MIT Solar Car Team Blog

No More Breaks

Hope everyone had a great Christmas and New Year’s! Our team was able to relax for a bit after finishing the composite layup. After 2 trips to Maine, 60 hours of work, and $55,000, Valkyrie‘s body has been completed! One of our members, Chris Pentacoff, compiled a cool timelapse video of the process. Check it out below!

Now that the team has taken a much-needed break, the next few months until the race are gonna get hectic. We plan to attend the MIT Energy Conference in late February with an almost-completed solar car. This means a completed solar array, mechanical system, and battery pack all integrated with the composite body. Not to mention that we’re looking for a new truck and trailer. Whew. Let’s hope this month is a good one.

Time to ASC: 195 days

Post written by Julia Hsu.

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Valkyrie Layup, Part 1

With a new year comes new members – lots of them – which makes it a perfect time to start from the basics. First on the agenda for the school year is Valkyrie’s body layup. Now, we have to give a big thanks to Custom Composites Technologies Inc. for really helping us out in this department. Not only did they give us a HUGE oven to bake our molds, but also a lot of workshop space to do the actual layup. The hitch? They’re actually located in Bath, Maine. So add a 3 hour drive (give or take traffic and aggressive drivers) and we’re good to go.

Did I mention that Custom Composites Technologies Inc. also made our molds? They’re really great. If you’re new to this, let’s start from the beginning so that you can really appreciate how much they’ve done for us. First, a male mold is made from a CAD model using a 5 axis CNC. Then the female molds that we actually use for the layup are made as the opposite of the original male mold – the bottom is the red mold and the top is the grey one. The thing about the molds is that the red one was sealed and the grey one wasn’t. So we sealed the top one after cleaning the molds thoroughly for anything that could prevent a good quality finish on the exterior of the car. Meanwhile, we started to make templates for the pieces of fabric going on the car and begin to cut the carbon fiber and kevlar..

If you’ve ever had to make templates and cut materials before, you’ll know just how complicated it can be. Between trying to fit lots of curves and taping materials carefully so they don’t fray, the night started to get pretty long. Finally we got around to sealing and Frekote-ing the molds (so that the carbon fiber and kevlar come cleanly off the molds) and we were ready to get everyone on their feet and putting the pieces of the car together. Then we started mixing epoxy.

In case this all is really new to you, epoxy is a mix of a resin and a hardener, or in other words, a little more work than pulling out a gluestick. Also, you want to mix it constantly and in smaller portions to keep it just right for applying to the fabric. As a result, we had an entire work table covered in plastic cups and epoxy which smelled a lot like fish (in case you were wondering). In hordes around the molds, people intensely applied epoxy all over the carbon fiber/kevlar (carbon fiber on bottom and kevlar with some unifiber carbon fiber on top). Now don’t take this as an easy task either – the canopy just about gave some of us migraines as we tried to fit the pieces we had just cut from templates, but after some quick modifications, things begin to fit properly.

Finally, we just had to vacuum seal both molds and stick them in the oven as we watched the sun rise out of windows that we didn’t realize were there before. Done at 7am. Not a bad 8 hours of work. Granted, that wasn’t the initial plan at all until the truck with our prepregs got delayed. Now mark your calendars – Valkyrie’s body should be finished this Saturday, November 2!

(Time lapse coming soon!)

Post written by Cyndia Cao.

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ANSYS, molds, and CFRP

You’ve heard the plans from Julia: we race next in the 2014 American Solar Challenge and shortly afterward the 2015 World Solar Challenge! We’re taking this extra time for development that we have been wanting to do for a while but haven’t had the manpower, time, or money. We’ll be running in the 2014 ASC with a new motor, giving us a noticeable bonus in power – the equivalent of eight to twelve additional solar cells. Our array encapsulation and modularization is maturing aggressively, but I can’t talk about that just yet . . .

Valkyrie, as we are referring to the ASC 2014 vehicle, will be the first of our solar cars with an all-composite chassis. This was a decision made with a great deal of consideration. Working with steel as a primary structural material has given us a great deal of flexibility in design and freedom in construction while meeting a high standard of crash protection. What we hope to achieve with a composite and largely CFRP (carbon-fiber-reinforced plastic) structure is even greater design freedom, even greater crash protection – CFRP can have an order of magnitude greater specific energy absorption than steel – at the expense of slightly less leeway and forgiveness in construction. Our toolmaking has improved to the standard we require for a composite/CFRP car and we are excited about improving those methods even further.

Speaking of molds: we are looking for a new home for Chopper del Sol’s molds! The molds reflect the 2012 ASC version, with straight front fairings. Taker will have to arrange shipping but otherwise they are likely free of cost. For more information, contact gosolar@mit.edu.

I’d like to welcome our newest sponsor, ANSYS. ANSYS’ FLUENT package will be the principal fluid simulation suite for the development of Valkyrie. Without well-packaged, flexible, and relatively computationally inexpensive modeling tools like FLUENT, the things we do would be significantly less tractable, more expensive, and more time consuming.

George
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Starting Anew

Hello everyone!

Sorry for the lack of updates, our team has been busy designing our next solar cars! After much consideration, the MIT SEVT has decided to compete in the 2014 American Solar Challenge with a three wheel vehicle. In conjunction, we will also be designing and constructing a four wheel vehicle in preparation for the 2015 World Solar Challenge. There will be plenty of work, but we want to race competitively and still be prepared for future races. With the change in design from 3 wheels to 4, there has been a lot of discussion about the overall structure and design. Currently, the aerodynamics team is working on simulations and designing the car shape. Here are some cool pictures of what they’ve been up to:

Simulation performed by Alastair Gregory.

Simulation performed by Alastair Gregory.

On the electrical front, a motor change is in order. Currently, our team is looking into Mitsuba and CSIRO as viable options. However, we won’t know for sure which motor to use until we perform some dyno testing.  On the mechanical front, the team is currently designing the suspension system to be improved from the last system. Overall, the team is excited to begin fresh and hunker down to build two vehicles in three years!

WOO!
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Thanks to Our Sponsors!!

Now that we’re at the beginning of another design cycle, we would like to give all our sponsors a big thanks to show them our appreciation. We wouldn’t be able to compete in solar car races if it wasn’t for the time, material, and donations given to us by our sponsors. These companies are kind enough to help out with molds, composite materials, PCBs, electronic equipment, batteries, and software – to name only a few things. On top of that they are truly interested in our team, and offer advice and encouragement whenever they can. Our sponsors are all great companies that excel at what they do, and are generous enough to help student teams like us build something as interesting and exciting as a solar-powered car. Check them out below!

Thanks Genasun and EMA Services!

Now that things have settled down a bit and Chopper is back in Boston, we would like to thank Genasun and EMA Services for all the invaluable help they gave us in constructing our battery pack.

First, a huge thanks to Genasun! Alex MeVay and Alexander Hayman of Genasun ( also alums of the team) designed our pack and battery protection system. They were also kind enough to offer us a place to construct the pack as well, and we spent several long days putting together all the batteries, PCBs, and wire cabling. Check out some pictures from the assembly party below!

David screws hardware into some of the PCBs 

 Kelly checks the alignment of the battery tabs before placing the top PCB 
Close-up of the batteries

Julia cuts zip ties holding the two PCB panels together. Almost done!


And of course, another huge thanks to EMA Services. who assembled our BMS boards free of charge. Thanks for helping us out, even during your vacation time!



The team is ready to get started designing again, and we look forward to working with Genasun and EMA Services, as well as all our other sponsors, for our next build cycle. Keep checking the blog, as we’ll be posting updates about our progress. 

More 2012 ASC Photos

Chopper del Sol’s top basks in the sun to get a nice morning charge.

Chopper del Sol in action during dynamic scrutineering.

Team members quickly push the car to the beginning position.

An official looks over the car before dynamic scrutineering.

The insides of Chopper del Sol.

Dillon practices the driver egress test.

The electrical team works on the battery pack.

The team prepares for the afternoon charge.

Officials look over the car as Chopper undergoes a morning charge.

The team poses at some farmland near Normal, IL.  

Our awesome America sticker on the nose of Chopper.

The team prepares to load the car into the trailer.

Sweet MIT logo on our fairings.

Dillon prepares to undertake dynamic scrutineering.

The team checks out the car at the finish line in St. Paul, MN.

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Fashionably Late

After arriving in Goshen, IN, the next stage stop was Normal, IL. Day 5 began alright, but about half an hour later, the car’s motor shut off and would not restart. The electrical team began to debug the problem in a nearby grass lot. However, to make the situation even worse, a thunderstorm poured down rain and created an unsuitable working environment. With no other options, the team decided to trailer Chopper del Sol to Normal, IL and try to debug the problem there.

The last and final day of ASC required teams to cross the finish line at St. Paul, MN. After arriving in Normal, IL, the electrical team spent all night fixing a battery pack issue and successfully had Chopper del Sol driving around….at least they thought so. About forty-five minutes into our drive to St. Paul, MN, the car’s motor shut off again and would not restart. Since the last stage stop closed at 4PM, the team had two options: push the car across the finish line or try to debug the problem and drive in with pride. True to the MIT spirit, the team decided to fix the issue and try to make the stage stop before 4PM.

Since it was raining heavily yet again, the team trailered Chopper once more to a parking lot about 20 miles from the finish line. At 2PM, the electrical team quickly got to work. After an hour and a half, the electrical team had successfully fixed the issue! With only thirty minutes to spare, the team sprang into action! By 3:55PM, we had driven 17 miles and only had 3 miles left to reach the finish line. Thanks to a MIT alumni at the finish line, the officials extended the finish line closing to 4:10PM. With only a few minutes to spare, the MIT team rushed forward to reach the finish line. At exactly 4:08PM, Chopper del Sol finished the 2012 American Solar Challenge.

The team is all smiles as MIT officially finished ASC in St. Paul, MN.

Despite all the setbacks, the MIT team never gave up. Even with all the late nights of work and despair, every minute of the journey was a valuable and fun experience for all the members. The 2012 American Solar Challenge was an underdog story that will never be forgotten. 

We would like to thank all our sponsors and fans for making 2012 ASC possible! Without your support, none of this amazing journey would have been possible. More pictures of the race and team will be uploaded to the blog shortly.
 
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Race Update: Day 4

As we said in our last update, Chopper Del Sol experienced a moderate crash on Sunday, the second day of racing for the American Solar Challenge. It came on a day that would have allowed us to move up to 2nd or 3rd place if we had been able to maintain our pace. But with the goal of winning the race a  very, very distant hope (we were penalized almost 1300 minutes for trailering our vehicle because the crash occurred so close to the start of the stage and the penalty is based on how many miles the car is trailered), we have set out with a new goal: to finish this race.

We arrived in Ann Arbor on Sunday afternoon and quickly set up a place to work in the parking lot of our hotel. The crash thankfully only damaged the composite body and didn’t affect anything structural. So we set out to patch up the broken composites and the slight jigsaw puzzle that the lower front part of the body had become. We worked through the night and all of the next day, and by the end of the day we had a functioning body. Meanwhile, our electrical team were working on the battery and some other issues that came about after the crash. The work continued until Tuesday morning, the start of the next stage. At 9:10am, Chopper Del Sol was again in one piece and was out on the road, prepared for another day of racing.

We headed out from Ann Arbor in the beautiful, mostly clear day. The heat was quite extreme, about 100 degrees fahrenheit (and even hotter in the car), making it quite difficult on our drivers. Julia started out the day, driving 170 miles to Kalamazoo, MI, where we had a checkpoint and Western Michigan University. The heat proved to caused some temperature issues with our battery pack, but beyond that, Chopper ran quite smoothly considering what had happened 2 days ago. After the check point, Dillon took control of the car and drove it to Goshen, IN. We have been able to pass a number of teams in this stage, although our overall time is still far behind the other times because of the penalties that we have received. But we are happy to be back out on the road and racing our solar car. Tomorrow morning we will head out to Normal, IL, the next stage stop.

More updates will be coming soon with pictures showing the work that has been done on the car and everything else that had been happening. Right now, we all need to get some rest in order to be ready for another race day tomorrow. Be sure to follow everything that is happening at http://americansolarchallenge.org/.

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ASC Day 1 & 2

As you might have read on our blog, we have been hard at work preparing for the American Solar Challenge 2012. We were very excited to start the race in Rochester yesterday, July 14.

Out of twelve teams, we were able to gain four positions over the course of the first day of racing while using relatively little battery due to good sun.

Today, we woke up to a thunderstorm that only worsened as the race day continued. Unfortunately, as we entered Ohio, the solar car hydroplaned and hit a pole on the side of the road. Our driver was well-protected and completely unharmed. However, the car sustained significant damage to the composite upper body.

The team is working diligently to repair the car and get back onto the road as soon as possible. We are confident that we will be able to finish all repairs by tomorrow afternoon and continue the race on Tuesday morning.