CMM uncertainty analysis with factorial design

The purpose of this research is to present a method to estimate the Coordinate Measuring Machine (CMM) measurement uncertainty. The approach is based on a performance test using a ball bar gauge and a factorial design technique. A factorial design was applied to carry out a performance test and to investigate CMM errors associated to orientation and length in the work volume. The CMM measurement uncertainty was estimated with components of variance obtained after statistical analysis of variance applied to volumetric measurement errors. An application was performed with a Moving Bridge CMM and the results were compared to the volumetric performance test proposed by ANSI/ASME B89.4.1 standard. The results showed that the proposed method is suitable to investigate CMM hardware performance and determine the contribution of machine variables to measurement uncertainty.