I started my own project a few years ago, but I only have a
few prototype track segments to show for it. I wrote up my
construction techniques for the rolling-ball list.
I spend too much time thinking about how to build things and not enough
time actually building them! Here are some pieces I've actually built:
Some people call these flip-flops. A device which alternates between
two output paths. This horizontal one either drops the ball straight
down (on the right side) or allows it to roll straight through. Each
action reverses the mechanism so that the next ball takes the other
path. As shown (sitting flat) the next ball would drop down and rotate
the interior mechanism clockwise:
Balls falling into the top hit the switch at the bottom and get diverted
down one of the two output channels. On the way out they flip the switch
so that the next ball takes the opposite channel. The wires which direct
the ball are too long in this picture, but I have since managed to trim
them to prevent jams with two balls in quick succession.
My plan for a desktop sized track is to start the ball manually by dropping it into a wire funnel.
This first one is pretty ugly. I was having a terrible time trying to get copper hot enough to melt solder once I reached a certain density of wire in the piece (it's a very good heatsink!). I actually completed it after I got my micro torch. The design flaw with this is that the ball can actually
slip out at the very top of the funnel.
I made another one based on a simpler concept. There are 8 wires, and the bearings are 5/8", so the circumference of the upper opening is 5". I just tweaked my new slip bender until it took a 5" wire and made a circle out of it.
I made a 2'x1.5'x1.5' frame out of type L 1/2" copper tubing. It's really
sturdy. It is supposed to be filled with copper tracks, but so far that
- vertical U turn
- The ball drops and reverses direction. My prototype is soldered into my ungainly collection of early copper and steel prototypes...
- straight and curved track
- Three wires in a U shape. No top wire is necessary except where the ball needs to trip a switch and has to be constrained so it can't jump.