Abstract
EDM technique of curved-hole using a metal ball electrode suspended with a copper wire was proposed in this report. By EDM using a copper-tungsten ball of 5.5mm in diameter suspended with cupper wire, the straight hole over 30mm in depth could be drilled into a steel workpiece at a constant machining rate. The electrode ball always vibrated during the process by the impact force associated with sparks, which would results in smoother exclusion of debris. Also, the machining of bended-hole was attempted by varying the tilt angle of the workpiece, and the hole with the bending angle up to 45° could be easy obtained. Moreover, by repeating the machinings of bended-hole, multiple curved holes could be machined by this method.
