Concurrent measurement of radial, axial and angular motions of spindle using concentric circle grating interferometers

6th report: Construction of made compact and rigid interferometers

Abstract

The purpose of this study is to measure a spindle error motions with 5 degree of freedom (DOF), concurrently. An ideal spindle must have only rotational motion with 1 DOF, therefore another motions with 5 DOF (= radial motions (2DOF) + axial motion (1DOF) + angular motions (2DOF)) are parasitic and unnecessary errors for spindles. In previous article, we measured a spindle motion for 2 DOF by using a concentric circle grating which is fixed on the spindle top and an optical sensor which can obtain 2 axes displacements. In this report, we made a compact and rigid optical sensor and checked its performance.