Development of a prototype Micro-Wire-EDM machine

With the demands on the minimization of surface roughness, decrease of the producible geometric dimensions and improvement of the machining accuracy, Micro-Wire-EDM with a wire diameter of 80 μm and below has been a key technology for micro-machining. The purpose of this paper is to develop three key techniques for a prototype CNC micro-wire EDM machine. These techniques involve the development of an open architecture CNC system with submicro-meter resolution of a two-axis linear motor stage, development of a wire transport system, development of a power supply system. The proposed CNC system is featured with open architecture human machine interface, modularity and DSP-based control. The wire transport system is presented to guarantee a smooth wire transport and a constant tension value. The power supply system consists of a low energy discharge circuit and an iso-frequency pulse generator. Pulse states are classified as open circuit, normal spark and abnormal discharge by means of the level of gap voltage and discharge current. Experimental results demonstrate that the developed prototype Micro-Wire-EDM machine has the potential of manufacturing micro-mechanism parts.