Abstract
In this study, we demonstrate a new method of micro-pin electrode formation by scanning EDM. A micro-pin electrode is fabricated by scanning EDM, in which the tool electrode approaches the side of the working plate in the horizontal plane. The rotating electrode is moved through the inside of the working plate, and then, a micro-pin WC-Co electrode is formed with a diameter of about 40μm. However, with this method, it is difficult to control the electrode diameter owing to occasional wear. To control the electrode diameter, we set two electrically isolated plates in position, and the movement of the electrode is controlled to keep the electrode in the center of the clearance by measuring currents in the isolated plates. As the results, the machined diameter closely corresponds to the desired diameter, and then, the 300μm diameter of the WC-Co tool electrode of 1.5mm length was changed to a 50μm diameter in 3 min of machining under twin power supply conditions.
