The solar array frame is one of the most crucial components of the car. Spanning the entire five-meter length of the vehicle, the frame provides the necessary support to safely and securely hold our solar array in place. Resting on top of the car’s metal chassis, the frame’s hinged design allows the team to rotate the solar panels directly towards the sun to get the most power possible during a parked charging session.
In 2019, our vehicle featured a raised solar array lofted above the body of the car. For the 2021 race, we made the design decision to lower the array to the level of the driver’s shoulders. Doing this will reduce the overall weight of the car, as well as create a more aerodynamic silhouette. RAHS Green Energy Team member Nigel Barnett (12) touches on this in his previous blog post, “Aerodynamics and the Iterative Design Process”.
We’re proud to say that with the help of our friends at Boeing and The Gill Corporation, our new array has been constructed almost entirely out of carbon fiber and other composite materials. A key characteristic of carbon fiber is its remarkable strength despite its light weight. This has been a boon to the team; the usage of such a light material for such a large part of our vehicle has significantly reduced our car’s weight as we head towards texas. As of now, we’ve weighed in the car at just under five hundred pounds — that’s a three-hundred pound decrease compared to our previous vehicle.
The use of carbon fiber in our solar array frame has also welcomed a new opportunity to learn about real-world manufacturing practices. During the construction process, team members have been hard at work cutting carbon fiber strips, mixing epoxy, and bonding pieces together. Using a combination of West Epoxy and 205 Hardener, we create an epoxy mixture that can quickly and effectively join two pieces of carbon fiber together.
But there’s no time to waste — the epoxy can go from a viscous liquid to a hardened piece of adhesive in no less than five minutes of open-air exposure. Team members must work fast and efficiently to place the epoxy between the attachment points of the carbon fiber. Abigail Jawili remarks on her experience using epoxy during the construction of the front two fairings. “Working on the front fairings was a very interesting and very fun process! It was a bit hard working with the epoxy because you didn’t want it to be too thick in some areas and have no areas with any epoxy. So you would have to think ahead on which areas needed epoxy and make the front fairings look nice.”
One key element to our victory in 2019 was in part due to our ability to charge the car efficiently before and after the race. As soon as we got off the track, team members rushed to the garages to set up the car to gather as much solar energy as possible in the time allotted. The team had installed a tilting mechanism on the car’s solar array that allowed us to rotate the panels to directly face the sun. This year, we intend to do the same. Nicknamed the “Piano Stand,” this year’s tilting mechanism will rotate around two steel pipes welded to the right side of the chassis.