Mousetrap Car

[Honda4LifeWes36]

Well I got my mouse trap car finished and sometimes it goes far and other times it sits still. It happens because on the rear axle, sometimes it slips off. What could I put on the axle to gain friction to turn the axle better??

[Honda4LifeWes36]

I have old CDs for my wheels and they just sit there and spin.

[CJM]

Ive never heard of this mouse trap car, could you explain it better?

[brian76708]

rubber bands

[chucked]

I used cd's on mine also, but I had low torque, so it didnt spin, took it forever to get all the way out, but distance is all that mattered. I extended the lever ALOT

[CJM]

After researching it a bit, somepeople swear by cutting up ballons and putting them on the cd wheels.

[161xchonda]

I built a mousetrap car for a high school Science Olympiad event last year, and am redoing it for this year's event as well. It had to go 9 feet up and stop, then return to the exact position it started in, so it did not use a lot of torque. If i remember correctly, I didn't use rubber bands. Though, i did test it while using them. My bar is about 10 inches long, connected to two mousetraps that are attached to each other. How long is your bar, and what is it supposed to do?

[Honda4LifeWes36]

Mine is supposed to go for distance but if it gets over 50 inches, we get the points. Its not my CDs that are spinning, its my rope off my bar that wont hold onto the axle to spin the tires.

It just slips off.

[gasguzzler]

Depending on how you have it set-up, when I was in high school I used a cork with a pin or nail in it to loop the fishing line onto. The angle of the cork also work as a gearing methon (wrap big section for torque and taper to smaller section for high speed so to speak). I believe I used super glue to get the cork to stick to the axle (although not preferred set-up). If I had to do it over again, I would've used a dowl rod cut down instead a cork.

I used big records for rear wheels. I used one wheel in front, which helped with less rolling resistance and easier to steer. Wheel bearings from RC cars will help your car go a long ways as well;) I believe I had our high school record at 31 meters.

Hope that helps,
Brian

[161xchonda]

Hmmm. I never had a problem like that. Mine was set up so that a string went from the rod to the axle. On the axle we attached a small pin, and looped the string around it. Maybe try something like that. The string is impossible to slip in this set up.

[derekhonda]

Originally posted by Honda4LifeWes36
Mine is supposed to go for distance but if it gets over 50 inches, we get the points. Its not my CDs that are spinning, its my rope off my bar that wont hold onto the axle to spin the tires.

It just slips off.

Are you not allowed to fasten the rope to the axle connected to the wheels? Because if it just slips off, glue it, staple it, pin it, whatever!

[CJM]

Perhaps use another type of rope? Shoelace string comes to mind as its not as slick.

[wilkin250r]

I'm thinking the "slip-off" feature is intentional. If the car is able to build momentum, and the rope is able to come off, it can coast for additional distance. Otherwise, your distance is done as soon as your string is done.

[Honda4LifeWes36]

Ya I got er fixed. Thanks guys! The only problem is it steers a little to the left because of the front tires.

But oh well. The big day is tomorrow