| The rotary axis is used in machine-tools as a means for providing rotational movement for the workpiece with respect to the tool. Concomitant to the utilities of the rotary axis, associated errors are also introduced during the machining process. The correction or compensation of these errors requires a precise measurement of theses errors.;The second method proposes an assembly for the measurement of the five other components of cinematic error is based on the application of five capacity sensors attached on the rotary table and a target with two spherical balls which is inserted in the spindle. A filtering method is also developed in order to isolate the effect of eccentricity from the measurements.;The measurement of cinematic errors is realized on two machine tools with two different drive systems for the rotary axis. One axis is driven by a direct linear motor while the other is worm gear driven.;The angular deviation which is measured by both instruments enables a partial verification of the validity of measurement done by capacitance sensors as well as the proposed filtering method.;Two methods have been developed for the measurement of cinematic errors of a rotary axis. The first method uses an autocollimator for the measurement of angular positioning error which is one of the six principal errors of the rotary axis. This error can be compensated by defining the proper compensation parameters in the machine tool control system.;The measured errors are used to conduct a statistical analysis on the repeatability and the precision of the rotary axis. Furthermore, the performance of the rotary axis of both machines-tools is compared. At the end, the reproducibility of the measuring instruments is studied by conducting measurements while repeating the measuring setup. |
