An analytical approach to design form – turning insert profiles; investigation of rake face design on tool life

Generating highly accurate profiles on the workpiece is an important issue when turning with form cutting tools. The geometric parameters of the cutting tools such as rake angle, axial rake angle and clearance angle directly influence the workpiece dimensions. In order to get accurate dimensions on the workpiece, a compensation is required on the cutting tool profile based on the relation between cutting edge profile and the tool geometry. In the mass production of ball bearings, the shield groove of the rings is processed with profile ground turning cutters. Each bearing type has different groove dimensions, thus hundreds of different form cutting tool designs are required. Therefore, individual cutting tool designs cannot be defined experimentally; a formulation is required which will yield the exact dimensions of the form cutting tool. In this study, a parametric formulation is developed in order to get accurate dimensions on the workpiece. Form tools were designed by considering the geometric parameters and cermet tools were fabricated by using profile grinding operations. The parametric formulation is verified with finished workpiece geometry measurements during mass production. After generating analytical approach, in order to investigate rake face geometry on tool life, two different rake face goemetry were designed and life test were done on the same type of shield groove profile. In addition to life test, cutting force were measured.