3D gear measurement by CMM

Gear checking by means of co-ordinate measuring machines is becoming more universal and precise on the basis of a full surface gear model consisting of substitute helical involute flanks. The substitute helical involute flank is equivalent to the best fit evaluation model of any other features in co-ordinate measuring techniques. This model allows us to pick up measuring points anywhere on the flank and to calculate gear parameters beyond common gear standards. Thus there is no need to scan profile, lead and pitch exactly at the defined lines. A further advantage of the universal substitute gear model is the improved measuring and evaluation accuracy. It allows us, furthermore, to ensure the traceability of involute gear measurement.