Precision micro EDM based on real-time monitoring and electrode wear compensation

Abstract

Micro electrical discharge machining (EDM) has been widely applied for manufacturing precise and complex 3D micro shapes. However, in 3D micro EDM machining, electrode wear, caused by discharged pulses, is a serious problem, which significantly affects machining accuracy. In this work, a real-time, micro EDM monitoring system was developed to classify and count the number of discharge pulses using the uniform wear method. Based on the normal number of discharges and tool wear, an empirical relationship between them was established. From this relationship, this study also proposed a new electrode wear compensation method, called as NNU method, based on the number of normal discharges and uniform wear method (UWM). Experimental results indicated that the grooves or 3D shapes could be fabricated with high accuracy.