Algorithm of Pencil-Cut Tool Path Generation for Five-Axis NC Machining of Complex Polyhedron

In this paper, a new method is proposed to detect clean-up regions and generate pencil-cut tool paths for machining complex polyhedron. The pencil-cutting is to remove the uncut volumes left at the regions that a larger cutter cannot machine during finishing process. In this paper, the surface is discrete by a series of quadrilateral grids. The method is used to gain the normal vector and the angle of two normal vector of adjacent surface to detect uncut regions. A technique of grids-scan is presented to overcome the limitation to judge the existing of the jerk points. A method of Reverse-calculate is used to gain the machining regions, which is fast and simple to identify the pencil-cut regions. A technique of the offset angle-bisector generates pencil-cut tool path accurately and availably that improves the machining efficiency of the complex surface. The simulation proves that the method is valid. The proposed techniques can be used in the CAD/CAM systems to generate pencil-cut paths for machining complex polyhedral models.