EDM contouring is more advantageous in electrode cost and machining flexbility than the conventional diesinking EDM. Though the contouring had been thought to be less accurate due to the electrode wear, it was found that the contouring could achieve comparable accuracy with the conventional method by using the steady state of the electrode wear. This method allows more electrode wear than the conventional method because the electrode wear in the steady state does not decrease the machining accuracy as long as the wear is adequately compensated for. This means that this method may be also advantageous in machining speed, because the machining speed decreases in general when the electrode wear is made lower. In order to make this method practical, modeling the electrode wear is important. Once the model has been constructed, it may be easier to determine machining conditions such as the shape of the electrode and the compensation for the electrode wear for the desired shape of machining.
In this paper, a new grooving method using this contouring method is proposed. First, the electrode wear model at the steady state is described. Based on this model, the way to determine the machining conditions for grooves of any cross-sectional shape is described and some machining conditions for actual experiments are determined. The experimental results are found to be similar to the prediction given by the model when the grooves were not deep. Therefore, it can be concluded that this grooving method is practicable at least for the shallow grooves.