Pallet fork jewels, CousinsUK sizing unclear ....

[Endeavor]

Hello All,

While manipulating the entry-& exit pallet jewels of an old lever pocket-watch, the impulse face of the entry jewel chipped. The exit-jewel is worn too, so I like to replace both jewels.

CousinsUK has a nice selection, but I'm not clear about their sizing

The jewels I have are 0.3mm x 0.5mm, the 0.3mm being the part which friction-fits in the fork-slot. Any bigger and you can't slide the jewels in, smaller the jewel drops out.

What does CousinsUK understands with "Width", in my case the 0.3 mm part or the height of the jewel, the 0.5mm part?

And if "width" is the 0.30mm size, how "high" is the jewel? (I need for sure the 0.5mm or slightly more)

Link to CousinsUK pallet jewels (wrist & pocket watch) : https://www.cousinsuk.com/search?searchTerm=Pallet (Entry) Jewels%2C Seitz

Edited December 4, 2022 by Endeavor

[VWatchie]

I don't know the answer to your question but my guess is that the width, as stated on Cousins' site, is the width between "the part which friction-fits in the fork-slot". That is, in your case 0.3 mm. Hopefully, you'll get a more precise answer but if not and you need to take a chance, I'd say go for 0.3 mm.

[Endeavor]

I get the same feeling, that the "width" is the thickness of the jewel what fits in the fork ...... however, I need the 0.5mm (preferable a bit more) from, for a lack of a better description, top to bottom. CousinsUK doesn't give any data on that ....

Perhaps I've to write to them tomorrow and ask ......

[nickelsilver]

Yes, it's the size of the fork slot. You don't get to specify the height, or length, it's just a "standard" size Seitz determined is sort of universal. You also have to accept the angle on the jewel face, which is for most older watches noticeably different from entry to exit, but a replacement jewel might not have exactly the same angle as the original (there are many many geometrical variations of the lever escapement).

 

But, most of the time a Seitz jewel works just fine.

[Endeavor]

2 minutes ago, nickelsilver said:

You also have to accept the angle on the jewel face, which is for most older watches noticeably different from entry to exit, but a replacement jewel might not have exactly the same angle as the original (there are many many geometrical variations of the lever escapement).

Thanks for the info

I guess I haven't much choice regarding the angle. The old pallet jewels, with the escapement wheel running on the low side of the jewels, were badly worn and when trying to manipulate them, they just seemed to crumble apart (?)

Entry-jewel with worn edges and scores over the impulse face;

Exit-jewel;

We have to see how the movement runs on new stones ....

[nickelsilver]

Some cheaper old watches have garnet pallet jewels. Garnet sits between 6.5 and 7.5 on the Mohs scale, where ruby is 9 (diamond is 10). I wonder if that's what you have there? Ruby pallet stones can wear, but you don't see it that often. Garnet is way more "crumbly" too.

 

When pushing in pallet stones brass or nickel tweezers are good, and I usually do the final pushing with pegwood. It's very easy to chip them. When adjusting, to come out I use a broken oiler with the tip stoned to a screwdriver shape, get in the back of the slot and twist (on a heater). To go in it's pegwood.

[Endeavor]

@nickelsilver @JohnR725and all other bright minds who can help me ....

The new Bergeon pallet jewels have finally arrived (took 3 weeks from the CousinsUK to DK). The old Garnet pallet jewels measured 31x50 (that is 0.31x0.5mm). With the escape wheel running on the low side of the jewels (as can be seen in the pictures above), I was hoping to get 31x60 or so. CousinsUK only gives the size of the fork-slots and the height is determined by Bergeon (discussed above).

The fork-slot size 31 wasn't available either, so it was either 30 or 32. To be sure of a fit, I ordered 30 and they indeed slide in, but with hardly any resistance.

The problem is the delivered height; only 40 (0.40mm). The height of the fork is 50 (0.5mm) This means, when the jewels are installed flat on the underlying surface, that the escape wheel will run on the edge of the jewel or even lower.

Adjusting the running height of the escape wheel is, in my eyes, problematic having burnished jewels.

When installing the pallet jewels, the fork (50) lays upside down and to ensure that the escape wheel teeth are hitting the jewels, the 40 jewels have to be installed on the high-side of the fork, leaving at least a 10 (0.1mm) gap underneath. Of course it would be even nicer if I could install them with a 15 gap, but lets first try to achieve the bare minimum.

Question is; how am I going to do that while ensuring that the jewels are installed horizontally?

Edited December 22, 2022 by Endeavor

[JohnR725]

I thought you were going to get us sort meta-jewels in addition to the specifically sized jewels? Because of your lucky in the assortment may be something is thicker perhaps

Also wishful thinking on my part but typically escape wheels like the taper their teeth so their axes dinner on the outside. That means you just have to get them to a lineup with wherever the jewels Are if you can. I'm not sure if it would be advisable to place two of them stacked on top of each other it probably be tough to keep them both exactly in alignment.

Usually when you're doing jewels in a pallet fork you have it in a tool designed to hold it when you're putting the stones in. I'm not necessarily referring to the very expensive escapement meter which sometimes on eBay isn't necessarily expensive there was one the other day was actually quite reasonable in price which I found quite amusing is normally there almost 1000 and whatever your current C is. But even just a simple brass plate with holes drilled in it C can put the pallet fork arbor into the hole would allow you to put the stones in and have them parallel to the pallet fork itself and then you can warm that in the alcohol lamp being careful not to get the pallet fork in the lamp otherwise the pivot can turn a pretty blue color. But I'm Going to deny all knowledge of how that could actually happen.

 

[Endeavor]

Thanks @JohnR725. The assortment I bought was for in this case not much of a help. In the assortment, the biggest jewels I could find were 30x40, the same as the specifically sized. I didn't compare them to see whether there was a pair (entry & exit), but if there was/is, that would have saved me quite a lot of money.

Having slept about the problem, I'm going to try to raise the jewels but putting 0.2mm stainless steel wire in the fork slots with the jewels on top. This makes 20 + 40 = 60. With the fork being 50 than the jewels should be 10 higher. If that works, that would be perfect and the same as effect a 30x60 jewel.

I do have a Bergeon prototype () clamp pallet warmer with a hole drilled in it, but not drilled through, thereby avoiding the burned pivot problem. I have to admit, the prototype isn't that slick (engineers are working on it), but it works

Stacking the jewels gives 2x 40 = 80 and with the fork being 50, that gives 30 excess on top, with the top-jewel having only 10 (+ shellac) to "hold-on". But stacking is perhaps an idea if the wire-method doesn't work. Using a much smaller jewel as "filler" could perhaps also work.

Edited December 23, 2022 by Endeavor

[Endeavor]

Just an update on how I got on with the pallet-jewels of CousinsUK, or rather Bergeon.

As described above, since the escape-wheel was running on the low side of the fork-jewels, it would have been nice to get jewels with the correct fork-slot size and higher than the thickness of the fork. The jewels would than "stick-out" underneath the fork when installed, covering the escape-wheel teeth fully. I didn't get the desired jewels, so some improvisation had to be done.

In order mount the jewels higher (or lower if you wish, with the fork in the correct position) a 0.2mm SS-wire was used as a temporary "filler" underneath the jewels. This worked very well.

Not having the jewels with the desired height, it was a total pain having to use these "filler-wires" each time the setting depth of the jewels had to be adjusted. Not having the proper equipment either, it took me many, many times to install the fork, check the setting depth, taking the fork out, place it on the pallet-warmer, insert the 'filler-wires, heat everything up and adjust one jewel at the time.

Initially the comment @nickelsilver wrote (https://www.watchrepairtalk.com/topic/23176-1975-omega-861-amplitude-after-24hrs/#comment-196690) was above my head. But now, after having played for days with these jewels until I finally got them right, I fully understand what he, and @JohnR725 said.

Drop-lock, draw (run to banking), total lock, horn clearance, safety-pin clearance and very important: moving one jewels effects the other, have become fully clear to me.

A very important lesson learned and I realize now that adjusting the jewels on the 1975 Omega 861 isn't going to be as easy as I initially though. The Omega has a shallow total lock on the exit and a heavy total lock on the entry jewel. Pushing the entry jewel in means extending the exit-jewel.

Anyhow, the new Bergeon jewels are installed at exactly the correct height, or low, so the escape wheel teeth do run fully on the impulse planes. Now I can concentrate on the balance timing screws

So, thanks to all for your excellent help and wishing you already a very prosperous 2023 !! 

 

 

Edited December 29, 2022 by Endeavor

[dadistic]

Outstanding!

Really neat to see you accomplish this, it's an inspiration.

Cheers!

[VWatchie]

10 hours ago, Endeavor said:

The Omega has a shallow total lock on the exit and a heavy total lock on the entry jewel. Pushing the entry jewel in means extending the exit-jewel.

This really has me confused. Have you now been able to determine that this is by design by Omega? In my (limited) experience the locking depth should be the same on both the entry and exit jewel, no? 

[Neverenoughwatches]

28 minutes ago, VWatchie said:

This really has me confused. Have you now been able to determine that this is by design by Omega? In my (limited) experience the locking depth should be the same on both the entry and exit jewel, no? 

From everything I've read up to now. Thats how i also understand it. This is where a nice really big pocket watch comes in handy to play with.

1 minute ago, Neverenoughwatches said:

From everything I've read up to now. Thats how i also understand it. This is where a nice really big pocket watch comes in handy to play with.

I think its time for a re-read

[nickelsilver]

28 minutes ago, VWatchie said:

This really has me confused. Have you now been able to determine that this is by design by Omega? In my (limited) experience the locking depth should be the same on both the entry and exit jewel, no? 

Should be, but on a production piece from several decades ago entirely possible that stuff slips through. They didn't have amplitude reading on the machines then (with some exceptions), it probably "kept good time" and off it went.

 

This was always an issue for me doing vintage work for a major maker (vintage being older than 40 years- going back to 1900); they still wanted 270 min horizontal and a delta of 30s max, on some really tiny calibers 100 years old. They would pay for it, but in some cases after 40h of work they'd say "ok good enough".

[JohnR725]

2 hours ago, nickelsilver said:

They didn't have amplitude reading on the machines then (with some exceptions), it probably "kept good time" and off it went.

You shouldn't say things like this on this group where amplitude is the most important thing and timing is of no real consequence at all. Yes there was a discussion a while back where they were obsessed with amplitude and I finally asked about the timekeeping but that was not the most important aspect of the watch running it was the amplitude.

 

[Endeavor]

10 hours ago, VWatchie said:

This really has me confused.

You are right, both should be equal, but the Omega I have they aren't.

I was describing what my Omega has; a "heavy" total lock on the entry and a "shallow" on the exit. This is not how it supposed to be and perhaps that may be the reason why I can't get the amplitude (sorry John ) much higher than 220 degrees horizontally on a full wound. And yes, the amplitude after 24 hrs DU is still above the Omega threshold of 200 degrees.

Having discovered the differences in the total lock of both jewels, I thought that this may be the reason of the relative low amplitude? (new main-spring and an escape-wheel recoil when the power-train runs out of power)

Here some pictures of my Omega 861;

Fully wound Dial-up;

After 24hrs;

But in vertical positions it is down to;

So far, due to lack of knowledge and experience, I haven't touched the jewels and perhaps I never will?

Knowing pretty well the history of the watch (it used to be my brothers) it was serviced 2x or 3x by a "prestigious" watchmaker in town. I doubt it very much that he would have touched the pallet-jewels and I think this is, as Nickelsilver pointed out, how they were set at the Omega factory.

Edited December 30, 2022 by Endeavor

[praezis]

5 hours ago, JohnR725 said:

You shouldn't say things like this on this group where amplitude is the most important thing and timing is of no real consequence at all. Yes there was a discussion a while back where they were

Objection, John! Imo amplitude is just 2nd place, after the main topic: beat error.

Frank

[Endeavor]

11 hours ago, nickelsilver said:

Should be, but on a production piece from several decades ago entirely possible that stuff slips through. They didn't have amplitude reading on the machines then (with some exceptions), it probably "kept good time" and off it went.

If this is indeed the case, and my watch is one of those which has "slipped through", would it than be wise for me to tinker with it? We have had this discussion before (https://www.watchrepairtalk.com/topic/23176-1975-omega-861-amplitude-after-24hrs/#comment-196625  

Now having worked on, and still am, on the pocket-watch jewels, without proper equipment, a 0.005mm adjustment as suggested in the link, is by hand not easy. It is going to be more a stroke of luck.

When I received the watch in 2017, the amplitude wasn't super high either (https://www.watchrepairtalk.com/topic/6842-omega-861-speedmaster-mark-ii/

Perhaps the watch has always had a "low" amplitude, and my brother blissfully unaware, never noticed?

Basically, the my question is, leave it or do an attempt to correct the jewels in the hope that the amplitude would increase?

Edited December 30, 2022 by Endeavor

[JohnR725]

21 minutes ago, Endeavor said:

Perhaps the watch has always had a "low" amplitude, and my brother blissfully unaware, never noticed?

What's interesting is for people work in a Swatch group service center all they have to do is regulate to a window. They don't have to please the people obsessed with numbers they just have to hit Somewhere within the window. I don't know how the factory does it though whether the factory actually tries to regulate closer to the actual specification or not.

Then of course the problem is you can't see the amplitude on your watch. I suppose if you have really good hearing you could hear out of beat so that might be an issue. But now we have these nifty timing machines with numbers to please.

[Endeavor]

7 minutes ago, JohnR725 said:

But now we have these nifty timing machines with numbers to please

A blessing or a curse ?

[Neverenoughwatches]

8 hours ago, JohnR725 said:

You shouldn't say things like this on this group where amplitude is the most important thing and timing is of no real consequence at all. Yes there was a discussion a while back where they were obsessed with amplitude and I finally asked about the timekeeping but that was not the most important aspect of the watch running it was the amplitude.

 

Enter the timegrapher, the root of amplitude obsession.  The only things a watchwearer wants to know is does it keep reasonable time and not make me late and  if and how often do i have to wind it up.

8 hours ago, JohnR725 said:

You shouldn't say things like this on this group where amplitude is the most important thing and timing is of no real consequence at all. Yes there was a discussion a while back where they were obsessed with amplitude and I finally asked about the timekeeping but that was not the most important aspect of the watch running it was the amplitude.

 

Just on a quick question John, a high amplitude of 300 + . What would be your thoughts with extra wear with that ?

[VWatchie]

22 hours ago, Endeavor said:

A blessing or a curse ?

I have learned the hard way that TMs should be taken with a big pinch of salt, at least the Chinese ones, and maybe even the expensive Swiss ones(!?).  I have had several examples where the amplitude has been shown wrong (always too low in comparison with reality). You have to get the gain setting on the TM right to get near the truth. I still remember being very disillusioned about an Omega cal. 268 until you suggested I'd take a slo-mo video of the balance which proved the amplitude was fine and the TM was off.

On 12/30/2022 at 5:18 AM, JohnR725 said:

You shouldn't say things like this on this group where amplitude is the most important thing and timing is of no real consequence at all. Yes there was a discussion a while back where they were obsessed with amplitude and I finally asked about the timekeeping but that was not the most important aspect of the watch running it was the amplitude.

The amplitude demands almost killed my interest in watch repair. I've had several movements that I put my heart and soul into which still didn't reach the "WRT amplitude standard" but still proved to be excellent timekeepers in the end. I have developed a very different attitude towards amplitude, which has helped preserve my interest.

On 12/30/2022 at 11:12 AM, Endeavor said:

Basically, the my question is, leave it or do an attempt to correct the jewels in the hope that the amplitude would increase?

It may or may not make a substantial difference. I'd wear it for a month to see how it fares as a timekeeper. If it fares well, you may not want to touch it, and if not I definitely think it's worth a shot. Personally, I would adjust the jewels either way for the satisfaction of knowing that the jewels sit as they should. It is not as fiddly as it may seem (and I'm not saying that in an attempt to impress anyone). A practice round (or possibly two) on a scrap fork should be enough to give you the required experience to do it on your precious Omega.

[mikepilk]

I had a similar problem with as As 1701- everything looked good and I couldn't get amplitude above 230°. (Like prasezis and JohnR725 I'm not fanatical about amplitude and beat error, but I like to see at least 240° when everything is looking good). 

Like yours, the lock of one pallet jewel was too deep. At Nickelsilvers' suggestion, I pushed it in a bit (easy to do) - and I gained 45° amplitude to 275°. 

https://www.watchrepairtalk.com/topic/24872-as-1701-this-may-have-me-beaten-what-can-i-do-next/

[Endeavor]

31 minutes ago, VWatchie said:

Personally, I would adjust the jewels either way for the satisfaction of knowing that the jewels sit as they should. It is not as fiddly as it may seem (and I'm not saying that in an attempt to impress anyone). A practice round (or possibly two) on a scrap fork should be enough to give you the required experience to do it on your precious Omega.

I've just been through a pallet-jewels change-out exercise, a total improvisation as the original 120 years old jewels just happened to be "out-of-stock".

With the Omega 861, I'm just like you, the knowledge that the jewels sit as they should before the total re-assembly. I just need to order a few bottles of adrenaline

18 minutes ago, mikepilk said:

I gained 45° amplitude to 275°

I wish I could say the same after I'm done

Well done !

Edited December 31, 2022 by Endeavor

[JohnFrum]

46 minutes ago, VWatchie said:

You have to get the gain setting on the TM right to get near the truth. I still remember being very disillusioned about an Omega cal. 268 until you suggested I'd take a slo-mo video of the balance which proved the amplitude was fine and the TM was off.

 

I saw the same thing with my newly acquired 1900 TM and the 7S26A I serviced. Ended up using a gain setting that agreed with the watchtuner phone app and keeping the same position of the stem against the microphone bracket to have the same before and after conditions.