On the removal of critical cutting regions by trochoidal grooving

Particularly in high-speed roughing by a straight end mill, contour-parallel paths often cause an excessive tool load in a critical cutting region such as a sharp corner and a narrow slot. Trochoidal grooving can be used to remove such regions safely, prior to high-speed contour-parallel cutting. This paper present a systematic tool path generation strategy for high-speed 2.5-dimensional end milling with the removal of critical cutting regions by trochoidal grooving. We first present a scheme to extract critical cutting regions for an arbitrary two-dimensional pocket contour by using its medial axis. A trochoidal tool path to remove an arbitrary contour can be generated also by using the medial axis. Two experimental case studies are presented to show the efficiency and tool wear progress in the roughing by a straight end mill with trochoidal grooving to remove critical cutting regions, in comparison with conventional contour-parallel roughing by a ball end mill.