Control technology for Micro-EDM machine and its applications

A micro-EDM (MEDM) equipment with four axes, three of which perform linkage movement, was developed. The micro electrode fabricating control technology and forming MEDM servo control technology as well as electrode wear compensation control technology were researched. After analyzing the servo mechanism performance, the method of using different control strategy for different machining aim is adopted. This method solves not only crawl problem of servo mechanism, but also the servo oscillation problem while fabricating micro electrode. Furthermore, a method of electrode wear compensation on-line was presented, in which the electrode wear compensation strategy is one part of micro-EDM machine control system. Therefore, the precise model of electrode wear as well as the special CAD/CAM system is hardly necessary, which greatly enhances the applicability of 3D microstructures machined by micro-EDM. At last, the micro electrode with minimum diameter φ6 μm and the micro hole with minimum diameter φ10 μm were machined on this machine, and a micro turbo with 24 blades, 4 mm of outer diameter, and a micro hemisphere with diameter φ150 μm were also machined by using above method.