Creation of long curved hole by means of electrical discharge machining using an in-pipe movable mechanism

The study deals with the development of an in-pipe movable mechanism to extend the length of the curved hole machined with our devised method. To establish a curved hole machining method, authors have developed the device installed on an electrical discharge machine (EDM), which can make an electrode move along a curved trajectory with electrical discharge machining performed. This results in the fabrication of curve holes. However, the length of the curved holes is limited, thus, the in-pipe movable mechanism is devised in the study to remove the limitation. The mechanism has a flexible body whose head is equipped with an electrode, and can make a curved hole longer by machining at the bottom of the hole, while passing through the hole fabricated by itself. From the experimental results, it is found that the mechanism can perform a stable electrical discharge machining and extend the curved hole length.