Jump to content

Pocket watch barrel bridge and barrel disassembly


Recommended Posts

I am trying to get an old pocket watch running for a neighbour of mine. It has Louis Eschholz Gotha inscribed in the case, which would make it easily 100 years old. As you can see, there is a key for winding and setting. Here's the partially disassembled movement, still in the case until I worked out how to remove it. It's got a cylinder escapement, so there was an exciting moment when I removed the balance.

DSC01704.thumb.JPG.4cc9d8ccacd1ffbb5286fba29781e265.JPG

What would have been the correct let the mainspring down?

Luckily no damage was done, so I got everything stripped down completely except for the barrel and bridge assembly. Any suggestions how I should proceed? Unfortunately the stop work is incomplete.

DSC01719.thumb.JPG.24ce12d930719e58112fc30d0d8cc50a.JPG

 

 

 

Link to comment
Share on other sites

It may have a two-piece barrel-arbor. That means that in order to remove it from the bridge, you must unscrew the sides of the arbor. That's what I had to do do on a Vacheron that I worked on recently.

When oldhippy wakes up, he may tell you that the arbor has left-handed threads, so be careful, and don't proceed until you know. You can snap the square off the arbor. Sorry to say, but I have done it.

If you indeed got as lucky as you think you did when you pulled the balance, it was probably because there was very little power left in the mainspring. All's well if it ends well. Good luck with the watch.

Edited by MrRoundel
Typo correction
  • Thanks 1
Link to comment
Share on other sites

Today I was an early bird and took some minutes to disassemble a bridge like yours.
I let the pictures speak for them self since there is not that much to comment.
One can like me be lazy and use a wrench as an vice, I also uce a circle to unscrew the nut part of the barrel arbour.
Hope this helps you...
 

1.jpg

2.jpg

3.jpg

4.jpg

5.jpg

6.jpg

  • Thanks 2
Link to comment
Share on other sites

The correct way would be to let the power down with the correct size watch key, by moving the click away from the ratchet, that is located under the little plate, held by the tiny screws. Always remember with a cylinder escapement there are no pallets, so power must be released first before any attempt is made removing the balance.

So you have the barrel and the bridge all together. Remove the barrel cape and remove the spring. The barrel arbor should unscrew and become two pieces, and then it will come away from the bridge. Many are not easy to take completely apart, if you find this my advice would be to clean it as it is, you do not want to damage the arbor. You have the thin plate off which exposes the ratchet, that is the part that is going to be the most dirty part and underneath.

I cannot remember which way the arbor unscrews. Its over 25 years ago for me. Not all arbors have the two holes as in the diagram above. so be careful. 

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

Just got to think about it when I read the part of letting  the power down, these movements have a stop function in the winding.
If you just let the barrel go in an uncontrolled way you might break the stop finger. I often find these ratteling in the watches from now and then, and I can't see it in your picture of the barrel bridge either.
 

Link to comment
Share on other sites

good show,  you did good by not removing the balance till the main spring was let down.  "no pallets in this design!"   a watch "with pallets"  it is proper to remove the ballance before spring let down.   keep up the good work.   vin

Link to comment
Share on other sites

5 hours ago, vinn3 said:

good show,  you did good by not removing the balance till the main spring was let down

No, I did not do good! I did very bad, but got away with it thankfully, as it's not my watch. Lesson learned. Look before you leap and all that. Thanks for the encouragement!

Link to comment
Share on other sites

Quote
12 hours ago, HSL said:

Today I was an early bird and took some minutes to disassemble a bridge like yours.
I let the pictures speak for them self since there is not that much to comment.
One can like me be lazy and use a wrench as an vice, I also uce a circle to unscrew the nut part of the barrel arbour.
Hope this helps you...
 

1.jpg

2.jpg

3.jpg

4.jpg

5.jpg

6.jpg

 

That is (almost) identical to the part I have. Could not have wished for better support, thank you! I do not have the two holes in the barrel arbour, so I can't use a compass or similar to unscrew it. I will try gripping the circumference with something. The action of the spring suggests it is a conventional right-hand thread, correct?

11 hours ago, HSL said:

Just got to think about it when I read the part of letting  the power down, these movements have a stop function in the winding.
If you just let the barrel go in an uncontrolled way you might break the stop finger. I often find these ratteling in the watches from now and then, and I can't see it in your picture of the barrel bridge either.
 

Part of the stop-function (the disc with the finger on it) was missing when I opened the case, so it may well have been broken by another bodger who got there before me. I have the Maltese cross part. I may have a go at making a replacement if it's not too difficult. Would you have a picture of the part I need? How is it held in place?

Link to comment
Share on other sites

17 hours ago, MrRoundel said:

It may have a two-piece barrel-arbor. That means that in order to remove it from the bridge, you must unscrew the sides of the arbor. That's what I had to do do on a Vacheron that I worked on recently.

When oldhippy wakes up, he may tell you that the arbor has left-handed threads, so be careful, and don't proceed until you know. You can snap the square off the arbor. Sorry to say, but I have done it.

If you indeed got as lucky as you think you did when you pulled the balance, it was probably because there was very little power left in the mainspring. All's well if it ends well. Good luck with the watch.

Thanks for the encouragement. I think it has to be a right-hand thread on the arbor, due to the direction the spring is acting. The mainspring did indeed have quite a bit of power left in it. There was a buzzing and a whirring for quite a while after I pulled out the balance, so it seems I have been very lucky indeed! I will check everything carefully again for damage. I have already found one cracked jewel.

Link to comment
Share on other sites

Good job. That was smart using that compass(?) for a "special wrench". I can't remember what I used. It might have been a junky set of tweezers. I'll remember the compass-tool.

Bob Tascione has a nice animation of the workings of the stopworks. In it, you should be able to see the shape of the part you need. It's on youtube. Search his name and you'll find it. Good luck.

Link to comment
Share on other sites

Glad I could help a little bit and Yes it's is a ordinary right hand thread on them.
It's quite common those are missing, as a fact I looked for one for a IWC 66 a while but ended up making one.

If you look a the sqare stem you will find a small hole in it, it's where you put a thin pin in to lock the finger piece into place.

  • Like 1
Link to comment
Share on other sites

10 hours ago, vinn3 said:

good show,  you did good by not removing the balance till the main spring was let down.  "no pallets in this design!"   a watch "with pallets"  it is proper to remove the ballance before spring let down.   keep up the good work.   vin

     no problem; keep going, you are learning to hate that type of escapment.  vin

  • Like 1
Link to comment
Share on other sites

22 hours ago, HSL said:

Glad I could help a little bit and Yes it's is a ordinary right hand thread on them.
It's quite common those are missing, as a fact I looked for one for a IWC 66 a while but ended up making one.

If you look a the sqare stem you will find a small hole in it, it's where you put a thin pin in to lock the finger piece into place.

Many thanks once again HSL! It looks like making one may be beyond me, but I will have a go and report back. The square stem does indeed have a hole for a pin. Some of the pin is still in there!

Link to comment
Share on other sites

  • 1 year later...
On 7/16/2019 at 2:47 AM, HSL said:

Today I was an early bird and took some minutes to disassemble a bridge like yours.
I let the pictures speak for them self since there is not that much to comment.
One can like me be lazy and use a wrench as an vice, I also uce a circle to unscrew the nut part of the barrel arbour.
Hope this helps you...

4.jpg

5.jpg

6.jpg

I am not here to judge your tools selection as I used the same "professional set" ?

However, I believe your comments above "split the barrel arbour" and "the gear is friction fitted and can be pressed out" maybe misleading. At least in my case, it was a screw-in two part arbour, not press fitted. And there was no way I could split the arbour as those two holes are ... just two holes...

IMG_2582 - Copy.JPG

Link to comment
Share on other sites



  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • in general this shouldn't be any change. but in general questions like this it be nice to know the specifics of the watch in other words how was it performing before it was cased up and what is it doing now.
    • just as a reminder this watch is a Swatch group product. This will bring up a problem like spare parts and technical information. that I found some links to some information on when I talk about your watch and some of the technical and basically your watch is equivalent to 2834-2 for which I'm attaching the technical sheets. But equivalent does not mean exactly the same you want to do a search on the group for C07 as we discussed this watch before including the technical differences how it's supposed to be regulated and basically because it's watch group there is no parts availability. https://calibercorner.com/eta-caliber-c07-xxx/   https://www.chrono24.com/magazine/eta-movements-from-the-2824-2-to-the-powermatic-80-p_80840/ https://www.watchuseek.com/threads/h-10-movement-details.4636991/ eta CT_2834-2_FDE_481857_15.pdf
    • people be honest.... Swatch is evil for the watchmakers and repairers, BUT not everything in watches from Switzerland is from the Swatch-Group. As far as i know, Selitta got sacked by Swatch as a Movement-Assembler for them and they started to produce Movements in their own Name with slight Modifications. As far as i know, they sell Parts to the Market for their Movements. In most cases, if a ETA-Movement fails, it is a valid Option to replace it with a Selitta Movement, which i consider the Solution for this Mess with the Swatch-Group...... I have no Connection to anybody at Selitta, but being a Swiss-Guy, i still like to have Swiss-Made Watches, but not from the Swatch-Group.   ok ? regards, Ernst
    • Just one more greedy act by Swatch. They started a number of years ago here in the US..cutting off supplies to watchmakers that could build complications that many Swatch houses couldn't even touch. Old school masters who had gone through some of the most prestigious houses in the world. Otto Frei has some statements on their page about it. I tell all my customers to avoid new Swiss watches like the plague,..unless they just want an older one in their collection that still has some parts out on the market, or they have really deep pockets and don't mind waiting months and paying through the nose to get it back. Plenty of others to choose from..IE Seiko,..or other non-swiss brands Even a number of Chinese brands are catching up with the Swiss,..and I think that in time, their actions will be their downfall
    • Yes. If that's not what you are experiencing...start looking for something rubbing. A 1st guess is that one of the hands is rubbing against the hole in the center of the dial. Especially if you now have lower amplitude in face up/ face down positions.
×
×
  • Create New...