Quote:
Originally Posted by TEguy
because everything is really light weight and only limited amount of input energy is allowed, drag will play a big part in slowing it down. Make sure you minimise that, otherwise it will stop real quick.
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Good point. Powdered graphite or light oil with powdered graphite makes car go good.
Quote:
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Originally Posted by TeaEeDude
As you already know ( I hope) what you are doing is converting potential energy to kinetic energy. Make sure you set it up so that the conversion rate is very slow, you want the weight to drop slowly and propel the car as it decends. Having one quick burst of energy will not be good in my opinion. The reason is the same - drag. High speed means lots of drag, keep the speed low and this will keep the drag low. Same applies to friction in the moving components. It is not a speed race, it is a distance race.
That is my opinion anyway. Oh and you really need to do something about your spelling 
Good luck |
So I have a bit of a different take.
First, note the rules specify the car should be able to coast after the weight is down.
So to begin with you have to engineer the thing to let the string loose from the axle. I think simply wrapping it tight should suffice.
Then to me, the faster a car is going the farther it can coast, oui/no? So what I have in mind is basically as in Craig's drawing, but having the axle cone shaped with the string wrapped starting at the small end and then progressively toward the fatter end so the car gets more torque at first and then less as it accelerates to higher speed.
At the very least, I wager no other cars have this design feature and it might get some credit for ingenuity.
