Lego Mousetrap Car

Do you need to make a Mousetrap car for science class? Do you have some Lego's around the house that aren't being used? Do you have 10 minutes of free time?

Well this simple design will leave you with a quick accelerating, compact mousetrap car that will beat the competition. With this design I ended up getting 1st place in acceleration, and 6th in distance.

Parts you will need:

Duct Tape
Fishing string
(x4) Small Lego Technic tires
(x2) Skinny gray spacers
(x2) Fat gray spacers
(x2) 1x16 bricks with holes in them (the yellow ones in the picture)
(x2) 1x6 plates
(x2) 1x8 plates
(x1) 2x6 plate
(x2) 1x4 plates
(x4) 4x6 plates
(x1) 10 long axle (about how many brick dots long it is)
(x1) 8 long axle
(x1) Red K'nex piece
(x1) Mouse Trap (duh...)

Simple Enough...

Attach two 4x6 base plates onto the top and bottom of what will be the front.

Add the two 1x8 base plates into the top of the vehicle.

Flip the car over and add the two 1x6 base plates as well as the 2x6 base plate.

Flip it back over and add the two 1x4 base plates to the top rear end of the car.

Flip the car over and add the final two 4x6 base plates onto the bottom of the vehicle.

Place the 8 long axle in the front of the car, and the 10 long axle in the rear.

Put the two larger spacers on the rear axle, and the two smaller on the front. Make sure to leave some space so that the axles can rotate easily.

Add the wheels!

For this step you need to attach the red K'nex on to part of the mouse trap (duct tape works well). Then you need to tie your fishing string on the tip of the red K'nex. Place the mouse trap on the vehicle and line it up with the front and sides.

Get a piece of duct tape and cut if in half, length wise. Attach the trap on the back over the V logo, and wrap it to the bottom. Then lift up the red K'nex part and release mechanism and attach a piece there and secure it underneath.

Now you need to wind it up, which some people find difficult. First you need to pull the string tight, but don't pull the trap up, just make the string taught. You should have around 3 inches of excess string behind the rear axle. Start wrapping it around the axle. Once you have around a half an inch or so left slide what you have done together. You then need to push the excess string under the taught portion, so that when you wrap it up more it will run over it and hold it there. Once you get that to work, wrap up the car from the wheels so that the string remains taught. Horrah! This wrapping technique allows for the release of the string after the mouse trap has expended its energy.

Oh, and make sure to wrap it the right way, or your car will go backwards...

With my testing, it didn't go straight. It used too... So I have no idea what went wrong. Well on the bumpy tile, and running over the measuring tape it ended up going 10 ft in 1.25 seconds. Pretty good!