For my Mechanisms and Things That Move class we were assigned to design and build a mousetrap powered car. The only requirements included: Using one mousetrap…and the car needed to travel 10 ft as fast as possible.
Initially my partner Gabby Levine and I made attempts to create our own wheels out of wood, to use a mouse ball as the front wheel on a single axle, and to use only the length of the mousetrap to unwind a string.
Building Wheels
Rear Axle
Under Construction
Early Prototype Testing
As that video shows…we didn’t quite make the 10ft requirement in our early car design. We mostly attributed this to both the weight of the car (wooden wheels, a solid mouseball) and the friction from some of our parts (an offcenter rolling sphere, and too much friction on the rear axle when the fishing wire unwound.
We adjusted our design by using a skateboard ball bearing for a front wheel, cds for the rear wheels attached to a slightly larger axle. We also added a wooden rod extension to the mousetrap lever arm so that the force of the lever was extended over a long length of time rather than let out all in one quick burst.
(please pardon the black box…the aspect ratio apparently didn’t match Youtube’s preference)
As shown in the video, our adjusted design still had a few problems including too much friction in unwinding the rear axle and the thinness of the wheels allowed the car to get stuck in-between the cracks in the floor. Overall I am rather pleased with the results though since it did much better in competition (and it even crossed the finish line in the finals!).
Mousetraps do not provide nearly as much power as I expected, but it was a fun class assignment and a very real experience with the double-edge sword named “friction.”