Position Tolerances Control Using Virtual Paper Gaging Techniques

The importance of correct prescription and verification in Geometric Dimensioning and Tolerancing is widely accepted and recognized, particularly if complex or interrelated tolerances are assigned, as usually occurs when using position tolerances and the associated modifiers. In position tolerancing verification, the adoption of visual techniques, usually recognized as “paper gaging”, in order to investigate part acceptance is very appealing because of their easiness of use, the explicit visualization of deviations and moreover suggestions on the extent of the hypothetical re-work. The current literature on paper gaging suggests a simplified approach which disregards form and orientation errors. Aim of the present paper is to address an extension of this technique that takes into account also the actual orientation deviations of the considered features. This methodology has been also implemented in a computer program that joins together the clearness of the visual approach and the precision of the computational techniques.