We have always used a gravity feeder for our chickens. For chicks we use the mason jar feeder (above). This works great, but only for a couple of months. By then the chickens eat enough that it must be refilled every other day, plus it is easy for them to knock over.
Next I purchased a gravity cat/dog feeder from the pet store. That worked pretty well until we increased our flock from 3 to 6 chickens. We were having to refill it every few days and access became a problem for the lower-rung hens.
There are bigger, poultry-specific gravity feeders for purchase, but I knew I could build my own for a fraction of the cost. And I finally did. Our coop is small so I used a 2-gallon bucket instead of the 5-gallon bucket many designers use. I used a jig saw to cut four openings at the base of the bucket, and screwed the bucket to a plastic planter saucer, using washers on the bottom bolts to help distribute the weight.
Version 1.0 worked okay. As you can see in the photo above, the tray was a bit small – not a lot of room for a chicken to peck, and easy for her to spill food. The openings were also a bit small so that the food eventually blocked the hole, not automatically falling into the tray when the food level dropped. This might not be an issue with pellets, but we use a layer mash containing Wheat, Barley, Rye, Peas, Lentils, Soy Meal, Flax Meal, Sunflower Meal, plus rock phosphate, calcium, etc, so powdery stuff tends to fills the spaces quickly. When I found myself shaking the feeder daily to let more food into the tray, I knew I would have to do better.
Version 1.1 seems to be working better. I attached a larger tray and cut bigger holes in the bucket so that food can more easily spill into the tray when the level drops. There are no ergonomic issues for the hens, and it is hard for them to waste food by having it leap out as they bill and peck about. As with many things chicken, this feeder may require further improvements.
Next up: Automatic waterer!