I really liked the excellent design by @moXDesign, but it was for a PiCam1, not PiCam2.
So, I've made the case a fraction wider, everything else is the same.
Obviously I also had to change the lid and the bracket.
You'll need to get the rest of the files (arm, clamp and thread) from the original:

https://www.thingiverse.com/thing:3224688

As a bonus, I've also created a short version of the arm, because my printer is in an enclosure and I don't have room for the original arm.