Framework for verification of positional tolerances with a 3D non-contact measurement method

New methods of data acquisition such as 3D scanners have become increasingly necessary for the verification of the geometric dimensioning and tolerancing (GD&T) specifications in the manufacture of industrial parts. This paper proposes a method for the verification of a positional tolerance in two cylindrical features in an industrial part digitized using a 3D non-contact scanner. Apart from enabling an adequate quantification of the obtained results, this method also permits the displaying of different ways of visualizing the results. The tolerance zone within which the used scanner carries out the analysis was measured and quantified. Some aspects taken into consideration were the geometric quality of the piece and the repeatability, the reproducibility and the uncertainty of the digital process, which comprises the acquisition and processing of the data. This research work concludes that the digital method presented hereby, with its corresponding virtual inspection, is valid for the verification of positional tolerances, even when it is required to maintain the GD&T specification regardless of the feature size. In addition, this article raises the discussion over the best way to compute the traditional datum referencing rules to the new data acquisition methods.