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Measurement errors caused by radius deviation of base disc in double-disc instrument for measuring an involute

A double-disc instrument for measuring an involute is introduced, whose measuring principle is the same as the ‘rolling artifact method’ developed by PTB. In this paper, measurement error and generation length deviation caused by radius deviation of the base disc are analyzed. In order to simplify the error compensation model and increase compensation accuracy, a new method, called the coordinate transformation method, is used to analyze measurement data, which can remove measurement errors caused by radius deviation of the base disc in theory. Two measurement experiments with different base discs prove the feasibility of the coordinate transformation method, and the consistency error of the measurements is 0.2 µm when the same involute tooth profile was measured.