Finding replacement jewel by size?

Hi all-
As you may have seen elsewhere, I picked up an Omega Rocket, plus a couple of 92EL3s as spare parts, and got it running! However, since the Omega top-plate of the motor uses a jewel + smaller motor pivot, I wasn't able to use the great brass plate with the Omega logo on it!

SO I figured: What if I just pressed out the jewel on the Omega top plate, and got a replacement jewel? Well, I've done the 1st half of that 😀

I used my staking tool to tap out the old one. It is 3.5mm on the OD, give or take a hundredth.

The pivot-hole I need it to work with is roughly 0.61mm (which was much harder measure, I ended up using an optical comparator to measure, and it appears to be just more than 0.024", so ~0.61mm.

I was hoping to find a place I could buy a handful of sizes to get the 'best fit', but can't seem to find anyone who sells them like this. I saw that a few places (ebay/etc) sell 'assortments', but they all seem to be too small, and not particularly specific or organized.

Does anyone know where I could get a jewel of those sizes? 3.5mm OD, ~0.61mm ID.

The jewel I took out was 1.20mm thick, but it is a 'jewel in brass' sorta thing, and the back of it is more brass.

Hopefully the pictures I included are helpful! That jewel has a pivot hold about 1/2 the size though.

I thought about stealing the brass(not jewel) from the other plates, but they have a different OD it seems...

My other thought; is there any way to ream out the existing jewel? Do they make any sort of diamond reamers for jewels?

I'll look into what it'll take to remove it from the Chaton, I never thought about it not being perminent.

Thank you so much for your advice!

I couldn't find any non-destructive way to remove a Chaton, nor a good way to get/fit a new one, but I have 2 ideas:

FIRST: I reached out to a company that makes custom jewels on ali-baba. It'll take a while to get it, but it'll be reasonably cheap. And this is a motor bearing instead of being a part of the motion works, so as long as it is 'close', I suspect it'll be fine.

IF THAT doesn't pan out: Just make a bushing around an easy-to-get jewel as an adapter. I have a LARGE lathe. I'll turn a 3.50mm 'pipe' with a centered but undersized hole in the middle. Parting to length will be difficult to do without the boring bar not going 'straight', so, I'll leave it a little long. I can press it into the plate, bolt the plate to a fixture that'll let me keep it centered, then turn it 'flat with the plate. I figure if I do so on the 'top' of the motor, it is just asthetic.

THEN, pick up a Seitz jewel with the right ID of 0.62mm. They are EXPENSIVE for some reason (like $20 each?), so I'll only have one shot 😀 Using a watchmakers broach, just broach it to the OD of whichever jewel I decide on, then press in the new jewel.

I'll have a bit of work to do with end-shake, but again, based on the fit of the existing motor, I don't think it matters all that much.


ANY flaws you an think of? Am I being a dummy on any of those plans?

SO as an update (I'll copy and paste this to the other thread too):

I got the 0.62mm jewels in today. HOWEVER, when I went to check them, they were too small center hole, so that was a waste of money (er, donation to the parts bin!).

I was able to finagle a way to get the pivot measured by my micrometer, and discovered it is a solid 0.63mm+, so I guess I ACTUALLY need a 0.64mm jewel. I'm a bit frustrated with my previous attempts to measure using the optical comparator, but I figured out that it is likely a tapered hole, so I was measuring a section that the pivot doesn't ride on.

HOWEVER, I ALSO decided to get brave and use my jewel setting tool to try to disassemble the other one, and to my surprised, it was 3 parts! AND, the inner jewel was a sensible 2.00+mm (just oversized 2.00mm, maybe 2.01 if rounding up). I ALSO see that 0.64mmx2.00mm is a common jewel size (https://www.hswalsh.com/product/064...-flat-flat-cylindrical-jewel-hole-mj110-64200).

THOUGH, that is the only source of them I can find. The profile matches too!

DOES anyone know of a good US seller for these? OR someone who at least I can get it a little cheaper from? Else I can just bite the bullet and buy those.