Automatic Fish Feeder - Part 1

Background

I have a fish tank. The first weekend that I went to parent's house after setting up the tank, I realized that I had a problem. I had no way of feeding the fish. Sure, there are time-release food pellets and other similar methods, but they weren't an option at the time. I tried to leave them without food for a day. When I got home, the fish had nipped and eaten each other's fins. This was a problem that had to be taken care of immediately.

Design

The longest part of this project was actually the design. I boiled my requirements down to these few points.

The feeder must:

• deposit a predetermined amount of food into the tank.
• be able to measure this food itself i.e. I don't want to make "food cartridges."
• feed the fish twice per day.
• be easy to refill when the food supply runs low.
• use flake fish food (as opposed to pellets, etc.).
• be cheaper than buying a retail fish feeder.

I drew a bunch of designs. One involved drilling a hole in the canister that the food comes in, mounting the canister to a platform, and have a solenoid shove a small amount of flakes in a small bucket out over the tank. One design had food slide into the center of a large, flat spiral. The spiral would rotate a full rotation to drop flakes into the tank.

I eventually settled on a design with an inclined cylinder. I cut a hole on the side of the cylinder near the bottom. Every 12 hours, the cylinder would be rotated a full rotation. Food would fall from the hole and slide down a ramp into the tank.