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Longines Balance staff pivots - are they too flat ?


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Reassembling my Longines 30L, I was expecting a nice high, and steady amplitude. My other Longines all behaved perfectly!

All the checks were passed, barrel+arbor, gear train, pallets, balance etc - all look good, yet it's barely running 😟

I thought I'd put a bigger lens on the microscope and have a look at the balance pivots. The top looks like it could do with a clean.

I know that pivots are sometimes flatter to reduce the difference between horizontal and vertical running,  but do these pivots look too flat?

 

TOP :

top.thumb.jpg.21e0f80eb5d31db35728e07258ac8b23.jpg

 

BOTTOM :

bottom.thumb.jpg.ed617d6c43cf397b8e975c0a45d55631.jpg

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How did the jewels look when you got it apart? The upper pivot looks a little worn, and almost like it has formed a bit of a burr around the tip. This could happen if they were super dry and it ran for quite some time in that condition. If it were mine I would give them a lick in the Jacot tool and round the ends slightly.

 

It is possible though that they were made flat. Some watches have flat pivots to help have closer amplitudes between flat and vertical, but rare to see on mid 20th century Swiss stuff.

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5 minutes ago, nickelsilver said:

How did the jewels look when you got it apart? The upper pivot looks a little worn, and almost like it has formed a bit of a burr around the tip. This could happen if they were super dry and it ran for quite some time in that condition. If it were mine I would give them a lick in the Jacot tool and round the ends slightly.

It looks like it hasn't been apart much. It does look like it's run a long time dry.  There's small dimples in the cap jewels. I think I'll replace them as they are not coloured - They are clear and not easy to find in a cleaning fluid.

I was planning a go with the Jacot tool. I hate trying to round the pivots. You need a lot of magnification, which restricts working space and I'm never sure how much to do 😟

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23 minutes ago, Nucejoe said:

 interesting tool and useful,  I wonder if its cutting edge is to be replaced with new?   Can be sharpened?  or is the tool itself disposed when worn out?  

 

If i remember it wasn't rated by another pro. Maybe the new ones available but said produced the wrong shape at the  pivot end ?

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Playing with the microscope to find a configuration that gives me enough magnification and working depth to shape the pivots on the Jacot tool.

I have the 'standard' Amscope stereo microscope with zoom. I usually use the standard 10X eyepieces with a 0.5X Barlow lens. Which gives a 165mm working distance, and 3.5X to 22.5X magnification. (see table below)

I removed the Barlow lens, and put in 20X eyepieces. This gives a working distance of 100mm (about 75mm from the ring light), and max magnification of 90X.  It seems a good compromise. See pic.

WIN_20240211_09_31_11_Pro.thumb.jpg.29a8619fdbbe0d31a75e47efeba4b364.jpg

image.thumb.png.3e7d3da4833da901b56cd7fd8165eabc.png

 

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18 hours ago, nickelsilver said:

But there is a tool for rounding them

Exactly how round do the pivots get ? 

 

20 hours ago, mikepilk said:

but do these pivots look too flat?

Yes it looks nice and flat. But it be nice if you had a slightly different picture Like at an angle at the end of the pivots so we could see how it looks. Specifically not straight down a slight angle so we can see and look for why it is flat perhaps.

And watch companies are rather interesting they don't always publish their technical but some companies do like eta  it's a separate Guide labeled manufacturing information it has all the really nifty technical stuff like the image I snipped out down below. Notice what it says about the balance staff? Now I'm sure it doesn't actually mean flat like yours it means It has a slight radius to it. Remember their trying to equalize the amplitude in all positions and by the way what does your amplitudes look like in other positions than resting on the flat ends of the pivots.

image.png.d1ae219065d4eaa4fa5e714cfb90d5db.png

Then this websites really not helpful. Conveniently I haven't memorized every single watch in the universe and I was looking for a picture of the movement but I do get a little bit of the history. History brings up a problem typically the older the watch but not always the more likely people have played with it and that means cleaning does not necessarily fix all problems. Like how does your escapement Look?

https://longines30l.com/wordpress/longines-the-movement

 

 

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1 hour ago, JohnR725 said:

Exactly how round do the pivots get ? 

Yes it looks nice and flat. But it be nice if you had a slightly different picture Like at an angle at the end of the pivots so we could see how it looks. Specifically not straight down a slight angle so we can see and look for why it is flat perhaps.

Just for you @JohnR725, I broke out the 2x Barlow lens - wow it's hard to get a steady picture with the microscope head on a long arm, attached to my desk, on a wooden floor.  

The ends are very slightly rounded, but you can also see grooves where the pivots have worn away against the jewel holes (look at the reflected light lines). The pic is the bottom pivot, the top was more worn. I was thinking that a new staff would be best, when it was decided - adding a bit more pressure on the burnisher, the balance jumped out of the Jacot and broke the top pivot 🥴.  (Not the first time I've screwed up on the Jacot tool). Idiot.

I want this watch to run well, so it's probably a good thing to get a new balance staff. I'll change the jewels too. I don't know if jewel holes actually wear? But if it's worn away the pivots, then a paste of hardened steel has been rubbing on the jewel for a long time, so probably. 

The cap jewels have slight dimples in from wear, and they are clear, not red. They're a nightmare to find in a liquid.

1.thumb.jpg.fc610b9b869bec33abe8fa913fe7ea5a.jpg

 

2.thumb.jpg.522d94c711140008d33145e7f5d3f56e.jpg

Edited by mikepilk
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18 hours ago, mikepilk said:

I'm aware of the tool. It's another of those ££ Bergeon tools which I would only use very occasionally.

With rampant inflation, even assets that used to be considered bad investments have become decent investments. It would seem to me that all assets today are better than money, and I would consider Swiss-quality tools an asset as they hardly wear (especially if you're an enthusiast) and are always in demand.

Cousins has this tool for £70. Let's say you buy it and have it in your possession for 10 years and then decide to sell it. I'd be extremely surprised if you then couldn't sell it for at least £70. 10 years from now assuming an average inflation of 3 % (likely way too optimistic) the same tool new will be £95, but I wouldn't be surprised to see it go for way more in 10 years!

So, if you want to preserve some of the value of your hard-earned money instead of seeing it evaporate into thin air and have some real use for your money in the meantime, then buy Swiss-quality tools! 😉

19 minutes ago, mikepilk said:

adding a bit more pressure on the burnisher, the balance jumped out of the Jacot and broke the top pivot

I've been using my Jacot more and more and perhaps one of the most important observations I've made is that the pressure needed varies massively with the diameter of the pivot and pivot shoulder. Escape wheel pivots can be burnished with little pressure in seconds, whereas centre wheels need considerably more pressure and time. So, applying the same pressure and time for all wheels just doesn't work and potentially leads to damage, especially to the arbor and pivot shoulder when too much pressure is applied and the burnisher slides up on the wheel arbor.

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Good points @VWatchie - I realise that you can get your money back on many quality tools. The tool is £70 at Cousins, +VAT = £84.  Maybe I will get one. But I do have the Jacot tool which should do the job, the only problem being the operator. And I prefer to invest my money in the stock markets.

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I have that Bergeon pivot rounding tool but I haven't had great results with it. In a recent video Kalle Slaap told he uses that exact tool for rounding so maybe I could have another try. Then again I have a jacot tool and I just made a rounding burnisher myself. Is it just my imagination or have the prices of jacots gone up a lot in ebay recently? I mean something that used to be 250 is now 400+ eur.

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5 minutes ago, Malocchio said:

I have that Bergeon pivot rounding tool but I haven't had great results with it. In a recent video Kalle Slaap told he uses that exact tool for rounding so maybe I could have another try. Then again I have a jacot tool and I just made a rounding burnisher myself. Is it just my imagination or have the prices of jacots gone up a lot in ebay recently? I mean something that used to be 250 is now 400+ eur.

All second hand tools seem to have gone up a lot on ebay. I think I paid  about £60 for my Jacot tool.

I only have a cheap Indian burnisher. I don't feel inclined to spend £144 on a flat bit of steel with a few scratches on it.

What does your rounding burnisher look like ?

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5 hours ago, mikepilk said:

The ends are very slightly rounded, but you can also see grooves where the pivots have worn away against the jewel holes (look at the reflected light lines). The pic is the bottom pivot, the top was more worn. I was thinking that a new staff would be best,

I was one set a lecture on precision timing and a comment made was the shop the person worked at changed more balance staffs for timing issues then for any other  reason. As you can see from your pivot there is definitely some issues.

6 hours ago, mikepilk said:

when it was decided - adding a bit more pressure on the burnisher, the balance jumped out of the Jacot and broke the top pivot 🥴.  (Not the first time I've screwed up on the Jacot tool). Idiot.

Is that something negative about the tool?

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4 hours ago, mikepilk said:

What does your rounding burnisher look like ?

It's just some escapement file I sanded smooth. The scratches I made with a diamond stone if I remember correctly. Here's a comparison with a Bergeon burnisher.

IMG_20240211_215143.jpg

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18 hours ago, mikepilk said:

But I do have the Jacot tool which should do the job, the only problem being the operator.

It's an absolutely fantastic tool but definitely one of the most practice-intensive. The risk of causing damage is unfortunately imminent, and there is a lot in what @JohnR725 usually says, namely that you have to use the tool every day to become good at it. Now, I personally think that's a slight exaggeration, but there's still a lot to it. For that reason, I understand why many refrain from using it, but if you want to get an optimal result, the pivots must be in as perfect condition as the jewel holes.

16 hours ago, Malocchio said:

Is it just my imagination or have the prices of jacots gone up a lot in ebay recently? I mean something that used to be 250 is now 400+ eur.

No, it's not your imagination! 

There are several explanations for the increase in prices, but the main one I think is the increasing interest in watches and repair. For example, about eight years ago when my interest was first piqued, you could buy a complete large set of used Bergeon mainspring winders on eBay for about £300. At the time I thought it was insanely expensive. That time will never come back 😢

A tip when looking for tools on eBay is to use German and French names and preferably also other languages instead of English. eBay is usually unable to translate the tool names in other languages into English so they do not appear in the search results. Among other things, that's how I managed to find my latest Steiner Jacot tool in near-mint condition for £170 (€195 )by searching the German name "Zapfenrollierstuhl" instead of "Jacot tool". Most of the time German sellers are aware of this and include the English name but once in a while, they don't and then the number of potential buyers shrinks.

About burnishers. I have the Bergeon and the Vallorbe burnisher. The Bergeon is tungsten carbide. The Vallorbe is hard steel. The difference is in my experience night and day. Also, the rounded edge on the Vallorbe is too large for normal wristwatch movements and better suited for pocket watches.

17 hours ago, Malocchio said:

In a recent video Kalle Slaap told he uses that exact tool for rounding so maybe I could have another try.

I'd be very interested in seeing that video. If you could provide a link to it I think many would appreciate it. Thanks!

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2 minutes ago, VWatchie said:

namely that you have to use the tool every day to become good at it.

That is what I was told by the person who taught me how to use the tool. The problem with a lot of hand eye coordination things like this is for somebody it may be insanely easy they could do it in their sleep in the dark and for others they may never Be able to work it out. Unfortunately in the world everybody is different and everyone's experiences different which doesn't necessarily make anyone's experience right or wrong.

 

3 minutes ago, VWatchie said:

No, it's not your imagination!

It seems to be a lot of tools that seemingly at one time were very very cheap now are not. Like the vintage black L&R  cleaning machines with its three jars that came out in the late 40s at around $49. That for quite a few years when he would go to the watch and clock shows or practically begin given away because a review is vintage and typically were missing the jars because are broken. Now on eBay they use the word vintage and was going to say they started 500 but it looks like they're starting at $600 and up. The vintage machines are actually costing more than the machines from India. So yes it seems to be a lot of tools that have gone up in price dramatically.

7 minutes ago, VWatchie said:

the pivots must be in as perfect condition as the jewel holes.

Thinking about must be in perfect condition if you look at the original pictures of the pivots in this discussion with the amount of scoring on the side of the Pivots burnishing it all down so as nice and even isn't that going to shrink the size of that pivot? Then with shrinkage of diameter isn't that going to be a problem?

 

 

 

 

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5 minutes ago, JohnR725 said:

The problem with a lot of hand eye coordination things like this is for somebody it may be insanely easy they could do it in their sleep in the dark and for others they may never Be able to work it out. Unfortunately in the world everybody is different and everyone's experiences different which doesn't necessarily make anyone's experience right or wrong.

That was very wisely said 👍

6 minutes ago, JohnR725 said:

Then with shrinkage of diameter isn't that going to be a problem?

Yes of course! If the pivot is badly worn and you need to shave off so much it causes excessive side-shake you will have to replace the jewel. Not sure how that works for a balance staff though as you would need a same-size chaton with a smaller jewel hole!? If you need to change the diameter of a staff that much I guess it is better to replace it.

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