mousetrap car instructions

Deceasing Rubbing Friction

By Doc Fizzix // Published Nov 17, 2005

Problem:
My vehicles axles slides back and forth causing the wheels to rub against the frame of the car and then eventually the vehicle slows or stops too soon.

Answer:
If the wheels rub against the frame of the vehicle then the frictional forces will cause the vehicle to come to a stop MUCH sooner than it should. The axles need to have some spacers added between the wheels and the frame in order to prevent the wheels from bumping into the frame.

Try the following to correct the problem:
1. Add thrust washers as needed between the wheels and the frame in order to prevent the wheels from sliding into the frame and the washers will also provide for a smoother rubbing surface with less friction. Try using flat metal washers as a thrust bearing, you can always use several washers if one is not enough, also use a little graphite powder on the thrust bearing.

2. You can also use plastic beads if you can find the right size to fit the axle. Anything that is smooth can be used as long as it fits on the axle and limit the side-to-side play of the wheels or axles.

3. If you are using bearings, the axle may be moving side to side. Carefully glue the axles to the bearings without getting glue in the bearings

See the following related articles to get started:

• basic mousetrap vehicle propulsions (how to make it move)
• how to make a good distance traveler
• how to make a good speed-trap racer