Solar Freaks

Thanks for the correction.

So ah... Who won?

amd when will the details be made avalible?

The top four were:

1st Box Hill High School Victoria NFG
2nd Melbourne High School Victoria Velox
3rd Belridge Senior High School Western Australia Solar Flair V
4th Moorebank High School NSW Raptor

Well done to all these cars and everyone who competed.

Congratulations to Box Hill.

How did the WA cars go and what was the weather like?

The winning car from Box Hill was called NFG.
Results will be up on the Tasmanian website within the next few days.

The top 4 seeds from the time trials on Saturday were all from WA. All these 4 made the Quarter Finals, however only Solar Flair V from Belridge SHS reached the Semi Finals.

miseli

thanks miseli

the weather on sat was fairly poor and stayed around 40%.

on sun the sun arrived and varied between 80-100% all day.

it was great to watch the cars post some really fast times.

Ok thanks, so that means four WA cars finished in the top eight?

Yes, 4 WA cars finished in the top 8 and 1 in the top 4.

I will be uploading the full results of the main and plate events up on the Tasmanian website shortly. You will notice that some of the sunlight percentages that are going to be listed are recorded as being over %100. In fact, most of the races when the sun was out were recorded at being over %100. This was either because the solar cell meter used was not calibrated properly, and/or, the clouds were helping to concentrate the sulight.
A number of the scrutineers mentioned that this second cause may have been quite possible, as cases of sunlight being magnified up to %200 have been recorded during the world solar challenge.

Anyway, the fastest lap off the competition went to Velox from Melbourne High School with a time of 16.18 seconds (new track record) in 122% sunlight for the 95m 1 lap. Yes, that's right, the track from the start around to the finish at the end of the hill straight is not 100m. The track drawings on the Tas website will tell you this. This was confirmed after a member from the National committee went around the track with a trundle wheel.

I can however also add that a test car that I had built for this year's rules, fully balasted but without egg and run for the first time on the Sunday of the event, recorded an unofficial lap time of 15.75 seconds at 108% sunlight.

If anyone out there has any photos or videos from the event (cars in particular), please contact me and I may be able to stick some up on the Tasmanian website. Just go to the contacts page on the Tasmanian website and send me a message.

miseli

miseli wrote:recorded an unofficial lap time of 15.75 seconds at 108% sunlight.miseli

OUCH!

what were u doing different to all the other cars? Or was it just a better car?

I expect one or two other cars may have also been able to crack 16 seconds given the right conditions. Some were not given the chance to run in over %100 sunlight. I would have liked to see the Winthrop car at over 100%.

Queechy high school from Tasmania recorded a 16.24 second lap in 90% sunlight a couple of years ago in Sydney 2006. This gives a projected time of about 15.85 seconds at 100%, so there have been cars in the past that were also up at this standard.

The fill factor on the car's panel was quite good, giving me slightly less ballast than some of the other cars. The panel output was about 6.6 W at 100% sunlight, giving a total car weight without egg of about 1075g.
The car was not super light (about 370g without egg and ballast).
I was going to test John Jeffery's maximizer up against the Easy max unit, but didn't get around to it. The lap was done with the Easymax. I suspect that there will not be a great deal of difference between the two in good sunlight.

Photos, 3D Autocad drawing files and screenshots of the car will be uploaded onto the Tasmanian Website sometime in the near future for everyone to have a look at.

miseli

I forgot to mention that the motor driving the car was a faulhaber 2232 6V motor. I have a Maxon with similar characteristics, but didn't get the chance to compare the two.

yes, it would be very interesting to compare the maximisers and motors against each other. the only problem is that it is almost impossible to get 2 races in exactly the same conditions. ideally, 2 identical cars would need to run against each other, but to get 2 cars the same is also near impossible. there will always be slight variables that we cannot control, but we can get a fair idea. from teh tests that i have done i believe that teh faulhaber is a better motor than teh maxon i have, even though it has a higher internal resistance. as for the maximisers, they easymax brings a noticable difference to the acceleration and top speed of the car.

miseli wrote:Queechy high school from Tasmania recorded a 16.24 second lap in 90% sunlight a couple of years ago in Sydney 2006. This gives a projected time of about 15.85 seconds at 100%, so there have been cars in the past that were also up at this standard.

You need to take into consideration the fact that this year the weight of the solar panel was measured differently, and resulted in higher weights than previous years.

miseli wrote:I was going to test John Jeffery's maximizer up against the Easy max unit, but didn't get around to it. The lap was done with the Easymax. I suspect that there will not be a great deal of difference between the two in good sunlight.

Correct. The Easymax has similar performance to the Box Hill maximiser (they both use synchronous buck converters), The main benefits are seen during acceleration, or low light, while the output voltage is low, other than that, the performance differences are negligible.

miseli wrote:I forgot to mention that the motor driving the car was a faulhaber 2232 6V motor. I have a Maxon with similar characteristics, but didn't get the chance to compare the two.

Which Maxon are you talking about??
Is it the one i mention here? faulhaber-vs-maxon-t8.html

Tony,

The panel I was using on the test car was the same that was used by a past car from a fellow team member back in 2006 at that same Sydney event that Queechy participated in. This panel power can be found on the Tasmanian Website on the RESULTS page by downloading the AIMSCC 2006 link. The car name is Frank and the power and volts at max power columns are mixed up. This same panel back then was measured at 6.52 Watts, so this year's 6.6 Watts 50% measurement was virtually unchanged.

The maxon that I have is from quite a few years ago and can also be found on the Tasmanian Website on the CHALLENGE HELP page under Maxon_RE-max_21. The Model I have is the 9V 221011 and has a significantly larger terminal resistance than the faulhaber 2232 6V. The faulhaber is the superior motor, but I would still like to compare the two, as they have some other similar characteristics.

miseli

miseli wrote:I can however also add that a test car that I had built for this year's rules, fully balasted but without egg and run for the first time on the Sunday of the event, recorded an unofficial lap time of 15.75 seconds at 108% sunlight.
miseli

That's very impressive, what kind of steering set-up does this car have?

Nemphis Mensa,

The car is rear wheel driven and has three wheels. All three wheels castor like trolley wheels. The guides are off-centre, so that the three wheels are able to form an isosceles triangle and give maximum stability. The setup is very similar to the Winthrop car.

I will be placing a few images on the Tasmanian website once I get the time.

miseli

miseli wrote:Nemphis Mensa,

The car is rear wheel driven and has three wheels. All three wheels castor like trolley wheels. The guides are off-centre, so that the three wheels are able to form an isosceles triangle and give maximum stability. The setup is very similar to the Winthrop car.

miseli

do u find that the carstoring wheels are an efficiant form of steering? - its like the bearings driving the car more than the track guiding the steering to drive the car.

Also what is the benifit of haveing the rear wheel castor (is it like the pics of Ecstacy's frame?)

Have a look at this thread.

corner-drag-t114.html

Yes, the original ecstasy had all trolley wheels.

Hello all,

I would firstly just like to second Tony that all trolley wheels are the most efficient model solar car setup. Not only does it prevent steering drag around corners, but also the possibilty of increased drag along the straights. Along the straights you say? Well, cars with fixed wheels and axels are often not aligned properly resulting in added drag and slower race times. Tests performed by Ian Gardner in Victoria confirm this.

Here are some 2D and 3D autocad drawing files from the 2008 test car that posted the 15.75 second lap time at last years nationals. They are not 100% identicle to the actual car but are pretty close.




For those of you that do not have access to Autocad, I will upload some screenshots or rendered images in the near future.

I will also include some actual photos shortly.

miseli

OK everyone,

Here are some autocad images of the 2008 test car.







I hope to include some actual photos once I get my hands on a half decent camera with some good resolution.

miseli