Abstract: A programmable manipulator having an arm which is movable in a plurality of axes and encoder apparatus for the axes operative to develop position signals corresponding to the actual position of the arm is provided adjacent a workpiece moving along a predetermined path, a conveyor for example, to perform a series of programmed operations on the workpiece.The programmable manipulator is provided with teach-programming apparatus for moving the arm during an initial teaching operation to different positions of the stationary workpiece corresponding to the desired series of operations of the manipulator relative to the stationary workpiece. Further, apparatus is provided for calculating digital representations during the teaching operation representing the positions of the arm accounting for the projected workpiece movement during playback and corresponding to the initial teaching positions relative to the workpiece.

Abstract: A method and apparatus are disclosed for controlling the initiation of cutting motions for cutting multiple start threads on a rotating workpiece held in a spindle of a numerically controlled machine. The numerical control contains an interpolator circuit responsive to a spindle feedback circuit connected to the spindle for generating a marker pulse and a predetermined number of spindle pulses for every revolution of the spindle. The apparatus provides input signals representing a particular threading start number relative to the total number of threading starts. Next, a control signal is generated which represents a number of spindle pulses as a function of the ratio of the particular threading start number to the total number of threading starts. Upon detecting an occurrence of a marker pulse which would normally initiate a threading motion, the apparatus is operative to inhibit a number of spindle pulses corresponding to the control signal.