So I gave it a shot, and mocked one of these up this weekend. Looks great.....but.....
I couldn't find the 3 inch street elbow that is mentioned, so I ended up buying a 3 inch street elbow from the drainage section of the plumbing department. So, my elbow is black in color.
I used a 3 and 5/8 inch hole saw (what I had), which gave the correct sized hole for the street elbow. (with a bit of play room)
The above would have worked great, if, I had the right street elbow. The one I bought did not have those little flanges on it, and when I put the hub end over the spigot end, there was a fair bit of play. Nothing a bit of silicon couldn't handle tho.
And finally, and here is where I need some help.... I can't get the stupid chickens to eat out of the darn thing. I removed their old feeder. Filled this one and placed it in the same spot. The bucket is hung from its handle so that the bottom of the holes are just below the chooks backs. I stuck each of their ends into the holes. I tried to entice them with some peanut butter, put a little trail from the opening to the feed. - they ate the peanut butter... but wont touch the food. Set the bucket out saturday afternoon, replaced with the old feeder sunday night right before dusk, and there was a feeding frenzy, that had obviously not ate from the new contraption. (I watch them at night for a bit when they eat before bed, and they were not eating, so I replaced with the old feeder)