Techniques for calibrating spindles with nanometer error motion

This work demonstrates techniques that advance the standard practice in spindle metrology and enable five degree-of-freedom calibration of precision spindles with nanometer-level error motion. Several improvements are described in this paper: (1) an improved implementation of Donaldson and Estler reversal that eliminates moving and realigning the displacement sensor, (2) frequency domain low-pass filtering of data to remove spectral content without distortion, (3) robust removal of low frequency components caused by thermal drift and fluctuations in air bearing supply pressure, and (4) three-dimensional display of the synchronous error motion in the radial and axial directions. Example measurements demonstrate the repeatability and reproducibility of the techniques. Furthermore, synchronous radial error motion of an air bearing spindle calibrated by multi-step, master artifact, and master axis techniques agree within 1 nm.