviation may comprise waviness. The systematic deviation may be along the path of the material dispensing mechanism (e.g., along the platform and/or the exposed surface of the material bed), and/or perpendicular to that path. For example, the controller may direct the material dispenser to alter the amount and/or rate of pre-transformed material that is dispensed. For example, the controller may direct alteration of a target height according to which the leveling mechanism planarizes the exposed surface of the material bed. For example, the controller may direct the material removal member to alter the amount and/or rate of pre- transformed material that is removed from the material bed (e.g., during its planarization). The control system may use the metrology data to control one or more parameters of the energy source and/or energy beam. The one or more measurements from the metrological detection system may be used to alter (e.g., in real time, and/or offline) the computer model. For example, the metrological detection system measurement(s) may be used to alter the optical proximity correction data. For example, the metrological detection system measurement(s) may be used to alter the printing instruction of one or more successive layers (e.g., during the printing of the 3D object).

[0294] In some embodiments, the detector and/or controller averages at least a portion of the detected signal overtime (e.g., period). In some embodiments, the detector and/or controller reduces (at least in part) noise from the detected signal (e.g., over time). The noise may comprise detector noise, sensor noise, noise from the target surface, or any combination thereof. The noise from the target surface may arise from a deviation from planarity of the target surface (e.g., when a target surface comprises particulate material (e.g., powder)). The reduction of the noise may comprise using a filter, noise reduction algorithm, averaging of the signal overtime, or any combination thereof.

[0295] In some embodiments, the controller (e.g., continuously, or intermittently) calculates an error value during the control time. The intermittent calculation may or may not be periodic. The error value may be the difference between a requested setpoint and a measured process variable. The control may be continuous control (e.g., during the 3D printing process, during formation of the 3D object, and/or during formation of a layer of hardened material). The control may be discontinuous. For example, the control may cause the occurrence of a sequence of discrete events. The control scheme may comprise a continuous, discrete, or batch control. The requested setpoint may comprise a temperature, power, power density, or a metrological (e.g., height) setpoint. The metrological setpoint may relate to the target surface (e.g., the exposed surface of the material bed). The metrological setpoints may relate to one or more height setpoints of the target surface (e.g., the exposed (e.g., top) surface of the material bed). The controller may attempt to minimize an error (e.g., temperature and/or metrological error) over time by adjustment of a control variable. The control variable may comprise a direction and/or (electrical) power supplied to any component of the 3D printing apparatus and/or system. For example, direction and/or power supplied to the: energy beam, scanner, motor translating the platform, optical system component, optical diffuser, or any combination thereof.

[0296] In some embodiments, a build platform assembly comprises a first piston assembly and a second piston assembly coupled together by at least one shaft, e.g., operationally coupled such as physically coupled. In some embodiments, the first piston assembly comprises a first piston and the second piston assembly comprises a second piston. The shaft may be arranged and coupled concentrically along a direction (e.g., vertical axis) relative to the first piston assembly and with second piston assembly, e.g., the shaft may be a central shaft. One or more shafts may be arranged about a periphery of the first piston assembly and second piston assembly and along the direction, e g., parallel to a vertical axis (e g., along a gravitational vector). The shaft may comprise one or more peripheral guide rods. For example, the shaft may be a central shaft, and the peripheral guide rod(s) may be peripheral shaft(s). The shaft may comprise a screw, e.g., a guiding screw. The guide rods may be any guide rods disclosed herein, e.g., a linear-bearing guide rod. The shaft may be any shaft disclosed herein. The shaft may comprise a translation mechanism such as a ball-screw jack or any other translation mechanism such as the ones disclosed herein. The shaft may comprise, or be operatively coupled with (e.g., coupled to), an encoder and/or a servo motor. The shaft may comprise a precision right-angle gear box. The shaft may facilitate vertical and/or linear translation between the first piston assembly and the second piston assembly.

[0297] In some embodiments, the build platform assembly comprises, or is operatively coupled with, one or more components (e.g., engagement features such as pads) configured to engage with an internal surface of the build module vertical wall(s). The build platform assembly may comprise a piston, e.g., a first piston and a second piston. The piston comprises, or is operatively coupled with, engagement features (such as pads) configured to engage with an internal surface of the build module vertical wall(s). The engagement features (e.g., pads) may be arranged in pairs, in each pair the engagement features (e.g., pads) oppose each other. The engagement features may be configured to engage with the internal surface of the build module at least in part by grasping, holding, or pressing upon, the vertical wall(s) of the build module, e.g., during operation. The engagement features may be arranged such that each pair of engagement features is coaxial with the interface plate, with the piston. The engagement features may be arranged such that each pair of The engagement features is coaxial with the first piston, and with the second piston. The engagement features may be arranged such that each pair of engagement features is coaxial with the central axis of the build module assembly. The central axis may be aligned with the adjusting coupler. In some embodiments, the adjusting coupler comprises a lead screw or a shaft. In an example, the shaft comprises the leading screw. The build module assembly may be configured to be arranged coaxially with the build module housing, e.g., along the central axis. Each pair of engagement features in a piston assembly may be separately actuated. Each pair of engagement features in a piston assembly may be actuated by a separate actuator, e.g., driver comprising as a motor or a secondary piston. The engagement features in a piston assembly may be aligned along a circumference of reversibly expanding and reversibly contracting shape(s). The expanded shape may correspond to the respective cross sectional shape (e.g., circle) of the build module body with which the engagement features are configured to contact upon expansion. The contracted shape may correspond to the sectional circumference shape (e.g., circle) of the build platform assembly. The expanded shape and the contracted shape may be of the same shape type, having different dimensions.

[0298] Fig. 27 depicts schematic views of example components of a 3D printing system. Fig. 27 depicts a vertical cross-sectional view 2700 of a build platform assembly in which fastening engagement features (e.g., pads or jaws) are configured to reversibly press upon an internal surface of the build module wall(s) and reversibly release from the internal surface of the build module wall(s), the engagement features distributed along a circumference of each piston assembly. The build module may or may not have structural features configured to align the build platform assembly with respect to the build module body during operation. In the example shown of build platform assembly 2700 is show with respect to gravitational vector 2790 pointing towards the gravitational center of the ambient environment. Build platform assembly in example 2700 include a first piston assembly 2702 including piston 2706, and second piston assembly 2704. First piston assembly 2702 and second piston assembly 2704 are coupled by a shaft 2708. Shaft 2708 is coupled with a servo mount 2710. First piston assembly 2702 and second piston assembly 2702 each include an engagement feature set that is a pad set. The pads comprises pads (e.g., jaws) such as pads 2712a-b. The first pad set of first piston assembly 2702 comprises pad 2712a. The second pad set of second piston assembly 2704 comprises pad 2712b. The pads each comprises pad (e.g., jaw) buttons such as 2714, e.g., screws. The pads in each set of pads are distributed about an outer circumference of a piston. Linear shafts 2716 couple pads (e.g., jaws) 2712 to respective pad (e.g., jaw) pins 2718. A (e.g., hydraulic) interface plate 2720 is coupled with, or is part of, the build platform assembly and arranged with respect to the second piston 2706 by supports 2722. A limit switch mount (not shown) can be mounted on the (e.g., hydraulic) interface plate 2720, e.g., to limit movement of the first piston assembly 2702 with respect to interface plate 2720 and/or to mount a build platform (now shown). Fig. 27 depicts perspective view 2730 of various components of (e.g., second) piston assembly 2732 as part of build platform assembly depicted in Fig. 15, example 1500. (e.g., second) Piston assembly 2732 includes (e.g., spiral) ring such as wheel 2734, wheel 2734 can be configured to pivot about lead screw 2750. (e.g., Linear) shaft 2736 is coupled with pin (e.g., jaw pin) 2738 of pad (e.g., jaw) 2740. (e.g., Linear) actuator 2742 is coupled with piston (e.g., housing) 2744 by (clevis) bracket 2746. Wheel 2734 can pivot along the opening of ports such as port 2751 , that causes at least a partial restriction on the pivoting movement. Shaft 2736 is inserted in port 2751 and guides the movement of wheel 2734. Depending on the direction of movement of the wheel, the wheel can either pull pad 2740 or push pad 2740 with respect to piston 2744. The piston assembly includes secondary (e.g., hydraulic) piston 2752 configured to cause pivoting of wheel 2734. Fig. 27 depicts another perspective view 2760 of various components of piston assembly 2762 with fasteners such as screw 2770 extracted. Piston assembly 2762 includes (e.g., spiral) wheel 2766 positioned with respect to pads (e.g., jaws) such as pad 2768.

[0299] In some embodiments, a build module comprises a kinematic mounting platform. The build module may be reversibly engaged/disengaged with the processing chamber utilizing the kinematic mounting platform. The kinematic platform may comprise a frame. The kinematic mounting platform may comprise one or more engagement mechanisms to secure the build module to the 3D printing system, e.g., to engage with the processing chamber. The engagement mechanism may comprise fasteners (e.g., ball fasteners). The kinematic mounting platform may comprise a frame configured to engage with a transit support mechanism. The frame may comprise a lifting feature. The frame may comprise a docking feature. The kinematic mounting platform may reversibly engage and disengage with the transit support mechanism (e.g., a trolley, hand truck, lift, hydraulic lift, or the like) configured to facilitate movement of the build module from the 3D printing system to an unpacking station.

[0300] Fig. 28 depicts a schematic example of 3D printing system components. Build module 2800 comprises, or is operatively coupled with, a kinematic mounting platform 2802. Kinematic mounting platform 2802 including a mounting plate 2804 and support planks such as 2806. The support plank may or may not be hollow. In the example shown in fig. 28, the support planks are hollow. Support planks such as 2806 define an inner volume that can be utilized to reversibly engage and disengage the kinematic mounting platform 2802 with a transit support mechanism or a frame of the 3D printing system (e.g., frame 906 depicted in Fig. 9). Kinematic mounting platform 2802 includes adjustable kinematic fasteners such as ball fastener 2808. Kinematic ball fasteners2808 may be arranged with respect to the mounting plate 2804 such that, when the build module 2800 is engaged with a frame of the 3D printing system (e.g., frame 906, Fig. 9), each kinematic fastener ball may adjust a position of the kinematic mounting platform 2802, respectively. The kinematic ball fasteners such as ball fastener 2808 may be adjustable along a vertical axis (e.g., aligned with a gravitational vector 2890), for example, to adjust a height, pitch, roll, and/or yaw of the kinematic mounting platform 2802 with respect to the frame.

[0301] In some embodiments, the 3D printing system comprises multiple build modules. The build module may engage with the processing chamber, accommodate the printed 3D object(s) in a printing cycle, and then disengage from the processing chamber. The 3D object may be unpacked from the build module in an unpacking stations distant from the processing chamber. The build module may be configured for transport, e.g., after the printing. For example, the build module may be configured to engage with the kinematic mounting platform. For example, the build module may comprise a lid to facilitate securing the 3D printed object(s) within upon and/or after disengagement from the processing chamber. The lid may comprise a shutter. The shutter may be configured to seal the interior of the build module from the external environment. The characteristic of the seal may be any seal characteristic disclosed herein. For example, the shutter may be configured to hermetically seal the build module hermetically, e.g., gas tight. For example, the shutter may facilitate gaseous exchange, but deter exchange of particulate matter between the interior atmosphere of the build module and the ambient environment external to the build module. The seal may be configured to maintain an internal atmosphere in the build module after its disengagement from the processing chamber, the internal atmosphere being different from the ambient atmosphere external to the build module. The different internal atmosphere may differ by at least one atmospheric characteristic comprising at least one component, temperature, or pressure. For example, the seal may be configured to maintain a positive atmosphere in the build module after its disengagement from the processing chamber, the positive atmosphere being above ambient atmosphere external to the build module. The at least one component may be a reactive agent present in the ambient atmosphere. The reactive agent may react with the starting material, debris, and/or printed 3D object at a time comprising during or after the 3D printing. The reactive agent may comprise oxygen, or water (e.g., humidity). The shutter may be configured to retain the atmosphere in the build module such that the reactive agent in the internal build module atmosphere is at a lower concentration as compared to its concentration at the ambient atmosphere. The build module may be configured to operatively couple to a load lock, e.g., during the 3D printing. The processing chamber may comprise a shutter, e.g., similar to the one disclosed herein with respect to the build module. Examples of 3D printing systems and their components (e.g., lids, shutters, load locks), related methods, devices, software, control systems, and other apparatuses can be found in International Patent Application Serial No. PCT/US22/52588, filed December 12, 2022, and in International Patent Application Serial No. PCT/US17/039422, filed June 27, 2017, each of which is entirely incorporated herein by reference.

[0302] Fig. 29 shows an example of a 3D printing system 2900 disposed relative to gravitational vector 2990 pointing to environmental gravitational center G. The 3D printing system 2900 may comprise, or be configured to operatively couple to, reversibly detachable and attachable build modules. The number of build modules is unlimited. For example, the system may comprise at least 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10 build modules. Fig. 29 shows an example of three stages in attachment and detachment of a build module (e.g., 2901 , 2902, and 2903) to a processing chamber 2910. Build module 2901 includes an elevator that can vertically travel along direction 2912, causing vertical translation of the build plate 2911 . Build module 2901 is approaching the processing chamber 2910. Build module 2902 assumes a position at which it is about to engage 2924 with processing chamber 2910. Build module 2903 includes a material bed in which a 3D object 2914 is disposed, which 3D object was printed while being the build module was engaged with processing chamber 2910. The build plate 2913 of build module 2903 is at a lower position as compared to build plate 2911 of build module 2901 , which lower position accommodates the material bed and 3D object 2914 that has been printed from the material bed using energy beam 2931 that entered processing chamber 2910 through optical window 2930. Each build modules 2901-2903 may travel in a general direction of arrows 2921 , 2922, 2923, 2924, and 2925 (e.g., directed by controller(s) and/or actuators) towards engagement with the processing chamber before printing (e.g., 2921 , 2922, and 2924), or away from the processing chamber after printing 2923 and 2925. 3D printing system 2900 is depicted relative to gravitational vector 2990 pointing to the environmental gravitational center G.

[0303] In some embodiments, at least one build module (e.g., 2901 , 2902, and 2903) engages (e.g., 2924) with the processing chamber to expand the interior volume of the processing chamber. At times, the build module may be connected to, or may comprise, a maneuvering device. The maneuvering device may comprise an autonomous guided vehicle (AGV). The AGV may comprise: a movement mechanism (e.g., wheels), positional (e.g., optical) sensor, or a controller. The controller (e.g., build module controller) may enable self-docking of the build module (e.g., to a docking station) and/or self-driving of the AGV. The self-docking of the build module (e.g., to the processing chamber) and/or self-driving may be to and from the processing chamber. The build module may engage with (e.g., couple to) the processing chamber. The engagement may be reversible. The engagement of the build module with the processing chamber may be controlled (e.g., by a controller). The controller may be separate from a controller that controls the processing chamber (or any of its components). In some embodiments, the controller of the processing chamber may be the same controller that controls the build module. The control may be automatic, remote, local, and/or manual. The engagement of the build module with the processing chamber may be reversible. In some embodiments, the engagement of the build module with the processing chamber may be permanent. The controller (e.g., of the build module) may control the engagement of the build module with a load lock mechanism (e.g., that is coupled with the processing chamber).

[0304] In some embodiments, the 3D object is removed from the build module inside or outside of the 3D printer (e.g., 3D printer enclosure). The translational mechanism (e.g., telescopic shaft) may push the build platform that carries the printed 3D object upwards away from the build module floor. Once the 3D object is pushed up, the 3D object may enter the space of the processing chamber. If the 3D object is generated from a material bed, a remainder of the material bed may fall off and exposed the printed 3D object. The processing chamber may be configured to facilitate removal of the remainder of the material bed, e.g., through slots in the processing chamber floor, e.g., in a similar manner to those depicted in fig. 5. The 3D object that is disposed within the material bed may be removed outside of the enclosure, e.g., by being enclosed in the build module. The 3D object may be removed from the build module in an unpacking station (also referred to herein as “unpacking system”). The unpacking station may be within the 3D printer enclosure, or outside of the 3D printer enclosure such as distant from the 3D printer. The enclosure of the unpacking station may be different (e.g., separate) from the 3D printer enclosure. The atmosphere in the separate (e.g., unpacking station) enclosure may be identical, substantially identical, or different from the atmosphere in the build module, processing chamber, and/or enclosure housing the processing chamber (e.g., 3D printer enclosure). The unpacking chamber may comprise a controlled atmosphere. The atmosphere of the unpacking chamber may be controlled separately or together with the atmosphere of the unpacking station enclosure. The unpacking chamber may comprise a shutter, e.g., similar to the shutter of the build module shutter disclosed herein. The build modules may dock to the unpacking chamber in a manner similar to the way the build modules dock to the processing chamber. The material bed comprising the 3D object may be separated from an operator (e.g., human). The unpacking operation may take place without contact of the operator with the pretransformed material (e.g., remainder). The unpacking operation may take place without contact of the pre-transformed material (e.g., remainder) with the ambient atmosphere. In a similar manner to engagement and disengagement of the build module with the processing chamber: the unpacking station may be sealed prior to engagement, or after an engagement with the build module (e.g., using an unpacking station shutter), for example, to deter atmospheric exchange between the external environment and the interior of the unpacking station. The build module may be sealed prior to engagement of the build module with the unpacking station, for example, to deter atmospheric exchange between the external environment and the interior of the unpacking station. The build module may be sealed prior to disengagement of the build module from the unpacking station (e.g., using a load lock shutter), for example, to deter atmospheric exchange between the external environment and the interior of the unpacking station. To deter atmospheric exchange between the external environment and the interior of the unpacking station may comprise to deter infiltration of one or more reactive agents from the ambient atmosphere. The reactive agent may comprise humidity and/or oxidizing agent (e.g., oxygen). The enclosure, unpacking station, and/or build module, may comprise an atmosphere having a pressure different that (e.g., greater than) the ambient pressure, e.g., have any atmosphere disclosed herein. The build module may comprise a first atmosphere, the processing chamber may comprise a second atmosphere, and the unpacking station may comprise a third atmosphere. At least two of the first, second, and third atmosphere may be detectibly the same. At least two of the first, second, and third atmosphere may differ. Differ may be in material (e.g., gaseous) composition and/or pressure.

[0305] In some embodiments, the unpacking station can engage with a plurality of build modules (e.g., simultaneously). The plurality of build modules may comprise at least 2, 3, 4, 5, or 6 build modules. The unpacking station may comprise a plurality of reversibly closable openings (e.g., each of which comprises a reversibly removable shutter or lid). A plurality of reversibly closable build modules (e.g., each of which comprises a reversibly removable shutter or lid) may engage with, disengage with the unpacking station simultaneously or sequentially. A plurality of reversibly closable build may dock to the unpacking station at a given time.

[0306] Fig. 30 depicts a schematic of a 3D printing system and components depicted relative to the gravitational vector 3090 pointing to the gravitational environmental center G. As depicted in Fig. 30, a collective waiting station 3000 is depicted in which several build modules and several frames are disposed, each of the frames configured to support a build module, e.g., with it kinematic mounting. A 3D printing system 3001 may engage with build modules during respective number of 3D printing cycles, e.g., one build module per building cycle. Collective waiting station 3000 can be utilized (i) to prepare (e.g., purge), (ii) store (e.g., under inert atmosphere), and (iii) transfer the build modules 3002, 3004, to their subsequent density. The build module may be empty and on destined to engage with a 3D printing system such as 3001. The build module may contain a printed 3D object on destined to an unpacking station. Build modules 3002, 3004 may be retained in collective waiting station 3000 while another build module 3005 is engaged with the 3D printing system 3001 , the build module 3005 disposed on framing 3050. The framing may facilitate translation of the build module about floor 3051 of the facility. Collective waiting station 3000 can include multiple individualized waiting stations 3006, 3008, 3010 each comprising a framing, e.g., similar to framing 3050. The 3D object may be unpacked from the build module at the processing chamber, at a dedicated unpacking station separate from the processing chamber, or at the waiting station. Individualized waiting stations such as 3006, 3008, and 3010 can be configured for (A) build module cooling, (B) unpacking (e.g., of parts and pre-transformed/transformed material), (C) pre-purge (e.g., prior to a 3D printing process), or (D) any combination thereof. Each individualized waiting station can have same or different configuration(s). Collective waiting station 3000 can include connections (not shown) for that can be reversibly engaged/disengaged with interconnects 3012 of a respective build module such as 3002, and 3004. Connections can include gas sources (e.g., helium, argon, nitrogen, or the like), electrical, and/or hydraulic pressure source. Connections can include control system, e.g., to control operation of a build platform assembly, and/or to maintain the atmosphere in the build module. Unpacking stations 3006, 3008, 3010 include a frame for reversibly engaging and disengaging with a build modules such as 3002, 3004. Individualized waiting stations 3006, 3008, 3010 can include a locking mechanism (not shown) to secure the build module and/or frame with respect to the individualized waiting station. Individualized waiting stations such as 3006, 3008, and 3010 can be configured to be supportive of a kinematic mounting platform of the build module, (e.g., kinematic mounting platform 2802 depicted in Fig. 28).

[0307] At times, the build module comprises a segmented build module housing that is modular, The segmented build module housing may facilitate an ease of manufacturing of a build module body, e.g., that may contribute to short manufacturing timelines and/or lower manufacturing cost. The build module body may comprise at least one segment. The build module body may comprise a plurality of segments. For example, the build module body may comprise at least two segments. A segment may be optionally affixed to the build module body to extend a length of the build module body, e.g., along a z-axis parallel to a gravitational vector. The segment may comprise an FLS that is (e.g, substantially) equal to an FLS of the build module body, e.g., an inner diameter, an outer diameter, a thickness. The segment may comprise a FLS that is (e.g., substantially) equal or less than an FLS of the build module body, e.g., a length. The segment may comprise a (e.g., substantially) same material at the build module body, for example, aluminum, steel, ceramic, or any other material disclosed herein. The segment may comprise a seal, e.g., any seal disclosed herein. The seal may be arranged with respect to the segment such that, when the segment is affixed to the build module body, the segment extends an inner atmosphere of the build module body. The seal may be a gas tight, hermetically sealed. The seal may be configured to maintain a different internal environment within the build module as compared to the external ambient environment. The different internal atmosphere may have any characteristic of the different internal atmosphere disclosed herein. For example, the seal may be configured to maintain positive pressure environment within the inner atmosphere of the build module, the positive pressure being above ambient pressure external to the build module. For example, the seal may be configured to maintain in the internal environment within the build module a lower concentration of at least one reactive agent, the lower concentration being relative to its concentration in the ambient atmosphere external to the build module. A positive pressure environment within the inner atmosphere may comprise a positive pressure environment within the inner atmosphere over a period of time including, e.g., during a 3D printing process, during/after the 3D printing process until/through an unpacking process, or for an extended duration (e.g., a week, a month, or longer). The segment may comprise hardware to affix the segment to the build module body such as fasteners. The fasteners may comprise bolts, gaskets, clamps, or the like. The fastener may comprise any fastener disclosed herein. The segment may comprise alignment features to assist with alignment of the segment with the build module body. The alignment feature may comprise tooled features, notches, slots, pins, or the like. The segment may comprise an engagement mechanisms, e.g., any engagement mechanism disclosed herein. The segment may comprise interconnects, e.g., any interconnects disclosed herein. The segment may comprise interconnects to connect to one or more interconnects of the build module. For example, the segment may comprise an electrical interconnect to connect an engagement mechanism of the segment (e.g., pins) to a power source and/or control lines through the build module. For example, the segment may comprise a gas interconnect to connect the segment to a gas purge or coolant connection. The segment may comprise one or more channels, e.g., utilized for temperature conditioning.

[0308] Fig. 31 depicts schematic views of example 3D printing system components. As depicted in Fig. 31 , a build module body 3100 includes segments such as 3102. The segments are aligned with a housing scheme 3104 of the build module body 3100, the segments being disposed concentrically, about a central axis 3106. As depicted in Fig. 31 , build module body 3130 includes segments 3132 that include engagement mechanism components such as 3134, e.g, receptacles, that facilitate reversible engage and disengage of the segment with a build platform assembly 3136. As depicted in Fig. 31 , build module body 3150 includes seals such as seal 3152. The Seals are arranged concentrically with respect to central axis 3156 of build module body 3150. The seals can be located (i) between the contacting surfaces 3160 of immediately adjacent segments 3158; and (ii) between contacting surfaces 3162 of a segment 3158 and the housing 3164. The immediately adjacent segments are devoid of another segment disposed therebetween.

[0309] In some embodiments, the 3D printing system comprises a build platform assembly undergoing translation with respect to a build module housing (e.g., build module body). The translations can be repetitive. The translation may be multi-incremental. The translations can be of different types. The translation may comprise a translation of a translation mechanism comprising a telescopic shaft.

[0310] Fig. 32 shows a flow diagram of a 3D printing process 3200. The 3D printing process comprises: in block 3201 , providing a device comprising: a build platform assembly configured to engage with a build platform configured to carry one or more three-dimensional objects during the three-dimensional printing, the build platform assembly being configured to translate such that a first portion of the build platform assembly is configured to translate in a first translation type in a direction and a second portion of the build platform assembly is configured to translate in a second translation type in the direction; in block 3202, engaging the build platform with the build platform assembly; in block 3203, affixing the first portion; in block 3204, translating the second portion in the direction to facilitate printing a first layer of transformed material as part of the one or more three-dimensional objects; in block 3205, affixing the second portion; in block 3206, detaching the first portion; and in block 3207, translating the first portion in the direction to facilitate accurate printing the second piston to facilitate printing a second layer of transformed material as part of the one or more three-dimensional objects that is carried by the build platform.

[0311] Fig. 33 shows a flow diagram of a 3D printing process 3300. The process comprises: in block 3301 , providing a device comprising: (A) a support and (B) a build platform assembly comprising a build platform that is configured to carry one or more three-dimensional objects during the three-dimensional printing, the build platform assembly being configured for a reversible engagement and reversible disengagement between the support and the build platform assembly, device being: (I) configured for the reversible engagement and reversible disengagement at least in part by being configured to facilitate reversibly affixing and reversibly releasing at least a portion of the build platform assembly with respect to the support, and/or (II) configured (a) for translation of the build platform assembly with respect to the support and (b) for synchronization of the translation with the reversible engagement and reversible disengagement; in block 3302, engaging (i) the build platform with the build platform assembly and (ii) the at least the portion of the build platform assembly with respect to the support; in block 3303, printing a layer of material as part of the at least one three-dimensional object; in block 3004, disengaging the at least the portion of the build platform assembly from the support; and in block 3305, translating the at least the portion of the build platform assembly in the direction to generate a second layer of material as part of the at least one three-dimensional object carried by the build platform. The layer of material may be a layer of transformed material. [0312] Fig. 34 shows a flow diagram of a 3D printing process 3400. The 3D printing process comprises: in block 3401 , providing (A) a device comprising a piston assembly configured to engage with a build platform being configured to carry one or more three-dimensional objects during their printing; and (B) a translational mechanism configured to alter a vertical extent of an exposed body of the translational mechanism that is operatively coupled with the piston assembly to facilitate additive printing methodology; in block 3402, engaging the piston assembly with the build platform; and in block 3403, translating the piston assembly at least in part by using the translational mechanism to facilitate the three-dimensional printing.

[0313] In some embodiments, the systems, apparatuses, and/or components thereof comprise one or more controllers. The one or more controllers can comprise one or more central processing unit (CPU), input/output (I/O) and/or communications module. The CPU can comprise electronic circuitry that carries out instructions of a computer program by performing basic arithmetic, logical, control and I/O operations specified by the instructions. The controller can comprise a suitable software (e g., operating system). The control system may optionally include a feedback control loop and/or feed-forward control loop. The controllers may be shared between one or more systems or apparatuses. Each apparatus or system may have its own controller. Two or more systems and/or its components may share a controller. Two or more apparatuses and/or its components may share a controller. The controller may monitor and/or direct (e.g., physical) alteration of the operating conditions of the apparatuses, software, and/or methods described herein. The controller may be a manual or a non-manual controller. The controller may be an automatic controller. The controller may operate upon request. The controller may be a programmable controller. The controller may be programed. The controller may comprise a processing unit (e.g., CPU or GPU). The controller may receive an input (e.g., from a sensor). The controller may deliver an output. The controller may comprise multiple controllers. The controller may receive multiple inputs. The controller may generate multiple outputs. The controller may be a single input single output controller (SISO) or a multiple input multiple output controller (MIMO). The controller may interpret the input signal received. The controller may acquire data from the one or more sensors. Acquire may comprise receive or extract. The data may comprise measurement, estimation, determination, generation, or any combination thereof. The controller may comprise feedback control. The controller may comprise feed-forward control. The control may comprise on-off control, proportional control, proportional-integral (PI) control, or proportional-integral-derivative (PID) control. The control may comprise open loop control, or closed loop control. The controller may comprise closed loop control. The controller may comprise open loop control. The controller may comprise a user interface. The user interface may comprise a keyboard, keypad, mouse, touch screen, microphone, speech recognition package, camera, imaging system, or any combination thereof. The outputs may include a display (e.g., screen), speaker, or printer. The controller may be any controller (e.g., a controller used in 3D printing) such as, for example, the controller disclosed in US Patent serial number 9,662,840 filed on October 31 , 2016; in US Patent serial number 10,434,573 filed on February 16, 2017; and in International Patent Application serial number PCT/US16/59781 , filed on October 31 , 2016; each of which is incorporated herein by reference in its entirety.

[0314] At times, multiple of tuning schemes can be generated for the one or more controllers, each tuning scheme selectable for a set of operating conditions and/or powder characteristics. For example, tuning scheme may utilize (i) a look-up table (LUT), (ii) historical data, (iii) experiments, (iv) physics simulation, (v) artificial intelligence, (vi) data analysis, and/or (vii) the like. The artificial intelligence may comprise training a plant model (a machine-learned model). The artificial intelligence may comprise data analysis. The training model may be trained utilizing (i) a look-up table (LUT), (ii) historical data, (iii) experiments, (iv) synthesized results from physics simulation, or (v) the like. In some embodiments, control scheme(s) can use a single plant model and project changes due to the temperature based at least in part on previously identified models. The control scheme(s) may be inscribed as program instructions (e.g., software).

[0315] In some embodiments, the control scheme used the controller(s) disclosed herein involve data analysis. The data analysis techniques involve one or more regression analys(es) and/or calculation(s). The regression analysis and/or calculation may comprise linear regression, least squares fit, Gaussian process regression, kernel regression, nonparametric multiplicative regression (NPMR), regression trees, local regression, semiparametric regression, isotonic regression, multivariate adaptive regression splines (MARS), logistic regression, robust regression, polynomial regression, stepwise regression, ridge regression, lasso regression, elasticnet regression, principal component analysis (PCA), singular value decomposition (SVD)), probability measure techniques (e.g., fuzzy measure theory, Borel measure, Harr measure, riskneutral measure, Lebesgue measure), predictive modeling techniques (e.g., group method of data handling (GMDH), I Bayes classifiers, k-nearest neighbors algorithm (k-NN), support vector machines (SVMs), neural networks, support vector machines, classification and regression trees (CART), random forest, gradient boosting, generalized linear model (GLM)), or any other suitable probability and/or statistical analys(es). The learning scheme may comprise neural networks. The leaning scheme may comprise machine learning. The learning scheme may comprise pattern recognition. The learning scheme may comprise artificial intelligence, data miming, computational statistics, mathematical optimization, predictive analytics, discrete calculus, or differential geometry. The learning schemes may comprise supervised learning, reinforcement learning, unsupervised learning, semi-supervised learning. The learning scheme may comprise bias-variance decomposition. The learning scheme may comprise decision tree learning, associated rule learning, artificial neural networks, deep learning, inductive logic programming, support vector machines, clustering, Bayesian networks, reinforcement learning, representation learning, similarity and metric learning, sparse dictionary learning, or genetic algorithms (e.g., evolutional algorithm). The non-transitory computer media may comprise any of the algorithms disclosed herein. The controller and/or processor may comprise the non- transitory computer media. The software may comprise any of the algorithms disclosed herein. The controller and/or processor may comprise the software. The learning scheme may comprise random forest scheme.

[0316] In some embodiments, the control system utilizes a physics simulation in, e.g., in a computer model (e.g., comprising a prediction model, statistical model, a thermal model, mechanical model). The computer model may provide feedforward information to the control system. The computer model may provide the feed forward control scheme. There may be more than one computer models, e.g., at least 1 , 2, 3, 4, 5, 6, 7, 8, 9 or 10 different computer models. The controller may (e.g., dynamically) switch between the computer models to predict and/or estimate the behavior of the optical elements. Dynamic includes changing computer models (e.g., in real time) based at least in part on a sensor input or based at least in part on a controller decision that may in turn be based at least in part on monitored target temperature. The dynamic switch may be performed in real-time, e.g., during operation of the optical system and/or during printing 3D object(s). The controller may be configured (e.g., reconfigured) to include additional one or more computer models and/or readjust the existing one or more computer models. A prediction may be done offline (e.g., predetermined) and/or in real-time. Examples of the calibration, control systems, controllers, and operation thereof, 3D printing systems and processes, apparatus, methods, and computer programs, are disclosed in International Patent Application serial number PCT/US19/14635, filed January 22, 2019, titled “CALIBRATION IN THREE-DIMENSIONAL PRINTING,” which is incorporated herein by reference in its entirety.

[0317] In some instances, the processing unit includes one or more cores. The computer system may comprise a single core processor, multi core processor, or a plurality of processors for parallel processing. The processing unit may comprise one or more central processing units (CPU) and/or a graphic processing unit (GPU). The multiple cores may be disposed in a physical unit (e.g., Central Processing Unit, or Graphic Processing Unit). The processing unit may include one or more processing units. The physical unit may be a single physical unit. The physical unit may be a die. The physical unit may comprise cache coherency circuitry. The multiple cores may be disposed in close proximity. The physical unit may comprise an integrated circuit chip. The integrated circuit chip may comprise one or more transistors. The close proximity may allow substantial preservation of communication signals that travel between the cores. The close proximity may diminish communication signal degradation. A core as understood herein is a computing component having independent central processing capabilities. The computing system may comprise a multiplicity of cores, which may be disposed on a single computing component. The multiplicity of cores may include two or more independent central processing units. The independent central processing units may constitute a unit that read and execute program instructions. The independent central processing units may constitute parallel processing units. The parallel processing units may be cores and/or digital signal processing slices (DSP slices). The multiplicity of cores can be parallel cores. The multiplicity of DSP slices can be parallel DSP slices. The multiplicity of cores and/or DSP slices can function in parallel. In some processors (e.g., FPGA), the cores may be equivalent to multiple digital signal processor (DSP) slices (e.g., slices). The plurality of DSP slices may be equal to any of plurality core values mentioned herein. The processor may comprise low latency in data transfer (e.g., from one core to another). Latency may refer to the time delay between the cause and the effect of a physical change in the processor (e.g., a signal). Latency may refer to the time elapsed from the source (e.g., first core) sending a packet to the destination (e.g., second core) receiving it (also referred as two-point latency). One-point latency may refer to the time elapsed from the source (e.g., first core) sending a packet (e.g., signal) to the destination (e.g., second core) receiving it, and the designation sending a packet back to the source (e.g., the packet making a round trip). The latency may be sufficiently low to allow a high number of floating point operations per second (FLOPS).

[0318] In some instances, the computer system includes hyper-threading technology. The computer system may include a chip processor with integrated transform, lighting, triangle setup, triangle clipping, rendering engine, or any combination thereof. The rendering engine may be capable of processing at least about 10 million polygons per second. The rendering engines may be capable of processing at least about 10 million calculations per second. As an example, the GPU may include a GPU by Nvidia, ATI Technologies, S3 Graphics, Advanced Micro Devices (AMD), or Matrox. The processing unit may be able to process algorithms comprising a matrix or a vector. The core may comprise a complex instruction set computing core (CISC), or reduced instruction set computing (RISC).

[0319] In some instances, the computer system includes an electronic chip that is reprogrammable (e.g., field programmable gate array (FPGA)). For example, the FPGA may comprise Tabula, Altera, or Xilinx FPGA. The electronic chips may comprise one or more programmable logic blocks (e.g., an array). The logic blocks may compute combinational functions, logic gates, or any combination thereof. The computer system may include custom hardware. The custom hardware may comprise an algorithm.

[0320] In some instances, the computer system includes configurable computing, partially reconfigurable computing, reconfigurable computing, or any combination thereof. The computer system may include an FPGA. The computer system may include an integrated circuit that performs the algorithm. For example, the reconfigurable computing system may comprise FPGA, CPU, GPU, or multi-core microprocessors. The reconfigurable computing system may comprise a High-Performance Reconfigurable Computing architecture (HPRC). The partially reconfigurable computing may include module-based partial reconfiguration, or difference-based partial reconfiguration. The FPGA may comprise configurable FPGA logic, and/or fixed-function hardware comprising multipliers, memories, microprocessor cores, first in-first out (FIFO) and/or error correcting code (ECC) logic, digital signal processing (DSP) blocks, peripheral Component interconnect express (PCI Express) controllers, ethernet media access control (MAC) blocks, or high-speed serial transceivers. DSP blocks can be DSP slices.

[0321] In some examples, the computing system includes an integrated circuit. The computing system may include an integrated circuit that performs the algorithm (e.g., control algorithm). In some instances, the controller uses calculations, real time measurements, or any combination thereof to regulate the energy beam(s).

[0322] Aspects of the systems, apparatuses, and/or methods provided herein, such as the computer system, can be embodied in programming (e.g., using software). Various aspects of the technology may be thought of as “product,” “object,” or “articles of manufacture” typically in the form of machine (or processor) executable code and/or associated data that is carried on or embodied in a type of machine-readable medium. Machine-executable code can be stored on an electronic storage unit, such memory (e.g., read-only memory, random-access memory, flash memory) or a hard disk. The storage may comprise non-volatile storage media. “Storage” type media can include any or all of the tangible memory of the computers, processors or the like, or associated modules thereof, such as various semiconductor memories, tape drives, disk drives, external drives, and the like, which may provide non-transitory storage at any time for the software programming.

[0323] In some examples, the computer system comprises a memory. The memory may comprise a random-access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), synchronous dynamic random access memory (SDRAM), ferroelectric random access memory (FRAM), read only memory (ROM), programmable read only memory (PROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), a flash memory, or any combination thereof. The flash memory may comprise a negative-AND (NAND) or NOR logic gates. A NAND gate (negative-AND) may be a logic gate which produces an output which is false only if all its inputs are true. The output of the NAND gate may be complemented to that of the AND gate. The storage may include a hard disk (e.g., a magnetic disk, an optical disk, a magneto-optic disk, a solid-state disk, etc.), a compact disc (CD), a digital versatile disc (DVD), a floppy disk, a cartridge, a magnetic tape, and/or another type of computer-readable medium, along with a corresponding drive.

[0324] In some instances, all or portions of the software are at times communicated through the Internet and/or other telecommunication networks. Such communications, for example, may enable loading of the software from one computer or processor into another, for example, from a management server or host computer into the computer platform of an application server. Thus, another type of media that may bear the software elements includes optical, electrical, and electromagnetic waves, such as used across physical interfaces between local devices, through wired and optical landline networks and over various air-links. The physical elements that carry such waves, such as wired or wireless links, optical links, or the like, also may be considered as media bearing the software. As used herein, unless restricted to non-transitory, tangible “storage” media, terms such as computer or machine “readable medium” refer to any medium or media that participate(s) in providing instructions to a processor for execution.

[0325] In some embodiments, the computer system utilizes a machine readable medium/media to execute, or direct execution of, operation(s). The program instructions can be inscribed in a machine executable code. A machine-readable medium/media, such as computerexecutable code, may take many forms, including (but not limited to) a tangible storage medium, a carrier wave medium, or physical transmission medium. Non-volatile storage media include, for example, optical or magnetic disks, such as any of the storage devices in any computer(s) or the like, such as may be used to implement the databases. Volatile storage media can include dynamic memory, such as the main memory of such a computer platform. Tangible transmission media can include coaxial cables, wire (e.g., copper wire), and/or fiber optics, including the wires that comprise a bus within a computer system. Carrier-wave transmission media may take the form of electric or electromagnetic signals, or acoustic or light waves such as those generated during radio frequency (RF) and infrared (IR) data communications. Common forms of computer-readable media therefore include for example: a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, DVD or DVD-ROM, any other optical medium, punch cards paper tape, any other physical storage medium with patterns of holes, a RAM, a ROM, a PROM and EPROM, a FLASH-EPROM, any other memory chip or cartridge, a carrier wave transporting data or instructions, cables or links transporting such a carrier wave, any other medium from which a computer may read programming code and/or data, or any combination thereof. The memory and/or storage may comprise a storing device external to and/or removable from device, such as a Universal Serial Bus (USB) memory stick, or/and a hard disk. Many of these forms of computer readable media may be involved in carrying one or more sequences of one or more instructions to a processor for execution.

[0326] In some instances, the computer system comprises an electronic display. The computer system can include or be in communication with an electronic display that comprises a user interface (Ul) for providing, for example, a model design or graphical representation of a 3D object to be printed. Examples of Ul’s include, without limitation, a graphical user interface (GUI) and web-based user interface. The computer system can monitor and/or control various aspects of the 3D printing system. The control may be manual and/or programmed. The control may rely on feedback mechanisms (e.g., from the one or more sensors). The control may rely on historical data. The feedback mechanism may be pre-programmed. The feedback mechanisms may rely on input from sensors (described herein) that are connected to the control unit (i.e., control system or control mechanism e.g., computer) and/or processing unit. The computer system may store historical data concerning various aspects of the operation of the 3D printing system. The historical data may be retrieved at predetermined times and/or at a whim. The historical data may be accessed by an operator and/or by a user. The historical, sensor, and/or operative data may be provided in an output unit such as a display unit. The output unit (e.g., monitor) may output various parameters of the 3D printing system (as described herein) in real time or in a delayed time. The output unit may output the current 3D printed object, the ordered 3D printed object, or both. The output unit may output the printing progress of the 3D printed object. The output unit may output at least one of the total time, time remaining, and time expanded on printing the 3D object. The output unit may output (e.g., display, voice, and/or print) the status of sensors, their reading, and/or time for their calibration or maintenance. The output unit may output the type of material(s) used and various characteristics of the material(s) such as temperature and flowability of the pre-transformed material. The output unit may output the amount of oxygen, water, and pressure in the processing chamber - the printing chamber (e.g., the chamber where the 3D object is being printed). The computer may generate a report comprising various parameters of the 3D printing system, method, and or objects at predetermined time(s), on a request (e.g., from an operator), and/or at a whim. The output unit may comprise a screen, printer, or speaker. The control system may provide a report. The report may comprise any items recited as optional output by the output unit.

[0327] In some instances, the system and/or apparatus described herein (e.g., controller) and/or any of their components comprise an output and/or an input device. The input device may comprise a keyboard, touch pad, or microphone. The output device may be a sensory output device. The output device may include a visual, tactile, or audio device. The audio device may include a loudspeaker. The visual output device may include a screen and/or a printed hard copy (e.g., paper). The output device may include a printer. The input device may include a camera, a microphone, a keyboard, or a touch screen.

[0328] In some instances, the computer system includes a user interface. The computer system can include, or be in communication with, an electronic display unit that comprises a user interface (Ul) for providing, for example, a model design or graphical representation of an object to be printed. Examples of Ul’s include a graphical user interface (GUI) and web-based user interface. The historical and/or operative data may be displayed on a display unit. The computer system may store historical data concerning various aspects of the operation of the cleaning system. The historical data may be retrieved at predetermined times and/or at a whim. The historical data may be accessed by an operator and/or by a user. The display unit (e.g., monitor) may display various parameters of the printing system (as described herein) in real time or at a delayed time. The display unit may display the requested printed 3D object (e.g., according to a model), the printed 3D object, real time display of the 3D object as it is being printed, or any combination thereof. The display unit may display the cleaning progress of the object, or various aspects thereof. The display unit may display at least one of the total time, time remaining, and time expanded on the cleaned object during the cleaning process. The display unit may display the status of sensors, their reading, and/or time for their calibration or maintenance. The display unit may display the type or types of material used and various characteristics of the material or materials such as temperature and flowability of the pretransformed material. The display unit may display the amount of a certain gas in the chamber. The gas may comprise an oxidizing gas (e.g., oxygen), hydrogen, water vapor, or any of the gases mentioned herein. The gas may comprise a reactive agent. The display unit may display the pressure in the chamber. The computer may generate a report comprising various parameters of the methods, objects, apparatuses, or systems described herein. The report may be generated at predetermined time(s), on a request (e.g., from an operator) or on a whim.

[0329] Methods, apparatuses, and/or systems of the present disclosure can be implemented by way of one or more computational schemes. A computational scheme can be implemented by way of software upon execution by one or more computer processors. For example, the processor can be programmed to calculate the path of the energy beam and/or the power per unit area emitted by the energy source (e.g., that should be provided to the material bed in order to achieve the requested result). Other control and/or algorithm examples may be found in International Patent Application Serial No. PCT/US17/18191 , filed February 16, 2017, titled “ACCURATE THREE-DIMENSIONAL PRINTING,” which is incorporated herein by reference in their entirety.

[0330] In some embodiments, the 3D printer comprises and/or communicates with a plurality of processors. The processors may form a network architecture. The 3D printer may comprise at least one processor (referred herein as the “3D printer processor”). The 3D printer may comprise a plurality of processors. At least two of the plurality of the 3D printer processors may interact with each other. At times, at least two of the plurality of the 3D printer processors may not interact with each other.

[0331] In some embodiments, a 3D printer processor interacts with at least one processor that acts as a 3D printer interface (also referred to herein as “machine interface processor”). The processor (e.g., machine interface processor) may be stationary or mobile. The processor may be a remote computer systems. The machine interface of one or more processors may be connected to at least one 3D printer processor. The connection may be through a wire (e.g., cable) and/or be wireless (e.g., via Bluetooth technology). The machine interface may be hardwired to the 3D printer. The machine interface may directly connect to the 3D printer (e.g., to the 3D printer processor). The machine interface may indirectly connect to the 3D printer (e.g., through a server, or through wireless communication). The cable may comprise coaxial cable, shielded twisted cable pair, unshielded twisted cable pair, structured cable (e.g., used in structured cabling), or fiber-optic cable.

[0332] In some embodiments, the machine interface processor directs 3D print job production, 3D printer management, 3D printer monitoring, or any combination thereof. The machine interface processor may not be able to influence (e.g., direct, or be involved in) pre-print or 3D printing process development. The machine management may comprise controlling the 3D printer controller (e.g., directly, or indirectly). The printer controller may direct the start (e.g., initiation) of a 3D printing process, stopping a 3D printing process, maintenance of the 3D printer, clearing alarms (e.g., concerning safety features of the 3D printer).

[0333] In some embodiments, the machine interface processor allows monitoring of the 3D printing process (e.g., accessible remotely or locally). The machine interface processor may allow viewing a log of the 3D printing and status of the 3D printer at a certain time (e.g., 3D printer snapshot). The machine interface processor may allow to monitor one or more 3D printing parameters. The one or more printing parameters monitored by the machine interface processor can comprise 3D printer status (e.g., 3D printer is idle, preparing to 3D print, 3D printing, maintenance, fault, or offline), active 3D printing (e.g., including a build module number), status and/or position of build module(s), status of build module and processing chamber engagement, type and status of pre-transformed material used in the 3D printing (e.g., amount of pre-transformed material remaining in the reservoir), status of a filter, atmosphere status (e.g., pressure, temperature, and/or gas level(s)), ventilator status, layer dispensing mechanism status (e.g., position, speed, rate of deposition, level of exposed layer of the material bed), status of the optical system (e.g., optical window, mirror), status of scanner, alarm (, boot log, status change, safety events, motion control commands (e.g., of the energy beam, or of the layer dispensing mechanism), or printed 3D object status (e.g., what layer number is being printed),

[0334] In some embodiments, the machine interface processor allows controlling (e.g., monitoring) the 3D print job management. The 3D print job management may comprise status of each build enclosure, e.g., atmosphere condition, power levels of the energy beam, type of pretransformed material loaded, 3D printing operation diagnostics, status of a filter, or the like. The machine interface processor (e.g., output device thereof) may allow viewing and/or editing any of the job management and/or one or more printing parameters. The machine interface processor may show the permission level given to the user (e.g., view, or edit). The machine interface processor may allow prioritize 3D objects to be printed, pause 3D objects during 3D printing, delete 3D objects to be printed, select a certain 3D printer for a particular 3D printing job, insert and/or edit considerations for restarting a 3D printing job that was removed from 3D printer. The machine interface processor may allow initiating, pausing, and/or stopping a 3D printing job. The machine interface processor may output message notification (e.g., alarm), log (e.g., other than Excursion log or other default log), or any combination thereof.

[0335] In some embodiments, the 3D printer interacts with at least one server (e.g., print server). The 3D print server may be separate or interrelated in the 3D printer. One or more users may interact with the one or more 3D printing processors through one or more user processors (e.g., respectively). The interaction may be in parallel and/or sequentially. The users may be clients. The users may belong to entities that request a 3D object to be printed, or entities who prepare the 3D object printing instructions. The one or more users may interact with the 3D printer (e.g., through the one or more processors of the 3D printer) directly and/or indirectly. Indirect interaction may be through the server. One or more users may be able to monitor one or more aspects of the 3D printing process. One or more users can monitor aspects of the 3D printing process through at least one connection (e.g., network connection). For example, one or more users can monitor aspects of the printing process through direct or indirect connection. Direct connection may be using a local area network (LAN), and/or a wide area network (WAN). The network may interconnect computers within a limited area (e.g., a building, campus, neighborhood). The limited area network may comprise Ethernet or Wi-Fi. The network may have its network equipment and interconnects locally managed. The network may cover a larger geographic distance than the limited area. The network may use telecommunication circuits and/or internet links. The network may comprise Internet Area Network (IAN), and/or the public switched telephone network (PSTN). The communication may comprise web communication. The aspect of the 3D printing process may comprise a 3D printing parameter, machine status, or sensor status. The 3D printing parameter may comprise hatch strategy, energy beam power, energy beam speed, energy beam focus, thickness of a layer (e.g., of hardened material or of pre-transformed material). [0336] In some embodiments, a user develops at least one 3D printing instruction and directs the 3D printer (e.g., through communication with the 3D printer processor) to print in a requested manner according to the developed at least one 3D printing instruction. A user may or may not be able to control (e.g., locally, or remotely) the 3D printer controller, e.g., depending on permission preferences. For example, a client may not be able to control the 3D printing controller (e.g., maintenance of the 3D printer).

[0337] In some embodiments, the user (e.g., other than a client) processor may use real-time and/or historical 3D printing data of one or more 3D printers. The 3D printing data may comprise metrology data. The user processor may comprise quality control. The quality control may use a statistical method (e.g., statistical process control (SPC)). The user processor may log excursion log, report when a signal deviates from the nominal level, or any combination thereof. The user processor may generate a configurable response. The configurable response may comprise a print/pause/stop command (e.g., automatically) to the 3D printer (e.g., to the 3D printing processor). The configurable response may be based on a user defined parameter, threshold, or any combination thereof. The configurable response may result in a user defined action. The user processor may control the 3D printing process and ensure that it operates at its full potential. For example, at its full potential, the 3D printing process may make a maximum number of 3D object with a minimum of waste and/or 3D printer down time. The SPC may comprise a control chart, design of experiments, and/or focus on continuous improvement.

[0338] In some embodiments, the build platform assembly comprises, or is operatively coupled with, one or more components (e.g., mechanical jaws, mechanical claws, or pads) configured to engage with the build module vertical wall(s), e.g., with an internal surface of the vertical wall(s) of the build module. The build platform assembly may comprise a piston, e.g., a first piston and a second piston. The piston comprises, or is operatively coupled with, engagement features configured to engage with an internal surface of the build module vertical wall(s). The wall(s) of the build module body may have an internal surface having a surface roughness. The surface roughness of the internal surface of the wall(s) may have a value comprising at most about 0.025 micrometers (pm), 0.05pm, 0.1 pm, 0.2pm, 0.25pm, 0.4pm, 0.8pm, 1.6pm, 3.2pm, 6.3pm, 12.5pm, 25 pm or 50pm. The surface roughness of the internal surface of the wall(s) may have a value between any of the aforementioned values (e.g., from about 0.025pm to about 50pm, from about 0.025pm to about 1 ,6pm, or from about 1 ,6pm to about 50pm. The internal surface of the wall(s) may be machined by a machine methodology comprising super finishing, lapping, grinding, smooth machining, medium machining, or rough machining. The internal surface may have a mirror finish grade roughness. The engagement features (e.g., pads) may be arranged in pairs, where in each pair the engagement features oppose each other. The engagement features may be configured to engage with the build module at least in part by grasping, holding, and/or pressing upon, the vertical wall(s) of the build module, e.g., during operation. In some embodiments, the engagement features are arranged such that each pair of engagement features is coaxial with (i) the interface plate, (ii) with the piston, (iii) with a lid placed on the top opening of the build module, (iv) with a circumference of the top opening of the build module, and/or (v) with the vertical envelope of the build module body. The engagement features may be arranged such that each pair of engagement features is coaxial with the first piston, and with the second piston. The engagement features may be arranged such that each pair of engagement features is coaxial with a long central axis of the build module assembly. The long central axis may be aligned with the adjusting coupler. In some embodiments, the adjusting coupler comprises a lead screw or a shaft. The shaft may be configured to facilitate movement of the first piston with respect to the second piston. In an example, the shaft comprises a leading screw. The build module assembly may be configured to be arranged coaxially with the build module body (e.g., housing), e.g., along the long central axis.

[0339] In some embodiments, the build platform assembly comprises engagement features. The engagement features may facilitate movement of the build module assembly with respect to the build module body, e.g., by facilitating movement of the first piston relative to the second piston. The engagement features may be configured to reversibly engage and disengage from an internal surface of the build module walls(s). The engagement features may comprise mechanical pads (e.g., mechanical claws). The build module assembly may comprise a first piston and a second piston, the pistons being configured to move relative to each other to facilitate movement of the build platform assembly relative to the build module body. The movement may be facilitated at least in part using the engagement features such as the pads. In some embodiments, a first set of engagement features (e.g., pads) is disposed along a circumference of a first piston as part of a first piston assembly; and a second set of engagement features (e.g., pads) is disposed along a circumference of a second piston as part of a second piston assembly. Along the circumference may comprise the engagement features (e.g., pads) of a set being disposed at least in part in the interior of a piston. Along the circumference may comprise the engagement features being disposed at the circumference of the piston. During operation, the engagement features may engage with the build module body, e.g., at least in part by grasping, holding, and/or pressing upon, vertical wall(s) of the build module body, e.g., interior surface of the build module body. Engagement of the engagement features in a set (e.g., as part of a piston assembly) with the build module body can occur simultaneously or sequentially. In some instances, directing engagement features of a first set to engage simultaneously with the build module body results in sequential engagement of at least two of the engagement features in the set, e.g., due to mechanical limitations in execution of the direction to simultaneously engage. For example, the build module may not be sufficiently vertically aligned. For example, the build platform assembly may not be sufficiently concentric with respect to the build module body. For example, the internal surface of the build module is not sufficiently smooth, e.g., with respect to the requested Ra value/range such as disclosed herein. Sufficiently may be with respect to the ability of two engagement features that are simultaneously directed to contact the internal surface of the build module, to physically (e.g., actually, in fact) simultaneously contact the surface of the build module in an accuracy that will not cause measurable rotation (e.g., pivoting) of the build platform assembly. In some embodiments, the piston may be designed to have a circular horizontal cross section, and the physical piston may have a horizontal cross section that deviates from a circular cross section. In some embodiments, the long axis of the build module body deviates from a vertical axis, e.g., due to a (e.g., slight) deviation from planarity of the facility floor on which the build module is disposed. The physical deviation(s) may be sufficient to cause a non-simultaneous (e.g., and rather a sequential) contact between the engagement features of the build platform assembly, and the internal surface of the build module body, when the engagement features are directed to engage simultaneously with the internal surface of the build module body. Such sequential engagement may result at least in part in rotation (e.g., pivoting) of that piston relative to the build module body and/or relative to the second piston. The rotation may be in the microlevel scale, e.g., to increase the precision error in movement of the build platform, such as disclosed herein. Such rotation (e.g., pivoting) may in turn rotate (e.g., pivot) the build plate coupled with the build platform assembly. Such rotation may rotate the material bed supported by the build plate. Such rotation may rotate the 3D object supported by the build plate. In some embodiments, pairs of the engagement features in a set of engagement features of a piston may be directed to engage sequentially with respect to other pair(s) of the piston; whereas engagement features in each set are directed to engage (e.g., substantially) simultaneously with respect to each other. In some embodiments, pairs of the engagement features in a set of engagement features of a piston may be directed to engage sequentially with respect to other pair(s) of the piston; and engagement features in each set are directed to engage sequentially with respect to each other. The pairs of engagement features may be concentrically arranged, e.g., as disclosed herein. The pairs of engagement features may be disposed at an angle relative to another, e.g., as measured by the acute angle. The acute angle may be different than zero. The angle of one set may be disposed at least about 10 degrees (°) 20°, 30°, 45°, 60°, or 90° relative to another set of the piston. The angle may be a planar angle, the plane being of the exposed surface of the piston or parallel to the plane of the piston. The angle may be any angle between the afore-mentioned angles, e.g., from about 10° to about 90°. In an example, the angle between the pairs of engagement features of a piston assembly is (e.g., about) 90° with respect to each other. In an example, the pairs of engagement features of a piston assembly are normal to each other, the pairs being disposed on a plane, e.g., horizontal plane.

Disengagement of the engagement features from the build module body in a set of engagement features can occur simultaneously or sequentially. In some instances, directing engagement features in a first set of a first piston assembly to disengage simultaneously with (e.g., disengage from) the build module body results in sequential disengagement of at least two of the engagement features in the set, e.g., due to mechanical limitations in execution of the direction to simultaneously disengage. Such sequential disengagement may result at least in part in rotation of the first piston relative to the build module body and/or relative to the second piston. Such rotation may rotate the build plate coupled with the build platform assembly. Such rotation may rotate the material bed supported by the build plate. Such rotation may rotate the 3D object supported by the build plate. In some embodiments, pairs of the engagement features in a set of engagement features of a piston may be directed to disengage sequentially with respect to other pair(s) of the piston; while engagement features in each set of engagement features are directed to disengage (e.g., substantially) simultaneously with respect to each other. In some embodiments, pairs of the engagement features in a set of engagement features of a piston may be directed to disengage sequentially with respect to other pair(s) of the piston; and engagement features in each set of engagement features are directed to disengage sequentially with respect to each other. The direction may be by one or more controllers operatively coupled with the engagement features. In some embodiments, the one or more controllers are operatively coupled with, or are part of, the control system of the 3D printer. In some embodiments, the one or more controllers are separate from the control system of the 3D printer. In some embodiments, the engagement and disengagement of the engagement feature from the build module body is reversible. The engagement and/or disengagement of the engagement feature from the build module body may include application of force towards the engagement feature (e.g., along a force vector). The force may comprise an electric, magnetic, pneumatic, or hydraulic force. The force may comprise a mechanical force. The force may be applied directly to the engagement feature or through at least one coupling component, e.g., a pin such as a mechanical pad pin.

[0340] Fig. 35 depicts schematic views of example components of a 3D printing system as horizontal cross sectional views. Example 3500 shows build module housing wall 3501 surrounding build platform assembly portion comprising piston 3503 disposed in the build module housing such that a gap 3502 is created between piston 3503 and build module housing wall 3501 , the gap 3502 being in the interstitial (e.g., intermediate) space disposed between piston 3503 and build module housing wall 3501 . Piston 3503 is disposed concentrically with respect to the build module housing about an axis running through center 3510. Piston 3503 is coupled with engagement features that are pads 3506a, 3506b, 3507a, and 3507b. Pads 3506a and 3506b are each operatively coupled with ring (e.g., wheel) 3521 , e.g., pivoting wheel. The wheel is configured to translate (e.g., rotate or pivot) about the axis running through center 3510. Depending on the direction of translation, pads 3506a and 3506b may contract simultaneously towards center 3510, or be pushed simultaneously away from center 3510. Pads 3507a and 3507b are each operatively coupled with ring (e.g., wheel) 3522, e.g., pivoting wheel. The wheel is configured to translate (e.g., rotate or pivot) about the axis running through center 3510. Depending on the direction of translation, pads 3507a and 3507b may contract simultaneously towards center 3510, or be pushed simultaneously away from center 3510. Rings (e.g., wheels) 3521 and 3522 may or may not have different radii. In an example operation, (A) application of force in direction 3504a is exerted towards pad 3506a to press pad 3506a (e.g., using a pin, not shown) onto the interior surface of build module wall 3501 (e.g., substantially) simultaneously to (B) application of force in direction 3504b is exerted towards pad 3506b to press pad 3506b onto the interior surface of build module wall 3501 ; and thereafter (C) application of force in direction 3505a is exerted towards pad 3507a to press pad 3507a onto the interior surface of build module wall 3501 (e.g., substantially) simultaneously to (D) application of force in direction 3505b is exerted towards pad 3507b to press pad 3507b onto the interior surface of build module wall 3501 . Such an example operation may curb rotation of piston 3503 in a rotation direction about center 3510, and with respect to build module housing wall 3501 . While Fig. 35 is described in terms of engagement of the pads with the build module body, a similar scheme may be utilized for disengagement of the pads from the build module body, where each of the forces are applied in the direction opposite to the ones depicted in 3504a, 3504b, 3505a, 3505b, towards the center 3510.

[0341] Example 3550 shows a more general example as compared to example 3500. In example 3550, build module housing wall 3551 surrounds build platform assembly portion comprising piston 3553 disposed in the build module housing such that gap 3552 is created between piston 3553 and build module housing wall 3551 , the gap 3552 being in the interstitial (e.g., intermediate) space disposed between piston 3553 and build module housing wall 3551. Piston 3553 is disposed concentrically with respect to the build module housing about axis 3560. Piston 3553 is operatively coupled with pads 3556a, 3556b, 3557a, and 3557b. Pads 3556a and 3556b are each operatively coupled with a first push-pull actuator (not shown) configured to cause pads 3556a and 3556b simultaneously to either contract towards center 3560, or be pushed away from center 3560, depending on the mode of actuation of the first push-pull actuator. In a first mode of operation of the first push-pull actuator (e.g., actuation in a first direction), pads 3556a and 3556b will be contracted simultaneously towards center 3560. In a second mode of operation of the first push-pull actuator (e.g., actuation in a second direction opposing the first direction), pads 3556a and 3566b are pushed simultaneously away from center 3560. Pads 3557a and 3557b are each operatively coupled with a second push-pull actuator (not shown) configured to cause pads 3557a and 3557b simultaneously to either contract towards center 3560, or be pushed away from center 3560, depending on the mode of actuation. In a first mode of operation of the second push-pull actuator (e.g., actuation in a first direction), pads 3557a and 3557b will be contracted simultaneously towards center 3560. In a second mode of operation of the second push-pull actuator (e.g., actuation in a second direction opposing the first direction), pads 3557a and 3566b are pushed simultaneously away from center 3560. The first push-pull actuator may exert a first force. The second push-pull actuator may exert a second force. The first force and the second force may be of (i) (e.g., substantially) the same in magnitude and/or (ii) (e.g., substantially) the same in direction relative to the center, that is with respect to either being towards the center 3560 or being away from center 3560. The first push-pull actuator and the second push-pull actuator may be configured to work simultaneously or sequentially with respect to each other. In an example operation, (A) application of feree in direction 3554a is exerted towards pad 3556a to press (e.g., push) pad 3556a (e.g., using a pin, not shown) onto the interior surface of build module wall 3551 (e g., substantially) simultaneously to (B) application of force in direction 3554b is exerted towards pad 3556b to press pad 3556b onto the interior surface of build module wall 3551 ; and thereafter (C) application of force in direction 3555a is exerted towards pad 3557a to press pad 3557a onto the interior surface of build module wall 3551 (e.g., substantially) simultaneously to (D) application of force in direction 3555b is exerted towards pad 3557b to press pad 3557b onto the interior surface of build module wall 3551 . Such an example operation may curb rotation (e.g., pivot) of piston 3553 in a rotation direction about center 3560, and with respect to build module housing wall 3551. While Fig. 35 is described in terms of engagement of the pads with the build module body, a similar scheme may be utilized for disengagement of the pads from the build module body, where each of the forces are applied in the direction opposite to the ones depicted in 3554a, 3554b, 3555a, 3555b, towards the center 3560. The push-pull actuator may comprise a ring (e.g., wheel), a lead screw, or a piston. The push-pull actuator may utilize electric, hydraulic, pneumatic, or magnetic force. The push pull actuator may be directly or indirectly coupled with the two opposing pads. Indirect coupling of the push-pull actuator to a pad may be through a pin.

[0342] In some embodiments, alignment is controlled during operation of the build platform assembly, the alignment of the build platform assembly relative to the build module body such as vertical wall(s) of the build module body. The alignment may utilize the engagement features. For example, the engagement feature (e.g., mechanical claw or pad) may engage with the build module body by entering a depression in an internal surface of the build module wall. The depression may run along at least a portion of the build module wall. There may be at least one depression along at least the portion of the build module wall. The alignment may re irrespective of the engagement features. The alignment may be of the at least one depression in the build module wall that engages (e.g., during operation) with a corresponding protrusion in the build platform assembly, e.g., a corresponding protrusion in the piston. The alignment may be of at least one protrusion in the build module wall that engages (e.g, during operation) with a corresponding depression in the build platform assembly, e.g., a depression in the piston. The depression and protrusion may be configured to facilitate alignment of the build platform assembly with respect to the build module body during operation, e.g., during movement of the build platform assembly (including any component thereof) with respect to the build module body, e.g., stepwise movement during 3D printing. Facilitating alignment may be at least in part by snuggly fitting the depression and the protrusion. The protrusion may comprise the engagement feature. The protrusion may be devoid of the engagement feature.

[0343] Fig. 36 depicts schematic views of example components of a 3D printing system as horizontal cross sectional views. While figure 36 shows in each of its examples four pairs of protrusion (e.g., claw) and depression, a smaller or larger number of such pairs may be used. [0344] Example 3600 shows build module housing wall 3601 surrounding build platform assembly portion comprising piston 3603 disposed in the build module housing such that a gap 3602 is created between piston 3603 and build module housing wall 3601 , the gap 3602 being in the interstitial (e g., intermediate) space disposed between piston 3603 and build module housing wall 3601 . Piston 3603 is disposed concentrically with respect to the build module housing about shaft 3608 (e.g., linear screw). Piston 3603 is coupled with (e.g., spiral) wheels 3612 and 3632. First wheel 3612 is coupled with pins 3606a and 3606c. Second wheel 3632 is coupled with pins 3606b and 3606d. Each pin is coupled with a pad from pads 3605a, 3605b, 3605c, and 3605d, respectively. Forces exerted in directions 3607a-d each respectively presses pins 3606a-d to respectively cause pads 3605a-d to transit (e.g., and press) onto respective pad receptacles 3604a-d disposed along the internal surface of build module wall 3601 . Forces 3607a and 3607c can be applied simultaneously by pivoting wheel 3612 about axis (e.g., of lead screw) 3608. Forces 3607b and 3607d can be applied simultaneously by pivoting wheel 3632 about axis 3608. In an example operation, (A) application of force in direction 3607a is exerted towards pad pin 3606a to translate pad 3605a onto receptacle 3604a disposed in the interior surface of build module wall 3601 (e.g., substantially) simultaneously to (B) application of force in direction 3607c is exerted towards pin 3606c to translate pad 3605c onto receptacle 3604c disposed in the interior surface of build module wall 3601 ; and thereafter (C) application of force in direction 3607b is exerted towards pad pin 3606b to translate pad 3605b onto receptacle 3604b disposed in the interior surface of build module wall 3601 (e.g., substantially) simultaneously to (D) application of force in direction 3607d is exerted towards pad pin 3606d to translate pad 3605d onto receptacle 3604d disposed in the interior surface of build module wall 3601 . While rings (e.g., wheels) 3612 and 3632 are displayed as having two different radii, they can be configured to have (e.g., substantially) the same radius.

[0345] Example 3630 shows build module housing wall 3631 surrounding build platform assembly portion comprising piston 3633 disposed in the build module housing such that a gap 3632 is created between piston 3633 and build module housing wall 3631 , the gap 3632 being in the interstitial (e.g, intermediate) space disposed between piston 3633 and build module housing wall 3631 . Piston 3633 is disposed concentrically with respect to the build module housing about axis 3638. Piston 3633 is coupled with (e.g., spiral) wheel 3642. Piston 3633 is coupled with (e.g., spiral) wheels 3642 and 3652. First wheel 3652 is coupled with pins 3636a and 3636c. Second wheel 3642 is coupled with pins 3636b and 3636d. Each pin is coupled with a pad from pads 3635a, 3635b, 3635c, and 3635d, respectively. Forces exerted in directions 3637a-d each respectively presses pins 3636a-d to respectively cause pads 3635a-d to traverse the interstitial space 3632 and press upon the internal surface of build module wall 3631. Forces 3637a and 3637c can be applied simultaneously, e.g., by pivoting wheel 3612 about axis (e.g., of lead screw or shaft) 3638. Forces 3637b and 3637d can be applied simultaneously, e.g., by pivoting wheel 3632 about axis 3638. In an example operation, (A) application of force in direction 3637a is exerted towards pin 3636a to press pad 3635a onto the interior surface of build module wall 3631 (e.g., substantially) simultaneously to (B) application of force in direction 3637c is exerted towards pad pin 3636c to press pad 3635c onto the interior surface of build module wall 3631 ; and thereafter (C) application of force in direction 3637b is exerted towards pin 3636b to press pad 3635b onto the interior surface of build module wall 3631 (e.g., substantially) simultaneously to (D) application of feree in direction 3637d is exerted towards pin 3636d to translate pad 3635d onto receptacle 3634d disposed in the interior surface of build module wall 3631 . The interior surface of build module wall 3631 includes aligning protrusions 3634a-d, each configured to intimately engage (e.g., snuggly fit) respectively with an opposing aligning depressions of piston 3633. In figure 36, the aligning protrusions and aligning depressions are shown with a gap to impress that they are separate structures, however, in the physical apparatus, each aligning protrusion is configured to intimately engage with its corresponding aligning depression to align the piston with the build module wall, e.g., during operation such as movement of the piston with respect to the build module wall. While rings (e.g., wheels) 3652 and 3642 are displayed as having two different radii, they can be configured to have (e.g., substantially) the same radius.

[0346] Example 3660 shows build module housing wall 3661 surrounding build platform assembly portion comprising piston 3663 disposed in the build module housing such that a gap 3662 is created between piston 3663 and build module housing wall 3661 , the gap 3662 being in the interstitial (e.g., intermediate) space disposed between piston 3663 and build module housing wall 3661 . Piston 3663 is disposed concentrically with respect to the build module housing about shaft 3668. Piston 3663 is coupled with (e.g., spiral) wheel 3672. Piston 3663 is coupled with (e.g., spiral) wheels 3672 and 3692. First wheel 3692 is coupled with pins 3666a and 3666c. Second wheel 3672 is coupled with pins 3666b and 3666d. Each pin is coupled with a pad from pads 3665a, 3665b, 3665c, and 3665d, respectively. Forces exerted in directions 3667a-d each respectively presses pad pins 3666a-d to respectively cause pads 3665a-d to press onto the internal surface of build module wall 3661 . In an example operation, (A) application of feree in direction 3667a is exerted towards pad pin 3666a to press pad 3665a onto the interior surface of build module wall 3661 (e.g., substantially) simultaneously to (B) application of force in direction 3667c is exerted towards pad pin 3666c to press pad 3665c onto the interior surface of build module wall 3661 ; and thereafter (C) application of force in direction 3667b is exerted towards pad pin 3666b to press pad 3665b onto the interior surface of build module wall 3661 (e.g., substantially) simultaneously to (D) application of feree in direction 3667d is exerted towards pad pin 3666d to translate pad 3665d onto receptacle 3664d disposed in the interior surface of build module wall 3661. The interior surface of build module wall 3661 includes aligning depressions 3664a-d, each configured to intimately engage (e.g., snuggly fit) respectively with an opposing aligning protrusions of piston 3663. In figure 36, the aligning protrusions and aligning depressions are shown with a gap to impress that they are separate structures, however, in the physical apparatus, each aligning protrusion is configured to intimately engage with its corresponding aligning depression to align the piston with the build module wall, e.g., during operation such as movement of the piston with respect to the build module wall. While rings (e.g., wheels) 3692 and 3672 are displayed as having two different radii, they can be configured to have (e.g., substantially) the same radius.

[0347] In some embodiments, a build module is coupled with, or includes, one or more controllers. The one or more controllers can be operatively coupled with, or included in, the control system of the 3D printer. The one or more controllers of the build module can be separate (e.g., disconnected from) from the control system of the 3D printer. In an example, the one or more controllers of the build module are autonomous. The one or more controllers may or may not communicate with the control system of the 3D printer. The build module may be engaged with a docking interface. The docking interface may facilitate maneuvering of the build module in space, e.g., along a floor of a facility. The docking interface may comprise one or more wheels. The docking interface may comprise at least one set of wheels. A first set of wheels may be configured to align with a first surface, and a second set of wheels is configured to align with a second surface different from the first surface. The docking interface may allow the build module to rest on a surface thereof, e.g., during maneuvering. The docking interface may be configured to operatively coupled with a transporter, e.g., as disclosed herein. The docking interface may be configured to facilitate coupling of the build module with a processing chamber and/or an unpacking chamber, e.g., as disclosed herein. The loading interface comprises a transport mating component (male) that facilitates mating the loading interface to a transporter such as the ones disclosed herein. The at least one controller associated with the build module may be disposed in one or more control housings coupled with the build module. The build module and the one or more control housings may be maneuvered together, e.g., as one entity. The at least one controller associated with the build module may be configured to (i) control translation of the build platform assembly with respect to the build module body and/or (ii) control (e.g., maintain) an atmosphere in the closed build module for a period, e.g., until any printed 3D object and associated starting material is removed (e.g., unpacked) from the build module. A control housing may comprise (e.g., may house) a gas source (e.g., a gas cylinder), or a coupling to a gas source. A control housing may comprise one or more controllers operatively coupled with sensor(s) such as various sensors configured to facilitate movement of the build platform assembly, e.g., optical sensors comprising an interferometer such as disclosed herein. The build module may comprise an access port (e.g., window) that is reversibly coverable and openable. The access port may be reversibly sealable and openable by a cover, e.g., manually such as at least in part using fastener(s) (e.g., screws). The cover may comprise a seal. The cover may be closed in a gas tight and/or hermetic manner. The cover may comprise an opaque or a transparent material. The cover may comprise elemental metal, metal alloy, polymer, or glass. The build module may comprise elemental metal or metal alloy. The build module may comprise an opaque or a transparent material.

[0348] In some embodiments, the build platform assembly comprises bellows. The bellows may enclose at least a portion of the build platform assembly to form an internal chamber with respect to the build module. The bellows may encircle at least a portion of the piston assemblies. The bellows may function as a powder seal. The bellows may prevent contamination of the internal volume enclosure by the bellows from pre-transformed, debris, and/or transformed material. The debris may comprise a gas borne solid. The debris may comprise soot, splatter, or spatter. The bellows may be gas sealed, e.g., hermetically sealed. The bellows may protect an expandable volume between the first piston assembly and the second piston assembly, e.g., prevent contamination of the internal volume with pre-transformed material, debris, or transformed material. The bellows may enclose a portion of the build platform assembly and a bottom region of the build module, e.g., a region below the build platform assembly. The bellow may enclose a volume of the build platform assembly including one or more optical components. The bellows may comprise any material disclosed herein, for example, steel or aluminum.

[0349] Fig. 37 schematically depicts perspective views of a build module and associated components with respect to gravitational vector 3790 pointing towards the gravitational center of the ambient environment external to the build module. Example 3700 shows build module 3702 having a cylindrical body closed (e.g., sealed) by lid 3701. The build module is engaged with docking interface 3703. The docking interface may be configured to facilitate coupling of the build module with a processing chamber and/or an unpacking chamber such as the ones disclosed herein. Build module 3702 is disposed on loading interface 3706 has a first wheel set including wheels 3710a and 3710b; and a second wheel set including wheels 3707a, 3707b, and 3707c. The first set of wheels is configured to facilitate traversal of the build module about a floor of a facility. The second set of wheels is configured to facilitate traversal of the build module into and out of a framing (not shown). A framing example can be seen in Fig. 30, 3050. The loading interface comprises a transport mating component (male) that facilitates mating the loading interface to a transporter such as the ones disclosed herein. Build module 3702 is coupled with at least one controller disposed in a first control housing 3709. The at least one controller may be configured to (i) control translation of the build platform assembly with respect to the build module body and/or (ii) control (e.g., maintain) an atmosphere in the closed build module for a period, e.g., until any printed 3D object and associated starting material is removed (e.g., unpacked) from the build module. Controlling the atmosphere may comprise controlling the one or more atmospheric characteristics, e.g., as disclosed herein. For example, control the pressure, reactive agent(s) level, and/or the temperature. First control housing 3709 may comprise a gas source, or a coupling to a gas source. Build module 3702 is coupled with second control housing 3704. Build module body 3702 comprises a covered (e.g., closed) access port (e.g., window) 3705 that can be reversibly removable and detachable. The window, e.g., when opened, may be used for inspection and/or maintenance of various internal components of the build module. The second control housing comprises one or more controllers operatively coupled with sensor(s) such as various sensors configured to facilitate movement of the build platform assembly, e.g., optical sensors comprising an interferometer such as disclosed herein. Example 3750 shows a partially exposed section of the build module and associated components shown in example 3700. An interior surface of build module body 3752 surrounds a build platform assembly comprising build plate 3751 , first piston assembly 3753 including engagement features such as 3771 , second piston assembly 3756 including engagement features such as 3772, and intermediate space sealed by bellow 3755. The build platform assembly is supported (a) by surrounding shafts each covered by a seal comprising a bellow such as bellow 3756, and (b) by a central shaft covered by a seal comprising bellow 3758. The central shaft can comprise a leading screw, e.g., operatively coupled with a motor such as a servo motor. The shaft can be a telescopic shaft, e.g., as disclosed herein. The build module is coupled (A) with first control housing 3759 comprising gas source components 3762 including gas a channel (e.g., tubing) and (B) with second control housing 3754. Second control housing comprises sensors (e.g., optical and/or metrology) and user interface 3760, controller(s) 3761 coupled with the sensor(s). The controller(s) of the first control housing may or may not be operatively coupled with the controllers of the second control housing. User interface 3760 may allow the user to monitor and/or control controllers of the first control housing and/or of the second control housing. User interface 3760 may allow the user to monitor gas flow, status of the build platform assembly, and/or sensor output. Build module 3752 is disposed on loading interface 3786 has a first wheel set including wheels 3767a, and 3767b; and a second wheel set including wheels 3768a and 3768b. The first set of wheels is configured to facilitate traversal of the build module about a floor of a facility. The second set of wheels is configured to facilitate traversal of the build module into and out of a framing (not shown).

[0350] Fig. 38 schematically depicts perspective views of a build module and associated components with respect to gravitational vector 3890 pointing towards the gravitational center of the ambient environment external to the build module. Example 3800 shows build module 3802 having a cylindrical body closed (e.g., sealed) by lid 3801. The build module is engaged with docking interface 3803. The docking interface may be configured to facilitate coupling of the build module with a processing chamber and/or an unpacking chamber such as the ones disclosed herein. Build module 3802 is disposed on loading interface 3806 has a first wheel set including wheels 3810a and 3810b; and a second wheel set including wheels 3807a, 3807b, and 3807c. The first set of wheels are configured to facilitate traversal of the build module about a floor of a facility. The second set of wheels are configured to facilitate traversal of the build module into and out of a framing (not shown). A framing example can be seen in Fig. 30, 3050. The loading interface comprises a transport mating component (male) that facilitates mating the loading interface to a transporter such as the ones disclosed herein. Build module 3802 is coupled with at least one controller disposed in a first control housing 3809. The at least one controller may be configured to (i) control translation of the build platform assembly with respect to the build module body and/or (ii) control (e.g., maintain) an atmosphere in the closed build module for a period, e.g., until any printed 3D object and associated starting material is removed (e.g., unpacked) from the build module. First control housing 3809 may comprise a gas source, or a coupling to a gas source. Build module 3802 is coupled with second control housing 3804. Build module body 3802 comprises a covered (e.g., closed) access port (e.g., window) 3805 that can be reversibly removable and detachable. The window, e.g., when opened, may be used for inspection and/or maintenance of various internal components of the build module. The second control housing comprises one or more controllers operatively coupled with sensor(s) such as various sensors configured to facilitate movement of the build platform assembly, e.g., optical sensors comprising an interferometer such as disclosed herein. Example 3850 shows a partially exposed section of the build module and associated components shown in example 3800. An interior surface of build module body 3852 surrounds a build platform assembly comprising piston 3851 having aligner 3879 configured to couple with a build plate (not shown), first piston assembly 3853 including engagement features such as 3871 , second piston assembly 3856 including engagement features such as 3872, and intermediate space sealed by bellow 3855 depicting a series of connected bellow portions. The build platform assembly is supported (a) by surrounding shafts each covered by a seal comprising a bellow such as bellow 3856, and (b) by a central shaft covered by a seal comprising bellow 3858. The central shaft can comprise a leading screw, e.g., operatively coupled with a motor such as a servo motor. The shaft can be a telescopic shaft, e.g., as disclosed herein. The build module is coupled (A) with first control housing 3859 comprising gas source components, and (B) with second control housing 3854. Second control housing comprises sensors (e.g., optical and/or metrology). The controller(s) of the first control housing may or may not be operatively coupled with the controllers of the second control housing. User interface 3860 may allow the user to monitor and/or control controllers of the first control housing and/or of the second control housing. User interface 3860 may allow the user to monitor gas flow, status of the build platform assembly, and/or sensor output. Build module 3852 is disposed on loading interface 3886 has a first wheel set including wheels 3867a, 3867b, and 3867c; and a second wheel set including wheels 3868a, and 3868b. The first set of wheels is configured to facilitate traversal of the build module about a floor of a facility. The second set of wheels is configured to facilitate traversal of the build module into and out of a framing (not shown).

[0351] Examples. The following are illustrative and non-limiting examples of methods of the present disclosure.

[0352] Example 1 : Inconel-718 powder having a diameter distribution of from about 20 micrometers to about 60 micrometers was dispensed on a build plate having a diameter of about 600 millimeters (mm) to form a powder bed at ambient pressure and atmosphere. The build plate supporting the powder bed was supported by a build platform assembly similar to the one depicted in example 1500 of Fig. 15., Fig. 27, and example 3750 of Fig. 37. The build platform assembly traversed down into a build module housing having a vertical traversal span of 600 mm, at increments of about 50 pm at a precision of +1-2 micrometers using a sensor configuration as depicted in Fig. 23 and Fig. 24, including a detector such as 2354 and 2454 (comprising an interferometer), encoders such as 2308 and 2406, and (planar) mirrors such as 2310 and 2410. The build module was the similar to the one depicted in Fig. 37, example 3700. [0353] Example 2: A build platform assembly supporting a build platform (build plate) of about 600 millimeters (mm) was disposed in a build module having a vertical traversal span of the build platform, the vertical traversal span being about 600 mm. The build module was the similar to the one depicted in Fig. 37, example 3700. The build module with the build platform assembly was coupled with a processing chamber in a configuration similar to the one depicted in Fig. 9, example 950; and in Fig. 30, 3001 , to enclose an internal atmosphere. The build platform assembly was similar to the one depicted in example 1500 of Fig. 15., Fig. 27, and example 3750 of Fig. 37, using a sensor configuration as depicted in Fig. 23 and Fig. 24, including a metrology detector such as 2354 and 2454 (comprising an interferometer), encoders such as 2308 and 2406, and (planar) mirrors such as 2310 and 2410.

[0354] Example 3: In a processing chamber, Inconel-718 powder will be dispensed by a layer dispensing mechanism (e.g., recoater), the powder will be dispensed above a build plate having a diameter of about 600 mm to form a powder bed. The build plate will be supported by a build platform assembly, the build platform assembly will be disposed in a build module coupled with the processing chamber. The build module with the build platform assembly coupled with the processing chamber will be in a configuration similar to the one depicted in example 950 of Fig.

9, and in Fig. 30, 3001. A layer dispensing mechanism will be used to form a powder bed. When idle, the layer dispensing mechanism will be parked in an ancillary chamber (e.g., garage) coupled with the processing chamber in which the build plate will be disposed, the ancillary chamber separated from the processing chamber by a door. The layer dispensing mechanism will comprise a powder dispenser and a powder remover. The powder remover will be configured to attract a portion of the dispensed powder to form a planar exposed surface of the powder bed using vacuum. The attracted powder will be conveyed using a material (e.g., powder) conveyance system for recycling and reuse in by the layer dispensing mechanism. The atmosphere in the material conveyance system will be similar to the one used in the processing chamber. The processing chamber will be under an atmosphere that is less reactive with the powder than the ambient atmosphere external to the processing chamber. The internal processing chamber atmosphere comprised argon, oxygen, and humidity. The oxygen will be at a concentration of at most about 1000 ppm, and the humidity had a dew point from about -55°C to about -15°C. The internal processing chamber atmosphere had a pressure of about 16 KPa above atmospheric pressure (e.g., above about 101 KPa), and will be at ambient temperature. The processing chamber will be equipped with eight optical windows made of sapphire in a configuration similar to the one depicted in Fig. 25 and in Fig. 9, e.g., 958. Each laser beam will be guided by an optical setup in an optical system enclosure, the optical system enclosure disposed above the processing chamber, the optical system enclosure comprising a galvanometer scanner. Each of the laser beams originated from a fiber laser and traversed its respective optical window into the processing chamber to impinge on an exposed surface of the powder bed to print layerwise a 3D object. Each of the laser beams will have a maximum power of about one (1) Kilo Watt, and a wavelength of about 1060 nanometers. A user will be able to view the laser beams during printing using a viewing window assembly disposed at a door of the processing chamber such as the door in Fig. 9, 902. The viewing assembly will comprise a reflective coating facing the interior of the processing chamber. The layer dispensing mechanism will form the powder bed by sequential layerwise deposition, the powder bed will be disposed in a build module above the build plate. The building module will have a 1000mm traversal span of the build plate. The build plate will be disposed above as part of a build platform assembly similar to the one depicted in example 1500 of Fig. 15, Fig. 27, and example 3750 of Fig. 37. The build plate will traverse down at increments of about 50 pm at a precision of +1-2 micrometers using a sensor configuration as depicted in Fig. 23 and Fig. 24, including a metrology detector such as 2354 and 2354 (comprising an interferometer), encoders such as 2308 and 2406, and (planar) mirrors such as 2310 and 2410. The build module was similar to the one depicted in example 3700 of Fig. 37. The powder bed will be used for layerwise printing a 3D object at least in part by using the lasers. The removed powder remainder not used for the printing, will be recycled using a recycling system as part of the powder recycling system that will be part of the material conveyance system. The recycled powder will be reused by the layer dispensing mechanism, e.g., recoater.

[0355] While preferred embodiments of the present invention have been shown, and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. It is not intended that the present disclosure be limited by the specific examples provided within the specification. While the present disclosure has been described with reference to the afore-mentioned specification, the descriptions and illustrations of the embodiments herein are not meant to be construed in a limiting sense. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the present disclosure. Furthermore, it shall be understood that all aspects of the present disclosure are not limited to the specific depictions, configurations, or relative proportions set forth herein which depend upon a variety of conditions and variables. It should be understood that various alternatives to the embodiments described herein might be employed in practicing the present disclosure. It is therefore contemplated that the present disclosure shall also cover any such alternatives, modifications, variations, or equivalents. It is intended that the following claims define the scope of the present disclosure and that methods and structures within the scope of these claims and their equivalents be covered thereby.