AN ENHANCED CUTTING FORCE MODEL FOR FACE MILLING WITH VARIABLE CUTTERFEED MOTION AND COMPLEX WORKPIECE GEOMETRY

An enhanced model for the prediction of static cutting forces in face milling is presented. The key features of the model include the abilit y to handle complex workpiece geometry, two-dimensional cutter feed pa ths, multiple pass machining, and effects of machine set-up errors. A two-dimensional boundary representation scheme is used to describe the workpiece geometry which may contain holes, slots, and other complex geometrical features. Variable cutter feed paths are represented by a combination of linear and circular arcs. In view of this and the compl ex workpiece geometry, a new algorithm for cutter-workpiece engagement determination is developed. Several sources of machine set-up error s uch as spindle and cutter axis tilt, and cutter center offset runout a re modeled and their individual as well as combined effects on key mac hining process variables such as the axial and the radial depth of cut illustrated. Results of model verification experiments are reported f or different workpiece geometry and cutter feed paths. A comparison of the predicted and measured forces shows good agreement.