Braided Galton Board - Probabilities with String

This is intended to be an intuitive demonstration of the Central Limit theorem. The Galton board is a standard way to show this with falling balls. However instead we use string, and have each possible path represented with one thread, and we can see at a glance which locations are probable.

The dowels are 12.5mm. I just hammered them into the lasercut wood, but you might want to glue if the tolerances are different for your lasercutter.

The string is 1mm builders cord, but anything should be fine.

I found it very difficult to thread without making a mistake. The strategy I ended up using was to hold the prevoius thread in my left hand and the next thread in my right. By jiggling my left hand I saw the old thread bounce, which gave a good reminder of where I was in the sequence, and hence to put the new thread in the right spot.