Producing Geometry You Can Trust
QC provided an engineer for our project who did a great job of collecting the dimensional data for the parts to be reverse engineered, creating the CAD models, and producing prints for manufacturing. He kept in regular contact with me throughout the project, allowing us to quickly resolve issues as they arose. He was also very responsive when asked to make changes to the prints. Overall, a superior job.
- Paul,
Power Generation
Go back to Archive
Scanning Tooling Cavities and Inserts
If you ever find yourself involved with tool repair or tooling re-development, here are some special considerations for reproducing tooling geometries with scanning technology.
Die and mold components have special needs when it comes to re-creating geometry with scanning techniques. Most objects that require scanning are prototypes or finished parts - all of which are "imperfect" when compared to the original design. When reverse-engineering a part, most of the time the goal is to re-create what the part should look like, using the liberty of design intent.
Tooling, on the other hand, is very close to the original CAD design. With molds and dies, there is no room for interpretation of "design intent". In addition, tooling tolerances are much less forgiving, particularly with inserts where the walls and shut-offs must be held within tenths. Most laser and white light scanning technologies are not capable of producing results accurate enough to replicate precision tooling components.
Despite these special challenges, the process for replicating tooling can be done well.
A critical first step is to identify the shutoffs and other critical surfaces for those that will be reverse engineering the tooling. This will help define the scanning and inspection methods to be used (when done properly, tooling components require multiple data-capture methods to ensure accuracy). Find out what data-capture methods will be used on your project.
Secondly, know what file type you will receive. If fully parametric, then every feature will be editable. In general, few tooling components should be "wrapped" as a NURBS-generated surface model. But some surfaces may have to be replicated that way, resulting in a hybrid parametric/NURBS file. Have that discussion with your service provider so that you'll know exactly what to expect from the model you receive.
Finally, insist on a live, 3D review of the finished model in comparison to the scanned tooling. When a component is modeled well, this review will provide the confidence you need to send the final design directly to your tool room.
©2010 David DeVowe
