Abstract: An auto-alignment laser interferometer system is developed for volumetric error measurement of CNC machining centers. The system is capable of the displacement measurement with the change of laser beam directions, whore multiple machine axes arc moved simultaneously, with automatic optic alignment, This capability provides a solution for quick evaluation of the overall volumetric error of a multi-axis machine tool. A novel approach, which is capable of direct measurement of the total position errors at the tip of the tool of a multi-axis machine tool without the use of an error model, is presented by only one the manual alignment of the optic set and laser path, The error vector components at different location in the machine work space are stored in a 3D lattice, The meshing concepts developed in the finite element method literature are used to predict the volumetric errors at any point in (he workspace. The strategies developed are testes on a CNC machine, and the results verify the effectiveness of the method.

Key words: Error compensation, CNC machining centers Auto-alignment Laser interferometer