Latin square three-dimensional ball plate (a practical approach to evaluation of coordinate measuring machine capability)

Abstract

Electronic coordinate measuring machines (CMM) represent the state-of-the-art in automatic three-dimensional measuring equipment. Current techniques for determining measurement capability of CMM are complex. A Latin square three-dimensional ball plate has been developed to evaluate the measurement capability of a CMM in three dimensions. The unique allocation of tooling balls in an XYZ space permits data to be obtained that is balanced statistically and can be analyzed quickly by using the analysis of variance techniques for a Latin square experimental design. The analysis of this data is used to determine quantitative measures of the precision and systematic error of CMM in three dimensions and to identify sources of error in machine geometry. This ball plate currently is used to determine CMM capability and to identify source(s) of error in machine geometry. This device requires 70% less time than some conventional techniques to estimate CMM capability in three dimensions.