Bottle Cap
thingiverse
I've got my Nuka Cola clock right here, check it out https://www.thingiverse.com/thing:2749594\r\n\r\nYou're welcome to use these blank bottle caps however you see fit, they'll import seamlessly into Tinkercad and allow you to add any text you desire, or you could print them face down with no design at all and still achieve a great look.
Download Model from thingiverse
With this file you will be able to print Bottle Cap with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Bottle Cap.