I've gone ahead and printed the latest design of the fpv ball.
Now the Field of view is nearly completly clear of the walls. Additionally I fixed all the small tolerance / clearance issues I had. The print took about 1h on coarse settings.
Partly because the camera brightens up the image because it sees a border all around (camera cutout too small), but mainly because the antenna is just in very weird angels when thrown so the reception is extremly bad most of the time.
I cut open a tennis ball and put in the fpv camera. To fix it's postition and dampen the impact when catching (do not let it hit the ground) I put some foam around it.
On the back side of the ball I cut a slit to put in and out the battery.
Ooooh, cool! Please post the photos (even the bad ones).
I think this will be a really cool thing but I suspect the spinning of the ball will be a problem. Perhaps it'll just make some trippy images ;-)