My effort so far:
I'm working on a full-time hammock, so weight isn't an issue. U-bolts from Home Depot with wing-nuts for easy removal (for laundering). 6" red oak 1x1's for the bars. I can detect no center ridge at all with this set up. Wonderfully flat...Mighty Mouse is a happy camper!
Something hidden. Go and find it. Go, and look behind the Ranges. Something lost behind the Ranges. Lost and waiting for you . . . Go! - Rudyard Kipling