A new approach to find gouge free tool positions for a toroidal cutter for Bézier surfaces in five-axis machining

Abstract

We implement and test a multi-point machining tool positioning technique that positions the tool using only a variation on gouge checking. The result is a method that is roughly twice as fast as an earlier method that performed a numerical search to find a tool position with multiple points of contact with the design surface. A GPU implementation provides an additional factor of ten speedup. Verification of the method was done via simulation and machining and measuring physical parts. Keywords 5-axis machining • Multi-point machining • Gouge checking 1 Introduction Two types of machines, 3-axis and 5-axis machines, are commonly used in manufacturing industries. 5-axis machining have additional degrees of freedom in rotation and tilting about the z-and x-axes, giving extra flexibility in machine kinematics

Tool positioning in five-axis machining on a tensor product surface using circular rays

“…We tested the algorithms on three bi-cubic Bézier surfaces used in another paper [14] to allow for comparison to that work. These surfaces include a convex surface, a concave surface and a saddle surface having both concave and convex regions.…”

“…In [14], the generated toolpath data was verified by first simulating the toolpath data using Tool-Sim [12], and then physically machining the three surface on aluminum stock using the same tool path with a DMU-80P Hi-Dyn tilt-rotary simultaneous five axis machining center. In the tests run in [14], the maximum error between the simulated machined surfaces and the corresponding designed surfaces was 0.01mm, while the measured error between the actual machined surfaces and the design surfaces was 0.05mm.…”

“…The algorithm proposed in this paper should give identical tool positions (with some numerical differences) to the algorithm given by [14] when both methods use the same toolpath footprint. The footprint used in [14] is the XY -parallel toolpath shown in Figure 1, having 10 passes in total with the first 9 passes separated by Side step = 18mm and a tenth pass at x = 150mm.…”

“…The algorithm proposed in this paper should give identical tool positions (with some numerical differences) to the algorithm given by [14] when both methods use the same toolpath footprint. The footprint used in [14] is the XY -parallel toolpath shown in Figure 1, having 10 passes in total with the first 9 passes separated by Side step = 18mm and a tenth pass at x = 150mm. Each pass contains 78 tool positions separated by Forward step =2 .0mm, out of which the first and last tool position of the pass is used to lift the tool to avoid gouging on the surface as the tool shifts from one pass to the next.…”

“…8 .D i ff e r e n c e si nm i l l i m e t e r s . We compared the tool positions generated by our algorithm and the algorithm in [14] on this toolpath, looking at the the drop distance for the first point of contact, the first point of contact itself, and the tool axis tilt angle. Note that while the footprint of the two methods is the same, there were significant differences in how the methods handled tool positions close to the boundaries of the design surfaces.…”