Instructables
This is an Instructable on how to build a catapult powered by a mousetrap.  It can shoot a variety of things but I specialized mine to shoot practice golf balls.  I used a weaker mousetrap, and it shot about 15-20 feet.
 
Remove these adsRemove these ads by Signing Up

Step 1: Materials

instructableandbday 046.JPG
dinglei01.jpg
needle_nose_pliers.jpg
For this project, you'll need:
-mousetrap
-wire clothes hanger
-an electric (preferably cordless) drill
-screws
-a nail
-the proper drill bit for your screws
-duct tape
-a small block of wood (I used a 10.5x3.5 inch block.) This is mainly to mount the catapult on, and anchor it down.
-needle nose pliers (with a wire cutter).


Step 2: Preparing your materials

First, we'll start with the mousetrap. Remove the tagged items until all that is left on the mousetrap is the spring and the hammer (the part that traps the mouse).  Next, on the hammer, clip the end of it on the side that the spring isn't connected to.  Straighten this out completely so there is an arm connected to the spring.



Next, on the clothes hanger, you want a piece of the wire to be about 1 foot, so cut on the two tagged spots.

Step 3: Drilling!

Hold your mousetrap down to your block of wood. You need to leave space for the arm to be pulled back, so attach your mousetrap closer to the front.  Drill two holes through both the block and the mousetrap.  Do them in the center of the front and the center of the back on the mousetrap.  Next, get out your screws and change your drill bit to a Philips head.  Put the screws into the guide holes to tighten down the mousetrap. Your catapult is now working, but we need to tweak it a little to improve it.
AndyPipkin1 year ago
If it catapulted the mouse, I would be impressed!
I removed the entire hammer and substituted a 20" wire hanger. The hanger has a 90 deg. bend that is slid into the spring. This removed some instability with the duct tape attaching wire to the unbent hammer. I'm working on a rubber band restraint of the lever so the ball launches at an upward angle. Pictures on the way.
tnmomof73 years ago
This a is terrific concept. My physics students would enjoy this as much as, if not more than, a mouse trap vehicle. It may be that if you restrain the lever arm at 90 degrees, maybe less, you will get more distance from the projectile. This would give you a definite launch angle and prevent the projectile from being in contact on any downward swing of the lever arm. Thank you so much for your idea!
Ninzerbean4 years ago
 Can you take a little movie? Please?
KnexFreek4 years ago

SWEET! looks awesome!!

jpguitardude (author)  KnexFreek4 years ago
Haha thanks. 
lemonie4 years ago
You've only got 1 photograph of this - could you add another, maybe with the loaded-projectile?

L
jpguitardude (author)  lemonie4 years ago
Just added it!