Method for Measuring True Roundness by Superposed Chain Rule

Abstract

There are two cases for measuring true roundness of a cylindrical work ; the one for the work with two centre-holes on its sides and the other for that without centre-hole. For one of the latter cases, the author previously mentioned both the theory and experimental results of the method based on the chain rule in which he regarded the circumference of the work as a series of straight lines. In that case, measurement was performed with regard to a set of the finite points on the circumference, not performed with regard to other points, and so, if we take other sets of the finite points and superpose true roundness measured from these sets each other, we could expect to obtain more precise results. Thus, he calls this method the superposed chain rule, and in this paper, he gives both theory and experimental results of the method, and examines whether it is to be practically applicable, and makes it clear that the precise test of the true roundness can easily be performed by this method.