Machining, Measurement, and Control Laboratory

Measurement of Motion Accuracies of Five-axis Machine Tools by using the Double Ball Bar Method DBB5
Yoshiaki Kakino, Soichi Ibaraki, Iwao Yamaji, Keiji Ogawa, Hidehito Ota

The inclusion of the application of the double ball bar (DBB) method to the accuracy calibration of five-axis machine tools into the revision of the ISO standards is currently under the discussion. This paper presents the modified DBB measurement device, referred to as "DBB5" in our study, where master balls are supported from the 45 deg direction to the spindle axis, such that the interference between the bar and ball sockets can be avoided. It can perform all the circular tests on XY, YZ, and ZX planes without changing the setup. It can be also applied to the calibration of static and dynamic errors in the position and the orientation of rotary axes on a five-axis machine tool. Experimental application examples of the DBB5 to the error calibration of a commercial five-axis machining center with a tilting rotary table are presented.
Key Words: Machining center, Five axes control, Double ball bar method, Motion accuracy, Error compensation.