Abstract: In five-axis machining, the rotary axis motions bring up non-linear error which relates to federate, configuration of machine tools, and so on and is difficult to solve common analytical solution. Using five-axis function, CNC must calculate in real-time non-linear error and lamp real-time feederate accordingly. In consideration of generality and computational simplicity in CNC software implementation, path non-linear error can be approximated by the non-linear error in path midpoint instead of seeking analytical methods, and a practical heuristics to calculate clamped feederate based on error setting is proposed using an approximate relationship between speed and non-linear error, both engineering oriented method are proved to be reasonable by simulation of typical machining programs.

Key words: 5-axis machining;rotation tool center point;non-linear error;feedrate control