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Jacot tool and pivot file burnisher question


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The Vallorbe tool is good but for watch work I'd stick with the Bergeon. The Bergeon is tungsten carbide vs hard steel on the Vallorbe, and the Vallorbe has a larger radius for conical pivots that doesn't work well on small watch sizes.

With all commercially made burnishers to be used on a Jacot tool you want a "left hand" tool for holding with your right hand. This is because they are often used with the part in the lathe and the burnisher held under the part, which inverts it.

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The burnisher removes a small amount of material. But that is not it’s purpose. It’s purpose is two-fold. It folds over the surface grains of metal which makes them smooth and achieve a polish. So thi

There were numerous funny little lathe-type tools made for refinishing pivots over the years, usually with one pivot supported in a cone center and the pivot to be polished sticking through a hole in

That all sounds pretty spot on. The Bergeon burnisher works much better haha. Especially for conical pivots, I think you'll find the Vallorbe is only good for large pocket watches (the radius is too l

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29 minutes ago, nickelsilver said:

Like Rodabod said it does remove metal

That wasn't my intention. My only intention for now would be to get the train wheel pivots and pivot shoulders perfectly clean, shiny and as friction-less as possible without removing any (or just a very minuscule amount of) material.

Perhaps some oil soaked peg wood with carved out straight angles and some Dialux rough would be a better idea?

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If you want clean pivots then clean the pivots. If you have pivots that have wear, then removing metal is the only way to restore them*, and the very best way to do that is the Jacot tool.

*to the point of removing the whole pivot i.e. repivotiong, but that's another subject

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32 minutes ago, nickelsilver said:

The Vallorbe tool is good but for watch work I'd stick with the Bergeon.

 

32 minutes ago, nickelsilver said:

With all commercially made burnishers to be used on a Jacot tool you want a "left hand" tool for holding with your right hand. This is because they are often used with the part in the lathe and the burnisher held under the part, which inverts it.

Wow, that's very valuable information considering the price, shipping cost, and time it takes to order these tools!

Having watched the video @jdrichard linked to it should have been evident (2:05:40), but it completely passed me by.

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12 minutes ago, nickelsilver said:

If you want clean pivots then clean the pivots.

And as always, I guess there are many ways to do that. What would be your preferred method?

What I've done so far is place the wheel in a hole in my staking block while holding the arbor or a spoke with my tweezers while working the pivot with some oil soaked peg wood with carved out straight angles and some Dialux rough. It feels pretty shaky, uncomfortable, and not very precise and that's how I came up with the idea of mounting the wheel in a Jacot tool.

Actually, I sometimes I also press down the end of the peg wood into the pivot and rotate the peg wood between my fingers.

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18 minutes ago, nickelsilver said:

If you have pivots that have wear, the removing metal is the only way to restore them

Would I be correct to assume that in most cases that would require replacing the jewel as well?

Sorry for bombarding you with my questions @nickelsilver, but I have tunnel vision on this topic for the time being. 🧐

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8 minutes ago, VWatchie said:

Would I be correct to assume that in most cases that would require replacing the jewel as well?

Sorry for bombarding you with my questions @nickelsilver, but I have tunnel vision on this topic for the time being. 🧐

It depends how much metal is taken off. The more taken off, the more side-shake you will have. 5 degrees of play from vertical is optimal side-shake. Much more than 5 degrees and you will need to think about another jewel with a hole to suit the new sized pivot.

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1 minute ago, Jon said:

Much more than 5 degrees and you will need to think about another jewel with a hole to suit the new sized pivot.

So, with a wide pivot I guess the original jewel most of the time wouldn't have to be replaced, and with a small pivot the need to replace the jewel would be more common, I guess?! Well perhaps self-evident...

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I have a link below that you might find helpful. Scroll down until you get to Joseph School of Watch Making. Then you want to download unit four.

at the bottom of PDF page 7 you going to find something of interest. notice there is a reference to the shape because the shape of the curvature of the burnisher has to correspond the shape of your pivot. Then notice and they follow up with a reference to refinishing. Unfortunately just because something is called a burnisher doesn't mean there is a universal standard of what the finish should be. I've noticed they range from being very course to basically shiny smooth. Elgin watch company made a sapphire burnisher one and was slightly frosted and the other was really really smooth and shiny.

then with your nifty new tool at find something to practice with before jumping in with a good watch. It's an interesting tool to learn how to use and requires a lot of practice if you want to be good with it. But if you know what you're doing you can produce some incredibly beautiful finish on the pivot.

https://mybulova.com/vintage-bulova-catalogs

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51 minutes ago, Jon said:

5 degrees of play from vertical is optimal side-shake.

Sorry for straying from the topic of this thread but I started it so perhaps I'm somewhat at liberty!? 😁

I believe 5 degrees is the consensus. I've read it on a few occasions before, but is there a consensus around end-shake?

I have a vague recollection of @Markmentioning 2/100 of a millimetre from watchrepairlesson.com (I could be wrong), and this statement by Anthony de Haas at A. Lange & Söhne.

If I recollect correctly, Mark doesn't suggest we somehow measure end-shake but develop a feel for it. The 2/100 of a millimetre was just and indication.

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7 hours ago, Jon said:

Industry standard of end-shake is between 0.02 mm to 0.06 mm, so I believe

So, it would seem Anthony de Haas knows what he's talking about. At 40X magnification under a stereo microscope I believe end-shake can be visually assessed pretty precisely. To get a good feel for what the 0.02-0.06 mm feels like I've secured the bridge with one train wheel at a time to get a good look at the end-shake play, and then I've adjusted the jewel until I basically no longer can see any end-shake but still have a spinning wheel. After that, I've adjusted it back so that I can see that <= 0.02 mm gap. Eventually, I hope to be able to assess the end-shake just by feel. Time consuming but good fun 😇

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7 hours ago, Jon said:

Industry standard of end-shake is between 0.02 mm to 0.06 mm, so I believe

are you sure there is an industrial standard?

the problem with a generalization of industrial standard is it can't possibly be correct. That's because the tolerances of a super tiny ladies watch versus an ancient American pocket watch are not going to be the same thing.  even Rolex for their balance and shake is not universally the same for all of their watches.

But what we could have as a general rule of thumb that it would be nice if your end shake is between this and this. Accepting that earlier watches probably were not made to the same tolerances and attempting to modify early watches to fit the perception of a modern standard is not what you're supposed to be doing. Unless you're just doing it to have fun and prove you can do it.

 

 

 

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11 hours ago, VWatchie said:

And as always, I guess there are many ways to do that. What would be your preferred method?

What I've done so far is place the wheel in a hole in my staking block while holding the arbor or a spoke with my tweezers while working the pivot with some oil soaked peg wood with carved out straight angles and some Dialux rough. It feels pretty shaky, uncomfortable, and not very precise and that's how I came up with the idea of mounting the wheel in a Jacot tool.

Actually, I sometimes I also press down the end of the peg wood into the pivot and rotate the peg wood between my fingers.

If you want to clean/polish pivots, you can just rest the pivot on a piece of box wood (or other wood) with a suitably sized groove cut in it and some metal polish of some sort applied. I’ve described it here previously, and I think it’s shown in DeCarle’s book. A think using a jacot tool for that purpose would be over-complicating things. 
 

 

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23 hours ago, VWatchie said:

Actually, I sometimes I also press down the end of the peg wood into the pivot and rotate the peg wood between my fingers.

That is how I *clean* pivots, but added a bit of fine polishing paste to the front of the peg wood before.

It can avoid a jacot tool in many cases.
Remember the many balance wheel pivots spoilt by burnishing. Once cylindric, they have poor tapered shape now.

Frank

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On 10/5/2020 at 10:10 PM, JohnR725 said:

are you sure there is an industrial standard?

the problem with a generalization of industrial standard is it can't possibly be correct. That's because the tolerances of a super tiny ladies watch versus an ancient American pocket watch are not going to be the same thing.  even Rolex for their balance and shake is not universally the same for all of their watches.

But what we could have as a general rule of thumb that it would be nice if your end shake is between this and this. Accepting that earlier watches probably were not made to the same tolerances and attempting to modify early watches to fit the perception of a modern standard is not what you're supposed to be doing. Unless you're just doing it to have fun and prove you can do it.

 

 

 

True... The endshake of a Waltham pocket watch will be very different to a ladies watch of about 6.5 lignes, not just because of size, but also, as you said, manufacturing tolerances, but some figure is helpful for the usual 10.5 to 13.5 ligne wristwatches from the last 50 years or so.

The figure I gave was for modern 'industry' standard, which are mainly Swiss and not an 'industrial' standard. 

I understand that facts and figures tend to be subjective, that's why I end sentences with 'I believe' because it isn't making it an absolute fact, because it is my belief.

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On 10/6/2020 at 11:56 AM, praezis said:

That is how I *clean* pivots, but added a bit of fine polishing paste to the front of the peg wood before.

It can avoid a jacot tool in many cases.
Remember the many balance wheel pivots spoilt by burnishing. Once cylindric, they have poor tapered shape now.

Frank

When I make a balance staff, which is about once a week, I rough turn the pivot leaving about 0.02mm on its diameter and then count on the Jacot to give me a beautiful cylindrical pivot coming off of the conical portion. The whole point of the tool is to get nice cylindrical pivots- with the exception of the 4th wheel runner, which will purposely produce tapered pivots. If a Jacot tool is making tapered pivots then it is out of alignment*, either from being dropped, or having its runners mixed up with another tool. Older tools aren't adjustable, though some have a "headstock" end that can be raised and lowered, but the more modern Steiner/Horia (Hahn) tools provide means to adjust the height and front-back alignment.

 

* in some cases when doing conical pivots, if the burnisher has too large of a radius it will make horrible unusable "tapered" looking pivots. The Bergeon tool above comes standard with a radius that corresponds well to most wristwatch movements. If buying a secondhand Bergeon carbide burnisher beware that the radius on some older ones is larger and really for pocketwatches. The very old Bergeons have a metal cap for the end, the middle period a purplish bakelite cap, and new ones an anodized purplish aluminum cap.

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https://uploads.tapatalk-cdn.com/20201007/450db96f34f26fa9d434e392f9f6be27.jpg This is the one to buy: Vallorbe, please stop looking for othershttps://uploads.tapatalk-cdn.com/20201007/148a198dc7cdcf0572ed5a044b4145ba.jpghttps://uploads.tapatalk-cdn.com/20201007/a8e4e298d49f2b706450ffa14c3671e5.jpghttps://uploads.tapatalk-cdn.com/20201007/7dd42cfb446857ea68557a24213f569b.jpg

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So if one does not possess a lathe, is a Jacot tool basically the only sure fire was to polish pivots if required?

When I was a fitter, I could file a fairly round surface and keep it round, but we weren't talking pivot size.

A Jacot tool seems to be the best way to go.

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11 minutes ago, Michael1962 said:

So if one does not possess a lathe, is a Jacot tool basically the only sure fire was to polish pivots if required?

When I was a fitter, I could file a fairly round surface and keep it round, but we weren't talking pivot size.

A Jacot tool seems to be the best way to go.

There were numerous funny little lathe-type tools made for refinishing pivots over the years, usually with one pivot supported in a cone center and the pivot to be polished sticking through a hole in a thin support. The part (they were mostly intended for balances) would be spun by a bow or other means, and you'd go at the pivot with whatever you like to use. Wood with abrasive, stones, whatever. But there is no support for the little pivot, and using abrasives on pivots could possibly lead to some imbedding in the steel and eventually wearing the jewels, and other stuff that in my mind makes them pretty useless tools.

 

For me the Jacot tool is the tool for finishing pivots. The pivot is supported along its length in the bed, the beds are graduated so that you can actually rely on them to stop your burnisher from cutting at a specific diameter*, and the burnisher does a dual job of both reducing the diameter and making the surface of the pivot significantly harder than before.

 

So yes, a Jacot is the tool for finishing/refinishing pivots whether you have a lathe or not. I just glanced around and I see 3 Steiner jacots of mine in use, my main one and two I've loaned to others in my workshop, and I have two more for backup hahaha. I don't collect them- I just use them so much that it makes sense to have duplicates.

 

*Not all Jacot tools have logical markings on the beds. But most, especially if they aren't totally ancient, will be marked in metric. A bed marked 10 should make a pivot that will fit a 0.10mm jewel (i.e. a few microns less than 0.10mm for the pivot diameter). It's good to get to know your specific tool, they can vary a little.

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1 hour ago, nickelsilver said:

There were numerous funny little lathe-type tools made for refinishing pivots over the years

Excellent and very informative post. Thank you @nickelsilver!

I have somewhat been able to successfully burnish an Omega cal. 268 third wheel pinion side pivot since I started this thread. The pivot was clearly worn so that the top and bottom section of the pivot was thicker than the mid section. I assess the difference was about 2/100  mm. Anyway, before doing this (as this wheel is pretty expensive to replace) I practiced on a few Vostok train wheels (which costs cents, rather than dollars).

Now, I'd be really interested to know what your No.1 tip (or tips) would be for using a Jacot tool and burnisher. Being a hobbyist I have no one to teach me and show me in real life (videos are helpful, but just not the same). What I've come up with so far is the following and I'd appreciate your comments. Please note that my numbered instructions below aren't meant as my opinion about how a Jacot tool should be used. I'm simply describing what I believe might be a correct or decent procedure based on my experience so far, and that's why I'd be interested in your comments.

1. Measure the pivot to be burnished. I use a Seitz jewel gauge as I find the measuring tool included in the Jacot tool kit difficult to handle.

2. Place the pivot in a bed 1 to 2 1/100 smaller than the pivot diameter. For example, if the pivot is measured to 0.20, place the pivot in a bed marked 0.19 or 0.18. Then push the "rod" (with the beds) towards the wheel until the pivot shoulder hinders the rod from going any further. Finally lock the rod in place.

3. Push the "snake teeth" to lock a spoke on the wheel and place a small amount of watch oil on the pivot.

4. Place the burnisher as flat as you possibly can on top of the pivot. For a train wheel the sharp edge of the burnisher goes towards the pivot shoulder and for a balance wheel the rounded edge goes towards the wheel. If necessary, use the coarse side first to shape the pivot perfectly round and then use the smooth side of the burnisher to make the pivot even smoother (mirror like). Yes, I got the Vallorbe burnisher as it was half the price of the Bergeon. For some reason I now wish I had bought the Bergeon instead. Should I get it or isn't it worth it now that I have the Vallorbe?

5. Spin the wheel back and forth with "medium speed" (that is, not excessively slow or fast)  while moving the burnisher back and forth over the pivot in opposite directions of the spinning wheel while trying to keep the burnisher as parallel into the shoulder as possible and as flat on top of the pivot as possible. Hold the burnisher lightly on top of the pivot but not so lightly that the pivot jumps out of the bed. Do not down-press the burnisher excessively on the pivot.

6. Keep going for about 30 seconds (0.20 pivot) and then check the result under strong magnification. I find my 20X/40X stereo microscope very useful in this context.

7. When happy with the result, polish the pivot lightly with a piece of peg wood charged with oil and some rouge (this truly makes it shine), and finally brush it off in some IPA.

I got a decent result following my own instructions, but am I doing anything wrong, or what could or should be improved or changed? I'd consider any comments, long or short, very valuable.

 

 

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