Mousetrap cars

[Willdabeast]

I was recently confronted with the challenge of making a "mousetrap car." The rules were simple, make a functional car using a few slabs of balsa wood some copper bars used as axles and CD's as wheels (and of course a mousetrap.) My group used a fairly simple design, simply cut out 3 pieces of balsa, two were long rectangles, about 2 inches by 10 inches. these were put on the sides of the car and glued to a 4 inch by 8 inch piece of balsa (which was put on top of the car, so it had a top and two sides, the top did not fully reach the length of the sides, we then had the idea of using only three wheels, we assumed that in the front if there was only one wheel, the weight on the axle would be less. (which would reduce the friction between the axle and the balsa. The cd did not fit in the middle so we had to cut out a rectangle from the 4 by 8 piece of balsa to make room for it. the back wheels were simply put on the sides so no more cutting was necessary. We glued the mousetrap to the platform we had made (the 4 by 8 piece of wood) we cut the rectangular bar on the mousetrap (the part that "squashes" the mice) and added a copper bar to it to extend the reach, we were hoping this would increase the distance the car could go. we then tied a string to the end of the bar we had attached, and tied the other end to the trap. when setting off the trap, the car reached around 10-15 meters.

 

I was just wondering if anybody else had some ideas for the car, or if you have made a successful car, and how you designed it. Thanks.

[Genecks]

Mice are too fast and agile to be captured by a car. Now, building a car that surreptitiously follows and shoots a dart at a small, moving object... that might work.

[richard]

I think the mouse trap is used for its spring to provide motive power. Its not a mouse trap car, its a mouse trap powered car.

[Willdabeast]

Yes. sorry i didn't explain that. the mousetrap is attached to a string which is wrapped around an axle, it's to make the car move. not to catch a mouse

[alan2here]

Are thease called torsion motors? They can be made with big springs to run stuff. They genrally have the trobble that retentioning the motor takes soooo much energy and they loose power as it unwinds.

 

Sorry to state the obvious and im not trying to be patronising but be carefull as mousetraps easely break fingers.

[Rocket Man]

are you supplied with the mouse trap? or can you get a better one?

if not, buy two more similar ones and mount their springs on the original trap

a thin spindle and big wheels make for longer travel on flat ground with less total force

 

if you have access to some sort of lathe, you can actually modify the spindle raduis to different spring tensions throughout the travel, giving you finer control over the force curve in the spring and how that relates to the drive wheels.

[Willdabeast]

are you supplied with the mouse trap? or can you get a better one?

if not, buy two more similar ones and mount their springs on the original trap

a thin spindle and big wheels make for longer travel on flat ground with less total force

 

if you have access to some sort of lathe, you can actually modify the spindle raduis to different spring tensions throughout the travel, giving you finer control over the force curve in the spring and how that relates to the drive wheels.

 

Yeah your supplied with one, and we were only allowed to use one. :/

[Willdabeast]

Are thease called torsion motors? They can be made with big springs to run stuff. They genrally have the trobble that retentioning the motor takes soooo much energy and they loose power as it unwinds.

 

Sorry to state the obvious and im not trying to be patronising but be carefull as mousetraps easely break fingers.

 

Haha! thanks for the advice. i've had my share of un expected snaps on my fingers. not the greatest thing to endure.