Abstract
This study deals with developing a new method to machine various shapes inside a straight hole. In general, holes machined by the practical methods have a straight shape with a constant cross section. This means that the practical methods do not have enough ability to control the shape of holes. In particular, it is very difficult to machine the hole whose cross section is complicatedly changing according to the depth of the hole. To solve the problem, the authors have developed the device which has the ability to machine'a complicated shape on the inside wall of a straight hole. This results in fabrication of the hole with the complicatedly changing cross section. The device has an electrode for electrical discharge machining whose motion can be controlled by a personal computer. However, its capability is not utilized for the maximum extent since the program to control the electrode motion is very simple. In this study, accordingly, the program is improved. From the machining experiment, it is found that a more complicated shape can be machined on the inside wall of a hole.
