This fidget keyring is a simple design using a 3 gear chain to do nothing but entertain its user. Turn the small gear and watch the other gears turn!

Requires 3x 10-12mm m3 bolts and 3x m3 nuts.

Revised Base & Top - moved both 30T Gears 0.5mm further from the 15T gear for easier spin.

Revised both gears - bored to 5.5mm for extra clearance / easier spin.

I've printed this on 0.15mm layer height using ABS on an UP! Plus 1.
0.25 layers would work well as a lot of the clearances are 0.5mm.

Press the nuts into their holes using plyers.

I had to shave some excess ABS from the axels with a scalpel form where the layers met printing the circles in order to allow for an easier spin of the gears.