Five-axis rake face grinding of end-mills with circular-arc generators

The rake angles and the cores of the end-mill cutting tools are very important for they control the cutting forces during machining, the strength of the cutting edges, the rigidity of the end-mills and the chips removal capability. Thus, grinding end-mill flutes with accurate rake angles and accurate cores is very crucial in cutting tools’ industry. Flutes grinding is normally accomplished using two axis CNC grinding machines; however, this requires grinding-wheels with free-form profiles, expensive and uneasy to make, and the produced cutting edges and the normal rake angles along these edges are inaccurate. Hence, this work extends the five-axis CNC grinding approach developed by the first author to grinding of circular-arc ball end-mills. The generic mathematical equations of the grinding-wheel orientations and locations are first derived. Then, the grinding-wheel path is generated and the produced flute surface is precisely modeled. With standard grinding-wheels, computer simulation for the grinding approach is conducted and proved to produce precise end-mill cores, accurate cutting edges and accurate rake angles along these edges.