The article presents a dynamic design approach of an ultra-precision machine tool based on the morphology requirements of the workpiece. Compared with common parts, optical parts not only have as many high requirements for surface finish and flatness, but also topographic properties, which leads to a big difference in design with traditional machine tools. This approach, from the topographic properties and functional requirements of the workpiece, demonstrates how to design and analyze the kinematic chain and configuration of the machine tool. Then, a finite element model and mathematical model are established to predict the topographic properties of the workpiece. The design and optimization of an ultra-precision flycutting machine tool is employed as a case study to elaborate the approach in detail. Preliminary machining trials have been carried out and provided evidence of the approach being helpful to design and optimize the ultra- precision machine tool used for optical parts machining.

The ultra-precision spindle is the key component of ultra-precision machine tool, which largely influences the machining accuracy. Its frequency characteristics mainly affect the frequency domain error of the machined surface. In this article, the error measurement setup for the ultra-precision aerostatic spindle in a flycutting machine tool is established. The dynamic and multi-direction errors of the spindle are real-time measured under different rotation speeds. Then, frequency domain analysis is carried out to obtain its regularity characteristics based on the measurement result. Through the analysis, the main synchronous and asynchronous errors with relatively large amplitude of the spindle errors are found, and the amplitude change law of these main spindle errors is obtained. Besides, the cause of the main synchronous and asynchronous errors is also analyzed and indicated. This study deepens the understanding of ultra-precision spindle dynamic characteristics and plays the important role in the spindle frequency domain errors’ control, machining process planning, frequency characteristics analysis and oriented control of the machined surface errors.