An Automated and Optimal Tool Path Planning System for the 3-1/2-1/2-Axis CNC Maching of Sculptured Parts

Some sculptured parts with complex free-form surfaces usually require expensive 5-axis CNC machining. In this work, a cost-effective and practical solution to the 5-axis sculptured part machining – 3-1/2-1/2-axis CNC machining scheme – is discussed. An automatic and optimal tool path planning system for 3-1/2-1/2-axis CNC machining is introduced. The system uses fuzzy pattern recognition method and Voronoi diagram to subdivide a complex sculptured surface into an optimal number of uniform surface patches, finds the optimal cutter/part orientation for each surface patch, and plans 3-axis CNC tool paths for them. This type of machining is carried out by rotating the part to the cutter/part orientations discretely and sequentially using a tilt-rotary table attached to the 3-axis CNC machine. Under each orientation, the corresponding surface patch is machined using the 3-axis CNC tool paths. This tool path planning system can automatically generate efficient tool paths for sculptured parts and make the 3-1/2-1/2-axis CNC machining scheme as an applicable alternative of 5-axis CNC machining method.