Tuesday, June 22, 2010

Homemade Catapult

A little scrap wood, a dowel, pipe cap, string, some screws and a donated bicycle inner tube.

The sides are attached with wood glue and four screws for each side.  On the arm, the cup is attached with two washers and a small bolt so it can be replaced with something lighter if need be.
The rubber strap attached to the dowel limits the forward motion. 

The rubber strap is tied in place.  The two screws on the base and  on the base of the firing arm have a small bit of soaker hose on them to protect the rubber strap. The rubber strap is in place and almost ready for firing.
The string is here to end the forward motion.  It has some knots in it for adjusting the launch arc.

Here is Dragonfly launching a Ping Pong ball.  Ping Pong balls do not break windows.  Eggs add excitement to the event as we found out later.

1 comment:

  1. VERY cool!
    (Oh..and I almost forgot... marshmallows were Joseph's favorites to fire. He and Julie would aim for each other's mouths!)

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