Help with JLC 424 balance please

[Aedui]

Hi All

I have a JLC 424 movement that needs a balance (complete). All the documentation I can find online suggests that calibre 438 parts can be used for 424 calibre (and a host of others). I’ve found 438 balances online (but not 424) so purchased one from the US. When I installed it in the movement the balance pivots don’t seem to be long enough - they’re not broken - and the balance rattles around as if they were.  Does anyone know if there is a specific balance for the 424 or another balance that would work in the 424, as the 438 appears too short? 
 

Many thanks, 
JP

[Nucejoe]

Have you checked upper and lower jewels to the staff? 

Jules borel list JLC 438 to replace 424, if jewels are Ok , I would shim the cock to lower it.

Regs

Joe

[nickelsilver]

I think there is some interchangeability but for sure the winding parts are different (I've made crown wheels for both), so wouldn't be surprised is the staffs or complete balances are different.  Do you have a broken staff? No need to replace the (rare) balance if so.

[Aedui]

Unfortunately I don’t have the original balance. 

[Aedui]

  On 5/7/2021 at 5:30 PM, Nucejoe said:

Have you checked upper and lower jewels to the staff? 

Jules borel list JLC 438 to replace 424, if jewels are Ok , I would shim the cock to lower it.

Regs

Joe

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Jewels are both in good shape. I’m not looking to sell this on so will have a look at shimming (never tried it). Thanks for the advice. 

[VWatchie]

  On 5/7/2021 at 5:30 PM, Nucejoe said:

I would shim the cock to lower it.

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Hmm... this has awoken my curiosity. The only context in which I've heard a shim being used is when we wish to increase the distance between the lower and upper jewels. Can you tell us a bit more? Thanks!

[Nucejoe]

  On 5/8/2021 at 9:22 AM, VWatchie said:

Hmm... this has awoken my curiosity. The only context in which I've heard a shim being used is when we wish to increase the distance between the lower and upper jewels. Can you tell us a bit more? Thanks!

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 Depends on where you place the shim,  if you shim ONLY  the outer side of the cock's locating pins, cock will tilt downward so will lower the jewel setting.

Regs

Joe

 

[Nucejoe]

  On 5/8/2021 at 9:07 AM, Aedui said:

Jewels are both in good shape. I’m not looking to sell this on so will have a look at shimming (never tried it). Thanks for the advice. 

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 Like I explained in response to VWatchie, depending on the location shimmed or jouged you can tilt to lower or raise the cock to a perfect endshake, I cut a piece of thin aluminun foil  to slide aprox 2mm of which  under the cock ( from the outer side of the cock)  , tighten the cock screw, observe the end shake, you can alter the end shake by sliding more or less of the foil under the cock to get to .02mm end shake. 

In your case considering that pivot gets out of the jewel hole, a ticker foil might be needed or give whatever foil you have two, three,,, folds. 

Good luck.

 

 

[Aedui]

  On 5/8/2021 at 1:31 PM, Nucejoe said:

 Like I explained in response to VWatchie, depending on the location shimmed or jouged you can tilt to lower or raise the cock to a perfect endshake, I cut a piece of thin aluminun foil  to slide aprox 2mm of which  under the cock ( from the outer side of the cock)  , tighten the cock screw, observe the end shake, you can alter the end shake by sliding more or less of the foil under the cock to get to .02mm end shake. 

In your case considering that pivot gets out of the jewel hole, a ticker foil might be needed or give whatever foil you have two, three,,, folds. 

Good luck.

 

 

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Many thanks to all, in particular Joe, for the detailed explanations and advice. Very much appreciated. 

[VWatchie]

  On 5/8/2021 at 10:09 AM, Nucejoe said:

if you shim ONLY  the outer side of the cock's locating pins, cock will tilt downward so will lower the jewel setting.

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Thanks Joe! That's very interesting. I never thought of the possibility. Do you have some hands on experience with this? How did it work out?

EDIT: Reading your next post, obviously you do! Thanks!

Edited May 8, 2021 by VWatchie

[Nucejoe]

  On 5/8/2021 at 5:59 PM, VWatchie said:

Thanks Joe! That's very interesting. I never thought of the possibility. Do you have some hands on experience with this? How did it work out?

EDIT: Reading your next post, obviously you do! Thanks!

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Yes.  It works fine and certainly beats jouging. 

[HSL]

  On 5/8/2021 at 10:09 AM, Nucejoe said:

Depends on where you place the shim,  if you shim ONLY  the outer side of the cock's locating pins, cock will tilt downward so will lower the jewel setting.

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Personally, I'm no fan of the shim theory, it might introduce more problems than it solves.
Most pivots are fitted so they will work with the balance jewel lying flat, and the cap jewel too.
If you tilt the balance cock forward or backwards the space for the side shake will be noticeable less
even too small maybe. The end shake will also be affected and the pivot will for sure not rotate correctly against the cap jewel.
A shim which lifts the balance cock straight up is okay if the end shake is to small, even seen people make small notches under the balance.
I rather fix the root of the problem without these shims.
But this is just my opinion. I made a quick drawing of my thoughts.

Edited May 8, 2021 by HSL
swinglish

[rodabod]

HSL is right. There is a time for shimming though - when you do not want to modify the watch movement or the balance staff. 

If this were my JLC, remembering that it is most likely quite a fine watch, I’d maybe look for a suitable staff and also consult the Ronda handbook (or equivalent online) to see what the variations in lengths are. 

[Nucejoe]

  On 5/8/2021 at 8:41 PM, rodabod said:

HSL is right. There is a time for shimming though - when you do not want to modify the watch movement or the balance staff. 

If this were my JLC, remembering that it is most likely quite a fine watch, I’d maybe look for a suitable staff and also consult the Ronda handbook (or equivalent online) to see what the variations in lengths are. 

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I suggest OP practices restaffing and poising on a lower grade oscilator not a new factory made balance complete. 

Regards 

Joe

[Nucejoe]

  On 5/8/2021 at 8:26 PM, HSL said:

Personally, I'm no fan of the shim theory, it might introduce more problems than it solves.
Most pivots are fitted so they will work with the balance jewel lying flat, and the cap jewel too.
If you tilt the balance cock forward or backwards the space for the side shake will be noticeable less
even too small maybe. The end shake will also be affected and the pivot will for sure not rotate correctly against the cap jewel.
A shim which lifts the balance cock straight up is okay if the end shake is to small, even seen people make small notches under the balance.
I rather fix the root of the problem without these shims.
But this is just my opinion. I made a quick drawing of my thoughts.

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You and rodabad are right in principle. I think OP is unlikely to rebuild his balance complete as good as the new one he readily has. 

Regards 

Joe

 

[Nucejoe]

Good thing different views came up in discussion here, just checked, Dr ranfft says;

" This movement was made with varying heights over long period"

therefore, the staff at hand is likely to be way too short to safely compensate for with shims. 

@Aedui , while your balance complete is of the right caliber,  the varying height is the problem here.

Regs 

joe

 

 

[JohnR725]

  On 5/8/2021 at 8:26 PM, HSL said:

Personally, I'm no fan of the shim theory,

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personally I like to know why they were shimming?

  On 5/9/2021 at 2:32 AM, Nucejoe said:

" This movement was made with varying heights over long period"

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we get an interesting problem with this watch. Like the quote above comes from the first link. Typically when I see that I think of evolution improvement and usually a whole bunch of different balance staffs. Like going from no shock protection to a variety of systems.

I've attached a couple links like the second one so we can look up balance staffs there does appear to be a size difference between the two variations of this movement. There is they also the curious fingerprint system that has a minor problem for this watch. Normally on the fingerprint system if all three were identical and they look almost identical in the picture they would only be one picture and all three numbers listed underneath. But the indication is that all three are different. This is where the PDF sucks the resolutions too low the physical book is a little bit better but not much. I think is a difference in some of the hole sizes.

As it appears to be easy for people to confuse which version of a watch they have I'm guessing somebody was confused. If you look at the staff sizing they are slightly different. So if you attempted to put the shorter version in dear watch that would be where the problem would be.

 

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&LeCoultre_424

https://www.balancestaffs.com/product.php

 

 

 

 

[HSL]

  On 5/9/2021 at 4:53 AM, JohnR725 said:

personally I like to know why they were shimming?

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I don’t think there will turn up a good answer to this question, maybe there was someone buying or making a balance staff which were or became slightly too long and came up with the Idea of put a shim underneath the bridge/cock to raise it up and by a coincidence it worked, a quick and dirty method was invented . (Some will say lazy Russian / Chinese watchrepairers invented it, but I don't think it is accurate. I don't think it is a factory feature either, must have been introduced later.  )
Mostly when the balance staff varies in height, the distance to the hub for the roller table and balance also differ a bit. One would think this could be compensated by at least pushing the roller table downwards after shimming so the impulse jewel comes into correct position, but this axis should be slightly conical so the roller table will get a nice and tight squeeze when pushed into place. Pushing the table down would ease the friction holding it in place because the diameter lower down is slightly smaller it would result in a moving impulse jewel instead.
This is an interesting subject and like with everything in horology one could discuss it for pages but it just will render down into the conclusion that one just has to learn either to measure up the old balance correctly before ordering one or learning the skill of making one yourself. I am a bit old-school and prefer the latter, or maybe the postal service in Sweden is so bad I was forced to learn it, can’t remember.

[clockboy]

Is it possible to move the lower Jewel setting in a touch. I have done this in the past using my Seitz jelling tool. Obviously this has its limitations but it has worked for me. Personally I don’t like the shim trick although I have come across this many times when servicing particularly with Soviet watches.

[Aedui]

I just love this forum and the enormous level of knowledge and experience and willingness to help contained within. I’ve learned a huge amount just by reading the posts.  Now for a  confession - I couldn’t understand when purchasing the 438 balance how there didn’t appear to be an option to select a longer balance staff given the possible variations mentioned in this thread. It got me thinking back to some help I received here last year in identifying a JLC movement I had back then. The poster stated “LeCoultre made a number of calibers on that base, the most common being the 424 and 438. You can tell the difference by measuring the movement thickness. 410 is 3.35mm, 424 and 438 are 3.50mm, then 413 is 3.90mm”.  This current movement is visually identical to the 424 I had previously, but I just measured it and sure enough it’s 3.90mm thick, suggesting it is in fact a 413.  Looking on www.balancestaff.com I found the following: the staff for the 413 is indeed longer than the 438(424). Problem now is that I can’t find a 413 balance, but at least I know what I’m looking for. I’m more than a little embarrassed I assumed it was a 424 and hope I haven’t caused any inconvenience or upset to those who have taken the time to suggest solutions or provide contextual information. I’m very grateful for what I’ve learned here and for the time people have taken to respond. PS I have a staking set but, you can probably tell, I’m not very comfortable with replacing the balance staff, even though they are much easier to source than the complete balance so I just need to find me a 413 balance now... anybody know of any going? 

[Aedui]

  On 5/9/2021 at 8:15 AM, clockboy said:

Is it possible to move the lower Jewel setting in a touch. I have done this in the past using my Seitz jelling tool. Obviously this has its limitations but it has worked for me. Personally I don’t like the shim trick although I have come across this many times when servicing particularly with Soviet watches.

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I think shimming was a standard part of the Russian watch manufacturing process.  I had a Poljot last year and the shim under the balance cock fitted the contours perfectly, suggesting it had been manufactured that way. 

[VWatchie]

  On 5/9/2021 at 8:20 AM, Aedui said:

I think shimming was a standard part of the Russian watch manufacturing process.

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I have done quite a few Vostoks (24XX) and all of them had at least one shim under the balance cock and sometimes two. These shims are smooth and quite soft and my guess is that they compensate for irregularities on the surfaces of the main plate and the underside of the cock which could otherwise cause the situation depicted in @HSL's excellent illustration.

Well, JM2C...

[Nucejoe]

  On 5/9/2021 at 8:15 AM, clockboy said:

Is it possible to move the lower Jewel setting in a touch. I have done this in the past using my Seitz jelling tool. Obviously this has its limitations but it has worked for me. Personally I don’t like the shim trick although I have come across this many times when servicing particularly with Soviet watches.

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Doesn't the lower end stone need to be moved as well ?    Lucky if OP can get by with moving the jewel only. 

Regs

[rodabod]

The most common reason for JLCs having different staff lengths for the same caliber is when they use different shock settings. There are sometimes three different types for a single caliber. 

If someone does wish to use a shim rather than finding the correct staff, then you should not that it can only be done to a small degree, otherwise the performance suffers due to the balance jewel being out-of-upright. This is what HSL was explaining already. 
 

 

[Nucejoe]

 Shimming comes to rescue a slightly short pivot  usually due to wear.

I certainly wouldn't recommend shimming to someone who can replace a balance staff with a new one and build a poised balance complete for a JLC.