Jelle Bakker made a Surprise Box for marbles (be sure to check out his You Tube channel.)  I thought it was really cool, so I decided to make my own out of K’nex. (I am even making one for marbles!)  Here’s how it works:  First, a ball enters through the top, but doesn’t exit out of the bottom.  Then a second ball enters through the top, hits a bell, and then exits out the bottom.  When a third ball enters in through the top, surprise!  It exits out the side along with the first ball.  Below are some pictures and the video.  Note:  I filmed and took pictures of the Surprise Box while it was attached to my upcoming ball machine.  Click Continue Reading to see the pictures.

-Knextus