Compensation for Thermal Deformation of a Compact Lathe in Cutting Operations Using a Coolant Fluid with Temperature Measurements at a Few Specific Points

Abstract

We previously designed a compact computer numerical control (CNC) lathe that arranges its heat sources so as to reduce their thermal deformation. However, a compact lathe often undergoes large deformation owing to unexpected thermal conditions arising out of the work environment or from operation of the lathe itself. Hence, we propose a method to determine equations predicting thermal deformation in a CNC lathe from temperatures measured at a few specific points. These equations enable one to effectively compensate for lathe thermal deformation. However, they cannot be applied to cutting operations involving a coolant fluid because the coolant fluid flow may lead to a complicated thermal deformation scenario. In this study, we attempted to more accurately compensate for thermal deformation, for cutting operations involving a coolant fluid, by adding simple calibration coefficients to the prediction equations. We applied the modified equations to a numerically controlled controller and validated our approach for cutting operations using a coolant fluid under various conditions.