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Saturday, November 10, 2012

Build Your Own Easy Catapult


  In a previous post I told you I was trying to remember how to build a two-hinged, three board catapult.  In preparation for the storm Sandy, we went to Home Depot for supplies.  We also picked up the supplies for the catapult.  The one I used for years for All Night Grad Parties wore out.  I hated to throw it away.  If I had had any idea that it was a one of a kind, with no plans on the internet, I would have taken pictures and measured it.  This model is on half the size of the one I used to own.  

My architect husband helped me to finally figure out the measurements and logistics of this toy.  I have a set of bean bag heroes I bought on Amazon.com.  When the project was completed, and my husband stomped on the board behind Superman's head, Superman went flying all the way across our deck.

So, how did we make it? 

  •  We bought 3/4" x 41/2" pine boards.  We had Home Depot cut them into thirds for us. 
  •  We found a scrap piece that was 1 1/2" thick x 3" wide.  We had Home Depot cut it into 4 1/2 " long pieces to match the width of the pine boards.
The first bottom board is 32" long.  The second bottom board is 231/2" long.  We cut the second board at home.  We hinged these together end to end with a 3 1/2" door hinge.  It comes with long screws, so buy 3/4" inch screws. You need TWO of these.  
                                  

 After the hinge is screwed on to the two boards, you need to screw the fulcrum block (thicker piece) on 11" from the center of the hinge, or 19 1/2" from the end of the longer piece of bottom board.  You have to mark it on the sides because you have to screw it on from the top side of the board (the side touching my counter). We used 21/2" wood screws to go deep into the fulcum.





The third piece of wood is only 26" long.  I will refer to it as the middle board.  Look at the top photo again.  Screw the second hinge 16" from one end of the board.  I turned the catapult upside down so that you could see the hinge makes a 90 degree angle up onto the fulcrum board.  Below is a side picture.  My husband told me to remind you to make SURE to have the shorter end of this middle board touching the longest board before you screw the other side of the hinge to the fulcrum board.  



                          

 If you notice in the top photo, the middle board extends out behind Superman's head.  That is where you place your foot to make him FLY.   I  will ask my husband later to make a drawing for you.  I hope this helps explain how we did this.  I can't wait to bring them to the Super Hero Party. 

This catapult was a GREAT success at both the party and at school to explain FORCE and MOTION.  The kids were so excited to stomp on it and make the bean bags fly.

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