Using rapid prototyping to produce electrical discharge machining electrodes

Presents the background to and efforts being made to find a direct production route using rapid prototype (RP) parts as the electrodes for electrical discharge machining (EDM). It would have the double effect of unlocking the potential of the EDM die sinking process and expanding the role of RP in the production environment. Thin coated stereolithography (SL) models have been used to erode hardened tool steel to a depth of 4mm. Machining efficiency of these copper coated RP models is not comparable to that of conventional machined solid copper electrodes. Parametric optimization has been applied, achieving substantial improvements in machining efficiency, At present these electrodes are suitable for semi-roughing or finishing cuts in EDM die sinking. Electroforming copper into SL cavities shows potential for manufacture of electrodes with comparable performance to that of solid copper.