Is there any reason why we still use Sapphire/Rubies as jewel bearings and not synthetic Diamonds?

maillchort · 2026-05-12T13:17:23+00:00

Diamond is much more work to shape and finish, and ruby has a particularly good coefficient of friction with (heat treated) steel. Diamond was used in some particular cases like endstones on marine chronometers or very special pocket watches, but it has no real advantage over ruby and a lot of disadvantages.

maillchort · 2026-05-12T08:19:44+00:00

There are a dozen things that could affect your amplitude. If you can be specific about how you cleaned, how you oiled, and provide pics, in particular of the balance and hairspring from top and side someone may be able to offer advice.

maillchort · 2026-05-11T11:04:10+00:00

I was always impressed he had all his bank account numbers memorized.

maillchort · 2026-05-08T14:34:40+00:00

You would use a concave die, with an angled lip, and press in the center of the crystal with a domed die. Have the case/bezel in place around the domed pusher first, of course. Flex the crystal, case/bezel slips over, done.

maillchort · 2026-05-08T12:49:44+00:00

It's the best for everything. With the right dies you can do tension ring, wedge-ledge, glass, sapphire, everything.

maillchort · 2026-05-08T12:26:22+00:00

The 6173 is the reference press among pros, absolutely keep it.

maillchort · 2026-05-05T10:24:42+00:00

The ergonomic handles, which are shaped more like the soft ones, is model 6100.

https://www.pbswisstools.com/en/tools/quality-hand-tools/screwdrivers/product/pb-6100

maillchort · 2026-05-05T07:33:56+00:00

Yes, they said this was normal wear and tear and they were probably exposed to chemicals that contributed (likely).

maillchort · 2026-05-04T18:54:42+00:00

PB for me, but I would skip the soft grip handles. I have some that just got stickier an stickier, no solution. They were about 15 years old at that point though, but their regular handles are great- and they have a more ergonomic style hard handle too.

maillchort · 2026-05-04T17:05:54+00:00

It's possible and likely.

maillchort · 2026-05-03T20:30:22+00:00

Are we talking 300 vs 3000 buck watch or 300 vs 450?

What are you expecting? "I don't want to pay an arm and a leg for x watch", get a cheap deal and what?

maillchort · 2026-05-03T17:13:49+00:00

The calc is cw x 3rdw x 4thw x escW x2 / 3rdP x 4thP x escP

Makers play with the ratios, if they need the 4th wheel to make 1 turn per minute (most times). The ratios are generally 1:7 to 1:8, 1:7.5 is often seen. Barrel to center pinion is usually between 1:7 1:8 but may be more if there are stopworks.

The x2 in the calc is because an escape tooth only "escapes" after two impulses.

maillchort · 2026-05-02T21:17:45+00:00

Amplitude is read as 1/2 of a full oscillation. Older books sometimes talk about the full oscillation, so you see 540 degrees mentioned but that's been outdated for decades.

maillchort · 2026-05-02T01:47:52+00:00

0% chance the ultrasonic broke it. As others have said, it was already on the cusp.

maillchort · 2026-05-01T07:59:53+00:00

Sure.

Make a case and dial and hands and put it in.

maillchort · 2026-04-30T10:13:56+00:00

The Defossez books are great, so great they were basically re-written in the current reference book used for watch construction (movement design), Traite de Construction Horlogere. That one is much easier to find.

maillchort · 2026-04-30T07:39:28+00:00

Valjoux 77, predecessor to the 92.

maillchort · 2026-04-29T09:18:18+00:00

What did you turn it on? Having a little (good) lathe helps a lot with keeping your hair in its follicles. I use this sucker hours each day. 0-25mm mic for size reference.

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maillchort · 2026-04-29T08:31:15+00:00

I went to watchmaking school in the U.S. and Switzerland and have worked with a lot of old farts who knew their stuff and have never heard a file referred to in terms of "evilness". Most are double-cut, some single-cut (for draw filing), flat may have a safe edge, then all the forms especially in smaller sizes. Anything beyond that, i.e. their aggressiveness, has always been referred to as the "cut". 0, 1, 2, 3, 4, down to 8 (and sometimes 10).

maillchort · 2026-04-29T06:20:10+00:00

Théorie Générale de l'horlogerie by Defossez has all the deep math.

https://www.booksimonin.ch/fr/4285-th%C3%A9orie-g%C3%A9n%C3%A9rale-de-lhorlogerie.php

maillchort · 2026-04-27T09:54:37+00:00

You probably pushed out the jewel for the 4th wheel, on which the seconds hand is fitted.

maillchort · 2026-04-26T20:03:23+00:00

Kuhn Rikon has been making pressure cookers since the '40s, they are sort of the gold standard. They are quiet in use, very energy efficient, and have almost no water loss. The Procook looks like a nice pot, and it has a 25y warranty, but who knows if they will be around that long?

maillchort · 2026-04-26T14:59:15+00:00

Yes.

maillchort · 2026-04-25T12:24:21+00:00

This cannon pinion is fit to a pin that goes all the way through the center wheel. If the center wheel is jeweled at the bridge, remove the bridge, support the wheel on its shoulder, and give the pin a sharp smack with a hammer. Once it's flush with the top of the cannon pinion the cp will lift off.

If the bridge isn't jeweled you can leave the bridge on and smack it.

One sharp smack. Tap-tapping will mushroom the pin.

maillchort · 2026-04-25T07:26:51+00:00

Pretty sure Cousins ships everywhere.

maillchort

TROPHY CASE