Digital Tolerence

Abstract

This article demonstrates the use of model-based definition (MBD), which can lead to improve productivity and reduce time-to-market. MBD is a method of annotating 3D computer-aided design models with geometric and tolerancing information. With Boeing moving to model-based definition, members of industry have approached the team in Montreal about investigating MBD’s usefulness. Experts believe that the MBD format, if widely adopted, would have implications for inspection. The part would be inspected against the tolerances contained within the CAD model rather than against the 2D engineering drawings, and that would speed the process and potentially make it even more accurate. The cultural change that will have to take place at most engineering companies will be difficult to tackle, and engineering and manufacturing managers know this. A model-based inspection software is being developed to read geometric, dimension, and tolerance information attached to a solid model. This will minimize operator input during development of coordinate measuring machine programs and improve the accuracy and integrity of the inspection process.