Abstract
A curved-hole machining method by EDM using an electrode consisting of a metal ball suspended with a lead copper foil from the spindle head of an electro-discharge machine has been proposed and the machining characteristics has been discussed . This report discusses the effects of the diameter and mass of the metal ball on electrical discharge machining. The use of a 5.5-mm-diameter ball electrode may provide stable machining performance under a wide range of electric conditions. On the other hand, with decreased ball diameter and mass, the stably machinable conditions are limited to lower discharge current and higher servo voltage. A smaller diameter hole can be machined by using a 3.0-mm-diameter ball under the optimum conditions. Additionally, a curved hole is successfully machined in this study by varying the tilt angles of the workpiece.
