Abstract: Currently, most five-axis tool positioning algorithms with a torus cutter do not consider the mounting inclination of the round inserts. This will thus lead to large programming errors in theory. In practice, the actual torus cutter is often non-circle generatrix. To solve the problem, the section curve of the cutter is analyzed, and a tool positioning algorithm through longitude separation approach for a cutter with non-circle generatrix is presented in this article. First of all, the tool surface is discretized into insert sections to obtain the error distribution between the tool and the design surface. Then, the tool position and orientation are adjusted according to the above-mentioned error distribution in order to make the tool contact the theoretical workpiece surface as closely as possible without gouging. Thus the optimal tool position is achieved. Simulation results show that the traditional five-axis tool positioning algorithms produce large machining errors, while the proposed algorithm can eliminate machining errors resulting from the mounting inclination of the round inserts, improve the surface machining accuracy, and generate the optimal tool position under given programming tolerance.

Key words: cutter with non-circle generatrix, longitude separation approach, tool positioning, tool path, five-axis, sculptured surfaces, machining