Abstract: This article focuses on the process of shaping the mixed rifle with a large spiral angle in the cannon, and proposes a cone-like cathode structure with asymmetric cuneiform working tooth. The degree of cone, length and the angle of the cuneiform working tooth were determined experimentally and those parameters were matched well. An expert system of ECM is then implemented. As a result, control of voltage and electric current can be respectively applied to the convex line of the rifle at exit and middle part of the tube. The on-line measurement and control of machining parameters can be performed simultaneously with the control of rotation and precession of the cathode as well. The manufacturing practice demonstrates that the cathode structure is appropriate and the control system is accurate.

Key words: technology and equipment for machine building , CNC-ECM , mixed rifle , a large spiral angle , CNC