We are excited to announce Revchem Composites as a material sponsor for our solar car Zephyr!
A major distributor of everything relating to composites, Revchem has generously donated all of the materials required to get our molds prepped for composite layups. For our small tooling foam molds we use sandable surface primers that allow us to get extremely smooth finishes on all of our parts. Revchem’s material donation has also been essential to getting our shell molds ready for composite layups. Because our shell molds are made from EPS (a.k.a. styrofoam), we need to shield the foam from reacting with the surface primers and composite resins. They have also provided us with tooling gelcoat for creating our fiberglass molds from our male plugs.
With all these high-end mold materials at our disposal, we can create the best molds and smoothest car CalSol has ever manufactured.
The brains of a solar car are essential. For our designs, we use a distributed network of a handful of microcontrollers. Each node in our network controls something different, such as managing the batteries, controlling the motor, or taking all the input from the driver. An important decision is choosing these brains, and we have reached out to NXP for their help. Last December, a few members of CalSol went down to NXP to show off Impulse and talk about our plans for the future. We received a very friendly welcome, and we are hopeful of a bright future with them.
One of NXP’s interesting products is their LPCXpresso boards. These development boards include both a microcontroller for rapid prototyping and a built-in JTAG debugger, the LPC-Link. This debugger gives us significantly more power than we have had previously, allowing us to step through our running code and see the complete state of the microcontroller!
NXP has given us 40 LPCXpresso boards and has agreed to provide microcontrollers and other integrated circuits as needed. The development boards have allowed us to quickly get up to speed, and we are already making our own prototype boards using NXP’s MCU’s. You can see one of our first boards with an NXP chip (made by team member Devan Lai) in the picture to the right. We are planning on using NXP’s Cortex-M0 LPC11C14 for many systems in the car. These microcontrollers only take a few milliamps to run, an incredibly low amount for how much power they have! This, combined with their integrated support for the CAN communication protocol, makes them well suited for our applications. As well, the move to a modern 32-bit ARM architecture allows our code to be both smaller and more efficient.
All of these improvements are incremental steps towards making our best solar car yet. We’re hard at work doing everything we can to increase performance, decrease power consumption, and maximize efficiency.
This past Tuesday, the motor team and several other members had the pleasure of taking a tour of Dahl-Beck Electric‘s motor repair facilities. Dahl-Beck is a local company based in Richmond that performs a wide range of repairs on industrial-scale electric motors brought in from customers around the world. They provide an incredible and invaluable service to clients who are able to bring in broken motors ranging from <1 hp to 10,000 hp and have them disassembled, evaluated, completely overhauled if necessary with new wiring and newly machined surfaces, enameled, painted, re-tested, and shipped back as good as new.
The CalSol motor team in particular is interested in Dahl-Beck’s ability to vacuum-impregnate motors with epoxy to ameliorate vibrations and insulate electromagnetic components. By requesting use of Dahl-Beck’s vacuum pressure impregnation (VPI) services, we could achieve a much higher quality potting of the current design of our stator than if we attempt to achieve it ourselves.
A big thank you to Dahl-Beck employees Kevin Sams and Dan Neal for taking the time out of a busy work season to give us a tour of their well-maintained facilities and chat about our motor project, and thank you to Mick Franssen of the UC Berkeley mechanical engineering student machine shop for introducing us to Kevin!
Be sure to check out photos we took on our Flickr.
The annual Cal Day event is coming up this Saturday on April 20th and CalSol will be on display!
Cal Day happens every April and is a great opportunity for all of Cal to show off what it’s got in store, especially for visiting prospective students, and this year there are there are more exciting things to see than ever before. CalSol, in particular, will be showing our current car Impulse as well as newly built parts for our new vehicle, Zephyr. Our suspension and controls teams have been hard at work to display numerous vehicle components, newly machined and laid up, so make sure to stop by the Etcheverry-Soda breezeway all day to see Impulse on display! We will also be manning a table in front of the Engineering Student Services office for questions and information.
We are super excited to announce that Airtech recently became a large materials sponsor of CalSol! The largest manufacturer of vacuum bagging and composite tooling materials, Airtech has generously donated some of their materials for our use on Zephyr’s shell. Since we have decided to go with pre-imprepregnated carbon fiber this time, we needed all new bagging materials that can withstand the elevated curing temperatures. We’ve also upgraded some of our other equipment, which will hopefully allow us to make an extremely nice shell for Zephyr.
Our new partnership with Airtech will give us the opportunity to improve our manufacturing process as we get ready to build CalSol’s most competitive vehicle yet. Thank you Airtech!