Interferometric measurement of workpiece flatness in ultra-precision flycutting

Purpose: The purpose of this paper is to show how an ultra-precision manufacturing process (flycutting) can be improved through interferometry. Design/methodology/approach: The paper presents a theoretical model of the machine tool cutting system and then uses interferometer measurements to validate the results. The model is then used to show some general findings relating process conditions to workpiece quality. Findings: A realistic cutting model can predict the workpiece flatness with excellent accuracy and closely match interferometer measurements. The process parameters in precision flycutting should be chosen such that the flycutting tool is in contact with the workpiece for an integer number of vibration cycles. The machine tool stiffness and structural damping will affect the workpiece quality, but the most significant improvements are made through thoughtful selection of the flycutter spindle speed as it relates to the machine dynamics. Originality/value: This paper presents a math model that accurately matches results obtained by experimental verification and extensive testing. Interferometry is shown to be an extremely useful tool in optimizing the process conditions in a flycutting manufacturing operation. Furthermore, the results are of general use to practitioners using flycutting in a variety of industrial applications.