Damas GTSP pocket watch

[AndyGSi]

3 hours ago, RichardHarris123 said:

Is it just the light or is the impulse jewel chipped?  

Well spotted, it does look like it's chipped.

[Alun]

Hi All ...

A further update....

It lives!!!!

I replaced the bottom hole jewel. However before I did that I tried to push the original back into place just as an experiment to see how the balance performed.

I managed to move it slightly before it disintegrated and the balance started to swing ...not brilliantly...but was 'better'.

After replacing the Jewell with a 1.2 x 0.12 hole jewel I had to get the end shake just right. Replacing the jewel did lift the roller table off the bottom plate and after a few tweaks with the seitz tool I got the end shake right.....so a lesson learned there.

The balance now swings and the watch runs and has been running for the last 6 hrs with a loss of about a minute...so it's been repaired for £9....which I'm happy with and it now goes into my collection...

Before you ask I have got a timegrapher and will put the watch on test tomorrow....I'm not expecting anything good but considering this 80 year old watch was dead it now lives on to fight another day.

To answer some questions...

Yes the impulse jewel is chipped but I'm not at the level of replacing one of those yet!

I used the Ronda 588 balance staff on what appears to be a Beguelin 23 at a size of 18.5 lignes.

Thanks everyone for your help I'm very grateful to you all. I've learnt quite a bit and bouncing ideas about has given me the confidence to try things out.

My next watch is going to be a nice silver cased Cyma Tavannes 919

 

[AndyGSi]

At least part and information for the Cyma 919 are more readily available.

I just need to find a click spring now for mine and see if she'll run.

[Nucejoe]

On 6/24/2024 at 6:54 PM, nevenbekriev said:

 It is still not clear why flipping the small plate with the cap jewel would lift the pivot. 

 One side of cap stone is flat   " flat "  ,  other side is not  true dome   " domed "   as domes in Kremlin are,   its just a bit domed plus the stones edge is tapered, this all lets it enter the oil sink of balance jewel.

 I am sure you know, pivots are suppose to protrude from the hole a bit, so pivot wouldn't jump out of the hole easy and in the event of a shock. 

Entry of tapered side into the oil sink, reduced the protrusion of the pivot which as a result lifted the balance , as you can see  it did in this case.

This is not a good practice in watch repair, because as I explained above, the said pivot protrusion is needed, to prevent the pivot jump out of the hole of the jewel in the event of a shock.

The problem with OP's watch is " the bottom balance jewel is pushed deep inside the mainplate, thus letting roller table rub and leaving OP  with  excess end shake.

 

Rgds

Joe

[nevenbekriev]

10 hours ago, Nucejoe said:

 One side of cap stone is flat   " flat "  ,  other side is not  true dome   " domed "   as domes in Kremlin are,   its just a bit domed plus the stones edge is tapered, this all lets it enter the oil sink of balance jewel.

 I am sure you know, pivots are suppose to protrude from the hole a bit, so pivot wouldn't jump out of the hole easy and in the event of a shock. 

Entry of tapered side into the oil sink, reduced the protrusion of the pivot which as a result lifted the balance , as you can see  it did in this case.

This is not a good practice in watch repair, because as I explained above, the said pivot protrusion is needed, to prevent the pivot jump out of the hole of the jewel in the event of a shock.

The problem with OP's watch is " the bottom balance jewel is pushed deep inside the mainplate, thus letting roller table rub and leaving OP  with  excess end shake.

 

Rgds

Joe

Hi Joe,

Well, we all know that usually one side of cap stone is domed.  No mater of that, flipping the whole plate with the cap stone in it, without shifting the stone, normally doesn't lift the balance. This is because the plate is normallhy thicker or at least of the same thickness as the stone itself. The flat side of the stone is flush with the plate surface, thus the domed side of the stone should not pop above the other side surface of the plate. This means that flipping of the plate should not lift the balance.

The hole stone MUST stay flat (or domed) side to the cap stone. If flipped, this may cause the pivot not to reach to the cap stone at all. This depends on the stone thickness and the ivot lenght thow

[Nucejoe]

Just now, nevenbekriev said:

Hi Joe,

Well, we all know that usually one side of cap stone is domed.  No mater of that, flipping the whole plate with the cap stone in it, without shifting the stone, normally doesn't lift the balance. This is because the plate is normallhy thicker or at least of the same thickness as the stone itself. The flat side of the stone is flush with the plate surface, thus the domed side of the stone should not pop above the other side surface of the plate. This means that flipping of the plate should not lift the balance.

The hole stone MUST stay flat (or domed) side to the cap stone. If flipped, this may cause the pivot not to reach to the cap stone at all. This depends on the stone thickness and the ivot lenght thow

Hi nev, 

 Balance bottom jewel having been pushed down in the mainplate,  weakens my stance and further supports your point, leaving me not much ground to argue with you.

Surely you agree that  flipping cap stone ( at the least )  is a   cost free    test to produce more data  , before deciding to make a balance staff, which is an advanced task.

Us human beings tend to go the route we are familiar with, sure making a balance staff would have solved the problem, which unlike many here, your good at. 

 Frankly, I am beginning to think, you will make a balance staff to cure headaches with, what's more confusing is; you get good results too.  

Rgds