When I first started in the Design and Engineering field, CAD was used primarily by large OEMs and some large suppliers. Most companies’ design work was done on drafting boards with vellum and pencils, or Mylar and ink.
As the technology evolved, CAD became more affordable, and increasingly necessary if one wanted to do business with certain OEMs. But while the design work was being done in CAD, the official documents were still paper – actual paper, created in CAD, printed, signed off by hand and distributed through the purchasing departments.
Eventually the paper gave way to PDF files for distribution, at least from the OEM; most companies still used paper (some still do!) internally to manufacture and inspect their products. They still create, release, and distribute 2D drawings and balloon the drawings for inspection purposes.
Technology has reached the point where a 2D drawing is really no longer necessary for the manufacture of a part or assembly, yet many companies still create them, even if the OEM does not provide one. Typically, the 3D model is used for fabrication, unless it is being done by hand. The creation, release, storage, and distribution of 2D drawings is huge. I am sure if companies actually looked at what it is costing them they would be shocked.
Some OEMs and other companies have an electronic way to handle the storage and distribution portion which is huge but the creation unless automated is still quite costly. Then there is the interpretation of the 2D drawings which can lead to quality problems, which we know is very costly.
There is a better way.
3D Master is a process whereby the 3D model is the master document. The 3D model contains all the necessary information to build and inspect the part or assembly. The workbench is called Functional Tolerancing and Annotation (FTA) by Dassault Systèmes, also known as Product and Manufacturing Information (PMI). All necessary dimensions, tolerances, GD&T, surface finish notes, etc. are contained within the 3D space. There is no need to create a 2D drawing, although one could very quickly if necessary.
The GD&T, dimensions, notes, etc. are placed in views in space. The view corresponds to the features being dimensioned. GD&T is verified to the selected standard (AMSE, ISO) and all feature control frames are created based on the established Datum structure and the feature itself, essentially the user is not allowed to violate the standard. And since the dimensions, and GD&T, etc. are attached to the model features, if the model is revised, the FTA information is also updated.
The data can be shared with tooling, quality, etc. throughout the entire organization. The information is available by either direct access to the CAD model or by access to a light model via a viewer, which for many users is enough.
The GD&T can be read by many CMM programs which read the FTA information and start to create a CMM program upon import. CATIA also has a STEP translator which can export the FTA data along with the rest of the 3D data so the information can be shared with tooling and other vendors.
The ability to create all the GD&T, surface finish, notes, and critical dimensions on the 3D model will save your company time and money while improving quality. There will be no issues trying to interpret what the design engineer meant, as the 3D model is the master. Users will have much more information available to them as they will be able to see the 3D model, the FTA, and query it for additional information if needed.
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