Among automakers, General Motors was an early adopter of 3-D printing/additive manufacturing (AM) in the 1980s and is accelerating both its use of, and investment in, the technology. Nearly 40,000 prototype parts are printed annually at GM’s Warren Technical Center, including about 75% of the 2021 Corvette’s bill of material used for assembly mockups. A host of tools and related items were made using AM for medical masks, face shields and ventilators.
A new Additive Innovation Lab at the Tech Center has trained over 700 technical staff. Later this year GM will open its nearby Additive Industrialization Center, aimed at further expanding AM applications into tooling and series production parts. Kevin Quinn (below), GM's director of additive design and manufacturing, spoke with editor Lindsay Brooke about AM’s future.
How is GM is incorporating AM into its overall product-development strategy, beyond rapid prototyping?
We think we can really drive value into the organization with 3-D printing and ultimately, to our customers. AM starts very far to ‘the left’ on the development-cycle timeline. It starts with one-off parts. You have a great design in math data, viewed on the screen, but nothing surpasses being able, as an engineer, to build vehicles around it. Now, with our dedicated resources we’re focused on taking 3-D to the next level: transitioning from a prototype and assembly/tooling mindset, to more production parts to support our vehicles.
Currently it is low-volume technology; it’s not a play that supports full-size-truck volumes. But to enable more niche-type vehicles, service parts, and accessories for personalization/customization, 3-D enables us to give customers exactly what they want without requiring a big capital investment. Our primary focus over the past three years is to push further into serial production – to first-built parts that are 3-D printed versus traditional manufacture. We’ll be making some exciting announcements about upcoming vehicles.
Do you see an inflection point coming where AM could take over for some CNC production machining, for example?
I don’t know that it will ever replace CNC. There will always be a home for some of the traditional methods. I’m one of the biggest proponents of 3-D printing but it can’t do everything. It’s not a replacement; it’s an augmentation. 3-D can even enhance some traditional methods such as injection molding. We’re also getting into sand printing of metal-casting cores.
What are the current challenges in creating more opportunities for AM?
Number one is cost—how do we continue to drive efficiencies with 3D from a cost perspective? Today we can make viable business cases for production in the thousands [of units]—but we need it to be viable volumes of tens-and-hundreds-of-thousands for 3-D to replace traditional tooling processes. The second challenge is throughput; in automotive we make lots of things compared with medical and aerospace. Third, we need greater breadth of automotive-grade materials for 3-D printing. We need more metal alloys that fit our needs; we don’t need a lot of titaniums and Inconels like aerospace does. We need more polymer types. And lastly, we need more of what I call ‘process industrialization’ for 3-D printing. It’s a great prototyping process and it’s been that for a long time. So, how do we continue to drive it towards mass production by enhancing the printing process for production?
What about AM in electric and autonomous vehicle development?
We did that slow build on the Corvette because it was an all-new architecture. Same thing with the EVs – new architectures so we’re using our 3-D learnings from the Corvette build on the EVs. On the autonomous side, as we develop and integrate the various sensors into those cars, we use 3-D to help quickly iterate the sensor housings, for example, to ensure we have the right field-of-view angles.
Talk about training engineers to think about designing for AM, and how it can be integrated in product development.
It’s a challenge for us as we try to get more 3-D-printed applications out there. And we have to educate our supply base as well. Our new Additive Innovation Lab is at the center of the Edward Cole Building at the Warren Tech Center campus. The Lab is the hands-on learning hub of our 3-D training – and it’s close to the Starbucks, so it gets a lot of daily traffic! A lot of engineers and purchasing staff are in that building and anyone can stop in and learn about the technology, for both polymers and metal, and how it can help their applications as well as learn about its limitations.
We’ve already trained over 700 folks in the Lab. And once you’re certified on the machines you can run your own prints. Our goal is to get all GM engineers educated on and thinking about 3-D printing applications. And very quickly the sign-up boards for those machines were five and six jobs’ deep. It’s a good problem to have!
Same thing with GM suppliers. We meet frequently with our supply base. For prototyping for sure we have some established operations that support our 3-D printing needs but the technology really scales when we get our suppliers involved. We’re really pushing it with them so they learn how 3-D can help their processes. Then they’re generating ideas back to us.
The AM facilities at many suppliers are a mixed bag. Some are very advanced, others not so much. I reckon there are various levels of competency among the supply base now, correct?
There is definitely a range of capabilities out there. Some suppliers are farther along the learning curve than others. For some of our suppliers we start them at the ‘101 course’ level. It might begin with purchasing a small hobby printer and locating it where engineers can play with it a bit.
Currently is most of GM’s use of AM with plastics, such as SLA and jet-type printers, rather than on the metals side?
Yes, I’d say the plastics piece is more advanced in terms of automotive usage, at this point. We are getting into the metals space and finding opportunities there. From a cost perspective, processing and [metal] powder costs in metal printing need to come down. They’re acceptable for aerospace and medical applications because those sectors don’t have the same magnitude of cost pressures we have in automotive. At the same time we need some materials development in the metals space. Metals development trails the plastics space. Yes, you can get aluminums and steels but not in the same breadth of alloys that make the most sense for automotive use.
Is the AM technology changing so quickly that the tools and capabilities available in 2022 will be very different than today?
The technology is advancing steadily but not in a huge leap every year or two. But in five years, yes, our use cases and the breadth of how we use 3-D will look a lot different. The number of startups in this space is huge.
Regarding AM use on the C8 Corvette, what part of that program are you most proud?
Just the amount and quantity of parts on that program – around 75% of the first engineering properties were 3-D printed. We mock up complete engines in some cases. It’s more fit-and-form evaluations on that car but we’re doing more functional evaluations with 3-D parts as well. Those first vehicles [C8] were used to refine the manufacturing process. Teams from the Bowling Green assembly plant came to our Warren Tech Center to assemble vehicles made with 3-D printed parts. It really helped make the in-plant processes more efficient. We also used 3-D printing to develop and refine the articulation of the Corvette’s convertible hardtop. Those parts were created and iterated quickly to get to the final design.
Where does GM expect to be in 18 months with its AM program?
The next big push is around production printing. You’ll see that we’re using the technology to print more production parts, or to make tooling for production parts. The primary focus of our new 3-D Industrialization Center coming online later this year is on production on a broader scale.