Free form surface representation and machining for complex parts

This paper presents a method for cutter path generation by directly intersecting the part surface with a plane to generate cutter contact (CC) points. The surface-plane intersection is traced out using the marching method. The surface patch is subdivided based on a loop detection criterion, and all the initial points can be found along the boundaries of subpatches. The biarc curve fitting is employed to fit the largest sequential data points on the intersection curve. The cutter location (CL) data is obtained for profile machining by offsetting the CC biarc curve in surface normal direction. For a general free form surface, approximation is taken to generate plane biarc curves to represent the CL data points. The method is tested in a rapid prototyping system for production a of foot last