CalSol Bleeds Carbon Fiber

The last three weeks has seen a whirlwind of activity from CalSol as dozens of us have pushed even harder than before, toiling away mornings and nights to finish all of our carbon fiber layups. Too many nights have the clocks turned to 1am just to be back at 9am that same day, but we love seeing the massive push of progress. We just entered Spring break and those involved are taking a very well deserved rest for a day – just one – then back to work Monday!

CalSol, unidirectional carbon fiber, carbon fiber, unidirectional, solar car
Zephyr top shell, in our oven, mid-layup with the unidirectional carbon fiber adding stiffness to the structure

Zephyr is being built with a brand new manufacturing method for the team called pre-impregnated carbon fiber and Sam – shell lead – has been the champion of this process. He put in the hours to prep work and designs for the entire rest of the team to help implement. Long rolls of carbon fiber fabric impregnated with thermoset resin is laid out onto our smooth, waxed mold surface. Then CalSol members smooth and stick the fabric to the mold using heat and pressure making sure that there are zero wrinkles or air bubbles in the surface. This process is repeated with a smattering of nomex core, foam, and uni-directional carbon fiber in various areas all to increase the stiffness of the final product. Once satisfied, a release fabric is applied to the carbon fiber, then a cottony breather fabric, and lastly a large vacuum bag encases all of the carbon. Vacuum pumps suck the air out of the bag and press the carbon fiber into our smooth mold. Finally, we close the oven door and bake the carbon fiber to set the resin in place.

Quite a long process right? But now we are proud to say that we have finished all of the layups! We would also like to thank Patz Materials and Technologies for their help in making the pre-impregnated carbon fiber for us

Please enjoy the following photos that outline our thousands of man hours spent over the last 3 weeks.

CalSol, top shell, carbon fiber, solar car, layup
CalSol members having fun while working on the top shell of Zephyr
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Support ribs on Zephyr’s top shell to give added stiffness to the solar cells
CalSol, oven, top shell, carbon fiber
This photo was taken at about 1:30am as we pushed to finish the final few crucial steps to preparing the layup to be cooked inside of our oven
CalSol, Zephyr, top shell, pre-preg
We decided to throw a small party while unveiling the final top shell layup. This was our largest pre-preg layup to date and everyone was anxious to see what it would look like!
CalSol, Zephyr, pre-preg
The party was a great success and the top shell came out great! The surface finish is impeccable and the quality of the result is incredibly high.
CalSol, Zephyr, carbon fiber
Just last night we released Zephyr’s bottom shell from its mold and we ecstatic to see that it was just as perfect as the top shell!







Our Beautiful Composites

CalSol has progressed massively since our last shell team update! At our previous check in we had only finished one of our 8 fiberglass molds, completed zero carbon fiber layups, and we had a long way ahead of us. Now every mold has been finished, brought to a perfect shine, and 2 of the 8 parts of our car have been baked into flawless carbon fiber shells!!! You can’t imagine how happy and excited the team is that the body of our car is coming together!

solar car, sanding, fiberglass molds, shine
The sanding was just getting finished here on our top shell mold
fiberglass mold, bottom shell, solar car, composites
Holly, Jason, Pragaash, and Pol finishing bolting on the supports for our bottom shell fiberglass mold


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Aldrich standing by the pre-preg layup of our canopy for Zephyr
pre-preg, carbon fiber, composite
Our canopy as it came out of the mold, isn’t it beautiful??
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Mandy and Sam holding up the rear fairing of Zephyr after some long nights of laying out the carbon fiber





BBQ’ing at Work Sessions!

Every Saturday of every week about 15 or more team members find their way out to the Richmond Field Station working on the solar cars from dawn til dusk. Some members are welding, some sanding molds, some building our oven, some spraying, and some doing strategy calculations. But above all else, everyone is working tirelessly on making Zephyr become a reality. We are putting our heart, soul, and backs into this project and it will be an amazing sight to see drive once we finish it up.

But all that work is dreadfully tiring! You may say, “how do they work all that time without burning out?”. Well we found the solution: BBQ’ing!

chili, lime, shish kabobs, shish kabobs, chili lime, grill
Chili-Lime Shish Kabobs!

The first thing we tried was simple frozen hamburgers; we had to start slow and easy to build up our grilling chops.

Round two was Chili-Lime Shish Kabobs! These turned out incredible too. Marinated the chicken for an hour while we chopped up the vegetables and onions, assembled our creations, and 2.5 minutes on the grill for each of the 4 sides of the kabobs. Cooked to perfection.

Round three was a return to hamburgers but from scratch this time! Minced onions, teriyaki sauce, ground beef, a touch of flour, and other seasonings all mushed up together made the perfect patty. Grilled until fully cooked but still incredibly juicy so all the flavor stayed in. Remember, don’t squash your patties on the grill! It squishes all the juice out of them and you lose the flavor.

teriyaki, burger, cheeseburger, juicy burger, juicy hamburger
The most juicy teriyaki cheeseburger EVER

The food keeps us together and keeps us moving forward on our mission to build the greatest solar car CalSol has yet produced!

Steering Wheel Molds

Sam Cohen with Steering Wheel Mold Designed by Parker Schuh
Sam Cohen with Steering Wheel Mold Designed by Parker Schuh

CalSol has been hard at work over our Winter Break touching up the designs on our shell, chassis, and suspension but in particular Sam Cohen and Parker Schuh on the Controls team have been working on creating a lightweight, carbon fiber steering wheel. To do this we first needed a 3D model of what we wanted the wheel to look like; this was designed by Parker and is shown below.

Steering Wheel 3D Model Designed by Parker Schuh
Steering Wheel 3D Model Designed by Parker Schuh


Once we had the model we needed to CNC (Computer Numerically Controlled) out the molds for the wheel in a high density tooling foam. This is a complex process using a 3-axis milling machine in the Etcheverry Student Machine Shop on campus. The bottom photo shows the process of spiraling inwards removing the proper amount of material as the ball end mill progresses. You can see Sam here holding one of the two molds that we machined – corresponding to the top of the steering wheel.

The next steps are to prepare the molds for the carbon fiber layup and for layup itself, stay tuned for updates on this awesome project!

Great work gentlemen!

CNC Machining of the Molds
CNC Machining of the Molds

Impulse on Display at Chabot Space and Science Center

Impulse at Chabot Space and Science Center
Here is a teaser for what is to come on November 17th at the Chabot Space and Science Center

The Chabot Space and Science Center is having a grand re-opening of Bill Nye’s Climate Lab on November 17th. CalSol was extended an invitation to not only help staff the event, but also to bring Impulse and have it on display throughout the event!

As kids come rolling into the facility they will get to see Impulse front and center in the entryway and for those that have never seen a solar car before it is quite the sight to see. Impulse is literally the kids’ first step of the day at their journey at Chabot because once they talk with us, we will give them a stamp on their lab dash cards, and they can continue on to learn more, play games, and attempt to win prizes!

CalSol is extremely proud to have been invited to and included in an event such as this, so thank you Chabot for the opportunity.

You can learn more about the event and the center itself here at their website:

We will see you there, and don’t forget to look for the students wearing CalSol shirts!

P.S. – As one more teaser to come by and check us out, the view from the facility is AMAZING.

View from Chabot Space and Science Center
View from Chabot Space and Science Center

CalSol Goes to the BERC Symposium

Impulse at the Richmond Field Station
Impulse at the Richmond Field Station

CalSol will be attending the BERC Symposium on October 18, 2012 to show off Impulse to the hundreds of people who have come to discuss the major energy issues and solutions of our time. Come out to see us on display in Lower Sproul Plaza from 6-9pm on Thursday’s portion of the events. You can learn more about the event and purchase tickets at their website:

Some topics of discussion at the event are about shale gas, carbon capture and sequestration, energy subsidies, utility scale solar, and much more! Maybe we aren’t utility scale solar but we have fully functioning proof of vehicle scale solar!

We will see you there!




Cal Homecoming – Go Bears!

Impulse at Homecoming!
Impulse at Homecoming with Pol, Alex, and Sam explaining Impulse to visitors

UC Berkeley just completed its homecoming weekend festivities which included us beating UCLA 43-17 at our brand new stadium as well as many of the engineering teams out on display for everyone to see! Impulse was out in front of Davis Hall on Saturday next to the super mileage vehicle, human powered vehicle, and concrete canoe teams. Hundreds of parents, alumni, and UC Berkeley affiliates wandered by our vehicle, all of them with mouths wide open in awe.

After a few hours of showing off our car to the public we packed up the display and drove Impulse back to the Richmond Field Station. We decided to take San Pablo Avenue instead of the freeway for the return trip because we wanted a more calm drive back. It’s also fun to take city streets because so many more people get to see the car and snap photos of it.

Go Bears!

Ben speaking with some visitors
Ben speaking with some visitors to the CalSol table

CalSol at the Sonoma Indy Grand Prix

Opening ceremony to the Gro Pro Indy Grand Prix hosted by Sonoma Raceway
Opening ceremony to the Gro Pro Indy Grand Prix hosted by Sonoma Raceway

CalSol attended the Go Pro Indy Grand Prix sponsored by Sonoma Raceway and got to show off Impulse to hundreds of race car fans and gear-heads alike. We got a prime spot to display the car in front of the autograph booth for the Indy car drivers and we were placed next to an all electric performance vehicle made by Kleenspeed Technologies. This is a shot of the opening ceremony to the race; they had American flags unfurling, cannons firing, fireworks lighting up, and all manner of celebrities and athletes to start the show off with a bang.

The Return Trip: Fast and Fun

Yellowstone National Park Lower Falls
Yellowstone National Park Lower Falls

On Monday July 23 we visited 3M’s facility to speak with them about all of their new technologies that could help us build our next solar car. We found many intriguing new tapes, velcro’s, adhesives, and coverings that we will definitely be integrating into our future projects. Thanks again 3M for inviting us to drop by!

That event finished up around 1pm and we decided to get going on our return road trip. 250 miles later we ended up in Fargo, ND. The place that we stayed at had an indoor pool which was well used by the team members that night. Not the most fascinating city, so we got up early the following day and set out for a long long long day of driving.

We completed 600 more miles along highway 94 which took us to Billings, MN. That drive was one of the most beautiful scenic drives that we have had in the last 5 weeks. Montana has the prettiest landscapes and scenery by far. We all couldn’t stop taking photos because each ravine, mountain, and plain was just stunning! All in all though this scenic drive was just a way to get us closer to our true goal: Yellowstone National Park.

ASC Day 3 – Another Day Complete

Sorry for the late blog post but racing has kept every one of us busier than we could ever imagine. We did want to keep everyone up to date on what has been happening though!

Finish line of day 3 in Ann Arbor
Impulse crossing the finish line of day 3 in Ann Arbor

We began the day in Mansfield, Ohio in a parking lot at Ohio State University with Oregon State with us. We cooked our oatmeal, we made our peanut butter and jelly sandwiches, and we charged the battery up as much as we could. This is our basic process every morning of racing and it went off without a hook.