Volumetric error of a three-axis machine tool: models of measurement and correction

The article considers the improvement of product quality in machining production, which is related to machining quality and, therefore, the accuracy of used equipment. It is noted that geometric errors, which account for up to 40% of the combined error of a multi-axis, specifically three-axis, machine tool, have the greatest influence on machining accuracy. In order to improve machining quality, it is necessary to adjust its parameters according to the measurement data obtained in the process of machine tool operation, which can be done using the methods of mathematical modeling. The authors developed models representing the volumetric error of a three-axis machine tool, taking into account the summands of the first (linear) and second (quadratic) orders of smallness. The developed models were comparatively analyzed. The article presents the results of experiments on measuring the volumetric errors of a STAN S500 system and adjusting these errors on the basis of a nonlinear theoretical model. Within the angular error range of 0–2.5′, the consideration of quadratic model terms in addition to linear terms does not lead to a marked reduction in the volumetric error. It is shown that in processing the measurement data of multi-axis machine tool equipment, it is sufficient to limit consideration to volumetric error components not exceeding the first order of smallness. The study results can be used in the acceptance and periodic control of the volumetric error of machine tools, as well as for the planned reduction of volumetric error.