A Method of Pitch Error Compensation Based on HNC-818B CNC System

The linear motion of CNC machine is generally converted from rotary motion of servo motor through a ball screw nut pair. As most CNC machine is controlled by semi-closed loop system, ball screw nut pitch error is among the main factors influencing machine positioning accuracy. A method is introduced in this article for CNC linear axis pitch error measurement and compensation by using RENISHAW XL30 laser interferometer. Experiments based on HNC-818B vertical machining center show that bidirectional pitch error compensation for ball screw drive mechanism applying this method can greatly improve the machine positioning precision.