After 30 years, we may finally be approaching the tipping point for additive manufacturing of end-use automotive parts.
There are few industries more poised for transformative change than automotive. Even if the dream of self-driving cars never comes to pass, the rise of the electric vehicle (EV) is enough to push new technologies and production processes into broader adoption.
Take 3D printing, for example.
Like EVs, 3D printers have been around long enough for the novelty to wear off and yet—unlike self-driving cars—there turned out to be a lot of practical value under all that hype. Over the past decade or so, we’ve seen 3D printing go from a niche technology used primarily for prototyping to more industrial applications, such as producing jigs, fixtures and tooling. The question is: Do we still have farther to go?
Or, to put it in automotive terms: Are we there yet?
The destination in this case is true additive manufacturing, i.e., using 3D printing to produce end-use parts for the auto industry—and electric vehicles could be the catalyst needed to get us there.
Tracing the Arc of Additive Automotive Applications
Like so many industries, the earliest application for 3D printing in automotive was prototyping. BMW was one of the first companies to use the technology for this purpose, producing prototype parts using stereolithography all the way back in 1991. Today, you’d be hard pressed to find an automaker that doesn’t have at least one 3D printer on hand for prototyping.
The next step in the additive/automotive partnership brings us closer to production, but still a ways away from end-use parts. Jigs, fixtures and tooling have all been growing as applications for 3D printing in the auto industry in recent years. From Mahle’s fixture for automotive HVAC assemblies to Dayco’s 3D-printed profile gauge, automotive engineers have been finding more and more ways to take advantage of the flexibility, cost-effectiveness and quick turnaround times that make 3D printing such an important technology for manufacturing.
Of course, the ultimate achievement is 3D printing parts that will actually go into production vehicles: the beginning of true additive manufacturing in the automotive industry. For that to happen, cost-per-part estimates need to come down. We’ve seen some indications of where the early inroads will be, with proof-of-concept parts such as Volkswagen’s 3D-printed metal shifter knob, which debuted at IMTS in 2018.
“In the next five years, I’d say it’s decorative interior components: things that are going to augment the customer experience and give them more influence over the aesthetics,” says Ross Adams. As Markforged’s business development manager for metal binder jetting, North America, Adams has a unique perspective on where additive manufacturing for automotive is likely headed. Markforged has been designing, developing and manufacturing 3D printers, software and materials for a decade.
“The biggest slice of the pie is end-use parts,” Adams says “But the lower-volume prototypes, tools and spare parts exposed some of the benefits of 3D printing beyond just cost-per-part, whether that’s in performance or supply chain. Right now, we’re just scratching the surface.”
So, if we haven’t hit the point of volume production for 3D printing yet, what will it take to tip the scales?
Luxury and Electric Vehicles Pave the Way for Automotive Additive Manufacturing
“We’re doing some specific types of automotive applications with luxury vehicles,” notes Adams. “You’re not making a car every minute, but maybe one every day, so the environment is one with lower risk, the engineers operate with fewer variables, and they can build up that internal competency.”
Luxury vehicles also have the benefit of being less constrained by cost and more focused on performance than those for the average consumer. This combination is what enabled Aston Martin to use 3D printing to develop a new suspension system in just six months.
The other automotive area that’s ripe for additive manufacturing is electric vehicles, especially as they become more common and the industry shifts from focusing on components for internal combustion engines (ICEs) to EV-specific parts. “A lot of the Tier-1, Tier-2 and Tier-3 suppliers have built their businesses around gears and sprockets,” says Adams. “All these drivetrain components that go into automobiles, most of which are using sintering technologies, like metal injection molding or pressed powder.”
With many of these drivetrain components rendered obsolete by electrification, Adams believes these suppliers will need to reinvent themselves to remain viable businesses, both in terms of their materials and their processes.
“Stainless steel isn’t really the primary material when we’re talking about electric vehicles—now it’s copper,” says Adams. “And metal binder jetting is a good complementary technology to those other sintering processes because it’s just using a different tool to get the part into shape before you put it in the furnace. The transition from steel to copper with this technology is pretty seamless compared to machining.”
Beyond the impending process and material changes, electrification could also drive broader adoption of additive manufacturing in the auto industry via lightweighting. Earlier this year, the head of the National Transportation Safety Board expressed concerns about the safety risks that the added weight of EV batteries pose to lighter ICE vehicles. The ability to reduce weight by redesigning parts for additive processes is one of the reasons 3D printing has gained so much traction in the aerospace industry.
Could we see a similar trend with EVs in automotive?
“In the near term, it’s hard to make an argument that additive is going make enough of a difference to offset the weight that batteries create,” says Adams. “But that’s just because the volume of applications for 3D printing isn’t yet mature enough for them to add up. And there’s a saying that a small change, multiplied by millions, becomes a big change.”
Individually, 3D printing and electric vehicles could each transform the automotive industry in their own right. Together, these two technologies will reshape vehicle production in ways not seen since the introduction of the assembly line. Changes of this magnitude happen slowly at first, but once they reach a tipping point, the transformation can seem to occur almost overnight.
When that happens, “Are we there yet?” suddenly becomes “How did we get here so quickly?”
