A NEW TECHNIQUE FOR VOLUMETRIC ERROR ASSESSMENT OF CNC MACHINE-TOOLS INCORPORATING BALL BAR MEASUREMENT AND 3D VOLUMETRIC ERROR MODEL

This paper presents a useful technique for assessing the volumetric er rors In multiaxis machine tools using a kinematic double ball bar. Thi s system has been developed based on a volumetric error model which de scribes the three-dimensional errors of machine tools. The developed s ystem requires input of the measured radial data performed on the thre e orthogonal planes, and analyzes parametric errors such as positional , straightness, angular, squareness, and backlash errors. The develope d system can also assess the dynamic performance of machine tools such as errors due to the servo gain mismatch. The developed system has be en tested using an actual machine tool, showing high potential for err or assessment of multiaxis machine tools. (C) 1997 Elsevier Science Lt d.