Study on the Improvement of Motion Accuracy of 5 Axis Control Machining Center (Measurement of Alignment Errors of the Rotating Axis and their Compensations)

Abstract

The five-axis machining center with the table-on-table structure has newly been developed, and verified that the alignment accuracy of the rotating axis is easier to be ensured when the motion range of the rotating axis is larger. For the table-on-table type machine structure, it is practically very difficult to completely eliminate the alignment errors of the rotating axis even when the machine is sufficiently accurately assembled. The study deals with the method to enhance the motion accuracy with NC error compensation, based on the errors measured by using DBB. The alignment errors of the rotating axis on five-axis controlled machining centers are measured by using three different methods, and the results are compared. It found that remained alignment errors can be drastically reduced by conducting NC error compensation, whose amount is calculated on the basis of measured alignment errors.