Here is a rough prototype of a smaller feeder with a metal hood for outdoor use.
Several changes due to the need to eliminate the side levers that operated the lid and to make it weather proof.
The treadle works opposite of the original allowing the metal hood to slide over the top. The wooden top is fastened to the sheet metal, take off the hood and the top comes with it. I can forsee having to push the hood back most of the way to train the hens, then sliding it forward a bit each day until they are used to going into the dark to get their food.
The large counterweight on the original made the door somewhat self locking as far as if a rat was to climb on the treadle and push on the swinging door. I had to add a magnet, a standard old style cabinet door magnetic catch, to make sure a rat won't push the door open. It holds a bit stronger than I'd like so I am going to put the hens to work this afternoon testing the new feeder. It takes a bit more weight to open, so training can be accomplished by putting several layers of electrical tape (or any type of tape) over the magnet surface to weaken the force or just adjusting the magnet back to where it is less strong. As the birds get used to stepping on the plate to open the feeder, either adjust the magnet closer to increase the strength or remove some of the tape off the magnet.
I also incorporated a galvanized steel back, bottom, and front, one piece that slides in. That makes it even more rat proof as even a rat can't chew through 31 guage steel. With the hood in place, the only place a rat could ever chew through would be the swinging door itself and that is 3/4" plywood.
I'll check the amout of laying pellets it will hold tonight and post. The weight went down to around 6# empty, 9 # shipping weight with packaging. I did a quick quote via US Mail, parcel post, to Oregon and it was $14.47, about two thirds the cost to ship the large one that far.