Abstract: An efficient method is proposed for the identification of motion error sources involved in CNC machine tools by Renishaw ball bar, which is characterized by low cost .simplicity of setup, and quick measurements. A volumetric error model, which was expressed functions of the tool location and its elemental errois, is developed. A method by combining the measured radial data performed on the three orthogonal panes in the machine work zone with the volumelric error models to identifying parametric errors such as positional, straightness, angular, squareness, and backlash errois is given in detail. The results from the experimental tests of error compensation of a CNC machine, which uses the error data obtained by the proposed identification method, show that the method is feasible and accurate.

Key words: CNC machining centers Ball bar Error identification