Improved Rotary Contact Method for 5-Axis Sculptured Surfaces Machining

The 5-axis tool positioning strategy named rotary contact method (RCM) for sculptured surfaces machining has been developed in our previous paper (Fan et al., 2012, "Rotary Contact Method for 5-Axis Tool Positioning," Trans. ASME J. Manuf. Sci. Eng., 134(2), p. 021004). The RCM finds the optimal tool positions by rotating the tool backward based on the offset surface, and can generate big machined strip width. However, the RCM can only guarantee a contact point because of the design surface's geometric asymmetry in most cases, which leads to the poor surface quality. To resolve this problem, the improved rotary contact method (IRCM) is developed in this paper. The parametric equation of the circular curve of the toroidal cutter defined by the backward and the sideward tilt angle of the tool is strictly deduced. According to the nested optimization of the two tool's angles, there are two contact points found between the tool's cutting surface and the design surface around the feed direction without gouging. Tool positions investigation, machining simulation and cutting experiment are all performed based on a test surface. The results verify the correctness and effectiveness of the IRCM and show that the IRCM can apparently improve the surface quality compared to the RCM.