Intended User: Most anyone.
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Seems simple, waiting on picture..

There is also a type of pell that uses 2 tennis balls, rope and some sand. I don't have any pictures as of yet, but some friends and I are in the process of making one. Its purpose is to increase accuracy and movement. In tennis ball #1 you put a hole in the 'top' and the 'bottom' of the ball and thread through it some of your rope. You want to have a foot or so of rope coming out of the bottom. Duct tape the rope around the bottom hole in ball 1 so that it doesn't slide down the rope.  Add sand through the top of the ball until it is full, then duct tape the top hole. Take your second ball and put holes in the 'top' and the 'bottom'. Take the rope that is coming out of the bottom of ball 1 and thread it into ball 2 pulling only a bit, just enough to tie a knot, out of the bottom of ball 2. Tie the knot and duct tape around it, add sand carefully through the top of ball 2, when it is full duct tape around the hole. Take the entire thing, which should have quite a bit of rope left at the top of ball

Parts List:   Rope, tennis balls, sand, and duct tape of course.