I wish I'd paid more attention to this thread, because it would have saved me money! I made a pvc feeder that came down, made a 45* angle, then had holes drilled in the top of the pipe. Problems: 1. they wasted lots of feed! 2. The feed got caught up in the angle and wouldn't fall down where they could get to it.
So, we went back to the drawing board and made this one. Works MUCH better - feed doesn't get hung up where the chickens can't get to it, and they waste a LOT LESS.