I've been struggling trying to secure the movement within the case using a variety of different o-rings placed in the groove of the movement ring (see red arrows). I’m trying to find an o-ring or possibly a wave washer that would fit perfectly in the groove. I’ve measured the dimensions (diameter/thickness) of a proper fitting o-ring but need to find an online seller of a custom o-ring/wave gasket. Any suggestions?

 

At the risk of stating the obvious, I just searched for "custom precision wave washer" and "custom o-ring" and a lot of seemingly promising results came up.

I have zero experience with any of the results you might find, though. I think the issue you may run into is that you probably want just one or a few, but not a batch of 100, or whatever.

Anyway, good luck!

 

Esslinger has a very nice selection of o-rings in many different thicknesses and diameters, minimum quantity 1.

 

P.S. If you can find a standard metal washer in the right size/thickness, you can just bend it to make it a wave washer. I see these a lot in vintage Russian camera lenses I restore---people use them as spacers to allow infinity focus on modern mirrorless digital cameras.

 

Could one bend a copper or brass wire to the right shape? I made my own rings for chain mail years ago. Just wound the wire around a steel rod to make a coil and cut it into rings. Wire this thin should be much easier to work with.

Perhaps a piece of soft plastic tubing could be trimmed to fit. If nothing else is handy perhaps a ring cut from the neck of a plastic bottle of some sort. Plastics used for shampoo bottles is usually very soft.

 

I thought about improvising in such a fashion but my concern is getting enough of a precise and secure fit without risking displacement with sudden movement. If the wire wasn’t so malleable and was a closed ring then I can envision this working. Hence why I’m trying to find a precise wave spring.

 

I've used Esslinger also. They have every diameter and thickness gasket that is relevant, no large minimum quantities, and very fast shipping to me in the states. Don't know about wave springs though. I didn't even know what a wave spring was until just now.