Machining, Measurement, and Control Laboratory

Construction of an error map of rotary axes by static R-test
Soichi Ibaraki, Cefu Hong, Chiaki Oyama

This paper presents an efficient and automated scheme to calibrate error motions of rotary axes on a five-axis machining center by using the R-test. During a five-axis measurement cycle, the R-test sensors nest measures the three-dimensional displacement of a sphere attached to the spindle relative to the machine table. This paper demonstrates intuitive, graphical presentation of R-test measurements to understand how error motions of rotary table changes in three-dimensional space depending on the swiveling angle. The separation of the influence of linear axis error motions, particularly squareness errors of linear axes, from the R-test measurement is also discussed.
Keywords: R-test, five-axis machine tool, calibration, error motion, squareness error.