My kids and people I work with are all playing Pokemon Go :-) and I still know that game from the time my kids were young. I sat down and decided to create a pokeball keychain. Its aboud 40 mm diameter and 3 mm thick. I created three different parts, one for the red parts, one for the white parts and one for the black parts. If you print them all they will click together to create a nice keychain. I used some glue in the back of the black container to make the keychain stronger. The files all contain two parts, so you can make two keychains in one print. This part was (of course) created with FreeCad and sliced using Cura.