A region-based 3 + 2-axis machining toolpath generation method for freeform surface

Due to the geometric complexity, tool orientations usually change dynamically during freeform surface machining with 5-axis machine tool. As the kinematic performance of the rotary axes is usually weaker than that of the linear axes, the real cutting speed is difficult or even impossible to reach the desired level, which further leads to low machining efficiency. This paper presents a region-based 3 + 2-axis machining toolpath generation method with 5-axis machine tool. The surface is first divided into several preliminary sub-surfaces using K-means clustering algorithm. A post processing procedure is then carried out to optimise the preliminary sub-surfaces to ensure the machinability. For each sub-surface, gouging-/collision-free tool orientations are first calculated and then the optimal combination of the fixed tool orientation and the feed direction is determined by maximising the average machining strip width for toolpath generation. The proposed method is tested by a case surface and the comparisons to some other traditional methods are also provided.