Ball Bar Measurement of Motion Accuracy in Simulating Cone Frustum Cutting on Multi-Axis Machine Tools

Abstract

The ISO accuracy test standard for five-axis machining centers was revised recently. A cone frustum cutting test by end milling, well-known for testing multi-axis controlled machine tools for aircraft part processing, is adopted in the ISO standard as a similar and precise test. It considers both the accuracy of the finished test piece and an interpolation accuracy test measured by ball bar in the same-feed motion of cone frustum cutting. Although it is possible to apply the ISO test methods to various structures of five-axis machining centers, the application of the cone frustum test to multi-axis machine tools with a rotary axis on the workpiece side is rare; thus, it is difficult to evaluate the test results. In this report, the ISO test method was outlined. Next, the ball bar cone frustum test was performed on a five-axis machining center whose two rotary axes were located on the workpiece side. The evaluation method of the test results is discussed. Moreover, the ball bar cone frustum test was also performed on turn-mill complete machining centers to confirm the effectiveness.