A Method for Determining Roundness and Actual Form of Circular Workpiece Cross Sections

Abstract

Determining a roundness value is essential for enabling fast, easy and smooth assembly of workpieces with circular fitting surfaces. In a number of cases, roundness specifications should be defined if other geometrical specifications are not sufficient for enabling reliable assembly. Various standards treat roundness as a deviation from an ideal circle, whereas, the actual cross section form is not treated at all. It seems this characteristic is not worth examining. Knowing the cross section form, however, enables determining various factors that result in undesirable deviations of workpiece cross sections from an ideal circle. This paper presents a new method which, in addition to determining roundness, can be used to determine the actual form of a circular workpiece cross section, using a coordinate measuring machine.