A 3-DOF spreading precision positional stage for ductile end-face fly-cutting of quartz glass

Ductile removal is widely employed to eliminate subsurface damage in brittle materials. Achieving this requires the cutting depth to be set extremely low, presenting significant challenges for error compensation and precise feeding of the machine tool. In this paper, a novel three-degree-of-freedom spreading precision positioning stage is developed to mitigate the effects of workpiece deflection errors and feed resolution on the depth of cut during the end-face fly-cutting process. First, a bridge and half-bridge composite structure is designed to facilitate the planar spreading of the spatial motion mechanism. A mathematical model of the composite structure is developed based on elastic beam theory. Second, the effects of various structural parameters on the amplification ratio of the structure are investigated. The accuracy of the theoretical model is verified by finite element analysis. Finally, ductile fly-cutting experiments on quartz glass are conducted using a precision 5-axis machine tool.