My latest Instructable is for a simple K’nex ball machine element called the In and Out Spiral. I call this element the In and Out Spiral because the ball enters close to the back bone, and as it goes down, it moves out away from the backbone but then moves in toward the backbone as it exits. Below are the link to the Instructable (be sure to click on it) and some pictures:
-Knextus
knextus 