A generic uniform scallop tool path generation method for five-axis machining of freeform surface

• Uniform scallop tool path has been generated via cutting simulation.
• Grass/CC rings are calculated both in parametric and 3D Euclidean space.
• Optimized methods are used to fast calculate the grass/CC ring.
• The method is free of local geometry assumptions; thus is more precise.
• The method is generic for any cutter, parametric surface and tool path pattern.

In this paper, a generic uniform scallop tool path generation method for five-axis machining is presented. Unlike the conventional methods which are based on the local surface geometry assumptions, this method is inspired by cutting simulation. Initially, the designed surface is planted with dense grasses. If a cutter is put onto the surface, the affected grasses will be cut short. All the affected grasses form a grass ring on the surface. When the cutter moves along the previous tool path, the envelope of the grass rings will form a machining band. Based on the machining band, cutter contact points can be found on the surface to ensure that the cutting edge touches exactly on the side of the band. These cutter contact points are fitted to construct the next tool path. In this way, all the tool paths can be generated recursively. An optimization is also developed to improve the computing efficiency of the path generation process. The proposed uniform scallop tool path generation method is generic. It can be popularized to (1) any kind of end mill with various sizes, (2) any kind of parametric surface and (3) directional- or contour-parallel tool path topologies. Another salient feature of this method is that it is free of local surface geometry assumptions, so the obtained tool paths are more precise. The proposed method is implemented and evaluated with several freeform surface examples. The feasibility of the method is also verified by actual cutting experiment.