Revolutionizing Automotive 3D Printing: Creating a Cobra in 6 Weeks

When you think of the latest in 3D printing, prosthetic limbs, building models and electronic gadgets might come to mind. Oak Ridge National Laboratory (ORNL), however, was determined to add a 1965 Shelby Cobra to that list, and they did so in a matter of weeks.

The 1965 Shelby Cobra was different though, revolutionary actually. The team was small, but mighty. Six engineers at ORNL, a few designers and painters at TruDesign and local representatives from BASF worked hand-in-hand to not only master the large-scale automotive 3D printing, but also achieved a 'Class A Finish' on this iconic vehicle.

Pictured above is the finished 3D printed 1965 Ford Motor Company Shelby Cobra replica. Photo courtesy of Oak Ridge National Laboratory.

The Project

In the automotive industry, manufacturers typically reserve 3D printing for rapid design and prototyping purposes.

ORNL first tried its hand at a large-scale automotive 3D printing project in partnership with Local Motor's printing the Strati, the world's first 3D printed electric car. The entire car, printed with acrylonitrile butadiene styrene (ABS) plastic reinforced with carbon fiber, was around 1,200 pounds, had less than 50 parts and only cost about $4,000.

 "That's our goal - to change manufacturing in the United States as we know it."

After printing the Strati, many car manufacturers started flocking to the lab making requests to show the vehicle at events. ORNL decided that it was time to create another prototype but this time they wanted to take it to the next level - not only would it have to be a lightweight, energy efficient car but it would need to be completely road-worthy. It didn't take long for the Department of Energy (DOE) to jump on board and back the idea.

But timing couldn't have been tighter. The DOE wanted the car finished in just six weeks - to 'wow' the industry at the 2015 North American International Auto Show in Detroit.

Printing capabilities, material usage, vehicle design and safety, weight reduction needs and parts procurement topped the list of challenges for the team in dealing with such a tight timespan.

"We showed that we can make a mold faster and cheaper than waiting for a part to be shipped to us, and that's a real game changer," said Lonnie Love, group leader of Manufacturing Systems Research Group at Oak Ridge National Lab. "We're going to change manufacturing. That's our goal - to change manufacturing in the United States as we know it."

The Perfect Car

The iconic Ford Motor Company Shelby Cobra was the perfect vehicle to 'print', with its recognizable appeal and numerous aftermarket products available.

And the stars continued to align as 2015 served as the 50th anniversary of the FIA Manufacturers Cup where Bob Bondurant first drove the Cobra.

"At the same time, someone came into my shop asking me to take pictures of the car to send to his brother-in-law," said Love. "I asked him who his brother-in-law was - it was Bob Bondurant."

It was fate.

Coating a 3D Printed Carbon Fiber Car

The real magic came when the hunk of carbon-fiber printed materials was transformed into a work of art that could compete with the rest of the cars on the show floor.

Pictured above is the coating process of the 3D printed 1965 Ford Motor Company Shelby Cobra replica. Photo courtesy of Oak Ridge National Laboratory.

"We knew we could print the parts, but were challenged with achieving that 'Class A Finish' on the printed material," said Love.

Luckily for ORNL, they had a composite coating expert in its back yard. Rick Spears, founder of TruDesign began working with carbon fiber before it was big in the U.S. market.

Sanding carbon fiber is much like working with concrete, but TruDesign was tasked with achieving a beautiful automotive finish. TruDesign needed to eliminate the ridges and bubbles that the 3D printed surface formed, and do so without maxing out the six-week time frame.

That's where BASF's partnership comes into play.

"We knew we didn't have time for mistakes, so we did hundreds of test panels," said Rick Spears at TruDesign. "We chose to use BASF's DIAMONT R-M Paint because it's what we have used for years, so we trust it and knew it would provide a quick, clean and durable finish."

Matching Bob Bondurant's winning car color was essential and BASF's color matching experts were able to do just that. They replicated that shiny, deep blue color using the DIAMONT R-M line.

So, what's next?

The Cobra serves as a real-world rolling laboratory, offering researchers opportunities to test innovative automotive materials, ideas and technologies. It not only stands as an example of another way to build a car, but also demonstrates the infinite possibilities of future technologies.

Drivers may soon be able to walk into a car dealership, choose a design and have a 3D printed car by the end of the day.

Check out this video to discover more about this six week project: