I have a food obsessed cat. All cats are food obsessed, but this cat will tapdance on my forehead at 4am if he thinks that he might run out of food in the next 7-10 days. Obviously, I'd like to use that sort of motivation for a good purpose, while reducing the nocturnal visits from Mr. Cowjangles. Enter the feeder ball.
This model prints in 2 pieces. I have included each piece individually, as well as a plate for your convenience. Both halves snap together with friction, and they hold together well. The finished product is about the size of a softball, with fairly generous-sized holes for the food to come out. You may need to shrink the ball a bit if you are using particularly small bits of food, or if you want to increase the cat/dog's frustration to hobo-stabbing levels.
.3mm resolution works fine here. I prefer this chunkier resolution for parts with friction fits. 10% infill produces a very sturdy exterior. You absolutely have to use supports. I basically never use rafts. I printed mine in Pet-G because of its dimensional stability and strength. At the typical Pet-G printing speeds, you're looking at 4 hours of print time per half, mostly due to the huge amount of support needed.