I created these and one other one recently for a Birds & Blooms magazine DIY feature.
It was to provide a solution for really inexpensive bird feeder construction at home.
I used everything from muffin pans, to remnant wood, to tray lids, and a few accessories.
I used jack chain for the suspension.
These were created for only $20 each.
To see more: http://www.gadgetsponge.com/posts/2013/2/4/repurposed-upcycled-hillbilly-bird-feeders-continuation-from.html