Impact of electrode length on EDM inclined hole drilling process

Impact of electrode length on EDM inclined hole drilling process is presented in this paper. By monitoring discharge status, the inclined hole drilling process could be divided into three stages: touch in stage, normal drilling stage, and breakthrough stage. Typically, touch in stage and breakthrough stage are featured with low drilling speed. Drilling speed of normal drilling stage is faster compared to others. In general, drilling speed with short electrode is faster than long electrode; it is related with pressure variation. The pressure loss of the short electrode is less than the longer electrode, especially for large length-diameter ratio electrode; thereafter, this could promote efficiency of flushing, thus result in higher drilling speed. Electrode length optimization is a practical way for promoting productivity in mass production.