Machined form error prediction based on volumetric error model of machine tool

Meeting the requirement of part form accuracy can guarantee that ultra-precision equipment realizes its key functions. Many factors influence the part form accuracy, in which the volumetric error of machine tool is the most pivotal. The machined surface form error prediction is studied through establishing direct relationship between the machine error components and form error. A method of predicting frequency domain multiscale form error based on the machine volumetric error model is proposed, which combines the volumetric error model, processing parameters and machining path, for predicting the multiscale form error. This method can provide theoretical reference for machining path planning as well as machine design, which can be applied for machining accuracy improvement. A case study for predicting the PV form error was carried out on a five-axis ultra-precision machine tool, in which the conical surface of a concave circular truncated cone was machined. The relative error between theoretical value and experimental value of the PV form error is 17.3%, which verifies the effectiveness of the method for predicting the low spatial frequency PV form error.