Marc has kindly sent me a little more info on what you should be looking for. Here are some suggestions:
The one that everyone has been using over the last 5 years or so is the Faulhaber 2232 6V which is a precision coreless dc brushed motor manufactured in Germany. This motor’s characteristics make it a great choice and definitely the one I would recommend using (although there are a couple of others that could potentially challenge it). The 2232’s quality however comes at a price and suppliers like Scorpio Technology or Erntec in Victoria have been selling this motor for around $150 each in recent times.
Many different solar car designs will work well providing that the build quality is there so be sure to mention this to your students (bad build quality is the most common reason why a lot of cars don’t perform up to their full potential). Both 3 and 4 wheeled cars have won the national event over the years so either will work although last year 10 of the top 11 cars were 3 wheelers. Teams down here in Tasmania usually opt to go for a 3 wheel design with all-wheel trolley wheel steering and this is what I would recommend as it is most efficient. Most Victorian schools and quite a few NSW and WA schools go for a 4 wheel fixed wheel design similar to the example car seen in Ian Gardner’s design hints pdf. The reason for this is that these kind of cars are probably easier to build and virtually all the components can be purchased from a company in Victoria. These cars can also be made to perform at a high level.
Don’t forget car aerodynamics and encourage the teams to keep this in mind when designing their car bodies. The single biggest opposing force that a top model solar car faces at top speed is the air drag and so a more streamlined design will go faster. The difference between having good and bad car aerodynamics on an otherwise sound design can sometimes be up to a full second in good sunlight and this translates to around a 7m – 8m difference on the track. Keep the designs nice and streamlined and don’t just concentrate on the front of the car which is cutting through the air. The rear is just as important as square ends will lead to flow separation and turbulence. Have a look at some of the life-sized solar cars for inspiration!
I’m not sure what kind of solar panels the teams were looking to use this year but I would perhaps suggest having a bit of a look at the option I have listed on the CHALLENGE HELP page. Since the students are new to the challenge I would strongly advise them to run with an electronics unit and for this you want a solar panel that has an output of around 14-18 Volts.
If you have any questions send them to me and I will forward them to Marc.