Avoiding tool exit in planar milling by adjusting width of cut

Tool failure and milling exit burr formation usually occur when the tool cutting edges move out of the workpiece. One of the most effective methods for minimizing these problems is to prevent the tool from exiting the workpiece while removing material. This can be achieved by special tool path planning. In this paper we presents a set of geometric algorithms that avoid tool exits in planar milling of 2D polygonal and curved contours. Tool paths are generated by offsetting the workpiece edges with appropriate widths of cut, depending on the edge types (straight or circular). A tool path planner is successfully implemented with those algorithms. Tool exits are thus completely eliminated in an automatic manner.