Abstract: A method and apparatus for vector machine control of a tool and a workpiece so as to perform desired electric discharge machine (EDM) operations on the workpiece in accordance with a polar coordinate frame of reference. The method for vector machine control calls for the processing of input data to derive vector magnitude data, vector angle data and Z-axis data. The tool is advanced in the direction of the Z-axis by a given amount to an offset position, and the tool is then successively advanced and withdrawn in the direction of a given vector angle (corresponding to the vector angle data) by a corresponding distance (corresponding to the vector magnitude data). The procedure may be repeated for successive vector angles and magnitudes, and may be further repeated at other offset positions in accordance with other vector angle and vector magnitude data.

Abstract: On-time and off-time control over the current pulses by the timing unit associated with the power supply for EDM apparatus is supervised by fault condition and voltage drop detectors to modify automatic operation of the timing unit. The fault condition detectors monitor gap conditions, and track voltage variations of the dc cutting current supply.