Study on the online test of spindle's dynamic radial error of machine tool

The dynamic spindle radial error is one of a most significant factor in evaluating machine tool performance. To improve the accuracy of the dynamic spindle radial error measurement, this paper presented some development of the three point method. The floating sample frequency data acquisition method is used to ensure the number of the harmonic components under different spindle speeds to be the same. So that, the error separation accuracy would not decrease with the increase of the spindle speeds. In order to avoid the effect of the white noise mixed in the measured data, the spindle profile was sampled at discrete time intervals for ten revolution speeds. After that, the ensemble averaging method was used to eliminate the white noise. An experiment system is set up to measure the dynamic spindle radial with the proposed method. The pure dynamic spindle radial error, roundness error and eccentric error under different spindle speed are obtained, and the results verity that the presented method can improve the accuracy of the spindle radial error measurement.