Optical evaluation method for run-out error of high precision spindle by separating rotational error with tool chucking error

Abstract

As the machine tools are shifting to high precision cutting, it is necessary to develop an effective instrumentation system and to establish an evaluation method for the spindle run-out error. In this paper, a new measurement system for the run-out error was developed by utilizing an transmitted light beam method. Also a new evaluation method was established by separating the run-out error into rotational error and tool chucking error. The measuring principle is based upon edge detection technique in which a halved photo detector is used to quantify the amount of the transmitted light through the both sides of the pin-gauge used as a master specimen. By providing two similar optical setups which are placed perpendicular to the rotating axis of the pin-gauge, an X-Y displacement measurement system of the pin-gauge was built up. The run-out error of the spindle can be known directly by evaluating the displacement of the pin-gauge through its Lissajous figure. Finally, it was clarified that the performance of the developed evaluation system is practically acceptable.