Ok, not quite a real atomic clock, not as accurate but so much fun... And you made it :)

BOM:

• 1 clock mechanism, preferably with a wall mount.
• 1 AA Battery.

Instructions:

• Print the included file (you'll need at least a 20cm*20cm print area).
• Add the clock mechanism and battery.
• Attach the clock handles.
• Enjoy your not-so-precise-but-still-atomic clock or give it as a gift.

Notes:

I used two filaments to add some contrast and make the "numbers" more readable. It's obviously not necessary but I feel it's so much better. You can scale this print on the Z axis to accommodate for different size clock mechanism. If you scale down on the XY axis, you might get in trouble fitting the mechanism through the hole.