It's a plain bearing, without roller elements like in a ball bearing. The lining of the grip boss is a low-friction material, maybe brass or PTFE etc which have natural lubricity, plus the...

For that kind of setup, you could omit the bearings since the grip boss is itself a greasable plain bearing.

Shredhead suggested this early.

The galvanized surface of the pipe might tear up the...

Shit quick sketch....331155

I think that with limited articulation of the ball joint, it would be best to have the ball joint stud axis pointed down. That would give equal range of motion for every swinging direction and also...

Of course. But those don't seem to be handed out with surplus chairs. Do they get rebuilt or reused?

Plus, you'd still have to build some mechanism to provide the side-to-side swinging that the...

Yeah I the one I mentioned uses a Ford superduty lower ball joint. Probably some other good options out there

Mine has been on truck springs for ten years, waiting for the right setup to hang. It's nice enough on the ground but hanging ones are better.

Built a patio last summer/fall so now it's time to...

Fave I've seen uses a big ball joint from a work truck. The z-axis swiveling is cool IMO.

Or you could use a big bolt/pipe thru the grip boss, with a clevis above. 2 degrees of freedom for that...