For my engineering design class our first project was to design and build a mousetrap vehicle.
Constrants:
-Must travel 35 feet
-Must carry a load of atlest 300 grams
-Can not use rat traps
Race Day Results:
Run 1- 300 grams, 5.6 seconds
Run 2- 300 grams, 5.25 seconds

Run 3- 700 grams, 5.3 seconds (RECORD)

Run 4- 300 grams, 4.01 seconds (RECORD)

The 2 records were for two different things. The one from run 3 is for vehicle value, which is the load / time. The vehicle value we got was 132. It was 40 points over the old record.

The record from run 4, was for speed, our professor said in her 20 years of teaching, she never saw a time below 5 seconds. So on our final run i went for broke, and won.

Step 1: Materials

You can find these materials anywhere or purchase them for a very cheap price.

-light weight wood strips
-5/16" X 5.75" threaded rod
-1/8" X 5.75" threaded rod
-2 standard mousetraps
-2 records
-2 CD type lids
-4 1/8" nuts and washers
-6 5/16" nuts and washers
-Metal and plastic zip-ties
-Tiny nails
-Wood Glue
-Fishing Pole
-Fishing Line
-2 5/16" Wing nuts
-1 5/16" square nut
-Duct Tape
-String
-2 1/2" pipe connecter thing
-2 3/8" pipe connecter thing
-SAFETY GOGGLES
-WD-40
-Hack Saw
-Electrical Tape
-Adjustable Wrenches

Step 2: Frame

See the picture below. If you have any questions, just ask and ill be glad to help.

Step 3: Axels

First grind the pipe connecter things so they are basically smoooth. Then drill the appropriate size holes in the frame. Then slide them into the holes and glue.

Next just slide the threaded rods into their holes.

For the rear axel, you have to add somethings while sliding the rod in. First add one wing nut then a washer, then the square nut, the second washer followed by the second wing nut.

Then WD-40 the hell out of it.

Step 4: Arm

This step isnt exactly hard but its not easy. Cut a slit in the end of the fishing pole, make sure its slit far enough and wide enough to slide over the mouse trap arms. Then take short skinny strips of duct tape and wrap the pole tightly. Then add both plastic and metal zip-ties.

Then take the fishing line and extend the arm out and make the string about 1-2 inches past the rear axel. Tie a knot around the tip of the fishing pole and then duct tape it.

Step 5: Wheels

Once the axels are all set, slide a nut then a washer followed by the wheel, then washer followed by a nut. make sure these are very tight.

For the records i put electrical tape on the edges so at the start it doesnt spin out.

Step 6: Test

SAFETY GOGGLES! and maybe a helmet..

To wind the string:
-Tie a knot around a small nail, and use a thin piece of duct tape.
-Place the nail into the slots in the washers and turn.

Because of the fishing pole, the arm bends alot, so please be extremely careful.