High Performance Machining Enabled by Adaptive Machine Components

A current drawback in high performance machining is the dynamic behavior of the machine tool. The dedicated Eigenfrequencies of the machine tool structure lead to not optimal cutting parameters due to the danger of chatter. Possibilities to overcome this drawback are on one hand the unwanted variation of the cutting parameters and on the other hand the variation of the dynamic properties of the machine tool components. The variation of the dynamic properties of these components requires high efforts and expenses.An approach to easily vary the dynamic characteristic of the machine tool is a carriage made out of Carbon Fibre Reinforced Plastic (CFRP) with adequate mass shifting by filling the built in chambers with a fluid. This leads to shifted Eigenfrequencies and therefore to optimal cutting parameters without chatter. The mass ratio between the empty lightweight machine tool carriage made out of CFRP and the one filled enables a significant frequency shift.Within this paper three issues will be addressed: first the frequency shift depending on the carriage's position will be examined, the frequency shift according to the filling strategy will be shown and finally the amplitude reduction related to the external excitation will be presented.