Physics Projct: Electric Car

[DrPizza]

Originally posted by: Evadman

Originally posted by: DrPizza

Originally posted by: TitanDiddly
In that case, borrow a 7.2v or 8.4v drill, chuck up a rod with a pulley on it. Build from there.

That's an excellent idea! However, two sizes of pulleys: bigger pulley on drill, smaller pulley on axle for speed; then small pulley on drill, larger pulley on axle for pulling strength.

Does anyone even read my posts anymore? Am I invisible?

/me waves to the gallery

bah. I disqualified your post. " The wheel and axle on your car must NOT be an object intended to be a wheel or axle. " "Cut to length and epoxy on some lawn cart wheels"
😛
Actually, I didn't notice the part about the bike sprocket.

 

[TitanDiddly]

Originally posted by: Evadman
TitanDiddly, car battery is > 9 volts.

Yeah, I forgot to mention as in my earlier post- you'll need a power resistor to drop 3 or so volts.

 

[imported_Tick]

Best and simplest solution:

Buy two drills
Mount drills on plywood board
Attach some kind of wheel to front
Chuck in large thin wheels for speed, small wide wheels for pulling chalenge
No gears, no nothing, just lock down triggers when you want to start.

 

[Evadman]

Originally posted by: TitanDiddly

Originally posted by: Evadman
TitanDiddly, car battery is > 9 volts.

Yeah, I forgot to mention as in my earlier post- you'll need a power resistor to drop 3 or so volts.

That would be an insane resister that would probably cost more than the rest of the project. A automotive starter pulls in the range of 3000 watts (in the range of 250 amps, my truck pulls more than 500 because that is as high as the meter I borrowed went).

So you would need a 3000*(9/12) = 750 watt resister at 0.012 ohms asuming 250 amps. Well, 6000 1/8th watt resisters would work too, but I don't know if they make the 1/8th watt ones in high enough resistance to put 6000 of them in parallel. It would be 1.2 * 10^5998 ohms each. More than a googol, but less than a googolplex.

 

[TitanDiddly]

Originally posted by: Evadman

Originally posted by: TitanDiddly

Originally posted by: Evadman
TitanDiddly, car battery is > 9 volts.

Yeah, I forgot to mention as in my earlier post- you'll need a power resistor to drop 3 or so volts.

That would be an insane resister that would probably cost more than the rest of the project. A automotive starter pulls in the range of 3000 watts (in the range of 250 amps, my truck pulls more than 500 because that is as high as the meter I borrowed went).

So you would need a 3000*(9/12) = 750 watt resister at 0.012 ohms asuming 250 amps. Well, 6000 1/8th watt resisters would work too, but I don't know if they make the 1/8th watt ones in high enough resistance to put 6000 of them in parallel. It would be 1.2 * 10^5998 ohms each. More than a googol, but less than a googolplex.

I made a 200 watt(continuous) resistor last week out of speaker wire. Also, this only needs to last the time it takes to go 10 meters. Not too terribly hard- get a 1000 foot spool of 24 gauge wire at surplus or a ham radio flea market.
Or you could get a 6v battery and 6v starter off of a VW.