At a clip too rapid for the human eye to discern, a laser beam fires into a pool of liquid polymer. Each time it does, it causes a tiny droplet of the goo to harden. Eventually, these little “pixels” start to come together, forming a solid part.
The process goes by a variety of names, including both 3D printing and additive manufacturing. It’s been around for several decades but is just beginning to take shape, much like that gooey liquid, into a serious tool for industry – as General Motors demonstrated this week with the formal opening of its new Additive Industrialization Center in Warren, Michigan.
Based within the sprawling General Motors Technical Center, the new facility will be able to create parts and tools out of not only liquid polymers but a variety of other materials, including powdered aluminum and titanium. Three smaller additive manufacturing facilities at the Tech Center have already provided parts for prototypes used in the development of the latest-generation Chevrolet Corvette, as well as tools used by workers at the GM assembly plant in Arlington, Texas.
“The core component of GM’s transformation is becoming a more agile, innovative company, and 3D printing will play a critical role in that mission,” said Audley Brown, GM director of Additive Design and Materials Engineering. “Compared to traditional processes, 3D printing can produce parts in a matter of days versus weeks or months at a significantly lower cost.”
As often happens, the idea behind additive printing was first described in a science fiction story published in the 1950s, described as “molecular spray.” Author Raymond F. Jones wasn’t far off from what GM is putting to work today, though one critical element, the laser, had yet to be invented. The first functional device, named a “Liquid Metal Recorder,” was patented in 1971 by Johannes Gottwald. It took another decade for the first really functional versions of the technology to be put to work.
Today, the most common approach starts with a digital rendering for a part or tool. That is used to operate a machine in which a laser takes aim at a specific spot at the top of a pool of liquid, which instantly hardens. Pixel by pixel, this grows to become a solid version of whatever was created in the computer.
Significantly, “it can create parts that are not possible with other manufacturing methods,” explained Greg Warden, GM executive director of Body, Accessories, Dimensional, Additive and Materials Engineering, in a media webinar this week.
One example can be found on the new Corvette C8R. The additive process was used to produce the race car’s oil inlet and tank. The traditional approach would have required 8 separate parts and 14 welds. The printed version has just 2 parts and no welds – and it is 32% lighter which can make a big difference on the track, noted Ali Shabbir, an engineering manager at the additive facility.
The new center, along with the other operations at the Tech Center now have about 75 additive printers. And they can use a mix of materials, including powdered metals and alloys normally not used in automotive manufacturing.
The primary application for the technology will be prototype vehicle development. As a new model, such as the retail version of the Corvette, goes through the process there can be frequent revisions made to early components. One example was the front air intakes on the sports car. Tweaking the inlet design conventionally would require the creation of new tooling, something that was both costly and time-consuming. Using a 3D printer, however, a new part could be ready in a day and cost next to nothing. Ultimately, GM officials say the new approach saved nine weeks of work.
“Additive is really enabling us to try solutions quick, so we can get products to market fast,” said Dominick Lentine, GM’s additive manufacturing team leader.
But GM has found there are plenty of other applications for the technology. It is being used to create customized tools at plants like the truck line in Arlington, and the EV factory in Lake Orion, Michigan.
When the automaker announced plans to start building the ventilator needed to hold treat coronavirus patients earlier this year it was able to speed up the process by using additive manufacturing for some of the parts needed for those devices.
And additive manufacturing is beginning to find application in new vehicles:
That includes some of the clips used in the battery pack for the GMC Hummer battery-electric pickup that will be launched next year;
The new Cadillac CT4 and CT5 Blackwing models will each have four 3D printed parts, including brackets and the emblems on their shifters.
Don’t expect to see the technology used for high-volume programs, at least anytime soon, cautioned Shabbir because it’s a lot slower than traditional processes like metal stamping or blow molding. It is “really suited to low-volume manufacturing. We’re talking hundreds, maybe thousands” of parts, not the hundreds of thousands needed on a high-volume program.
But taking things the next step is not out of the question, said Shabbir, and Sam Abuelsamid, principal auto analyst with Guidehouse Insights, agrees.
“As the technology advances, we’ll get to the point where you can mass-produce components at scale,” he said, while stressing that is likely “still five to 10 years away.”
Abuelsamid noted the technology could find use beyond the factory, however. It is not uncommon for customers to have to wait, when they need service or repairs, for parts to be shipped from a warehouse. Additive manufacturing could eliminate such waits, he suggested, if a dealer had a 3D printer that could be used to produce the part using the factory’s digital rendering.
GM is by no means the only automaker turning to 3D printing. Ford has used the technology for its various high-performance, limited-volume Shelby Mustang models, for example.
Suppliers are tinkering with the process, as well. One, 1016 Industries, this month unveiled a version of the McLaren 720S supercar that had a number of traditional parts replaced with those recreated through additive printing.
“Our testing has proven that a car can use 3D printed technologies and be drivable,” said 1016’s CEO Peter Northrop.