MT Magazine March/April 2023

FEATURE STORY

ADDITIVE ISSUE

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weight of 5,812 pounds; the GMC HUMMER EV SUT pickup truck tips the scales at 9,640 pounds. Whatever the weight of the CELESTIQ, evidently that additive part has excellent performance characteristics. But There’s This There are two things to know about the CELESTIQ that we’ve kept until now: • The vehicle will have a starting price in the realm of $300,000. Roma said that because this is a hand-built model, customers will be able to have levels of personalization and customization that have heretofore not been even considered. Those choices will certainly have an effect on the price of the car. Conceivably that $300,000 is simply a placeholder that will soon have several significant digits added to it. • The Artisan Center will build no more than six vehicles at any one time. These cars will be built to order. You won’t drive by your local Cadillac dealer and see several parked on the forecourt. Even though this is a production vehicle, the volumes are comparatively small. Perhaps the best way to think about this is to know that in 2022, Rolls-Royce Motor Cars delivered a record 6,021 vehicles globally. And Rolls-Royce has an entire factory dedicated to its vehicles, including a highly popular (comparatively speaking) SUV. (Rolls-Royce’s first use of additive was for the Ghost Extended model launched in 2020; it used beam melting, Multi Jet Fusion, and selective laser sintering.) But Roma made a point about the use of additive for the CELESTIQ and what it means more broadly to GM: “This will help open our manufacturing team’s mind to what’s possible.” He believes that when it comes to deploying additive, there will be an exponential curve, going from hundreds of parts to tens of thousands. The Importance of Tools But there is another place where additive makes a difference. Roma said that they are also using it for producing tools like

check fixtures and assembly fixtures. He said that these tools can otherwise cost tens of thousands of dollars. Again, both cost and time are saved by making the tools with additive. Tools and fixtures are applications that GM is using additive for. Not only are there time and cost benefits, but by being able to make them with polymers rather than metal, they can be significantly lighter than metal versions.

(Image: Steve Fecht for GM)

And there is another important factor: Ergonomics. Sticking with Cadillac: The Escalade is produced at the Arlington Assembly plant in Texas (along with GM’s other full-size SUVs, the Chevy Tahoe, Suburban, and GMC Yukon). To prep the plant for production of the current-generation vehicles, GM invested approximately $1.4 billion in the plant, everything from 1,450 new robots to laser scanners to precisely locate the positions on body panels where piecing is required for assembly. But another thing that they did was use additive to produce some 100 different tools used in the plant. Previously, these tools were made with aluminum. And while aluminum is light, a given tool that is handled by a worker would weigh between 10 and 40 pounds. It wouldn’t take too long before “aluminum is light” would seem an absurd statement. So, using a nylon carbon fiber composite, tools are made that weigh a more manageable three pounds. Roma has been at GM since 1993. He’s had a variety of roles, including race engine team manager for the Cadillac CTS-V racing program. He’s worked on the Camaro, Corvette, GTO. So, when he says of additive, “It’s exciting stuff,” it is clear that this is something that is more than a run-of-the-mill addition to the design, engineering, and production tool set.

Some Reasons Why GM Uses Additive

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• Permits a quick build of physical parts from digital designs

• Permits early testing of fit and function

• Allows fast design iterations

• Reduces overall product development time

• Reduces tooling costs, from fixtures to molds