Re: Building a toy car that travels a distance of 31 feet

June,

There's another question in the archives that might help you a lot. Try out this link:

Re: How do you build a car only powered by an elastic band?

In the above article, he suggests wrapping the band rather than twisting it. I'm not sure exactly what a #10 rubber band looks like, but if it's the thin & wide type, you're right, it probably won't twist too well. It's more likely to bind up with itself than twist. A thin rubber band should twist well, you'll just have to twist it a lot. Stretch it a little bit before hand too.

If you do the wrapping trick, cutting the rubber band so it's no longer a loop may be helpful.

If you have to stop at exactly 31 ft, I'd consider using some type of braking mechanism. A string wrapped from a front axle to a rear axle would make a great brake. It would work kind of like a cassette tape; winding from one side to the other, and stopping when it's completely transferred form one to the other.

Good luck!

Your Mad Scientist
Mike Scannell