Tool path regeneration for mold design modification

This paper proposes a novel mold modification tool path regeneration algorithm for three-axis CNC machining based on ball end-mills. It utilizes the existing tool path points that have been generated for the original mold design prior to modification. With the proposed algorithm, a closed profile of the tool path points for the boundary of the modified region is first calculated. It is proven that if the boundary of the mold modification is interference-free, only the tool path points inside this boundary are affected by the mold modification. The tool path points that are outside the boundary can be reused to machine the modified mold. When the affected tool path points are detected, they are removed and replaced by the new tool path points. The scallop height values for the modified region are then checked. If the scallop height is greater than the given value, more CL points are added to this region to maintain the required surface finish. The algorithm has been tested on several industrial parts, and it is proven to be efficient and robust. The generated new tool path is interference-free and meets the required surface finish. (C) 2003 Elsevier Science Ltd. All rights reserved.