Abstract At present, the thermal de

Abstract At present, the thermal deformation law of the horizontal CNC lathe spindle has not been observed, whereas noeffective model for the radial thermal drift error for the CNClathe spindle exists. In order to solve these problems, the thermal deformation of the spindle was investigated on a CNClathe, and the temperatures along with the radial thermal drifterrors of various rotation speeds were obtained. Based on thetest result analysis, the radial thermal drift error mechanismand the complete thermal deformation during the warmup andcooldown phases were expounded. The “Liu-loop” of thespindle was drawn, and the corresponding two basic characteristics were described. Ten types of spindle thermal deformations are listed, and the relationship between the radialthermal drift error and the temperatures of the key pointswas established by a physically based modeling method.The criteria for the spindle thermal determination and thecompensation value expression for the workpieces with various lengths were given. Finally, the effectiveness of the proposed model was proved by simulations and experiments.