Patent US 4,296,474

A system and apparatus for inspecting machined parts and determining out of tolerance parts includes a coordinate measuring machine for providing signals representative of the actual locations, relative to an arbitrary coordinate system, of features to be inspected in or on the part. An input device provides signals representative of the nominal locations and the allowable tolerances therefrom of the features relative to a predetermined coordinate system. A programmable data processor operating under the control of a program processes the actual and nominal location signals and causes a mathematical translation and rotation of the actual location signals to their closest fit to the nominal location signals relative to the predetermined coordinate system. The processor then compares the nominal and closest fit signals and provides difference signals representative of the differences therebetween for comparison with the tolerance signals to provide out-of-tolerance signals when the difference signals are greater than the tolerance signals. An output device provides indications of the out-of-tolerance signals to indicate when parts are out of tolerance and should be rejected.