The Bridgestone World Solar Challenge is the world’s premier solar powered challenge. The BWSC happens every 2 years and this year is the 30th anniversary from its beginning back in 1987. Teams mainly from Universities, come from all over the world to compete in this challenge. We from the Jönköping University compete with 33 teams. This journey is a 3000 km journey straight through the Outback of Australia. We race from 8:00 in the morning until 17:00 at night, camping out wherever we finish for the day. This competition is all about engineering capability and testing new limits. Teams have a little over a year to design and build our race cars.  For the JU Solar Team, one of the most valuable resources we have is time. 

One of the most valuable resources is time

Normally when talking about key characteristics of building a solar powered race car, one of the first things that comes to mind is the weight of the vehicle. In 2015, our team chose to build our car chassis and body entirely out of carbon fiber. While at first glance this may seem like a wise choice due to the characteristics of strength and weight of carbon fiber.
However, our alumni from the previous generation ended up learning some of the consequences of working with carbon fiber. 

First, carbon fiber is very expensive to work with. Also, it is very time consuming to build with carbon fiber and our team had only enough time to build one body so it had to be right the first time. Unfortunately, about halfway through the build, the car was shaping up in a less than ideal manner and we became aware that we had used too much epoxy and was weighed significantly more than anticipated. To add pressure, the team still had other components and systems that they wanted to test such as the motor, battery, suspension and many more that were not testable until the carbon fiber body was finished. The end result was a combination of suboptimal choices that we knew we could improve on next generation.

Docol steel is the perfect solution

For 2017, the JU Solar Team set out to learn from past mistakes. We decided that for this year, we wanted to work with a material that saved us time. The choice became quite clear for us, using lightweight automotive grade Docol steel was the perfect solution. Our car is still using a lightweight carbon fiber shell for the aerodynamics but the core of our car is all steel.

With steel, we have been able to design and weld out first prototype within a few weeks. This chassis served as a test bed, allowing us to test and develop other key components of our vehicle simultaneously. This extra time allowed us to improve other areas of our vehicle and has been crucial this year. It is as if we have extra months of time that other teams will not be afforded. While being able to test different areas of the vehicle has been significant, the benefits don’t end there. Given the easy nature to fabricate steel, we have been able to go through a series of prototype designs of steel chassis, adding strength while reducing weight. Our finished product was a steel chassis that weighs only 25 kilos. Our target weight of Solveig is set to be at 165 kilos, a massive improvement from the 230 kilo weight of our 2015 race vehicle Solbritt. 

The Bridgestone World Solar Challenge involves some of the most reputable schools from all around and in every sense of the word is a true engineering challenge. The JU Solar Team is very proud to have support from Docol to use the best solution for our vehicle. With their support, we will set off to do better than ever before.

John Ingold
Management Team Leader, JU Solar Team

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