Would you like to print out a new part?
Carroll Shelby's Cobra roared onto the scene in 1962 and immediately shook up the motoring world. The formula of pairing a lightweight British body with a powerful American V-8 proved highly effective and many took notice.
Now, 50 years later, there's a new Cobra poised to be another unique game-changer. However, its ramifications may greatly impact auto manufacturing, rather than racing.
The Department of Energy's Oak Ridge National Laboratory near Knoxville, Tennessee, built this super snake. While it appears like the majority of both genuine and replica Cobras, don't let looks fool you. This one was 3-D printed.
"It's a technology demonstrator," said Brian Post. Post serves as an engineer and associate research staff member who worked on the project. "It serves to show what you can do in the field."
The undertaking was started last fall and components were "printed" using the ORNL's Big Area Additive Manufacturing machine, or BAAM.
"Traditional 3-D printers can print about 1 cubic inch an hour," Post said. "Our machine can do 1,000 cubic inches an hour."
Another benefit of the BAAM is its size output. Post reports other printers can't print items larger than one cubic meter. The BAAM is able to print as large as 6.6 feet wide, 13 feet long and nearly 3 feet deep.
Greatly simplifying the process, 3-D printing is comparable to use of a hot glue gun. Design dimensions are input via a computer to the printer, where plastic material is heated. Once it melts, it is then "printed" out of the glue gun in thin layers upon layers until the desired thickness and shape is achieved.
The components for the Shelby were strengthened by including carbon fiber in the heated compound mix. Printed pieces include the frame, powertrain and suspension mounts, body components and the dashboard.
The car's 1,400-pound curb weight comprises 500 pounds of 3-D printed parts and 20 percent carbon fiber. By comparison, other conventional Shelby kit cars, and even most originals, tip the scales around 2,300 pounds.
The team originally wanted to come up with its own auto design but settled on creating a Cobra based on the availability of reproduction parts. By securing existing components, such as the windshield, seats and wiring harnesses, the development time was greatly shortened.
A total of six weeks was needed to design, manufacture and assemble the one-off vehicle. Printing time totaled 24 hours. The powertrain is a 75-horsepower electric motor and battery pack. Range is 30 miles on a full charge.
Performance wasn't the goal of the project but the lab team couldn't resist calculating some numbers. "Since it's electric and full torque comes off the line, we figure it's good for 0-60 miles per hour in 5.5 seconds," Post said.
Before you expect to find printed electric racers tearing up tracks or gleaming at local cruise nights, hold your horses. There are no plans for the Oak Ridge facility to churn out 3-D printed Cobras, at least not en masse. After all, it's a lab, not a car factory.
Rather, builders hope their efforts will inspire and motivate others to move the manufacturing technology forward. It's a big task but this ultracool Cobra seems up for the challenge.