By: Jacob My machine has a balloon that you blow up on the end. Air fills the balloon and it expands to push up a tube acting as a teeter totter. The ball is in one end of the cardboard tube. When it's tilted the ball goes from one end of the tube to the other and falls out that end into the top of a pop bottle that funnels the ball into another cardboard tube. Then that tube brings the ball back to you.
TroubleshootingA big problem was finding the right size tubes. I eventually found all of them. The te balloon wouldn't push up the tube where the ball starts out. I had to fix it so it would.
Reminds me of . . .A machine I've seen that works like mine is a teeter totter. It uses the same idea as the cardboard tube where the ball originally starts out.