BACKGROUND

[0001] Additive manufacturing devices produce three-dimensional (3D) objects by building up layers of material. Some additive manufacturing devices may be referred to as "3D printing devices" because they use inkjet or other printing technology to apply some of the manufacturing materials. 3D printing devices and other additive manufacturing devices make it possible to convert a computer-aided design (CAD) model or other digital representation of an object directly into the physical object.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] The accompanying drawings illustrate various examples of the principles described herein and are part of the specification. The illustrated examples are given merely for illustration, and do not limit the scope of the claims.

[0003] Fig. 1 is a block diagram of a control system for forming three- dimensional (3D) printed cages with internal dividers, according to an example of the principles described herein.

[0004] Fig. 2 is a diagram of an additive manufacturing device for forming 3D printed cages with internal dividers, according to an example of the principles described herein.

[0005] Fig. 3 is an isometric view of a 3D printed cage with internal dividers, according to an example of the principles described herein. [0006] Fig. 4 is an isometric view of a 3D printed cage with internal dividers, according to an example of the principles described herein.

[0007] Fig. 5 depicts a top view of a 3D printed cage with internal dividers, according to an example of the principles described herein.

[0008] Fig. 6 is a side view of a 3D printed cage with internal dividers, according to an example of the principles described herein.

[0009] Fig. 7 is a front view of an internal divider with a 3D printed object, according to an example of the principles described herein.

[0010] Fig. 8 is a flow chart of a method for forming 3D printed cages with internal dividers, according to an example of the principles described herein.

[0011] Fig. 9 depicts a non-transitory machine-readable storage medium for forming 3D printed cages with internal dividers, according to an example of the principles described herein.

[0012] Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements. The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover, the drawings provide examples and/or implementations consistent with the description; however, the description is not limited to the examples and/or implementations provided in the drawings.

DETAILED DESCRIPTION

[0013] Additive manufacturing devices form a three-dimensional (3D) object through the solidification of layers of a build material. Additive manufacturing devices make objects based on data in a 3D model of the object generated, for example, with a computer-aided drafting (CAD) computer program product. The model data is processed into slices, each slice defining portions of a layer of build material that is to be solidified.

[0014] In one example, to form the 3D printed object, a build material, which may be powder, is deposited on a bed. A fusing agent is then dispensed onto portions of the layer of build material that are to be fused to form a layer of the 3D printed object. The system that carries out this type of additive manufacturing may be referred to as a powder and fusing agent-based system. The fusing agent disposed in the desired pattern increases the energy absorption of the layer of build material on which the agent is disposed. The build material is then exposed to energy such as electromagnetic radiation. The electromagnetic radiation may include infrared light, laser light, or other suitable electromagnetic radiation. Due to the increased heat absorption properties imparted by the fusing agent, those portions of the build material that have the fusing agent disposed thereon heat to a temperature greater than the fusing temperature for the build material. By comparison, the applied heat is not so great so as to increase the heat of the portions of the build material that are free of the agent to this fusing temperature. This process is repeated in a layer-wise fashion to generate a 3D object. The unfused portions of material can then be separated from the fused portions, and the unfused portions recycled for subsequent 3D formation operations.

[0015] Another way to form 3D printed objects is to selectively apply binder to areas of loose build material. In this example, a “latent” part is prepared inside a build bed filled with build material. The build bed may be transferred to a furnace where a first heating operation removes solvents present in the applied binder. As solvents are removed, the remaining binder hardens and glues together build material to convert the “latent” part into a “green” part. The green part is then removed from the bed. As a result of this operation, residual build material may be caked onto the green parts. It may be desirable to remove residual build material from green parts in a cleaning operation. In some examples, the green parts are loaded into a sintering furnace where applied heat can cause binder decomposition and causes the build material powder particles to sinter or fuse together into a durable solid form.

[0016] In yet another example, a laser, or other power source is selectively aimed at a powder build material, or a layer of a powder build material, to form a slice of a 3D printed object. Such a process may be referred to as selective laser sintering. [0017] In yet another example, the additive manufacturing process may use selective laser melting where portions of the powder material, which may be metallic, are selectively melted together to form a slice of a 3D printed part. [0018] In one particular example of additive manufacturing referred to as laser fusion, an array of lasers scans each layer of powdered build material to form a slice of a 3D printed object. In this example, each laser beam is turned on and off dynamically during the scanning process according to the image slice. Similar to a fusing agent-based system, this laser fusion process is also layer-by-layer.

[0019] In yet another example, the additive manufacturing process may involve using a light source to cure a liquid resin into a hard substance. Such an operation may be referred to as stereolithography. Accordingly, a device which carries out any of these additive manufacturing processes may be referred to as an additive manufacturing device and in some cases a printer. [0020] While such additive manufacturing operations have greatly expanded manufacturing and development possibilities, further development may make 3D printing a part of even more industries. For example, 3D printing may allow for the production of small or delicate geometries. These small or delicate geometries may be brittle and prone to mechanical damage during post-production and/or distribution. However, it may be desirable to clean the object before distribution, which cleaning may subject the part to mechanical forces. That is, there is a balance to be struck between part cleanliness and part breakage.

[0021] Accordingly, the present specification describes the formation of a 3D printed cage around the 3D printed objects which 3D printed cage protects 3D printed objects from mechanical damage and that also facilitates object cleaning and handling. For certain objects however, additional protection may be desirable. For example, high aspect ratio objects, even with a support cage, may bend and deflect inside the cage and slip through gaps in the cage opening. Accordingly, the present specification provides for the formation of a 3D printed cage that can support high aspect ratio objects, such as nasopharyngeal swabs, through production, cleaning, and distribution all while facilitating cleansing of the 3D printed objects. That is, the 3D printed cages not only protect the 3D printed objects form external damage, but also protect the 3D printed objects during the printing and cooling processes as well. In one test, less warpage of high aspect ratio parts was observed.

[0022] Specifically, the 3D printed cages of the present specification have bars. However, the bar density or spacing varies on different surfaces of the 3D printed cages. That is, on the sides of the cage, aligned with the long axis of the 3D printed object, a less dense cage pattern may be printed as compared to a cage pattern on ends of the cage. This less dense cage pattern along the sides provides for part accessibility secondary post-processes. For example, the parts may be cleaned with a bead blaster or other cleaning mechanism such as an ultrasonic cleaning device. In another example, the parts may be coated with a paint, polish or other material through the cage bars. As yet another example, the parts may be sterilized through the less dense cage pattern along the sides.

[0023] The ends of the cage have a tighter cage pattern. This tighter cage pattern at the ends keeps the 3D printed objects from falling out of the cage throughout manufacturing and distribution. This may protect the parts from mechanical damage and also enables object tracking. For example, were a 3D printed object to fall out of the 3D printed cage, the 3D printed object may get mixed with 3D printed objects in a different batch. Moreover, each 3D printed cage may be labelled and tracked individually.

[0024] The 3D printed cages of the present specification also include internal dividers to keep 3D printed objects from bending or warping along their long axis. The internal dividers also reduce the motion of the 3D printed objects during manufacturing and distribution. The reduced motion protects the 3D printed objects and prevents them from contacting and potentially breaking against other 3D printed objects or the 3D printed cage housing. In one particular example, these internal dividers have a thin-walled honeycomb structure.

[0025] Specifically, the present specification describes a control system. The control system includes a cage controller to determine dimensions of a 3D printed cage to surround a number of 3D printed objects. The 3D printed cage includes internal dividers to separate the number of 3D printed objects. The present specification also describes an additive manufacturing controller to generate additive manufacturing instructions to simultaneously form the number of 3D printed objects and the 3D printed cage to surround the number of 3D printed objects.

[0026] The present specification also describes a method. According to the method, slices of multiple 3D printed objects are formed. Slices of a 3D printed cage are formed around the multiple 3D printed objects. At least one surface of the 3D printed cage has a higher bar density as compared to at least one other surface of the 3D printed cage. Internal dividers with holes therein are also formed around the multiple 3D printed objects. The internal dividers and holes individually support and separate the multiple 3D printed objects. These operations may be performed in a layer-by-layer fashion.

[0027] The present specification also describes a non-transitory machine- readable storage medium encoded with instructions executable by a processor. The machine-readable storage medium includes instructions, that when executed by the processor, cause the processor to determine dimensions of a number of 3D objects to be printed. The machine-readable storage medium includes instructions, that when executed by the processor, cause the processor to determine, based on dimensions of the 3D objects to be printed, dimensions of a 3D printed cage to surround a number of 3D printed objects. As described above, the 3D printed cage includes internal dividers to separate the number of 3D printed object. The machine-readable storage medium includes instructions, that when executed by the processor, cause the processor to generate additive manufacturing instructions to simultaneously form the number of 3D printed objects and the 3D printed cage.

[0028] Such systems and methods 1) protect the 3D printed objects inside the 3D printed cage from mechanical damage while being accessible for cleaning; 2) allows for high density printing of high aspect ratio geometries; and 3) automatically generates the 3D printed cage with its associated dimensions based on dimensions of the 3D objects to be printed. However, it is contemplated that the systems and methods disclosed herein may address other matters and deficiencies in a number of technical areas.

[0029] As used in the present specification and in the appended claims, the term “controller” may refer to an electronic component which may include a processor and memory. The processor may include the hardware architecture to retrieve executable code from the memory and execute the executable code. As specific examples, the controller as described herein may include computer readable storage medium, computer readable storage medium and a processor, an application specific integrated circuit (ASIC), a semiconductor-based microprocessor, a central processing unit (CPU), and a field-programmable gate array (FPGA), and/or other hardware device.

[0030] The memory may include a computer-readable storage medium, which computer-readable storage medium may contain, or store computer usable program code for use by or in connection with an instruction execution system, apparatus, or device. The memory may take many types of memory including volatile and non-volatile memory. For example, the memory may include Random Access Memory (RAM), Read Only Memory (ROM), optical memory disks, and magnetic disks, among others. The executable code may, when executed by the controller cause the controller to implement at least the functionality of defining 3D printed cages to be printed simultaneously with, and around 3D printed objects as described below.

[0031] Turning now to the figures, Fig. 1 is a block diagram of a control system (100) for forming three-dimensional (3D) printed cages with internal dividers, according to an example of the principles described herein. As described above, a 3D printed object may be formed by selectively hardening powdered build material in particular patterns. In some examples, this may be done in a layer-wise fashion, wherein individual slices of a 3D printed object are formed. This process is repeated layer-by-layer until the 3D printed object is formed. In general, apparatuses for generating three-dimensional objects may be referred to as additive manufacturing devices. The system (100) described herein may be implemented on a computing device that is coupled to the additive manufacturing device, where such an additive manufacturing device is a fusing-agent based system, a system where a “green” part is passed to a sintering device to sinter particles together, a selective laser sintering device, a selective laser melting device, or a stereolithographic device, among others. [0032] The system (100) includes a cage controller (102) to determine dimensions of a 3D printed cage to surround a number of 3D printed objects. That is, in addition to forming the 3D printed objects themselves, the additive manufacturing device may simultaneously form the 3D printed cage that is to surround the 3D printed objects. That is, the additive manufacturing device may form the 3D printed objects and the 3D printed cage in a single bed of the additive manufacturing device at the same time. That is, a layer of powdered build material may receive fusing agent in 1) a pattern that defines a slice of the 3D printed objects and 2) a pattern that defines a slice of the 3D printed cage. As described above, the 3D printed cage may include internal dividers that support and separate the 3D printed objects that are formed within a given 3D printed cage. The cage controller (102) determines the dimensions of both the 3D printed cage and the internal dividers and specifically does so based on the dimensions of the 3D objects to be printed. For example, the 3D printed cage and internal dividers may have various parameters such as thickness, density, size, shape, etc. These values may be determined based on the dimensions, such as a length of the 3D printed object and the cross-sectional area of the 3D printed object.

[0033] The control system (100) also includes an additive manufacturing controller (104) to generate additive manufacturing instructions to simultaneously form the number of 3D printed objects and the 3D printed cage to surround the number of 3D printed objects. In one example, the additive manufacturing controller (104) may alter or generate a manufacturing file associated with the 3D printed object. For example, a design file may exist for the 3D printed object, which design file indicates materials, sizes, shapes, and other properties of the 3D printed object. In this example, the additive manufacturing controller (104) alters the design file associated with the 3D printed object to include the 3D printed cage and the internal dividers therein. In another example, the additive manufacturing controller (104) generates the design file associated with the 3D printed object.

[0034] Another example of a manufacturing file that may be altered or generated is a build file. The build file includes information used to control the additive manufacturing device components. For example, the build file may include power specifications to be used to form a 3D printed object and may also indicate quantities and densities of different agents used to form the 3D printed object. In this example, the additive manufacturing controller (104) may alter or generate this build file associated with the 3D printed object to define the surrounding 3D printed cage and internal dividers.

[0035] In one example, the additive manufacturing controller (104) may change an orientation of the 3D printed objects to enhance space efficiency and thermal loading of the 3D printed objects as the 3D printed cage is formed. That is, formation of the 3D printed cage may thermally alter the 3D printed objects. Accordingly, the additive manufacturing controller (104) may adjust the position of the 3D printed objects to offset any alteration based on the 3D printed cage formation.

[0036] Accordingly, the present control system (100) provides a way to specify the properties of the 3D printed cage, which may be based on any number of criteria including dimensions of the 3D printed object.

[0037] Fig. 2 is a diagram of an additive manufacturing device for forming 3D printed cages with internal dividers, according to an example of the principles described herein. As described above, the additive manufacturing device may be a fusing agent-based device (as depicted in Fig. 2), a bindingagent based device, or other type of device. While Fig. 2 depicts a specific example of an agent-based device, the additive manufacturing device may be any of the above-mentioned devices or another type of additive manufacturing device.

[0038] In an example of an additive manufacturing process, a layer of build material may be formed in a build area. As used in the present specification and in the appended claims, the term “build area” refers to an area of space wherein the 3D printed object is formed. The build area may refer to a space bounded by a bed (208) and walls. The build area may be defined as a three-dimensional space in which the additive manufacturing device can fabricate, produce, or otherwise generate a 3D printed object. That is, the build area may occupy a three-dimensional space on top of the bed (208) surface. For simplicity, the walls of the additive manufacturing device have been removed to illustrate other components. In one example, the width and length of the build area can be the width and the length of bed (208) and the height of the build area can be the extent to which bed (208) can be moved in the z direction. Although not shown, an actuator, such as a piston, can control the vertical position of bed (208).

[0039] The bed (208) may accommodate any number of layers of build material. For example, the bed (208) may accommodate up to 4,000 layers or more. In an example, a number of build material supply receptacles may be positioned alongside the bed (208). Such build material supply receptacles source the build material that is placed on the bed (208) in a layer-wise fashion. [0040] Fig. 2 clearly depicts the build material distributor (210). The build material distributor (210) may acquire build material from build material supply receptacles, and deposit acquired material as a layer in the bed (208), which layer may be deposited on top of other layers of build material already processed that reside in the bed (208).

[0041] In some examples, the build material distributor (210) may be coupled to a scanning carriage. In operation, the build material distributor (210) places build material in the build area as the scanning carriage moves over the build area along the scanning axis. In some examples, the additive manufacturing device includes a roller (212) or other component to smooth and level the build material.

[0042] Fig. 2 also depicts the agent distributor (214) which forms the 3D printed object and the 3D printed cage. The agent distributor (214) does so by depositing at least one agent onto a layer of powdered build material. The agent distributor (214) may distribute a variety of agents. One specific example of an agent is a fusing agent, which increases the energy absorption of portions of the build material that receive the fusing agent to selectively solidify portions of a layer of powdered build material. An energy source may temporarily apply energy to the layer of build material. The energy can be absorbed selectively into patterned areas formed by the fusing agent, while blank areas that have no fusing agent absorb less applied energy. This leads to selected zones of a layer of build material selectively fusing together. This process is then repeated, for multiple layers, until a complete physical object has been formed. Not only is the fusing agent deposited in the pattern of the 3D objects to be printed, but in the pattern of the 3D printed cage as well as the internal dividers that make up the 3D printed cage.

[0043] The agent distributor (214) may deposit other agents to form the 3D printed object. For example, the agent distributor (214) may deposit a binder agent that temporarily glues portions of the 3D printed object together.

[0044] In some examples, an agent distributor (214) includes at least one liquid ejection device to distribute a functional agent onto the layers of build material. A liquid ejection device may include at least one printhead (e.g., a thermal ejection based printhead, a piezoelectric ejection based printhead, etc.). In some examples, the agent distributor (214) is coupled to a scanning carriage, and the scanning carriage moves along a scanning axis over the bed (208). In one example, printheads that are used in inkjet printing devices may be used in the agent distributor (214). In this example, the fusing agent may be a printing liquid. In other examples, an agent distributor (214) may include other types of liquid ejection devices that selectively eject small volumes of liquid.

[0045] Fig. 2 also depicts the control system (100) which as described above determines the dimensions and layout of the 3D printed cage as well as the instructions to send to the additive manufacturing device to form the 3D printed cage and the 3D printed objects.

[0046] Fig. 3 is an isometric view of a 3D printed cage (316) with internal dividers (318), according to an example of the principles described herein. As described above, the 3D printed cage (316) may provide protection for the 3D printed objects disposed therein and also provides access to the 3D printed objects for cleaning devices to remove unfused build material. [0047] That is, after the additive manufacturing process, unfused build material may adhere to the surfaces of the 3D printed objects. It may be desirable to remove the unfused build material for a number of reasons. For example, unfused build material that remains adhered to 3D printed objects cannot be reused and therefore results in wasted material. It may also be desirable to clean the parts, and particularly so for certain 3D printed objects. For example, in the event a medical device, such as a nasopharyngeal swab, is 3D printed and is to be inserted into a nasal cavity of a user, it may be particularly desirable to clean off unfused build material. The 3D printed cage (316) of the present specification provides cleaning devices access to the 3D printed objects all while containing and protecting the 3D printed objects. That is, the 3D printed cage (316) may include a number of bars that 1) protect the 3D printed objects from mechanical damage and 2) provides access to devices such as sandblasting or liquid nozzles.

[0048] As depicted in Fig. 3, the bar density on different surfaces of the 3D printed cage (316) may be different. Doing so may allow access to the 3D printed objects disposed therein, while preventing the 3D printed objects from falling out of the 3D printed cage. For example, ends of the 3D printed cage (316), which ends may be perpendicular to and adjacent short ends of high aspect ratio 3D printed objects, may have a denser bar spacing to prevent 3D printed objects from sliding out of the cage. By comparison, sides of the 3D printed cage (316), which sides may be parallel with the length of the high aspect ratio 3D printed objects, may have a less dense bar spacing to allow cleaning devices to interact with the 3D printed objects.

Fig. 3 also depicts the internal dividers (318) that individually separate and support the 3D objects to be printed. Specifically, the internal dividers (318) restrict the motion of each 3D printed object based on a difference in size between a hole in the internal divider (318) and the 3D printed object that passes therethrough. Note that Fig. 3 depicts a specific number of internal dividers (318) at a specific spacing and with specific characteristics. However, as described above, the cage controller (Fig. 1 , 102) may determine a variety of values for these parameters, which values may be selected based on the dimensions and parameters of the 3D objects to be printed. As described above, the 3D printed cage (316) and internal dividers (318) may be printed at the same time as the 3D printed objects. While Fig. 3 depicts a rectangular 3D printed cage (316), the 3D printed cage (316) may have any variety of shapes including a cylindrical box.

[0049] Fig. 4 is an isometric view of a 3D printed cage (316) with internal dividers (318), according to an example of the principles described herein. Specifically, Fig. 4 depicts the 3D printed cage (316) with the bars removed for ease in illustration of the internal dividers (318). For simplicity, Fig. 4 depicts three internal dividers (318) with one 3D printed object (420) found therein. As described above, the internal dividers (318) include a variety of holes wherein a 3D printed object (420) may pass, or is positioned within, a hole. While positioned in a hole, the 3D printed object (420) has limited mobility such that it is maintained separate from other 3D printed objects (420). Accordingly, each 3D printed object (420) is physically separated from other 3D printed objects (420) such that the 3D printed objects (420) do not collide with one another, potentially resulting in mechanical damage to the 3D printed objects (420). Moreover, ensuring that the 3D printed objects (420) are separated from one another allows a cleansing agent to pass therethrough. For example, were the 3D printed objects (420) to be in contact with one another, a cleaning agent such as air or water may not be able to pass therebetween. As such, the 3D printed objects (420) may not be sufficiently cleaned. Fig. 4 also depicts a particular example where the internal divider (318) has a honeycomb structure. [0050] As described above, the characteristics of the internal dividers (318) and the 3D printed cage (316) may be automatically determined by the cage controller (Fig. 1 , 102). That is, the cage controller (Fig. 1 , 102) may receive as input, the dimensions of the 3D printed objects (420) and a number of 3D printed objects (420) to be placed in a 3D printed cage (316), and may alter a skeleton file to generate a 3D printed cage (316) customized for the 3D printed objects (420) formed therein.

[0051] As one particular example, the cage controller (Fig. 1 , 102) may determine a number of internal dividers (318) based on dimensions of the 3D printed objects (420) to be contained in the 3D printed cage (316). That is, the potential deflection of a 3D printed object (420) is dependent upon its length and its cross-sectional area. Accordingly, the number of internal dividers (318) may be selected based on the length of the 3D printed object (420) and the cross- sectional areas of the 3D printed objects (420) along its length. The number of internal dividers (318) may be such that the 3D printed objects (420) do not warp or bend past a predetermined threshold. In the example depicted in Fig.

4, there are three internal dividers (318), however different numbers of internal dividers (318) may be implemented to prevent warpage and/or bending of the 3D printed objects (420).

[0052] As another example, the cage controller (Fig. 1 , 102) may determine a spacing of the internal dividers (318) based on the dimensions of the 3D printed objects (420). That is, as depicted in Fig. 4, the internal dividers (318) are evenly spaced. However, it may be the case that the internal dividers (318) are not evenly spaced as one portion of a high aspect ratio object may be less prone to bending or warping. For example, one end of a high aspect ratio 3D printed object (420) may have a greater cross-sectional area such that it is not as likely to bend at that location. Accordingly, internal dividers (318) at that end may be spaced farther apart.

[0053] As another example, the cage controller (Fig. 1 , 102) may determine a thickness of the internal dividers (318) based on the dimensions of the 3D printed objects (420). That is, longer and thicker 3D printed objects (420) may be heavier as compared to shorter and thinner 3D printed objects (420). The cage controller (Fig. 1 , 102) may select an internal divider (318) thickness that ensures the internal divider (318) can support the weight of the 3D printed objects (420).

[0054] In some examples, the characteristics of each internal divider (318) may differ from other internal dividers (318). For example, the cross- sectional area of the 3D printed objects (420) may change along its length. Accordingly, each internal divider (318) may have different characteristics to specifically support and separate a portion of the 3D printed object (420) that aligns with that internal divider (318). As a specific example, a size and shape of holes on a first internal divider (318) may be different than a size and shape of holes on a second internal divider (318). For example, one end of the 3D printed object (420) may include a rectangular cross section while another end of the 3D printed object (420) includes a circular cross section. Accordingly, the internal divider (318) adjacent the rectangular cross section may have holes that are rectangular while the internal divider (318) adjacent the circular cross section portion of the 3D printed object (420) may have a circular cross section. [0055] Accordingly, the cage controller (Fig. 1 , 102) may craft internal dividers (318) that are customized to the 3D printed objects (420) to be formed therein. Moreover, as described above, each individual internal divider (318) may be independently crafted so as to most effectively support the 3D printed object (420).

[0056] The dimensions of the 3D printed cage (316) itself may also be determined based on the dimensions of the 3D printed objects (420). That is, the cage controller (Fig. 1 , 102) may determine a thickness of the 3D printed cage (316) bars and the density of the 3D printed cage (318) bars based on a length of the 3D printed objects (420). For example, the 3D printed cage (316) bars on the ends of the 3D printed cage (316) may be spaced closer together than the cross-sectional area of the 3D printed objects (420) so that the 3D printed objects do not slip out of the 3D printed cage (316). Similarly, the cage controller (Fig. 1 , 102) may determine the properties of the sides of the 3D printed cage (316) such that a cleaning device may adequately access the 3D printed objects (420). Accordingly, the cage controller (Fig. 1 , 102) may craft the 3D printed cage (316) to be customized to the 3D printed objects (420) to be formed therein.

[0057] Accordingly, the present control system (Fig. 1 , 100) may parametrically and automatically determine the properties of the 3D printed cage (316) and the internal dividers (318) based on the dimensions of the 3D objects (420) to be printed. A specific example of determination of dimensions of the 3D printed cage (316) and internal dividers (318) based on the 3D printed object dimensions is now provided. [0058] In this example, the 3D printed object (420) may have a diameter of 3 millimeters (mm) and a length of 150 mm. Receiving a file with this information, and without additional input from a user, the cage controller (Fig. 1 , 102) may automatically determine a bar spacing along the sides of between 5 - 20 mm, with openings of 9 square mm. Such a spacing would allow a cleaning device access to the 3D printed objects (420) within the 3D printed cage (316). The cage controller (Fig. 1 , 102) may also determine the bar spacing along the ends to be 2 mm along one axis and 7.25 mm along another access. For both the ends and sides, the bar thickness may be between 0.5 and 5 mm.

[0059] As described above, the dimensions of the internal dividers (318) may also be based on the dimensions of the 3D printed objects (420). Based on the aforementioned dimensions of the 3D printed objects (420), the holes of the internal dividers (318) may have a center-to-center spacing of 5.45 mm, which may provide a 2.35 mm gap between adjacent 3D printed objects (420) with the aforementioned dimensions. A thickness of the internal dividers (318) may be between 0.5 and 5 mm. Note that the above is a specific example of how the cage controller (Fig. 1 , 102) may, without additional information outside the design and/or build file for the 3D printed object, generate a 3D printed cage (316) for the 3D printed objects (420).

[0060] Fig. 5 depicts a top view of a 3D printed cage (316) with internal dividers (Fig. 3, 318), according to an example of the principles described herein. Specifically, as described above, the 3D printed cage (316) includes a first surface with a bar density that is different than a bar density on a second surface. Specifically, as depicted in Figs. 5 and 6, bars on an end of the 3D printed cage (316) are packed more tightly together as compared to bars on sides of the 3D printed cage (316) to prevent the 3D printed objects (Fig. 4, 420) from falling out. Were the bars on the side packed as tightly as those on the top, a cleaning device may be blocked from access to the 3D printed objects. [0061] Fig. 6 depicts a side view of a 3D printed cage (316) with internal dividers (Fig. 3, 318), according to an example of the principles described herein. Specifically, as described above, the 3D printed cage (316) includes a first surface with a bar density that is different than a bar density on a second surface. Specifically, as depicted in Figs. 5 and 6, bars on the sides of the 3D printed cage (316) are packed less tightly together as compared to bars on ends of the 3D printed cage (316) to allow access for secondary post-processes. If the bars on the top were packed as loosely as the bars on the side, the 3D printed objects (Fig. 4, 420) may slide out of the 3D printed cage (316).

[0062] Fig. 7 is a front view of an internal divider (318) with a 3D printed object (420), according to an example of the principles described herein. Again, for simplicity, just one 3D printed object (420) is depicted in the internal divider (318). However, other instances of the 3D printed object (420) may similarly be aligned with other holes of the internal divider (318).

[0063] As depicted in Fig. 7, in some examples, the internal divider (318) is not in contact with the 3D printed object (420). That is, the walls of the hole may be separated from the 3D printed object (420) by unhardened build material, which unhardened build material may be removed in a post processing operation. Accordingly, following cleaning, the 3D printed object (420) is not attached to the internal divider (318) and is free to move around within the hole. Doing so may allow for an enhanced efficacy in secondary post-processes. For example, the 3D printed objects (420) may freely move about within the hole such that upon manual agitation, the 3D printed objects (420) may rotate and expose different surfaces to the cleaning agent.

[0064] In some examples, the cage controller (Fig. 1 , 102) determines a size and shape of the holes based on the dimensions of the 3D printed objects (420) passing through. That is, as described above and is depicted, the shape of the 3D printed object (420) may be hexagonal and the holes may also be hexagonal. That is, each hole may have a shape that is congruent with a cross- sectional area of the 3D printed object (420) that passes therethrough. Doing so may reduce thermal defects.

[0065] Fig. 8 is a flow chart of a method (800) for forming 3D printed cages (Fig. 3, 316) with internal dividers (Fig. 3, 318), according to an example of the principles described herein. As described above, additive manufacturing involves the layer-wise deposition of build material and hardening/curing/sintering/fusing of certain portions of that layer to form a slice of a 3D printed object (Fig. 4, 420). Accordingly, in this example, the method (800) includes sequentially forming (block 801) slices of multiple 3D printed objects (Fig. 4, 420). In the case of an agent-based additive manufacturing device this may include depositing layers of build material and a fusing agent to form slices of a 3D printed object (Fig. 4, 420). This includes sequential activation, per slice, of a build material distributor (Fig. 2, 210) and an agent distributor (Fig. 2, 214) and the scanning carriages to which they may be coupled so that each distribute its respective composition across the surface. [0066] The method (800) also includes forming (block 802) a 3D printed cage (Fig. 3, 316) to surround the multiple 3D printed objects (Fig. 4, 420). As described above, this includes forming the 3D printed cage (Fig. 3, 316) such that at least one surface of the 3D printed cage (Fig. 3, 316) has a higher bar density as compared to at least one other surface of the 3D printed cage. Internal dividers (Fig. 3, 318) are also formed (block 903) with holes therein. The holes individually support and separate the multiple 3D printed objects (Fig. 4, 420).

[0067] As described above, the formation of the 3D printed objects (Fig. 4, 420), 3D printed cage (Fig. 3, 316), and internal dividers (Fig. 3, 318) may be performed simultaneously. That is, a layer of build material may be deposited and fusing agent may be deposited 1 ) in a pattern of a slice of the 3D printed objects (Fig. 4, 420), 2) a pattern of a slice of the 3D printed cage (Fig. 3, 316), and 3) a pattern of a slice of the internal divider(s) (Fig. 3, 318).

[0068] Fig. 9 depicts a non-transitory machine-readable storage medium (922) for forming 3D printed cages (Fig. 3, 316) with internal dividers (Fig. 3, 318), according to an example of the principles described herein. To achieve its desired functionality, a computing system includes various hardware components. Specifically, a computing system includes a processor and a machine-readable storage medium (922). The machine-readable storage medium (922) is communicatively coupled to the processor. The machine- readable storage medium (922) includes a number of instructions (924, 926, 928) for performing a designated function. The machine-readable storage medium (922) causes the processor to execute the designated function of the instructions (924, 926, 928).

[0069] Referring to Fig. 9, determine object instructions (924), when executed by the processor, cause the processor to determine dimensions of a number of 3D objects (Fig. 4, 420) to be printed. Determine cage instructions (926), when executed by the processor, may cause the processor to, determine, based on dimensions of the 3D objects (Fig. 4, 420) to be printed, dimensions of a 3D printed cage (Fig. 3, 316) to surround a number of 3D printed objects (Fig. 4, 420). In this example, the 3D printed cage (Fig. 3, 316) includes internal dividers (Fig. 3, 318) to separate the number of 3D printed objects (Fig. 4, 420). Generate instructions (928), when executed by the processor, may cause the processor to generate additive manufacturing instructions to form the number of 3D printed objects (Fig. 4, 420) and the 3D printed cage (Fig. 3, 316) to surround the number of 3D printed objects (Fig. 4, 420).

[0070] Such systems and methods 1) protect the 3D printed objects inside the 3D printed cage from mechanical damage while being accessible for cleaning; 2) allows for high density printing of high aspect ratio geometries; and 3) automatically generates the 3D printed cage with its associated dimensions based on dimensions of the 3D objects to be printed. However, it is contemplated that the systems and methods disclosed herein may address other matters and deficiencies in a number of technical areas.