It's a simple moon phase clock.

i've made it using a simple quartz clock as "motor".

You 'll need :

• a simple quartz clock (and a battery)

• all the 3D printed parts

• maybe some glue to maintain the top part

The gears :

I've used 8 gears named from A to H, A for the hours part of the clock and H the gear with the two moon. 

i need a reduction ratio of 4x29,53 = 118.12:1

so with a little (and ugly :p) script of mine i choose  :

A=12      B=68      C=30      D=37       E= 23      F=49      G=15     H=119

you can check the ratio on this  web page