This is a two part cityscape ring. I usually cut them in acrylic, but they also look badass in wood.

The file here is a size 7 ring, but its easy to swap out the inside circles. Once you get up to about 8.5 you may run into trouble with the walls being too thin, widening the design should fix that.

A calling card with working planetary gears. Astound your friends, frustrate your nemisii.

(Update: I've moved the gears slightly to the right, reducing the number of cut parts to assemble.)