Shell Eco Marathon
As we were thinking of our design, we tried to make the most simple yet aerodynamic design possible for the cheapest price. In the end our team came up with a design where the front of the car would be curved and we would have a straight top and a curved back. Our CAD designer came up with the first sketches of our design as need in the picture below. However, as we started to manufacture our car, we changed certain parts of our shell.
As we started to build our car we made the front tip sharper and extended the shell to cover up the back wheel to have a smoother, more modern design. We chose not to include the front wheels into our shell because it would over complicate the fabrication process and wouldn’t offer any significant benefits to our car and its performance. Knowing that most cars in Shell-Eco Marathon drive in speeds around 25 mph with the average being 15 mph, we knew that our aerodynamics didn’t have to be over-complicated because the difference of drag would be negligible.
After a few weeks of research, we decided that fiberglass was the best best option for our team. This is because of how lightweight and durable fiberglass is. Furthermore, we know that fiberglass is much most cost effective and easier to fabricate than carbon fiber. We purchased our fiberglass and used release film and Epoxy in making our frame. We used release film so that we could easily take of the frame from our mold and used Epoxy to harden our fiberglass fabric.
Our team wanted to have a light yet durable and safe frame for our car. We also wanted to make the car building process as easy as possible for ourselves. We had aluminum and steel in our mind and we consulted different teams and our local metal supplied and we decided on aluminum.
While making our design, safety was always on our mind. We made two long aluminum hollow bars to make a rectangular shape(1 ½ inch) with smaller bars(1 ¼ inches) going across to make it as stable as possible. Furthermore, we made two smaller bars to go across the the sides of the frame shoulder height to the driver with cushioning to prevent injury to our driver. Furthermore, we used .063-090 aluminum sheeting to cover the bottom of our car frame and to use it as a fire retardant material between the driver and the engine. The same aluminum sheeting was used while making our seat for our driver.
We bought 1 ¼ inch and 1 ½ inch bars and .063-090 aluminum sheeting from from a local metal supplier. We used self-locking screws to screw the metals together and use L-shaped brackets from Home Depot to strengthen our connections. Lastly, we used 217-B 1” Woven fiberglass tape around our screws to make our design as stable and safe as possible against all impact. We also used pool noodles as cushioning for the side bars to make the ride as comfortable and safe as possible in case of an crash.
For more information: