The CNC milling machine is extensively used in manufacturing of the die and the box-type parts. As the increasing requirement of the mechanical product's qualities, the components also need higher and higher precision. However, the cutting force induced error affects the machining accuracy of the machined parts seriously. Furthermore, accurate measurement of the cutting force in CNC machining is very difficult. To solve this problem, a motor current-based cutting force induced error detection and modeling method is proposed in this paper. The motor current is obtained from the window function of the Fanuc CNC system. The cutting force induced error model is established according to the least-square method. The motor current-based error model can implement the cutting force induced error fitting effectively, and the fitting accuracy of X, 17, and Z-axis are 97%, 96%, and 84%, respectively.
