Machining of a test artifact is an attractive method of evaluating the performance of a machine tool because the tests are often quick and do not require special instrumentation. An appropriate artifact should be complex enough to assess a machine's capabilities but simple enough to minimize difficulty in measurement and allow correlation between measured artifact errors and machine tool error motions. Two artifacts being considered for inclusion in an international standard as test artifacts for five-axis machining centers are a cone frustum and a truncated square pyramid. This study examines both artifacts. The artifacts are machined on a five-axis machine tool with a tilting rotary table where the tilting axis is a non-orthogonal B'-axis. To ensure simultaneous motion of all five axes, the artifacts are setup with the artifact axis inclined relative to the rotary table. Tests conducted with differing inclination angles show very different axis trajectories. As such, the machine's error motions manifest themselves very differently on the artifact and the measured profiles of the machined artifact appear very different. Where possible, the measured profile of the test artifact is compared with results of instrumented tests (i.e. telescoping ballbar tests).
Proceedings Title: Proceedings of the ASPE Annual Meeting
Conference Dates: November 13-18, 2011
Conference Location: Denver, CO
Conference Title: American Society for Precision Engineering Annual Meeting
Pub Type: Conferences
five-axis machine tools, test artifact, complex coordinated motion, machine tool metrology