A comprehensive method for calibration of volumetric positioning accuracy of CNC-machines

A comprehensive method for measuring the systematic errors of CNC-machine tools has been studied. The method used for measurement and calibration of machine tool errors should be general and efficient. The objectives of this study include:

1.	Volumetric error modelling.
2.	Experimental procedure for error measurement.
3.	A tool position and path compensation method.
4.	The verification method.

Using the same method, the machine tool status can be completely identified and its accuracy can be enhanced by software error compensation. The point compensation method can be used as a means for modifying the nominal tool path and on-the-machine inspection where the machine tool is used as a coordinate measuring machine. The validity of the error calibration method proposed in this paper was shown using a vertical 3-axis CNC machine with a laser interferometer and a ball bar technique.