An algorithm for determining the optimal cutter length in 3-axis milling

Fixed 3-axis milling has been the most popular method for the die and mold fabrication. Determining the optimal cutter length is a time consuming and critical task in process planning, especially for milling deep and complex molds for bumpers, inner panels and lighting components of automobiles. In this paper, the authors propose an inverted offset based method for automatically determining the optimal cutter length. Inverted offsetting is one of Minkowski sum operation with a solid model and an inverted shape of a milling cutter. In the 3-axis milling, the optimal cutter length can be derived by comparing two inverted offsetting results: an object from the part shape and the inverted cutter, and another object from the workpiece shape representing the prior machining result and the inverted zero length cutter. An experimental system is developed and some computational experiments are performed to confirm the practical applicability of the method.