Generation of a regularly aligned surface pattern and control of cutter marks array by patch division milling

In this paper, a patch division milling technique that can generate a geometric surface pattern by means of a ball-end mill on a surface is proposed. The finished surface is divided into many same-size small patch segments such as triangles, quadrilaterals, or hexagons. The whole inside area of each patch is machined along a helical tool path with a high feed rate. A geometric surface pattern is generated by the cutting edges of the ball-end mill within the patch area, and after the machining of a series of patches, the machined surface is covered with many patches. It is shown that the aligned state of the cutter marks array on the patch can be controlled by the cross-feed, the feed speed per tooth, the number of teeth and the side length of the patch. A simulator was also developed to predict the aligned state of the cutter marks array in the patch. Comparing the machining on the patch division milling between an inclined flat surface and a cylindrical surface, the regularly aligned surface pattern and cutter marks array were found to agree well with the simulation results. The objective of this research is to establish the cutting method of generating regularly aligned surface pattern on the complex-shaped workpiece efficiently. If the surface pattern on the complex-shaped workpiece could be formed only by the ball-end milling with a machining center, it will be a very effective tool for the machinery industry.