Performance analysis and optimal design of fast tool servo used for machining microstructured surfaces.

Ultra-precision machining with a fast tool servo (FTS) is one of the leading methodologies for the fabrication of microstructured surfaces. FTS is an independently operated positioning device that plays an important role in the machining system. The complexity of surface features and the surface quality depend largely on the behaviour of FTS. In this paper, according to the analysis of required performance, a novel FTS is developed with structural parameters optimized by the finite-element analysis (FEA) method. Finally, a series of tests are carried out to evaluate the performance of the FTS and validate the value obtained by the FEA software. The results show that the FTS has a travel of 20 μm, a positioning resolution of 5 nm, a static stiffness of 33.62 N/μm, and a dominant natural frequency of 2191 Hz and demonstrate the validity of the optimal design method.