Error Calculation for Rotation Axes of Five-axis Machine Tool

To calculate the motion errors of rotary axes of five-axis machine tool,a measurement method based on double ball bar(DBB) theory was proposed in this paper,and the calculation formula were derived.Five of six-DOF motion errors of rotary axes could be separated form length changes of DBB by using this method,the last one was an angle error which could be measured by the indexer of a laser interferometer.Through this method,errors which were created by indirect measurement using rod gauge would be avoided.This method can be applied to calculate the motion errors of rotary axes of various multi-axis machine tools.