I found one out of Oklahoma City, OK and it is made of galvanized metal and is rat resistant/proof. Low cost and easy for chickens to use. http://thecarpentershop.net/
$65 plus shipping. Very nice units.
I was very interested in trying to make the "build your own" chicken feeder. After looking at it I knew that I could not build it myself. I am not the type that can do something that complicated since I have no experience and tools to do it.
I went ahead and found one that is already made and...