I've been thinking of this stand for a long time, and even enlisted my friend Grizz on a little of the math involved (yes, there was math - but it wasn't really needed.) I'm calling it Arc de fin.
4 1-3/8" galvanized fencing top rails, 12 u-bolts, a 2x12 and 2 1-3/8 sleeve connectors later, I have my arc stand, inspired by the Hammaka bow stand. This was the inspiration - as soon as I saw this stand, I knew I had to make one from aluminum. Took me almost a year from thought to fruition, but here it is.
Details: I used 4 10.5' poles for the legs, and cut the center arc pole to 8.5'. 20' footprint, 8' high at its peak, 6' wide legs. I had planned on using 2 aluminum 1/4" plates for the connector bracket, but couldn't find where I left them so I fudged it up with the 2x12. I will correct that as soon as I locate my aluminum. I used a tube roller to bend the tubes, which I purchased at Harbor Freight just for this purpose. For anyone thinking of doing this, buy 1-1/2" aluminum stock for your poles - it's easier to find someone else who will bend it for you if you don't own a pipe bender, and a lot cheaper. Line up your bending first. I called a zillion places looking for someone to bend 1-3/8" pipe, and nobody had the right size mold. I used a 1-1/2" mold to bend mine, and it was fine.
Another little technical note. I tried different suspensions, and all work fine. But I did notice that you need to have the "triangle" in your suspension with this stand to move the center of gravity in closer towards the middle of the stand. If you string a bar, or a tight straight cord between the legs and then attach to that with a straight line from your hammock, the legs pull in towards each other. If you have a triangle suspension, the arc works as it is supposed to and distributes the weight evenly across its length, more or less. That is why there are so many lines hanging from the stand - I was playing with suspensions.
The poles were $8.97 each, the U-Bolts $2.79 each, and the sleeve connectors were $1.97 each so the materials were $75 with tax, roughly. Once the poles were bent and I figured out a bracket for the legs, it took about a half hour to throw it together. I spent a lot of time stress testing it today, and hanging in it with a regular no-net hammock. It does "stretch" a little, but it is solid. I will be sleeping in it tonight.