Probing Variance Separation on Coordinate Measuring Machines

This paper presents a method to estimate the non- repeatability of measurement and its sources on a coordinate measuring machine. The approach uses, as input data, the residuals obtained from the separation of machine and probe systematic errors on a CMM using multi-step redundancy probing of the machine's own master ball. The objective is to use data not explained by those error models in order to separate the contributions to the probing results randomness originating from the machine approach direction and from the probe triggering direction. Such information can then be used as input to the estimation of measurement uncertainty.