Non-Isoparametric Three Axis NC tool path generation for finish machining of sculptured surfaces

Sculptured surfaces are usually machined to their final shapes by a series of rough and finish passes. After each pass, excess material may be left at some concave or C1 discontinuous areas. Traditionally these undercut areas are “cleaned up” by repeatedly machining the whole surface with progressively smaller cutting tools. We present an algorithm for automatically identifying areas with excess material, and generating tool paths for machining them to within the desired tolerance.