Industrial Need: Actual milling machines must follow a repeatable and accurate behavior to substitute grinding operations (users often speak about 15µm/m precision requirements on medium/big machines). Two major sources of inaccuracy are: the physical effect of temperature on machine structures extensions; the geometrical precision of part and the deformations caused by weights and wears. Past approaches tended to solve thermal elongation of machines using an off line approach, the intention was to identify a machine thermal model that could predict machine elongation. Researchers could realize that the overall precision of part being machined could be increased but the local precision caused by strong hysteresys of thermal cooling down cycles could not be properly modeled by their approaches. While lack of stiffness has been wildly investigated by changes in the design and employ of new materials, the geometrical positioning accuracy of machines mainly depends on the quality of interface components among mechanical structures, the time spent during machine set-up, calibration and tuning. Today MTB try to limit these errors by well done, but expensive in production time interfaces among movable parts; a long and accurate machine installation at the customer place to ensure the correct perpendicular movement of machine axes; the use of measuring and compensating procedure.
Funding SchemeCSC - Cost-sharing contracts