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Pallet jewel fixation


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Hello,

 

Trying to service an old Pierce watch and relized that one of the pallet jewels had come somewhat lose and was pointing towards the sky.

 

I managed to push it back to what I believe is the correct position but the shellac is obviously cracked and won't support the jewel as desired.

 

I have attached a photo of what it looks like now.

 

Now I'm wondering what would be the best way to fix it again. I have seen and read about shellac flakes, brass plates and open fire and get kind of nervous....

 

My immediate thought was to remelt the existing shellac where the thing sits in my staking tool and then heating locally with my fine tipped soldering iron.

 

Grateful for feedback on my thoughts here as I'm afraid I will just make things worse if I try to remove the old shellac and put new on.

 

And comments/experiences on the melting process are welcome. Is my idea at all viable? e2ae3bbc04d83474e34c5ab391c77f7f.jpg

 

 

 

 

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I suggest a pallet setting tool to achieve a good repair. Heat & shellac is used to attach the stone.  I have positioned the pallets stones to the same depth and it has worked every time. I use this tool to achieve  .

IMG_2331.thumb.jpg.64103b28f59f81e9c4b7fa50439668f1.jpg

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Wow... that looks like something to pull out teeth with... and I can't even guess how to use it.

Thanks for feedback. I'll start googling for more info on these tools and their usage. It looks pretty old so I suppose one has to find them on ebay these days?

To get me started on my project, I hope I won't be damaging anything by remelting the existing shellac and let it fix the stone where it currently is?

At least that would let me assemble and evaluate the rest of the watch. This then assuming that the current stone position is good enough for the movement to run, even though it may not be optimal.

Your thoughts are appreciated.






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Clockboy that is a monster of a tool figuratively speaking, me of little experience would attempt to heat the shellac locally probably with a very small jewelers blow torch, might not be the correct way but it might juSt work, I know it's not the correct way but it might work.

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Thanks Transporter, I will give it a try and let you know how it goes.

Regarding the tool, there's a couple available on ebay. And with one there was a picture showing where to mount the fork and how the long arms over the scales allow for accurate manipulation of the jewel depths.

Intriguing...!


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All you need is here http://raulhorology.com/2012/08/eta-6498-escapement-fitting-the-pallet-staff-and-jewels-setting-depth-of-lock-and-run-to-banking/

By the way, which calibre is that? If it's a Pierce 134 then you will struggle to find a replacement. If it's a 103, then I've managed to find those recently and all is not lost if things go wrong

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Will study with interest. One thing that strikes me when reading quickly: the total lock value is supposed to be 1,5-2 degrees as defined in the drawing. But how do you actually measure to verify those (not so big) no's in real life? Is this where the scales on Clockboys tool come into play?

I think my movement is the 103. I can't find any clear no's stamped but comparing with the pictures on the ranfft website indicate this. I have attached a snapshot of my movement from during my disassembly.

Any hints on where to find parts is appreciated.
0ac0a083683c307f730b3d5282b2dd3d.jpg0ac0a083683c307f730b3d5282b2dd3d.jpg


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As you say, looks like a 103; assuming the diameter is correct then the set lever, set spring and yoke on the other side are the signature.

That being the case, you can get parts here https://www.cousinsuk.com/category/pierce-movement-parts

You will spend a long time looking for the tool which Clockboy has. I've been watching watchmakers tools on ebay for a couple of years and never seen one. The 1.5 to 2 degrees is only there for guidance and you will need to do this by eye. Measuring is an expensive exercise https://www.cousinsuk.com/product/pallet-alignment-tool-bergeon

You will find further explanation of how to check this in Donald deCarle's practical watch repairing book.

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managed to upload the same picture twice...

have attached the other side now.

Thanks for the hint about Cousins. I have bought stuff there before but didn't even bother to look as I thought my Pierce movement would be way to old and lost for anyone to hold parts for. I will definitely get me a spare fork to use if the one I have goes south.

Regarding jewel setting tools you may be surprised by the link below. The guy actually have 2 that looks pretty similar to Clockboys. States he won't ship outside the US though...

http://www.ebay.com/itm/VINTAGE-SWISS-MADE-PALLET-STONE-SETTER-ADJUSTING-TOOL-WATCHMAKERS-TOOL-/152538193413?hash=item2383fc1e05:g:CyoAAOSwCQZZDQLi

 

IMG_0306[1].PNG

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As pallet setting tools are not easy to find, I screwed a handle to an old brass pocket watch main-plate.

You can sit the lever pivot in one of the holes, so that the pallet jewels sit flat on the plate. 

I then heat it over a meths burner. It's not difficult, but go easy with the heat - shellac melts surprisingly easy (75-90C)

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Thanks Mikepilk, that's certainly worth a try. I do have a couple of pocket watches that are beyond repair (at least for me) that I will look at using for this. 

Looking more closely at the dial side photo of my movement I realize that someone has made some interesting improvisations...

as I have seen on other movements, the setting lever spring (at least I think that's the name) has broken off and to avoid that the setting lever clutch falls out someone simply shifted the whole bridge sideways and fitted a washer on top of the exposed wheel to avoid that from falling out and to keep the bridge in a "good" position. 

I guess it somehow works...

And more parts for me to chase down...

 

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  • 3 weeks later...

Hi all!

So I'm back on my Pierce 103 pallet fork problem...

I did some trials to remelt the shellac along the lines proposed by Mikepilk and as such it doable... except that adjusting the pallets is something of a nightmare and I never got the thing to run.

So off to Cousins for a new pallet fork.

Slipping this in there I realize that these old and probably worn movements are possibly not that precise and may vary between individuals. Putting a bit of tension on the main spring, I expect to be able to see the fork jump between banking pins when helping it a bit.

But as can be observed in the photo one of the pallets gets stuck corner-to-corner on the escapement wheel and is not released properly.

I suppose the correct procedure would again be to start fiddling with the pallet position?

But I can't help feeling that shaving off just a tiny bit of the banking pin that's preventing the release as shown in the photo would also allow the pallet to move a bit further and be released.

I would be happy to hear any comments and advice to all this.

31664a4c16993126998b4fa9190ea433.jpg

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In some movements the banking pins can be adjusted as they can be turned in a concentric movement. However shaving off some of the banking pins is real bad idea because you are increasing the pallet folk travel which will cause all sorts of other issues. 

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you guys are not easily fooled into the cheap and dirty short cuts are you...:biggrin:

I saw some articles about adjustable banking pins and how this can influence overall efficiency and power. 

What I note is that my sticking phenomenon doesn't happen all the time but varies with the rotation of the escapement wheel. This leads me to think that the involved pivots, hole jewels, escapement wheel etc. may be somewhat worn and possibly not of the best precision from start.

For the movement to run, I presume all those variations will have to be "handled" by the lock-release pattern between pallet fork and escapement wheel and demanding a larger tolerance for these variations and probably ending with less tight timing accuracy for the movement?

I appreciate your comments to my line of thought here. 

But first step is obviously to get the thing running... 

I'll get back to my trials with the pallet jewel positions. I will have to get some shellac and start the positioning from scratch rather than remelting. 

Thanks for the valuable feedback!

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  • 3 weeks later...

An update....

Got a bar of shellac (will last a million years...) and started all over with the original pallet fork.

First try ended just as the new replacement; no proper release of the escapement.

Second try; pushed the stone in a fraction (at least I think so, it's not easy to tell...).

Amazingly enough the movement kick starts and runs with a very decent amplitude and a (not so good, but something I can live with for now) beat error of 3,5 ms.

Cool... there's hope for the persistent!

Thanks for the advice to stay off the banking pins :-)




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  • 2 years later...
18 minutes ago, margolisd said:

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