While it is no secret that General Motors is going big on additive manufacturing technologies—it has approximately 75 additive machines on its R&D campus in Warren, Michigan, 24 of which are in the just-officially opened 15,000-square-foot Additive Industrialization Center (AIC), a purpose-built facility to help productionize the technologies, including selective laser sintering, selective laser melting, Multi-Jet Fusion and fused deposition modeling, deploying equipment from Stratasys, EOS and HP—what’s interesting is that it is looking at additive as another process in the company’s product development and manufacturing toolbox.
Corvette C8 brake cooling duct printed with additive manufacturing. (Images: Steve Fecht for GM)
As Dominick Lentine, Additive Manufacturing team lead, who concentrates on the manufacturing uses of additive puts it, “We’re not looking for one killer application. We can stamp, mold, cast or 3D print a part.” Whichever makes the most sense, they’re going to use.
But it is clear that the use of additive is going to do nothing but grow at GM as the company works to speed product development and reduce costs.
Essentially, GM is using additive for:
- Functional prototypes
- Low-volume production parts
Of the three, tooling is, according to Ron Daul, GM director of Additive Manufacturing and Polymer Centers, the biggest application of the three.
Tooling is a big application for additive. This is for use at the Arlington Assembly plant.
For example, they’re using nylon-carbon fiber body quality tools at the Arlington Assembly Plant built with additive—about 100 of them—that were made with additive rather than the conventional steel and aluminum tools used. According to Lentine, there is an 84% weight reduction, a 91% cost reduction, and a 10-week lead time reduction (from 14 to 4 weeks).
At Orion Assembly, they have produced a roof load arm fixture with additive that is robotically manipulated. In this case, there is a 65% weight reduction compared to the welded steel assembly that had been previously used and they were able to build the additive tool in less than a week rather than the five that the steel tool required.
A C8.R Corvette oil inlet and tank. It had been an assembly consisting of eight welded components; it is printed in two.
Lentine notes that the lighter tool has the potential of reducing cycle times as it can be more readily manipulated. Or there could a capital expenditure reduction, as the use of lighter tools can lead to the use of smaller robots.
Ali Shabbir, GM engineering group manager of Additive Manufacturing and Design Product Applications, calls additive “a game changer in the manufacturing tooling space.”
Yes, there are things like the additive Corvette brake cooling ducts that were used for functional testing. These ducts, Shabbir says, were used in place of injection-molded ducts. They produced the ducts in less than a week rather than the 10 it takes with conventional processes. There was a 64% cost save. Shabbir describes additive as providing “unparalleled speed and agility” for the development process.
“The number of production parts we do is small now,” Shabbir says, adding, “But I do see that growing.”
According to Daul, the material that has been most widely used so far is nylon and carbon fiber as it works well in the tooling applications. But he thinks that as the number of applications grows, there will be an increasing amount of polymers and metals that will be used in the additive applications.
Underscoring the importance of additive at GM, Greg Warden, GM executive director of Body, Accessories, Dimensional, Additive and Materials Engineering, says, “Additive manufacturing plays a critical role in helping provide agility and speed across product development and manufacturing.”
How carbon fiber is utilized is as different as the vehicles on which it is used. From full carbon tubs to partial panels to welded steel tube sandwich structures, the only limitation is imagination.
According to Sandor Piszar, Chevrolet truck marketing director, “We engineer and build our trucks with customers’ expectations in mind.”
If automotive tire upstart Amerityre can perfect its polyurethane tires, we may soon have to revise the phrase "where the rubber meets the road."