I wanted to have a steampunk-esque wall clock in the living room, but none really looked the way I wanted.. so I made my own.
Print, paint as desired, use glue to stick the gears on ("cogwheel" is the large main clock part). I used a very basic 2$ clockwork with smooth movements (no tick-tick-tick) from banggood. I had no way to hang it on a nail, so I added a basic hanger (use doublesided tape).
The "seconds" gear is stuck to the little nub that goes in the center, so it rotates slowly. It's thin and light for this purpose. If your clockwork comes with an actual seconds hand, cut it down and glue the gear on.
I printed mine in PETG, and used Revell model colors. No need to even put a base coat on.
Seconds gear in action

Mendel90

No

No

0.2mm