Technique for something like a small curtain ring?

What about just using a round over (radius) bit with guide bearing on the router to do the insides Could do the out side as well if desired.
e.g., turn a 20mm x 20mm square/sharp edged ring. Use a 10mm radius bit and round all for edges. quick sand, job done.

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Originally Posted by ozka

What about just using a round over (radius) bit with guide bearing on the router to do the insides

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Interesting idea.... this got me thinking of potentially using a round over bit like a scraping tool on the lathe - pre made quarter circle in carbide. Would just need a safe way to hold it.
I don't know about using a router on such a small circle - could be a bit dangerous even on a router table with something suitable to hold the ring. Could possibly do it this way if I bored out holes in a larger board then went round the holes with the router and a guide bearing bit, then cut pieces from the board. could then friction chuck or take the mandrel approach to finish the outside. Hmm another technique to add to the growing catalogue :)

Make a similar chuck to the expanding mandrel I described above But make it a 4 jaw collet chuck. Use a hole saw to cut your circles so that they are exactly the same size each time. In the end of your 4 jaw collet chuck, drill a hole 1/2 the width of the blank for the blank to fit. Use a hose clamp to force the 4 "fingers" to hold the blank. You can finish one side of the inside, flip it and do the other side. Then use the above expanding mandrel to finish the outside of the ring.

Or, take a flat board, about 8" square. Drill your rings using a hole saw, drilling both the outside and inside rings leaving it rough size. In the center of the 8x8, drill a hole with the outside diameter of the rings. With a saw split one side into the hole, clamp pressure on that saw kerf should hold the ring in place. Then use a router table with a round over bit to do the inside, then finish the outside with the expanding mandrel.

I stumbled across this idea: http://youtu.be/APGEDaVBhqI

Revisited this after deciding to do a puzzle for my nephews birthday. Thanks for all the ideas - the approach that I have settled on that works perfectly is a collet style wooden holder that grips the ring around the outside. This allows you to turn and finish that final inside edge of the ring that I was finding impossible with all the other methods I tried. This is what I did:
* I turned a cylinder
* hollowed it to a diameter slightly smaller than the outer diameter of the rings
* cut a v groove on the inside face of the hollow cylinder for the ring to locate in
* cut slots through the cylinder to allow the "jaws" to flex open and closed
* used a hose clamp to tighten the jaws around the ring
A few pictures to show the approach for anyone interested:
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