An Evaluation Method of Radial Accuracy for Ultrahigh Precision Air Spindle.

In this paper, the authors newly developed the vector indication method to understand radial run-out of ultrahigh precision air spindle. The run-out of rotating spindle was measured by two sensors located perpendicularly to each other on horizontal plane. The new algorithm was presented to get the instantaneous vector of displacement of spindle center for digital processing. It was made clear that the vector indication method was able to confirm the behavior of spindle motion more clearly than Lissajou's figure. Furthermore, the authors removed the form errors of master ball used as the measuring target and the difference between two sensor gains.