So, this is not in itself really cool, but it’s a test for something I hope to be able to make that is. But I needed a cylinder of a certain size, and I wanted to do it on the Glowforge.
I cut a living hinge of appropriate size. (I first cut one to the exact circumference I wanted, then wondered why it was oversize. You have to subtract off 2x material thickness from the diameter to get the outside dimension correct.) Cut two discs to serve as end caps, and two rings to act as clamps. The rings turned out to be too fiddly and not tight enough, so I sawed out notches to give some play and used clamps to tighten them down for gluing.
But that side’s not going to be visible, so that’s okay.
The tube is ~1.9" OD, in Proofgrade draftboard.