Ultra-fine finish EDM method and apparatus

摘要

An improved method of and power-supply system for EDM whereby machining pulses of on-time in the order of 10 to 100 nanoseconds are passed through an EDM gap to assure ultra-fine finish EDM results by using the gap current build-up characteristic resulting from each individual machining pulse and thereby timing the termination thereof to compensate for a delay caused by the inherent presence of a stray impedance in the gap power circuit lines. The machining pulses can be in the form of successive, intermittently interrupted trains of elementary pulses of which on-time is defined at a minimum which provides a minimum unit of stock removal by each pulse.