Rotor Key Ring

Many moons ago, I saw a picture of an old (possibly centuries old) brass key ring that kept the keys in place with rotating discs.

After a long time of the idea noodling around in the back of my head, the construction suddenly clicked, and (after a few iterations), this is the result.

I made mine out of 3mm plywood, but something much more rigid would be better, if you're able.

The instructions on how to use the keyring are here: http://www.instructables.com/id/RotorKeyRing/