Abstract: By means of using a disc cutter with a concave end instead of traditional ball-ended or flat-ended ones, and adjusting the cutter axis to move relatively to the component being machined according to some special rules, the envelop formed by the trace of the tool-nose in each pass and the required surface have the same derivatives up to the second order in the plane normal to the feeding direction. Thus the machining width in each, tool pass increcasecs greatly and efficiency is raised highly while the same accuracy is guaranteed. The algorithm of tool position and traces is discussed mainly.

Key words: CAD/CAM, Numerially controlled machining, Sculptured surface