MAG introduces 5-axis volumetric error compensation for large machine tools

VEC is offered as a standard option on new MAG machines and is available through MAG's service group for field upgrade of legacy machines. The system is said to give a practical and affordable way to raise a machine's process capability so it can hold tight tolerances along all arbitrary contours and orientations, within a volume encompassing several metres. Multi-axis VEC gives the ability to run a large high-value part with confidence, without, stops, checks and rework. Multi-axis VEC collectively treats all of a machine's degrees of freedom that affect tool point positioning, unlike conventional calibration methods that sequentially examine machine motion one axis at time. Conventional approaches to volumetric compensation are generally limited to three linear axes and the associated total of 21 potential motion error sources. However, a typical five-axis machine with linear and rotary axes can have 43 potential error sources, not just 21. MAG's multi-axis VEC system compensates for all these, and even more, in machines with unique and more complex multi-axis configurations. MAG's VEC solution considers the full interrelated effects resulting from the kinematic stack-up of the machine tool axes. This holistic methodology enables volumetric error compensation for every point orientation and path combination inside the work volume. Boeing, MAG, API and Siemens were members of the industry/government consortium that developed the VEC under the program for Volumetric Accuracy of Large Machine Tools (VALMT). Other participants were the National Center for Manufacturing Science, U.S. Air Force Logistics Center, Naval Foundry and Propeller Center, U.S. Navy Fleet Readiness Center, East, and U.S. Army Anniston Depot. The system was tested and proved out on three large machine tools offering different axis configurations.