Rotary-coordinate and shuttling-element cutting strategy for ultra-precision diamond turning of optical...

Toolpath generation techniques have become increasingly critical in ultra-precision diamond turning for optical microstructures due to the dramatically enhanced geometrical complexity of the machined region. However, the conventionally used spiral toolpath is required for interpolation from the structural models, leading to random instability of the feeding axis and additional profile error between the toolpath and designed structures, which means an enlarged effect on the machining quality in ultra-precision machining. In this paper, a rotary-coordinate and shuttling-element cutting strategy based on integrated geometrical modelling and spiral toolpath generation is presented for ultra-precision turning of optical microstructures. Using the innovative rotary-coordinate and shuttling-element cutting method, the point clouds for the micro-structured modelling can be scattered along the spiral shape which can be directly fitted as the final toolpath. A series of simulation and cutting experiments have been carried out to realize the effectiveness of this method, and it is found that the preparation time in diamond turning can be significantly reduced along with ameliorating the machining quality.