PURPOSE: To set a spinning machine at high accuracy in NC control of a spinning machine by teaching relative position of a roller to a mandrel in coordinate of arbitrary representative point, and moving the roller by a continuous curve passing that point.

CONSTITUTION: Z, X axes of a mandrel are manually operated while measuring the clearance T that corresponds to finished thickness of the work by a clearance gauge etc. Points (a), (b), (c) are inputted to a microcomputer of the controlling device, and teaching is made by PTP. When the tool is returned to point (a), and changed to continuous pass, and a roller 11 is sent to point C at a specified feeding speed, the roller can be moved exactly along the external form curve of the mandrel. When spinning forming is performed moving the roller by multi-cycle, the pass is drawn on the picture of an X-Z plotter, and marks are given to representative points 1W5... on the curve. Then, teaching is made from 1 successively, and continuous moving is given to the curve by continuous pass from 1, and the locus is recorded on the X-Z plotter.