Detroit — Additive manufacturing is advancing. And with the advancement comes more opportunity for the process to play a significant role in automotive manufacturing.
For evidence of this, look no further than Ford Motor Co., which in December showed off its 135,000-square-foot Advanced Manufacturing Center in Redford Township, Mich., just west of Detroit. The center — a $45m (€39m) investment — houses about 100 workers in addition to manufacturing technologies such as 3D printing, augmented and virtual reality, robotics and other digital manufacturing efforts.
The center has 23 3D printers and is working with 10 additive manufacturing companies — one of which is Carbon, a 6-year-old additive manufacturing company based in Redwood City, Calif., touting a proprietary approach to the 3D printing process.
In contrast to the traditional layer-by-layer printing approach, Carbon uses what it calls Digital Light Synthesis technology enabled by its proprietary Continuous Liquid Interface Production (CLIP) process, which uses digital light projection, oxygen-permeable optics and programmable liquid resins to produce parts that have high-quality mechanical properties, resolution and surface finish. The company said parts printed with this process are similar to injection moulded parts and have consistent and predictable mechanical proprieties — an important requirement for automotive applications.
Carbon A 3D printed HVAC lever arm for an older model Ford Focus is made with Carbon's epoxy-based EPX 82 material.
Printing on demand
With Carbon's technology, Ford has been able to design and produce digitally manufactured end-use parts in three production vehicles, including the 2020 Mustang Shelby GT500, which was unveiled 14 Jan at the North American International Auto Show in Detroit.
"Why do we care about additive manufacturing at Ford?" asked Ellen Lee, the automaker's technical leader for additive manufacturing. "Essentially, the attributes of additive manufacturing — mainly that we can make a three-dimensional part without the need of a mould or a tool, in addition to the design freedoms of those parts that we can make — provide use with values in efficiency, agility and performance."
Lee spoke 16 Jan at an additive manufacturing symposium held at Cobo Center during the Detroit auto show's industry preview. She was joined on stage by Paul DiLaura, vice president of enterprise partnerships at Carbon.
The process allows automakers like Ford to "more nimbly respond to the dynamic changes in the market and our complex supply chain," Lee said.
Lee and DiLaura highlighted three automotive applications using Carbon's technology and epoxy-based EPX 82, a high-strength engineering material with long-term durability and mechanical properties comparable to glass-filled thermoplastics, the company said.
On an older model Ford Focus, the automaker is now 3D printing HVAC lever arms, as needed.
"This part was originally produced with a 30% glass-filled PBT [polybutylene terephthalate] material and injection moulded," DiLaura said, adding that it would have been time-consuming and expensive for Ford to get a new tool out to produce these parts, which would then take up physical warehouse space.
For the Chinese market only, Ford is 3D printing an auxiliary delete plug on the F-150 Raptor. In China, DiLaura said, there is a regulation that prohibits the use of certain kinds of lights, including spotlights that are on vehicles here in the United States. Ford needed to remove the spotlight and remove the switch on the instrument panel that controlled the spotlight and then cover up the switch opening with a delete plug.
"It's a relatively low-volume scenario for the Chinese market, so it would've been quite expensive and time-consuming to … design that tool and stand it up and produce the parts," he said.
With Carbon's 3D printing process, Ford was able to cycle through more than 14 designs in 19 days to design and test the parts that are now on the F-150 Raptor in the Chinese market.
The third application discussed was the electric parking brake bracket on the Mustang Shelby GT500. In previous models of the vehicle, DiLaura said, the part would have been stamped out of steel and there would be two versions: a left-hand part and a right-hand part.
"Carbon and Ford worked together in order to create this design — a unique design that would've been very difficult to injection mould — that is a mono design," he said. "So, it works on both the left-hand side of the handle and on the right-hand side of the handle, which improves the ease of installation."
The 3D printed part is 60% lighter than the stamped steel equivalent.
Material costs for 3D printing are typically higher than materials used for injection moulding, Lee said. But costs are gradually coming down as volume increases and manufacturers move into production.
When Carbon first launched in 2013, DiLaura said, the company's materials cost between $300-$400 per liter. A year ago, that cost was slashed to $150 (€130) per liter and now it's $50 per liter (€43.5).
But cost aside, it was the optimised use of materials, shortened time frames, ability to quickly iterate through designs, weight savings as well as the convenience and agility of prints on demand that made for a good business case for implementation at Ford.
"We're thrilled to be able to now have Ford's first production applications using an additive manufacturing process for polymers in production, but we know that we, Carbon, need to continue to develop our own capabilities and enhance what we offer," DiLaura said.