F1 in Schools Help - basizeland's project

[basizeland]

Thanks everyone our car ran a time of 1.049sec but it was really humid which slows the cars down because the air is thicker.

We had a promo run with the current Australian record holder which set a time of 0.985sec and we beat that car so our car would have been really fast if it wasn't as humid.

[Smokes]

Hi Brett,Just a thought on the bearings

We currenlty have found using finishline cross country chain lube and ceramic bearings the best way to get really free spinning bearing in 1/12th scale rc cars. The added bonus it the oil is a wax so doesn't attract dirt. You could also try trinty royal oil ptfe based oil as well. but this seem to attract dirt(rubber) after few runs if your careful so you have to wipe the bearings down really well after using this stuff. 1 would recomend asking a few fast guy a your local rc club what there tricks are.
it might help to get your time under 1 sec.

[ashf1mclaren]

hi brett do you know what makes the razorbacks car so fast? is it bearings? or something else?

[ashf1mclaren]

hi again brett was your car long or short?

[basizeland]

Hey Smokes we have ran full ceramic bearings before but they were really expensive because we needed them to be smaller than 10mm in diameter but we used ceramic hybrid bearings at our national final where we washed out all lubricants so that it was running dry because we have tried WD-40 and silicon spray but they didn't help at all. I will have to give the chainlube a shot because there is no harm in trying it.

I am not sure why the Razorbacks car was so fast because it has a weird design but there was two other cars that ran under a second on the same day and they were all completely different with one of them having bushes and the other 2 bearings. It was held in Canberra where the humidity was low on this day and it is about 800m above see level which makes the air thinner.

Our car is 190mm long so its sort of in the middle

[ashf1mclaren]

thanks basizeland what time did the razorbacks and the other car run at on the day and what was your time under 1 secound?........i guess the speed seems to come from a extremely efficient bearing design and with a small amount of fancy aerodynamics, did you have any evidence that a shorter car was faster or the reverse?

[basizeland]

The razorbacks ran a time of 0.985, Akula ran a time of 0.988 and Redline Racing ran a time of 0.989. We got a time of 1.049 but they ran under a second at the end of 2008 and we did this time in 2010. The reason that we ran a shorter car was to save weight.

[ashf1mclaren]

hi brett i have found the f1 in schools australia post video round up i also shows you car vs the razorbacks briefly
http://www.youtube.com/watch?v=MA_qL5yA57s
stop it about 1.05mins then your car is on! looks great also have you got any photos you took of the cars on the day? if so could you post them please

[mep]

Hey everyone I just got back from the Australian National Final where we won the whole competition so now we are representing Australia at the 2010 World Championship which is being held in Singapore in September. I would like to thank everyone for helping me out and hope that you guys will be willing to keep giving me ideas and and feedback on our car. One of the reason that we won was because of the collaboration that I did with this forum.

Thanks again
Brett

Cool.
So you won a trip to Singapore?

One of the reason that we won was because of the collaboration that I did with this forum.

How this affected your performance exactly?
I mean do you have to explain your design and the work with the forum to some judges or does just the time count?

How will you continue now?
Are any improvements on your car planned, how about your wind tunnel idea?
Will you realize it?

[basizeland]

Yeah our trip to Singapore is all paid for except our accommodation because REA who run the competition in Australia pay for most of our expenses when we go the the world competition.

The competition isn't just about the cars speed and design, as we have to write up a 20 page portfolio showing everything that we have done as in testing, collaboration, development etc. On the day we also have to give a verbal presentation on what we have done and present our pit display to the judges that are looking at our portfolio.

There are a few things that I feel need improving and the main one is the wheels because the guys from Australia that have been overseas reckon that the main part of it is the wheels, so I want to find a way to reduce rolling resistance.

We are getting an F1 Puck from Vast Motion in Australia which is a small accelerometer that fits into the canister housing and it records the speed of the car as it is going down the track and it can tell you whether the car is on the track or if its off the track and whether it has it the walls. This should help us out a lot to see what the car is doing as it goes down the track.

[ashf1mclaren]

hi basizeland i think it would be great if you could find a bearing company as they could design you some amazing bearings..............do you no what height the guide lines down th track are at? and the finish line beam for time?........i have looked on google for reducing rolling resistance, this happen to be for bicycles but similar, you may also need to look at something called tribology which deals with how surfaces interact with each other in motion. you can reduce friction studying this.......heres a link

http://en.wikipedia.org/wiki/Tribology

http://www.madsci.org/posts/archives/20 ... .Ph.r.html

many thanks ash

[basizeland]

I am pretty sure that the guideline is 2-3mm off the track and the timing beam is 24-25mm above the track surface.

[ashf1mclaren]

thanks basizeland, thats great information!......i have some more questions about your car design how thick are the sidepods? the front aerofoil? and rear aerofoil and have you though about testing the car in cfd at a lower/higher air density to make up for humidity of singapore?

http://en.wikipedia.org/wiki/Density_of_air

[basizeland]

Our sidepods are 21mm thick and the front wing is 1.5mm thick. I was thinking of doing something like that with having the air denser in cfd or finding somewhere that can control the temperature and humidity so that I can set the track up there and see the difference in the cars speed.

[Smokes]

Hey Smokes we have ran full ceramic bearings before but they were really expensive because we needed them to be smaller than 10mm in diameter but we used ceramic hybrid bearings at our national final where we washed out all lubricants so that it was running dry because we have tried WD-40 and silicon spray but they didn't help at all. I will have to give the chainlube a shot because there is no harm in trying it.

I am not sure why the Razorbacks car was so fast because it has a weird design but there was two other cars that ran under a second on the same day and they were all completely different with one of them having bushes and the other 2 bearings. It was held in Canberra where the humidity was low on this day and it is about 800m above see level which makes the air thinner.

Our car is 190mm long so its sort of in the middle

Have you tried company call acer bearings they specialise in RC car bearings. I found that you can induce too friction by making the bearing too small. The smaller the diameter the less area there is to spread the the load across the races so the friction increases. it may be an idea to test using 2 bearings per an axle to improve wheel control and spread the load across the bearings. or go for a wider and larger diameter bearing which may be a cheaper but heavier option.