Machining, Measurement, and Control Laboratory

Identification of Motion Error Sources on Five-axis Machine Tools by Ball-bar Measurements (1st Report)
-- Classification of Motion Error Components and Development of the Modified Ball Bar Device (DBB5) --

Soichi Ibaraki, Yoshiaki Kakino, Takayuki Akai, Naoshi Takayama, Iwao Yamaji, Keiji Ogawa

The inclusion of the application of the double ball bar (DBB) measurement to the accuracy calibration of five-axis machine tools into the revision of 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${}^{\circ}$ direction to the spindle axis. It can perform all the circular tests on XY, YZ, and ZX planes without changing the setup. This paper first presents the classification of motion error components of a five-aixs machine tool into location and component errors. Experimental application examples of the DBB5 to the calibration of location and component errors assciated with rotary axes on a five-axis machine tool are then presented.
Key Words:   five-axis machine tool, measurement, ball bar, component error, location error