A special contour machining method of high precision non linear CAM curve is presented in this paper.

Various NC programs to machine sphericity thread form based on ellipse contour are developed using macro programs. This method can be used for the contour machining of all types of conic.

This method provides each axis with an additional compensating function according to the contour errors by adaptive fuzzy inference control, so the CNC system contour machining accuracy is modified.