I was over there with the kid today, got some stuff done, but I forgot to take any pictures...
We decided framing it as an octagon would be way easier than framing it as a circle and still look very cool.
After bolting the frame together with 1/4" bolts I focused on orienting it relative to the property lines.
After lining up four of the posts square with the sides, securing them with stakes and leveling the sections of ring between each them, I noticed something looked off.
I checked the corner where my lines came together, it was not 90°.
The lines are equal distance off the property lines, the property lines just don't intersject at 90°.
I had to leave it for the night, but I think I'll need to move two of the four posts.
Going forward I will affix boards to the inside edges of each section and make sure there each inner corner measures 135°.
Once I get it all squared up and level I plan on pouring a very narrow slip form masonry wall underneath it.
This will give me a place to build framing.
I'm imagining 2x6 sill plates and headers, with who knows what in between.
I have many ideas, will probably default 2x6 studs.
The trampoline ring will probably end up inside the framed out wall, but that
should be ok.
The trampoline frame is in fact, unnecessary.
I considered a hex or octagonal build without it, but the ideas kept me coming back to using the posts of the frame anyway.
Not only has the frame gotten me started, it also means the building will be useful at most stages of construction.
Even with no walls or roof, it will be a place to hang hammocks from.
The most popular DIY hammock tripod stands are made of 2x2 lumber, so I am not really worried about the strength of the frame for hanging hammocks.
A flat walkable roof will need its own support.
I think I will aim to get a slopped roof in place first.
A 3" pvc pipe could be the center post for a conical tarp roof.
Rachet straps can be the rafters and a 12/12 roof pitch will need a tarp that's about 20 feet across.
This seems like a simple way to protect things from weather, plus I like the big top circus tent flavor.
I imagine it might be rather sloppy as well.
I have cheap hammock that I will try out on the frame as soon as I have it stable.