Reduce pivot length

[FredrikP]

I'm working on a watch were I need to reduce the pivot length. 

How do I reduce the length and what tools do i need to do this ? See attached picture, Red is new length of pivot.

 

[Neverenoughwatches]

Hey Fred, can you give us more details please. In particular why you want to make this modification, but also which movement you are working on and some pictures to help us visualise want you want to express.

When starting to learn watch repair we often make decisions to do things that aren't necessary, that can be achieved in a different and less involved way, that are detrimental to the movement. It can take years of knowledge and experience to learn NOT to make these mistakes. If it seems like a major modification in your head then it probably needs re-thinking and another head to look at the decision in a different way. Not that what you're asking is a major modification, but a simpler answer and process for what you want to achieve might exist.

[Bonefixer]

My first thought is “Why?” And my initial response is “Don’t”. 
 

Even unbending a pivot, they just break. They’re so brittle. I imagine to do what you’re suggesting will require a lathe and a Jacot tool to reburnish the pivot. I can’t imagine something like end cutters would work (like shortening a stem)

[nevenbekriev]

Pivot length reducing is possible by grinding and then burnishing for example. But, before doing something, please explain what You need to achieve, as may be what You think is wrong and will lead to wrong result.

[FredrikP]

I'm working on the citizen 0201 and citizen 1802 movements.

For this specific case the movement has problems with the escape wheel pivots hitting the Upper cap jewel, so that there is friction between the escape wheel pivot and the jewel reducing the amplitude of the movements. (See attached pictures).

To check if this was the problem, I ran the movement without the cap jewel spring, showing very large improvement in amplitude. Also pressing gently on the cap jewel slowed the movement down.

This is my fifth or sixth 0201 1802 movement I'm working on and this specific one had the wrong escape wheel mounted. It was an escape wheel for the 17J movement. I'm guessing that the person that had this movement before me had problems with amplitude and tried to solve this by replacing the 21J escape wheel with a wrong 17J escape wheel.

This seems to be a common problem on the 0201 and 1802 movements, were people mix up the escape wheels. 

The 17J escape wheel has a totally different mechanical design, because the jewels for the escape wheel does not have a cap jewel, so the pivots looks more like the design on the pivots for a pallet fork.

/Fredrik

Edited December 18, 2024 by FredrikP

[nevenbekriev]

So You actually need to use 'normal' type pivots escape wheel in movement with cap jewels. You can use grit 1000 or 2000 sanding paper glued on something flat to gently grind the pivot tips (of course, diamond disks, Arcanzas stone... can be used), BUT the best way is to shift alittle the jewel setting(s) in order to increase the axial free play.

[FredrikP]

So I basically have two options?

1) Move the Z-position by adjusting the position of the jewel inserts in the train bridge/base plate. See golden parts encircled in attached picture of underside of train bridge.

2) Grind the pivots of the escape wheel

For 1) To move the jewels position in Z-direction, I would need to "push" the golden parts in attached picture ? Do I use a staking set or some other tool to do this ?

For 2) How Do I make sure the pivot grind is perpendicular and the "chamfer" is nice and rounded ? What tool / methods?

 

 

 

[Neverenoughwatches]

43 minutes ago, FredrikP said:

So I basically have two options?

1) Move the Z-position by adjusting the position of the jewel inserts in the train bridge/base plate. See golden parts encircled in attached picture of underside of train bridge.

2) Grind the pivots of the escape wheel

For 1) To move the jewels position in Z-direction, I would need to "push" the golden parts in attached picture ? Do I use a staking set or some other tool to do this ?

For 2) How Do I make sure the pivot grind is perpendicular and the "chamfer" is nice and rounded ? What tool / methods?

 

 

 

You have the third option of replacing the escape wheel with the correct one, if thats an expensive option then personally I would make space for the pivots using a jewelling tool, this is much quicker than the adjusting of the  pivots route, fully adjustable and also reversible.  Where as cutting the pivots back and shaping them will be more time consuming to get right, a modification to a consumable part that really has no business being in this movement. 

[FredrikP]

25 minutes ago, Neverenoughwatches said:

You have the third option of replacing the escape wheel with the correct one, if thats an expensive option then personally I would make space for the pivots using a jewelling tool, this is much quicker than the adjusting of the  pivots route, fully adjustable and also reversible.  Where as cutting the pivots back and shaping them will be more time consuming to get right, a modification to a consumable part that really has no business being in this movement. 

Yes, agreed that a reversible option would be the best! The problem I'am having is with the correct escape wheel (ew). I replaced the 17J ew with the 21J ew because the 17J ew did not really work in the 21J movement. The amplitude got really messed up in the crown up, crown down positions.

I'm speculating in that the previous owner tried to replace the escape wheel with a 17J ew, but the movement did not work with this part and then decided to sell it on (to me...).  This is the second time I've seen a movement with the wrong 17J ew mounted in a 21J movement for the citizen 0200, 1800 type.

Ok so I think I will go for the reversible solution with pushing the jewel inserts with a jeweling tool.

I've ordered the following jeweling tool from AliExpress, hopefully this tool do the job. However if this proves to be crap I will pay for a "real" one

[Neverenoughwatches]

3 hours ago, FredrikP said:

Yes, agreed that a reversible option would be the best! The problem I'am having is with the correct escape wheel (ew). I replaced the 17J ew with the 21J ew because the 17J ew did not really work in the 21J movement. The amplitude got really messed up in the crown up, crown down positions.

I'm speculating in that the previous owner tried to replace the escape wheel with a 17J ew, but the movement did not work with this part and then decided to sell it on (to me...).  This is the second time I've seen a movement with the wrong 17J ew mounted in a 21J movement for the citizen 0200, 1800 type.

Ok so I think I will go for the reversible solution with pushing the jewel inserts with a jeweling tool.

I've ordered the following jeweling tool from AliExpress, hopefully this tool do the job. However if this proves to be crap I will pay for a "real" one

This horia clone is not too bad tbf and for the money is worth every penny, but obviously nowhere near the quality of a genuine Horia. The pusher and stump ends will benefit from dressing and polishing. Good magnification is needed when using it to help lining up with the jewels, as the tolerances can leave a little to be desired, yet still a very workable tool . 

[caseback]

5 hours ago, FredrikP said:

 

I've ordered the following jeweling tool from AliExpress, hopefully this tool do the job. However if this proves to be crap I will pay for a "real" one

You might need to take the tool apart to clean it. The most important quality difference between these clones and the original however, is in the pushers and stumps. But if you happen to have a Seitz tool, you could use the Seitz pushers. They are usually 4mm as well. 

[Neverenoughwatches]

Case is right, the pusher and stump quality is quite different, as far as I know and makes perfect sense the Horia steel is better as well. The clones can come with 3mm or 4mm stumps,  but like Case states the pushers are all 4mm, I seem to think that Seitz pushers though are too tight due to a few hundredths discrepancy, dont quote me just yet until I get home and double check that fact. The clone has been known to have some slop in the spindle threads that needs to be taken up before the tool starts to press, cant say I've noticed that with mine. So basically you might get a good clone or a not so good clone depending on the manufacturing that day and the quality control. My experience with it has been ok.

But if I had the chance of a good pre-owned  Horia set for say £400ish or just the tool for £200ish I would grab it, its about a two grand combined new item.

Edited December 19, 2024 by Neverenoughwatches

[nevenbekriev]

This can be done without jeweling tool. If You prepare thin washer (just round piece of thin sheet) that will go through the hole for the setting, then You can put it on the setting and press on it with flat face punch which is wider than the hole. Thus the setting will sink as much as the piece thickness.

14 hours ago, FredrikP said:

For 2) How Do I make sure the pivot grind is perpendicular and the "chamfer" is nice and rounded ? What tool / methods?

this is not balance pivot, so no point to worry about such insignificant details.

[VWatchie]

14 hours ago, Neverenoughwatches said:

You have the third option of replacing the escape wheel with the correct one

Personally, I believe the only reasonable option is to replace the escape wheel with the correct one. The wheel pivots are completely different. In one case, the shoulder is entirely flat, while in the other, it is cone-shaped. Furthermore, the design of the pivot's tip, which rests against the cap jewel, is insignificant in one case and critical in the other. Additionally, I am doubtful whether the oil will properly adhere and remain in place over time.

1 hour ago, nevenbekriev said:

no point to worry about such insignificant details

Depending on the movement and the level of ambition, it can make a significant difference from an aesthetic perspective. My impression is that serious watchmakers always refine the pivot tip after modification, especially on more expensive movements. Personally, I don’t care, not because I’m not serious, but because I’m unsure how to go about it and don’t want to risk potentially damaging something.

[Neverenoughwatches]

3 hours ago, nevenbekriev said:

This can be done without jeweling tool. If You prepare thin washer (just round piece of thin sheet) that will go through the hole for the setting, then You can put it on the setting and press on it with flat face punch which is wider than the hole. Thus the setting will sink as much as the piece thickness.

Thats an interesting idea Nev, not sure I'd be completely comfortable with it, but interesting nevertheless making use of a spacer to adjust the depth of the setting. 

1 hour ago, VWatchie said:

Personally, I believe the only reasonable option is to replace the escape wheel with the correct one. The wheel pivots are completely different. In one case, the shoulder is entirely flat, while in the other, it is cone-shaped. Furthermore, the design of the pivot's tip, which rests against the cap jewel, is insignificant in one case and critical in the other. Additionally, I am doubtful whether the oil will properly adhere and remain in place

I'm still a bit unsure as to which pivot type is being used. The movement has capped jewels for the escape wheel bearings, but the escapewheel being used has simple pivots, thats what I understand . The diagram shows coned pivots to be trimmed, that bit I dont get ? and Fred also said he has the correct escapewheel, but that doesn't work ? Either ?  Or have I lost the plot somewhere in Fred's explanation? 

Ah I've just re-read the posts, Fred is apparently using the correct escapewheel - my mistake - but the pivots are too long and he wants to reduce them.  Sooo maybe the plain pivot escapewheel installer reduced the endshake by moving the settings in to accommodate the plain escapewheel and now they need moving back again to accommodate the coned pivot escapewheel . Phew, could be mystery solved

[nevenbekriev]

48 minutes ago, Neverenoughwatches said:

Thats an interesting idea Nev, not sure I'd be completely comfortable with it, but interesting nevertheless making use of a spacer to adjust the depth of the setting. 

I'm still a bit unsure as to which pivot type is being used. The movement has capped jewels for the escape wheel bearings, but the escapewheel being used has simple pivots, thats what I understand . The diagram shows coned pivots to be trimmed, that bit I dont get ? and Fred also said he has the correct escapewheel, but that doesn't work ? Either ?  Or have I lost the plot somewhere in Fred's explanation? 

Ah I've just re-read the posts, Fred is apparently using the correct escapewheel - my mistake - but the pivots are too long and he wants to reduce them.  Sooo maybe the plain pivot escapewheel installer reduced the endshake by moving the settings in to accommodate the plain escapewheel and now they need moving back again to accommodate the coned pivot escapewheel . Phew, could be mystery solved

Actually, having lathe, one can turn dedicated pusher to make the setting sink as much as needed, the pusher may be turned more if one go is not enough.

I too am not sure what exactly is the case, but if the wheel is of the correct type, then we just see another case showing that swapping parts from different donors sometimes doesn't work fine. Especially for escapement parts, where depth of the escapement can be affected too.

2 hours ago, VWatchie said:

Depending on the movement and the level of ambition, it can make a significant difference from an aesthetic perspective. My impression is that serious watchmakers always refine the pivot tip after modification, especially on more expensive movements. Personally, I don’t care, not because I’m not serious, but because I’m unsure how to go about it and don’t want to risk potentially damaging something.

We speak here about the tip of the pivot. One will need a microscope to observe it, and will have to remove the cap jewel beforehand. If 2000 grid sanding paper used, the finish will be good and with natural rounding too. Yes, no problem to use the jacot tool or the lathe to shorten and burnish the top as by the books, but the performance will not differ at all in both cases

[Neverenoughwatches]

1 hour ago, nevenbekriev said:

If 2000 grid sanding paper used, the finish will be good and with natural rounding too. Yes, no problem to use the jacot tool or the lathe to shorten and burnish the top as by the books, but the performance will not differ at all in both cases

This has me thinking Nev...that a pivot finish with 2000 grit..then no more can be achieved with it ?  An example of -- The Law of Diminishing Returns--.....whereby more effort does not yield any more success. 

[caseback]

25 minutes ago, Neverenoughwatches said:

This has me thinking Nev...that a pivot finish with 2000 grit..then no more can be achieved with it ?  An example of -- The Law of Diminishing Returns--.....whereby more effort does not yield any more success. 

Or worse: 

Schmidt's Law: If you mess with a thing long enough, it'll break..

[nevenbekriev]

2 hours ago, Neverenoughwatches said:

This has me thinking Nev...that a pivot finish with 2000 grit..then no more can be achieved with it ?  An example of -- The Law of Diminishing Returns--.....whereby more effort does not yield any more success. 

Rich, I am talking not about the cylindrical part of the pivot, but only about it's tip.  For sure the movement with 17 jewels (no cap stones on EW) works fine. For sure friction in such wheel will be more in horizontal, no mater how rough will be the tip that rests on cap stone. By the way, when no cap stones on  EW, this helps to minimize difference in amplitudes horizontal/vertical

Edited December 19, 2024 by nevenbekriev

[Neverenoughwatches]

2 hours ago, caseback said:

Or worse: 

Schmidt's Law: If you mess with a thing long enough, it'll break..

Like it

55 minutes ago, nevenbekriev said:

Rich, I am talking not about the cylindrical part of the pivot, but only about it's tip.  For sure the movement with 17 jewels (no cap stones on EW) works fine. For sure friction in such wheel will be more in horizontal, no mater how rough will be the tip that rests on cap stone. By the way, when no cap stones on  EW, this helps to minimize difference in amplitudes horizontal/vertical

No reason to polish the tips like a mirror for horizontal positions but the sides of the pivots will run smoother in their bearings in vertical positions when they are burnished.  

[VWatchie]

16 hours ago, Neverenoughwatches said:

Ah I've just re-read the posts, Fred is apparently using the correct escapewheel - my mistake

Gosh, are you Sherlock or something!? (I'm not being sarcastic!) I re-read it too and was sure he was trying to get the 17J escape wheel to work in the 21J movement, which, IMO, would have been a very bad idea. Anyway, I am glad you could conclude that all that's needed is to move the settings 

It goes to show how difficult communication is (or how thick "some people" are )

[Neverenoughwatches]

1 hour ago, VWatchie said:

Gosh, are you Sherlock or something!? (I'm not being sarcastic!) I re-read it too and was sure he was trying to get the 17J escape wheel to work in the 21J movement, which, IMO, would have been a very bad idea. Anyway, I am glad you could conclude that all that's needed is to move the settings 

It goes to show how difficult communication is (or how thick "some people" are )

The information is in his posts, it just became a bit confusing. 

No not Sherlock Holmes, more like his bumbling buddy Dr. Watson sometimes though

Fred's first cad drawing was also of a cone shaped pivot.  Elementary my good sir

[VWatchie]

12 hours ago, Neverenoughwatches said:

The information is in his posts, it just became a bit confusing.

I feel a bit relieved but also slightly embarrassed because I actually hadn't read the post you quoted. I assumed it was only about the jewelling tool 

[RichardHarris123]

1 hour ago, VWatchie said:

I feel a bit relieved but also slightly embarrassed because I actually hadn't read the post you quoted. I assumed it was only about the jewelling tool 

I had to read it several times before I understood. 

[Geotex]

In this type of situation, could the proposed jewel setting adjustment change the interaction between the escape wheel teeth and the pallets or is it too small of a shift to worry about them no longer being in the right plane?