Damas GTSP pocket watch

[Alun]

Hi everyone.... hopefully someone will be able to kindly help me with a Damas pocket watch I am trying to restore?

It came to me in not too bad a state but it had the inevitable broken balance staff.

I thought hey this will be easy, look up damas, find the calibre, look up the balance staff and replace it...bingo....how wrong could I have been!

There's not really a lot of info about regarding these watches. I learnt that Damas is a trade name of Beguelin and they made a few different 19ligne watches.

Mine measures 18.5 lignes which I found strange as I always thought GSTP watches were 19 lignes(urban myth??)

It has the same bridge layout as a calibre 9 but the click spring and keyless works are different.

I'm guessing there must be a load of these watches about and someone knows the history and ultimately what calibre was used??

So my learned friends what calibre is this Damas watch so I can ultimately find a balance staff to fit it?

Thanks 

Alun

[AndyGSi]

This looks like your movement.

https://ranfft.org/caliber/2336-Damas-185-hunter-Beguelin-BTC

No, sorry not quite the same, should have been this one.

https://ranfft.org/caliber/2334-Damas-185-open-face-Beguelin-BTC

Edited June 13, 2024 by AndyGSi

[Alun]

3 hours ago, AndyGSi said:

This looks like your movement.

https://ranfft.org/caliber/2336-Damas-185-hunter-Beguelin-BTC

No, sorry not quite the same, should have been this one.

https://ranfft.org/caliber/2334-Damas-185-open-face-Beguelin-BTC

Hi there...thanks for your reply....no that's the one I found that has different keyless works and the click is different.

Unless of course my one was a 'newer version' of the calibre.

[AndyGSi]

From Bestfit and Ranfft so think it worth a try getting this balance staff.

https://ranfft.org/caliber/2333-Damas-23-Beguelin-BTC

What measurements can you get from the broken staff?

 

Edited June 13, 2024 by AndyGSi

[Alun]

15 hours ago, AndyGSi said:

From Bestfit and Ranfft so think it worth a try getting this balance staff.

https://ranfft.org/caliber/2333-Damas-23-Beguelin-BTC

What measurements can you get from the broken staff?

 

Hi there thanks again for your help...

I don't think it's that staff.

The broken staff measures (with a tolerance for my crude measuring)

A=402(but has a pivot missing)

B=173

J=132

G=56

K=93

The A length seems too small....but the best fit has the right keyless works.....I wonder if the keyless works is common to another calibre?

Just for info the balance cock is original as the machining pattern on the movement matches...so I'm assuming it isn't a '**BLEEP**' movement.

This is why it's stumped me!

 

[AndyGSi]

Are you using digital calipers to measure the staff?

As far as I'm aware this is the full list of staffs and nothing seems to match yours.

[Alun]

Thanks again for your reply..

I'm using a digital calipers....I can't afford the luxurious and indeed proper measuring instrument for staffs...hence my crude method that requires a tolerance and a bit of 'engineering judgement'

I'm just a keen amateur who like fixing/restoring watches.

Yes I've looked up the Balance staffs for Beguelin ~19lignes watches and two came up the 588 and the 6002.

But the 588 doesn't fit (roller table fouls the bottom plate) and the 6002 isn't that far away measurement wise....so I'm stumped

Hence my question to the forum about the calibre of the watch...was it 'special' ?

[AndyGSi]

So going back to the start.

Which pivot has broken?

Have you got and tried a 588 and how do your measurements of this compare to the actual?

[nevenbekriev]

Guys, I will suggest to do as watchmakers do when they make balance staff for unknown movement and no original staff in it to make measures at all. First thing to do is to determine the size A.  This is done by putting the balance cock in place and measuring the distance between tops of the top and bottom cap jewels. Then measuring the thickness of the cap jewels and subtracting the sum from the distance between tops gives the size A.

For measuring the size B it is needed to fix a 0.15 - 0.2mm plate on top of the pallet fork cock with some rodico, then measure the distance from the top of the plate to top of the bottom cap jewej and subtract the thickness of the cap jewel.

[Nucejoe]

Will you be kind and show the balance complete? 

Is it a flat spring or overcoil ?    Balance staff for over coil is longer.

Rgds

Edited June 15, 2024 by Nucejoe

[AndyGSi]

14 hours ago, Nucejoe said:

Will you be kind and show the balance complete? 

Is it a flat spring or overcoil ?    Balance staff for over coil is longer.

Rgds

It should be a Breguet Overcoil.

[Alun]

39 minutes ago, AndyGSi said:

It should be a Breguet Overcoil.

Hi there thanks for your reply....yes I believe it's a Breguet Overcoil.... please see photo.

[Alun]

16 hours ago, nevenbekriev said:

Guys, I will suggest to do as watchmakers do when they make balance staff for unknown movement and no original staff in it to make measures at all. First thing to do is to determine the size A.  This is done by putting the balance cock in place and measuring the distance between tops of the top and bottom cap jewels. Then measuring the thickness of the cap jewels and subtracting the sum from the distance between tops gives the size A.

For measuring the size B it is needed to fix a 0.15 - 0.2mm plate on top of the pallet fork cock with some rodico, then measure the distance from the top of the plate to top of the bottom cap jewej and subtract the thickness of the cap jewel.

Thanks for your reply....that's great advice. I'll try a do it then best I can.

15 hours ago, Nucejoe said:

Will you be kind and show the balance complete? 

Is it a flat spring or overcoil ?    Balance staff for over coil is longer.

Rgds

I just posted a photo

[Alun]

17 hours ago, AndyGSi said:

So going back to the start.

Which pivot has broken?

Have you got and tried a 588 and how do your measurements of this compare to the actual?

Sorry I must have confused you...many apologies.

The balance staff pivot has broke. The bottom pivot.

I bought and tried a Ronda 588....it has slightly more end shake that I would like but not really bad. However, looking through my microscope I can see the roller table fouling the bottom plate. The roller table has been pushed fully on.

I was asking about the movement because the 588 didn't work...and the alternative seems to be a very very rare 6002....so I'm trying to pull on the expertise of this forum to see if anyone has knowledge/experience of fixing these movements.

If I can get it going it would be a nice working addition to my GSTP PW collection.... cheers Alun

[AndyGSi]

So a couple more questions.

Are you sure it's a 588 and can you measure and compare with the below.

Is the pivot jewel sitting correctly.

 

[Alun]

3 hours ago, AndyGSi said:

So a couple more questions.

Are you sure it's a 588 and can you measure and compare with the below.

Is the pivot jewel sitting correctly.

 

Hi there.... sorry for tardy reply...I'm enjoying father's day!

Good point about the bottom jewell. I did have a look and it appeared ok....but that's not to say it's been 'moved'....I'll try and do the measurement check over the next few days and see where that gets me.

I did check the 588 I bought against it's spec and it checked out ok (obviously with a tolerance)......I bought it from a reputable parts dealer probably everyone on here has used...

One thing that does confuse me is that the watch measured 18.5 lignes bang on....and the 588 Ronda is for a 19 lignes watch....hence my original question about the identity of the watch.

Btw I bought the 588 as it was available and cheap and seemed to be used on quite a few calibres....so I thought I would give it a go as it had two chances pass/fail.....and it failed

[nevenbekriev]

10 hours ago, Alun said:

I was asking about the movement because the 588 didn't work...and the alternative seems to be a very very rare 6002....so I'm trying to pull on the expertise of this forum to see if anyone has knowledge/experience of fixing these movements.

If I can get it going it would be a nice working addition to my GSTP PW collection.... cheers Alun

See, making new staff takes me 30 minutes and I often say that pocket watch with broken balance staff and no other problems is actially watch without problems. So fixing ypu watch is a piece of cake. Just lathe is needed and skills for working on it

[Alun]

7 hours ago, nevenbekriev said:

See, making new staff takes me 30 minutes and I often say that pocket watch with broken balance staff and no other problems is actially watch without problems. So fixing ypu watch is a piece of cake. Just lathe is needed and skills for working on it

Thanks for the great advice....if you would like to donate a lathe to me so I could learn that would be fantastic

[Alun]

On 6/16/2024 at 1:51 PM, AndyGSi said:

So a couple more questions.

Are you sure it's a 588 and can you measure and compare with the below.

Is the pivot jewel sitting correctly.

 

Hi there sorry for delayed reply.....

I measured the length of the staff I bought (588) and it measured 475 long. I used a micrometer and a digital Vernier and they both read the same. 

I also inspected the bottom balance staff jewell a bit more closely and it's a bit low for my liking. I have a seitz jewelling set so I'm going to replace it as I'm not happy with it's condition (looks slightly cracked) 

So I'm now looking for a bottom balance staff jewell...!

[nevenbekriev]

Are You sure that the jewels are pressed in, not rolled? Is the cap stone cracked or the hole stone? Is the flat surface of the cap stone even with the surface of the plate it is in? Does the plate lay tight in it's 'nest' in the main plate?

What happened to the balance staff? I Guess that You have riveted it to the balance, am I right? If so, how the balance stays in the movement? Is there enough distance between it and the pallet fork cock?

[AndyGSi]

I thought the jewel didn't look brilliant from your original photo.

[nevenbekriev]

3 hours ago, nevenbekriev said:

Are You sure that the jewels are pressed in, not rolled? Is the cap stone cracked or the hole stone?

Well, I saw the photos now. The jewels are pressed, so no problem to use the jewelling set. Yes, the hole stone needs to be replaced. But it will not change anything in the positioning in height of the balance.

[Alun]

1 hour ago, nevenbekriev said:

Well, I saw the photos now. The jewels are pressed, so no problem to use the jewelling set. Yes, the hole stone needs to be replaced. But it will not change anything in the positioning in height of the balance.

Hi there....yes the bottom balance staff hole jewell is pressed in and yes I agree, if I don't press the jewell in far enough the end of the pivot won't be touching the cap jewell and the staff would have 'bottomed out' on the hole jewell . Therefore, I think I've found a secondary issue (broken hole jewell) that I would have found out after fixing the staff issue....thoughts?

However, in the back of my mind it's a Ronda 6002 staff (or something that's not a 588). If it is it's game over as I can't seem to find one.

I'll double check the bottom cap jewell is sitting flush with the plate....and I'll give the top jewels in the balance cock another look...just in case.

[AndyGSi]

The 6002 are available but only 0.006mm longer than the 588.

[Alun]

2 hours ago, AndyGSi said:

The 6002 are available but only 0.006mm longer than the 588.

Yes you're right....6 microns isn't going help.....and the B measurement is only 3 microns more too....I'll have a really good look at that bottom jewell set up.