Bringing A Solar Car From Concept To Reality

Solar cars may sound like something out of the future, but students at the University of Michigan, and all over the world, design, build and race them each year. In fact, these aren’t just tiny school projects – these teams are sponsored by major auto manufacturers, and each car often ends up costing over a million dollars to create.

Recently, the University of Michigan Solar Car Team unveiled their 2013 car, “Generation”, at the GM Renaissance Center Winter Garden on June 18th to great fanfare prior to the upcoming World Solar Challenge in Australia.

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The World Solar Challenge will be attended by over 47 teams from 26 different countries and covers over 1,800 miles.

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While this is a friendly competition, desire to win is still fierce among teams. Many of the design and mechanical components of the Generation vehicle are top secret understandably, so we can’t say too much about the guts of the car. We were, however, able to speak with Operations Director and student Aaron Frantz, who gave us details of the current vehicle.

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Generation was designed and built over the course of a year by over 100 student team members and is designed to be as lightweight and energy efficient as possible.

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The University of Michigan Solar Car Program has four divisions dedicated to the successful creation of their Solar Cars:

Engineering: Composed of engineers who focus on the aerodynamics, body, mechanical, electrical and micro-electrical systems.

Business: Markets and advertises the team in order to procure the necessary resources to construct the state-of-the-art solar electric vehicle.

Strategy: Maximizes the performance of the vehicle on race day by performing extensive weather tests and also designing custom software to analzye and predict the most efficient way to run the race.

Operations: Takes care of all logistics and also maintains a safe and effective camp abroad for several months.

Precision Board Plus PBLT-20 and PBLT-30 HDU, donated by Coastal Enterprises, was used to make male plugs for the upper and lower surfaces, canopy and chassis. After being CNC machined by Excel Pattern Works, the Precision Board was coated with Duratec for a smooth finish before being sprayed with fiberglass by General Motors to create female molds which were then used to make carbon fiber tools.

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Interesting facts about the car:

  • There is no air conditioning, only a small vent for the driver to get fresh air
  • Drivers are switched after no more than 6 hours
  • The car is equipped with a speedometer and a rear-view camera
  • A chase and lead vehicle accompany each solar-powered car throughout the course of the race
  • The University of Michigan chase vehicle houses the Crew Chief and Head Race Strategist, who monitor all aspects of the solar vehicle using high-tech equipment through the entire course of the race
  • The car has absolutely no transmission and is powered by a single “in-hub motor
  • Teams may only race between the hours of 8:00 AM to 5:00 PM, camping overnight where ever they happen to be at 5:00.

Until the start of the World Solar Challenge in October, Generation will be undergoing extensive testing to ensure safety and reliability for the race.

Be sure to check back in this fall for an after race update and pictures from the Australian Frontier.

Precision Board Plus PBLT-20 machined by Excel Pattern Works prior to being coated with Duratec and sprayed with fiberglass:

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Hybrid SAE Racing: Can Electricity & Combustion Work Together?

The University of Michigan Formula SAE team recently competed in the Formula Hybrid International Competition. Closely related to the Formula SAE competitions we have written about in the past, Formula Hybrid is widely regarded as the most challenging of the SAE CDS competitions. As a matter of fact, an unofficial Formula Hybrid slogan is: “Formula Hybrid – Everything else is just too easy!”

Michigan Hybrid SAE Car

The competition includes acceleration, autocross and endurance events. Student teams design and construct a Formula Hybrid car powered by electricity and combustion, and are responsible for building all aspects of the car from high power electronics to mechanical systems.

One of the most impressive features onboard the University of Michigan car is a system known as the dSPACE MicroAutoBox II, which is an electronic brain designed to regulate the rpm’s of the two electric motors onboard. The electric motors power individual front wheels, which coupled with a 250cc combustion engine, enable the car to achieve superior acceleration. This feature earned U of M students the Chrysler Innovation Award, which came with a prize of $1,000.

Hybrid SAE Car

Formula Hybrid Co-Captain Kara Stoltze was kind of enough to put me in touch with A.J Jayasinghe, Aerodynamics Division co-lead, about just how the students designed this car. Body design was created using Solidworks, and the aerodynamics were analyzed using X-Flow, which is a software program by Next Limit Technologies.

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After the car was designed and the students were sure they could make a mold based off the design, they used a CNC machine to create the molds using a combination of Precision Board Plus PBLT-10, PBLT-15, PBLT-20 and PBLT-30, donated by Coastal Enterprises. The molds were then coated with Duratec and allowed to cure before using them as plugs for the aerodynamic body and other interior components. According to Miles Justice, also Aerodynamics Division co-lead, the Precision Board Plus worked great because of how fast it machined and how easy it was to laminate together.

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Unfortunately on race day, the discovery of a fuel tank leak and a short in the cooling system during a pre-race technical inspection forced emergency repairs on the students before they could enter the competition. This caused them to miss the first two dynamic events with significant delays ultimately affecting their overall score. Continuing on and fighting hard, they still managed to take 4th place overall out of 12 competing schools.

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According to Kara, “The biggest challenge with Formula Hybrid is, by far, integrating the two powertrains to have a succesful hybrid. Getting both powertrains to work is one thing; getting them to work together is a whole different ballgame.” Coastal Enterprises would like to congratulate the entire University of Michigan Hybrid SAE team and wish them luck on next year’s car!

Hybrid SAE Car

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Solar Powered Car: Tomorrow’s Transportation?

The University of Michigan Solar Car Program is leading the nation in the advancement of solar car technology. With help from major companies, including General Motors, the team is moving steadily forward to make solar cars a reality. They recently won their fourth consecutive North American Solar Challenge with the Quantum Solar Powered Car, and placed 3rd in the World Solar Challenge. All molds for Quantum were made using donated Precision Board Plus HDU.

The North American Solar Challenge is an intense 8-day competition spanning over 1500 miles, with the solar cars navigating America’s highways amid traffic. As an all volunteer program, over 100 students helped in the 2 year build process of Quantum. The very first solar car competition was held in 1990, and the first solar car winner (also University of Michigan) had a top speed of 24.7 mph. In comparison, the 2011 Quantum solar car can reach up to 105 mph!  With allotted race hours from 9-6PM, Quantum finished 10 hours ahead of all the other cars under solar power alone in the 8-day competition.

We had the opportunity to speak with students Cole Witte, Engineering Director and Eric Hausman, Operations Team Member, about some of the details of Quantum. First off, the car does have a battery in case of a breakdown or inclement weather, and can go from 2-300 miles on the battery alone. There are no pedals and all acceleration controls are located on the steering wheel. Quantum was sponsored by General Motors this year, who provided an entire caravan of support vehicles.

When asked why this years car was able to perform so well, Eric stated that this year had the best aerodynamic design ever. They took full advantage of a free design consultation from Exa, a simulation-driven design company. For the most part however, the work is done entirely by students. Most of the students are mechanical, aerospace, electrical engineering or computer science majors.

There are 4 subdivisions within the engineering division on the team, and each are assigned to various systems of the car:

  • Mechanical – Responsible for the design and manufacture of the structural components of the car (composites, suspension, brakes, steering etc.). Pretty much every point of the car will be touched by a mechanical engineer at some point in the construction phase.
  • Aerodynamic – Responsible for designing and analyzing the outside aerobody of the car, making the most aerodynamic car possible.
  • Power and Electrical – Work with all high voltage systems on the car, including the battery, solar array and motor.
  • Micro Electrical – Design all of the low voltage control systems on the car, and write most of the software used across the car.

Here is an interesting interview with Cole Witte, Engineering Director for the 2013 project:

1. What is your role in the Michigan Solar Car team?

Cole: My role on the team is the engineering director for the 2013 project. As the engineering director I am responsible for coordinating the design, development and manufacture of the 2013 solar car. This involves working directly with over 50 engineers to ensure integration of all the vehicle systems.

2. How long have you been a part of the team?

Cole: I’m starting my 4th year with the team. I joined the team my freshman year in the fall of 2009 as a mechanical engineer, raced with the team in 2010 in the North American Solar Challenge, worked on the development and manufacture of Quantum, and traveled to Australia in the fall of 2011 to race Quantum in the 2011 World Solar Challenge.

3.  Precision Board Plus was used to make molds for the Quantum Solar Car, how did the mold making process work?

Cole: For all of our large scale molds (vehicle, body, chassis, etc.) they used a 2 step mold making process. A positive pattern of the car is CNC machined from Low Temp Precision Board Plus, sealed and finish sanded. From there they use the pattern to create a fiberglass mold of the car. The mold is then removed from the pattern and used to create the final composite parts. For the small scale molds (wheel covers, ducting, electrical enclosures, etc.) we have the mold directly machined from High Temp Precision Board Plus, which we then seal and polish to the final mold surface. We use the High Temp Precision Board Plus for this process since the composite pieces are made using pre-preg materials and cured in an autoclave or oven.

4. What benefits did you notice by using Precision Board Plus?

Cole: Precision Board Plus allows us to get a very precise mold surface for our direct machined molds. Often times they come off the mill with a very finished surface that only requires final polish sanding. The dimensions and geometry are very critical with all of our parts, and with using the high temperature material we’ve never had issues with expansion or deformation even at high pressures in the autoclave. When it comes to the large patterns that we manufacture, being able to maintain a constant surface finish across the whole part is critical, with little to no change due to material variation.

5. This is Michigan’s 4th consecutive national win, and you are currently in the process of building the 2013 car. Will we be seeing any drastic changes?

Cole: There are definitely   big changes in store for 2013. The World Solar Challenge has changed the regulations this year and now require 4 wheels (instead of 3), so it is a major game changer for all teams.

Additional information can be found on the University of Michigan Solar Powered Car Facebook page.

Many, many more pictures can also be seen on the UM Solar flickr page.