My 7 year old recently acquired a fish bowl with a betta fish.
Apparently, the PLA plastic used in 3D printers doesn’t degrade significantly in a fish tank, so I started looking for aquarium decorations we could print. And I came across a design for a fish feeder: https://www.thingiverse.com/thing:1257953
I started modifying it to accommodate our fish bowls. She asked to help out, so I suggested she do a sketch of her design.
Her design has a timer, and uses a suction cup to attach the feeder to the bowl. I was skeptical, but she found a suction cup and demonstrated it would stick to the curved wall of the bowl.
I then set her up with Tinkercad. Here’s the 3D model she made of her design:
Our fish feeder is still a work in progress, we’ll post pictures of our project when it is complete.