I don't have a picture right now, but mine is a trough 40" wide with a 2' tall x 40" wide x 3.5" deep hopper constructed above it. It holds a 50lb bag of feed easily.
The opening between the hopper and the trough is opening 1-1.5" due to not being able to cut straight. And about 1.5" from the opening to the front lip. The lip of the trough is about 2" high. I mounted the entire thing above the ground, so to make it even more difficult to bill food onto the floor. Between the difference between the level of the food and the front lip, and the height from the ground, I think I have prevented billing out onto the ground. The small opening of the trough also makes it difficult to perch, so no crap in the food.
Part of the reason I went with the big hopper design is that I have 30 chicks and I don't want them ever out of food because when I had a smaller feeder whenever it emptied and I refilled it they would swarm it creating opportunities for fighting and excessive pecking. With the food available all the time there is not the big rush and crowding at the feeder.
[Edit] Found a couple pictures with the feeder in the background
This shows the bottom feeding trough.
This shows just the right side, but includes the height of the hopper.
Built mine a little while back and am very pleased with it's function and full bag holding ability.
There was some mild concern about the ladies standing on top and pooping into the food, but it has been a non-issue thus far. Probably because they have higher places to stand...
