Fixtures & Tooling Special Machines

rear axle assemblies

Fit Fixtures Designed with 3D Product Data

Headliner Adhesive "Fit at Assembly" is the universal escape clause for engineers who design automotive assembly tooling. It means that the last step in engineering a tool requires the application of a great deal of hands-on skill and experience on the shop floor to make the design conform to the reality of both the part and the production process... an expensive and time-consuming process.

But, "Fit at Assembly" has been banished from the lexicon of at least one tooling supplier because the concept, and the time-honored process it represents, are no longer adequate to meet the needs of today's automakers. The new watchwords are "Design For Manufacturing" and "Shop Engineering," two concepts made possible by an innovative, proprietary approach to 3-D modeling that defines a new process for engineering and manufacturing assembly tooling.

No Time For Old Methods

The 3-D modeling capability we developed is built around a customer integration of CAD, surfacing, rendering, animation, and translation capabilities from a variety of sources.

Simultaneous Engineering With A Twist

By basing the engineering and manufacturing process on customer- supplied electronic data, rather than paper drawings or hard models, we are able to enter into truly interactive simultaneous engineering projects with its large automotive customers. More often than not, that means that we first engineer and then build assembly tools for components that do not even exist outside the customer's computer and our 3-D models. It also means that both we and the customer can examine a wide range of design possibilities before arriving at an optimum solution.

A case in point is our instrument panel (IP) installation tool. The tool is designed to center the IP inside the body, providing equal clearance on both sides. It's a simple sounding task that has presented automakers with a persistent challenge for many years.

IP centering is a very common component of "fit and finish" ratings performed by a number of consumer magazines and other organizations every year. This problem is that the stack-up of body assembly and IP tolerance often approaches 1/2 inch, which is enough to cause interference with door panels, and is noticeable to the consumer.

Because the tolerance stack-up is unpredictable, simply locating the IP from the centerpoint of the supporting crossmember does not assure precise centering in the finished passenger compartment. Even with special training, skilled installers are not able to consistently center the IP because the body in white provides no reliable visual indicators.

Stepping Up To The Challenge

A customer approached us with the challenge, and proposed a multi-model year development project using a current model as a prototype testbed, with a fully implemented solution scheduled for a future model year production to coincide with a major interior re-design. We accepted, and decided that the multi-year nature of the project made it ideally suited for its 3-D model based system.

Our first challenge was to build a 3-D model of the IP from the dozens of individual component parts listed on the customer's bill of materials. This was not as simple as it might sound, since the datasets for the various components resided with a variety of different groups within the customer's organization.

We consulted with interior designers, ducting engineers, wiring systems people, radio and electronics groups, and many other sources before they got all the data they needed. Their perseverance paid off and they ended up with a 3-D model of the IP and its associated structures.

More Than Just An Engineering Tool

We found that our models are excellent tools for group meetings to thrash out design problems. As the IP model progressed, we began sending details to its fabrication shop for machining. By the time the final assembly drawings for the tool were completed, the tool was built.

We literally built the whole tool before we generated the assembly. Everything fit, because everything came from the same set of customer data. When the tool was delivered to the plant for pilot testing, it worked the first time it hit the floor.

Building On Success

With that success under its belt, our staff and the customer began improving the design to incorporate the lessons learned in a production environment. Future production tools would be more difficult to design because the IP was not only changed, but came in three distinct variations for different models built on the same platform. It was also considerably larger than the one variation of the IP.

Changing The Car To Make The Tool Work Better

As the project developed, we modified our model to incorporate the evolving changes to the IP, and then returned tool data to the customer for evaluation and further modification. During this process, we identified an opportunity to improve the installation process if the customer would modify his process to supply a pair of locating holes to assist the tool in centering the IP. After much discussion, and many iterations and simulations using our 3-D model, the customer agreed to include the new locating holes on the subsequent model year body.

The revision to the customer's design is just how simultaneous engineering is supposed to work. It is a perfect example of what happens when it's done right.

Supported by the confidence developed during the pilot project, we are building more tools using the same methods. Each tool is released for manufacturing as it is finalized, well before the customer's product is made.

Peak Industries has been a supplier of custom automation and assembly components and special machines and systems for the automotive and other manufacturing industries since 1966.