Abstract:This paper is devoted to selecting an optimal ball-end tool for machining channel parts with sculptured surface on the multi-axis machining. A method is proposed that based on analyzing the feasible tool orientation of a given single point. Critical tool directions are obtained by establishing and analyzing the mathematic model of cutting tool motion. After researching the differences between visibility direction on the single point and feasible tool orientation of a given ball-end, maximum tool size can be calculated without collision between tool and workpiece. Furthermore, minimum tool length is obtained according to optimize the feasible tool orientation after selecting maximum tool size. Finally, an impeller is machined in a five-axis machining to verify the validity and correctness of the presented approach. Meanwhile, the changes of maximum tool size and minimum tool length on the whole machined surface are given. The machining results used different tools are compared and analyzed. The results suggest that the maximum tool size and minimum tool length can be achieved for machining channel parts with sculptured surface by implementing the developed method, and the machining efficiency and machining stability can be significantly improved.