By Ben Gardell | 3D Printing Consultant
The use of 3D printing in the automotive industry has been one of the many ways that manufacturing is being brought back to the United States. One of the more iconic cars in American history, the Shelby Cobra, was recently reproduced using the same technology that we use here at R&D Technologies every day. The body of the car, and many other parts of the vehicle, were 3D printed and finished as a demonstration of how digital manufacturing can be integrated in the automotive industry. Read more about this exciting project here.
I had my own personal experience with this at the college level during my time with the UNH FSAE team. Our goal was to build a scale open wheel (or formula one) style race care and compete internationally against teams around the world. There were many rules that dictated the design of the race car, but the one that affected our speed the most was the engine intake restriction. We had to design a race car with an intake restriction of 20mm, which is a hair larger than a 10 cent coin. This is done to limit the torque that the race car is able to achieve and level the playing field. In order to get the most power from an engine and overcome this restriction for the competition, the intake manifold for the car has to be custom designed. Using the Helmholtz resonance phenomenon it is possible to build up air pressure in a cavity behind the restriction. If matched correctly with the desired horsepower and torque curves, this effect can force air into the engine for added horsepower and torque.
Getting beyond all the technical jargon we did not have an efficient way to build this custom intake design. Our only possible route for such a unique geometry would be to 3D Print the part. We 3D Printed the intake manifold on a Dimension Elite 3D Printer and were able to finish the inside of the intake. We then laid up the outside of the 3D Printed part with carbon fiber for strength. In hindsight, I would have gone about this with a few other tricks up my sleeve. It is possible to print, using the FDM technology, in only support material. This would allow a carbon fiber to be layered up on the support material, which could then be dissolved away. Also, if I was going to go the route of 3D Printed material, ABS material reacts well with acetone, which would be used as a smoothing agent. Or again as another alternate route, if the part was printed in a stronger material such as Ultem 9085 or Ultem 1010, no carbon fiber would be necessary (as shown in the picture to the right).
Now that I have been working for R&D Technologies Inc. I have also seen many other areas where 3D printing has been used to benefit the automotive industry. Of course some of the cooler rapid prototyped parts are used in race cars, but the consumer automotive manufacturers use them every day as well. This includes mock ups for trade shows, rapid tooling for custom work, and many other possibilities. As always, the exact future of 3D Printing is a little unclear, but it will continue to have a major impact on high end motor sports and the automotive industry.