By chickens, do you mean hens? If so I made one of these out of PVC pipe. Only difference with mine is I put a different fitting at the bottom so the feed splits into two feeding stations and finished with a elbow fitting. You can face these forward and slightly upwards and they work really well. I fill the tube at night and it means I don't have to get up very early to let the hens out.
hen feeder
Did you know, that what you thought I said, was not what I meant :S
