Now see...I'm going to get in trouble. OT advice warning!
IME, you really don't need to make up any PVC contraptions to have space saving and go cheap....a piece of guttering with a cap of woven wire, mounted on the wall of your coop and with some support for the bottom(bricks work) is much easier. The wire keeps birds from flicking and scratching through the feed and the open face of the whole length of the feeder is an easy to fill solution.
I tried the PVC feeder and soon discarded it for a more practical and easy solution. You should have seen the work I did to make the durn thing...too much.
We have scrap wood from our coop renovation. Never thought about the wire. That's the problem...they seem to bill it out of every feeder we've tried - even the hanging feeder. This is definitely an idea to explore in spring.