Simulation of the Working Diameter in 3-Axis Ball-end Milling of Free Form Surface

Abstract

Free-form surfaces are used in many aspects of the industry. When machining these surfaces using three-axis ball-end milling, the tool's working diameter continuously changes, due to the change in the surface geometry which affects the surface quality. This change in working diameter occurs from one point to another and continues along the surface even in the case of a constant tool path. Using a simultaneous five-axis milling machine can solve the problem, however, this solution comes at a high cost and complexity. This paper gives insight into the calculation of the effective diameter at each point of the milled surface and presents the effect of the different parameters by simulation. The simulation applies the geometric method, based on the coordinate transformation of the intersection curve. The presented simulation approach ensures optimization method for both the cutting process and the tool path. The ultimate goal is to reduce the cutting speed change considering the change of the current working diameter by controlling the spindle speed point to point, resulting in a more homogeneous surface.

Keywords

• ball-end milling
• effective diameter
• free-form surface
• surface roughness
• three-axis milling