A method of stability lobes building in ball end milling of inclined surfaces. Part 1. Initial data

In this paper a method for pediction of stability lobes for the milling of inclined surfaces with spherical end mills is developed. The first part of the paper describes the source data of calculation procedure. They are specific cutting force components, values of insertion and exit angles. To determine the latter values the original equation describing the variation of angles for various the radial depths of cut, the amount of overlap and lead angle is proposed. To analyze the stability of the spherical end milling of inclined surfaces it is proposed to take into account the cutting force acting normal to a cut-off layer. Made a priori assumption that for small lead angle the process will be more stable in a down milling than when ascending, and vice versa, with the lead angle close to 90 °, the process will be more stable to the upward milling. Confirmation of this hypothesis will be considered in the analysis of stability lobes and experimental studies in the second part of the paper.