Abstract
The study deals with developing a new method to fabricate various shapes inside a hole. A hole shape is limited to straight one in the practical machining manner. However, it often happens that the best hole meeting the requirement is not straight but more complex shaped one. In the study, hence, a new device is developed, which can make complicated shapes inside a hole. The device consists of an electrode for electrical discharge machining and some mechanical parts, and is installed on an electrical discharge machine (EDM). The device and EDM move as a reciprocating block slider crank mechanism. Namely, a translational motion of the EDM head can be converted into a rotational motion of the tool electrode. This results in machining the shape similar to the electrode locus. Consequently, if the machining mechanism is applied inside a hole, a semicircular shape can be created inside the hole. Moreover, the use of the electrode with slits makes it possible to fabricate fins inside the hole. From experimental results, it is found that the device has the potential of fabricating the semicircular space and the fins inside a hole.
