Micro- and nano-scale spindle perpendicularity modulation method to enhance the quality of milled surfaces

Abstract The remarkable advances in ultra-precision machining technology have forced a re-examination of the effect of spindle perpendicularity errors on the milled surface quality at the micro-nano scale. In this paper, a method of spindle precision adjustment is proposed to improve the surface finish quality. The sensitive errors in the machining process are identified based on the multi-body kinematic theory by taking the milling process as an example. A 2-DOF rotation platform is designed, optimized, and fabricated. The static model of the platform is established based on the elastic beam theory and verified by finite element analysis. The structural parameters are optimized via the response surface method combined with the Pareto front. The experimental results reveal the effects of spindle speed, voltage amplitude, vibration frequency, cutting depth, and feed rate on the platform’s modulation performance. The static modulation experiment shows that the perpendicularity error between the spindle and the guideway can be reduced from 92.5 μrad to 0.25 μrad. Lastly, milling experiments show that the surface quality can be improved by 37.6% after spindle modulation.