1、The algorithm is composed of three primary phases, i.e. , the reconstruction of the free form surface with discrete points based on a special Hermite's interpolation; the definition of the hogging areas by means of the curved surface intersection and tool path arrangements.

2、A new algorithm of automatic generation of interference free cutter location path for nc machining of free form surfaces with flat end cutters is proposed.

3、The paper discusses the difference method of solving the 4th ordered elliptic partial differential equations and its application to the design of blending and free form surfaces.