Mathematical Approaches in Evaluation of Circularity Measurement

Abstract

Measurement of form features becomes reliable and a necessity for conformance of accuracy defined on the modeled geometry with the manufactured geometry. Evaluation of form errors in manufactured parts is essential in determining its conformance to the tolerance specification. These specifications are established to provide acceptable limits on part variation in order to ensure functional equivalence. In the present work, the form errors are evaluated for circularity by Three Point Method. The results are compared with the CMM results. The part or component considered for the work is an eccentric shaft. The shaft is divided into different datum (Z) levels. The input data for the part (component) is taken by inspecting the part by advanced measuring instrument viz., Coordinate Measuring Machine.