We have been out of radio contact with our underdog University of Western Sydney Solar Challenge team for the last few weeks, that’s because there have been some major changes in the works. Champion yacht builders, engineers whose credits include James Cameron’s award-winning submarine, and technology from Australia’s peak science organisation are all coming together to snatch victory from better funded rivals. This is the Solar Challenge team, proudly supported by Gizmodo.
Support the UWS Solar Challenge Team! If you have marketing/sponsor dollars (hello car makers, telcos and electronics multinationals) or engineering support to donate, please contact Greg at UWS Solar Car.
The Challenge
25 engineering and industrial design students from UWS are working together to build a car powered entirely by the sun, ready for a race across the spine of Australia. In October next year the team will race the car from Darwin to Adelaide as the underdog, pitted against better funded rivals.
Team Diary: Week 13
When we last checked in with the team, they were showing off the half-finished car that had been the best hope for victory. The resin was still drying, the design had been tinkered with and the rules hadn’t been kind. In reality, this wasn’t the vehicle that was going to win the Solar Challenge.
The team sat down and made the tough decision that the existing car they had was going to be the prototype for the final build, and that they would start again from scratch to completely overhaul the final product.
New designs mean new ideas, and these new ideas are coming from some of the most talented designers and engineers in the world. One of the team members worked on the submarine that safely carried James Cameron down to the bottom of the ocean floor, and into the record books. Another member — the designer — worked on some of the world’s most successful yachts, including the Wild Oats and the Alfa Romeo team boats for the Sydney to Hobart races. These are genius-level individuals, all working towards one goal: first place.
The New Design
The team had to face facts: the old design was heavy, inefficient and slower than it needed to be. The resin had soaked into the shell, making the car heavy, the motors weren’t running as efficiently as possible, and the driver was in the wrong position. Something had to be done.
To comply with the new rules, the driver position has now been moved forward, making for a 9 per cent increase in aerodynamic stability, and the chassis is getting a complete overhaul. The old material slowed the car down with unnecessary bulk, and the team’s designer, Andrew Whitney — the ex-champion yacht contributor — decided upon a Nomex core with a honeycomb weave. For those playing at home, Nomex is the stuff Batman’s suit is made out of.
For those of us in the real world, though, Nomex is used in aviation because it’s lighter and stronger than foam, and has the added benefit of not soaking up epoxy resin like the last chassis did.
The new car will also ditch the single motor design and move towards two motors. This is a tough decision for a car that needs to focus on low-energy consumption, but mechanical lead Albert Mahoney and James Cameron submarine-contributor Ben Grant decided that this was the right course of action. Here’s why:
Mechanically it had a whole bunch of advantages:
• The spring rates and adjustments on the rear shock absorbers were now the same across the back with an equal unsprung mass on the back wheels. This makes life much easier for the mechanical team who needs to get the balance and handling correct on the car.
• Regenerative braking is now much safer, being balanced over both rear wheels instead of one.
• The motor controls have a built in function to allow active differential speed control of the car. So when we go around a corner the inside wheel will have to turn slower than the outside wheel. So we can tweak the differential speed to actually improve the cornering ability of the car not that we expect to be doing much circuit racing other than scrutineering.
The only problem with the new engine system is that it’s going to cost an extra $18,000 to purchase, meaning the team needs telco, motoring, scientific and/or corporate sponsorship to get to the start line and show just how good Australian backyard engineering still is.
The build rolls on!
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Our team still needs sponsors, so if you’re keen to help the underdog get a leg up in this amazing contest, contact Greg at UWS Solar Car.