Angular Positioning Measurements on Rotary Tables with Autocollimator and Polygon-Mirror

Picture above: Measurement on a rotary table with autocollimator and polygon-mirror
Picture above: Measurement of the c-axis of a machine tool
Picture above: Error diagram

The angular positioning accuracy (position uncertainty) is an overall characteristics to evaluate the accuracy of a numerical controlled rotary table or a rotating axis of a machine tool. It includes all systematic and coincidental deviations, which arise after positioning on the rotary table. A special feature of our software compensates the angle errors of the polygon mirror by means of 2 separate series of measurements. Therefore the measuring accuracy is exclusively specified by the accuracy of the autocollimator.

We accomplish angular positioning measurements with the high precision ELCOMAT 2000 of Moeller Wedel Optical, which can measure deviations of 0,1 arc seconds.

Our measurement software corresponds to the recommendations of the VDE/DGQ guidelines regarding the evaluation of the angular positioning accuracy. Hereby positioning deviation, positioning uncertainty, minimum, maximum and average variance of positioning as well as minimum, maximum and average dead spot are measured.