Simultaneous measurement of cylindrical parts profile and rotating accuracy using multi-three-points-method.

On the direct measurement of roundness of cylinder, the reading of the indicator generally includes the rotating error of the measuring system. However the measurement system of roundness using a vee block and indicator has no rotating errors in the readings. The most serious disadvantage of this arrangement lies in the difficulty of establishing the actual shape of the circular parts by the readings of the dial indicator, which will depend on the used angle of the vee block and on the number of lobes present on the circular part. But this disadvantage will be now improved by applying this arrangement procedure since the calculated or analyzed values of the readings will be able to establish the actual shape of the circular parts if the values will be selected suitably. The selected angles of the vee block are used 60°, 90°, .120°, .135° and 180° in this experiment. By this procedure the standard shape will be able not only to measure but also to know the rotating accuracy of the measuring system.