Five-axis machine tools are computer-numerically controlled (CNC) machines that can move, cut, or mill a part on five different axes at the same time. Because of inherent geometric errors, manufacturers must make adjustments when calibrating these machines. Several different approaches exist to help compensate for the errors, but none of them provides a complete picture. Researchers at Missouri University of Science and Technology set out to find a way to eliminate that piecemeal approach and develop a new way to capture complicated geometric errors and automatically generate compensation tables.
In collaboration with colleagues at Boeing Research and Technology in St. Louis, the researchers used a laser tracker to quickly measure the motion of all axes over the entire workspace of an industrial five-axis machine. Based on these measurements, they generated a set of compensating tables that could be used to improve the accuracy on a variety of machine tools and related platforms.