Sensing and compensation of tool wear in milling EDM

Milling EDM enables machining of complex cavities with simple cylindrical or tubular electrodes. To assure an acceptable machining accuracy, milling EDM requires compensation of the tool electrode wear. Existing wear compensation methods are mostly based on off-line prediction of tool wear. This paper discusses a new wear compensation method, incorporating real-time wear sensing based on discharge pulse evaluation. Tool wear is continuously evaluated during machining, and the actual wear compensation is adapted on the basis of this real-time wear evaluation. The advantages of the developed wear compensation method are illustrated with simulations and experiments.