what the...?

lol pretty weird way of doing things... put it does look like an interesting truck!

You'd get your 10ft pretty quick! I'd go with an 18th brushless system and a 1320 lipo 2s though.. - That will fit on a mousetrap...

I wonder, could you use the mouse trap to spin up a propeller attached to a flywheel so it would continue to provide some thrust after the string ran out? Or better yet, just use heavy, thin, large diameter, wheels. Mouse traps have quite a bit of torque so it would still achieve respectable velocities, and the wheels would store energy like a flywheel. You said you were allowed to use more than one trap, right?

yes sir! as many as needed i believe. this is nt my project so i cannot be sure but i do remember him saying theres not limit.

If you want big wheels, some people used 12'' records.
If you can use more than one at a time (say 3) then you could use big wheels with a really long lever on each one and set them of at the same time. I'd be like gearing it up a lot, but you'll have 3 times the power to cope with the big wheels and gearing.
OR...if you wanted to make it really complicated you could set the traps up to work one at a time (when one finishes it triggers the next one). Wind the second and third strings onto a one way bearing that fits on the axle (so the string doesn't get unwound by the axle turning). You'd have to have something keeping the bearing from turning until the trap is triggered, so the string doesn't get unwound again, that would probably be the hardest part (as long as you can find the right one way bearing easily). Since getting off the line takes the most power, the second and third traps could use bigger levers (same as a bigger pinion), since it's already got momentum.
3 mouse traps would have the power to go way more than 100ft if done right.

Three traps in series sounds more complicated than would be necessary. Triggering them at the same time and using gearing 3 times taller would accomplish the exact same thing, minus the drag of 2 one way bearings.

Yeah, that's what I was thinking too, but it would good to see it done. He only has to get 10ft anyway I guess, so it doesn't take much effort to do that.

ya 10 ft should be pathetically simple. its due thursday so im going to read up on patricks post sometime this week and get it done!

Did you finish it yet? What did it get? 100ft, 200ft? :tongue:

well we used your CD idea and WOW i swear there was a little brushless motor hidden somewhere. the thing had some crazy torque! itd peel out a little then go pretty fast! i got it up to 185ft i believe in my backyard.

but when i did it at school there was some wind..... the surface area of the CDs did not like it and i only for 115 ft before it fell over lol... but its ok i still got 105 points extra credit!! haha!

thanks alot for your help patrick! it would have sucked if i didnt listenin to you!

Well done getting over 100ft, too bad about the wind though.

My daughter is doing this project her 8th grade physics class this year. She will be give all the material, which includes CD wheels. They can't use anything other that what is given them. Grades are given by distance. I am going to show her this thread. Thanks for the advice.