Abstract: A rectification method based on CAGD is presented for electrode orbiting in EDM machining. The approach uses the techniques of general offset surface to modify the free form surface of electrode, so that the effect of electrode orbiting can be eliminated and the machining precision can be increased. The basic approach consists of reading parameters from IGES files of trimmed electrode surface, adaptive sampling of the surface, general offset of sampled points and fitting these points with NURBS surface under error control. In the end, some results of rectification are also presented.

Key words: EDM, Electrode orbiting, General offset surface, Mixed-flow pump, Orbit of shaft centerline, Starting period, Vibration