Jump to content

Recommended Posts

Posted (edited)

I have a Girard Perregaux 9377GA I'm restoring and it house a GP caliber 440 movement which is based on AS 1920. Obviously, there is no parts available if i search with GP 440 but with AS 1920, there is a lot so I ordered a balance complete for AS 1920 at Cousins. I received it now but upon checking, I noticed that the GP 440 have the hairspring without a stem, just a long terminal curve and the balance cock have the "plates" to pinch the hairspring while the new balance have a stud attached to the terminal curve and the curve is much much shorter. The "stem" on the balance cock is not removable (I tried pushing but the whole regulator assembly flew off, causing a small heart attack but after 30 mins of fiddling, i managed to reassemble the regulator assembly).

I'm wondering if it is ok if I can pull the old hairspring from the old balance and install on the new balance so the hairspring work with that setup ? Beside the hairspring, the balance looks identical.

Having the terminal curve without a stud attached mean it is more adjustable ? The GP 440 is an observatory chronometer (precursor to COSC) so I guess the adjustability range is greater than a standard movement.

Here is a photo to illustrate the difference :

IMG_1790.thumb.jpg.7e7ae59b0d1c42b9959e4a32b9c01e99.jpg

Edited by Xilikon
Posted

Hairspring off of one might not produce the right beat with the other wheel.

You also degrade the perfect poise each balance complete already has.

Both calibers originally came with chrono grade oscilators whereas I am not sure if the aftermarket one you got from cousins is chrono grade as well. 

So anyway you look at it,  you risk loosing the precision your watch suppose to deliver by transferring hairspring.

Above picture shows a removable stud, transferring a stud to other will not affect your oscilators grade. 

 

Posted
1 minute ago, Nucejoe said:

Hairspring off of one might not produce the right beat with the other wheel.

You also degrade the perfect poise each balance complete already has.

Both calibers originally came with chrono grade oscilators whereas I am not sure if the aftermarket one you got from cousins is chrono grade as well. 

So anyway you look at it,  you risk loosing the precision your watch suppose to deliver by transferring hairspring.

Above picture shows a removable stud, transferring a stud to other will not affect your oscilators grade. 

 

neither cutting hairspring affets the grade,  to get rid of the stud. Cut as close to the stud as you can, use a nail clipper.

Posted
1 hour ago, Nucejoe said:

Hairspring off of one might not produce the right beat with the other wheel.

You also degrade the perfect poise each balance complete already has.

Both calibers originally came with chrono grade oscilators whereas I am not sure if the aftermarket one you got from cousins is chrono grade as well. 

So anyway you look at it,  you risk loosing the precision your watch suppose to deliver by transferring hairspring.

Above picture shows a removable stud, transferring a stud to other will not affect your oscilators grade. 

 

It's not an aftermarket, it's the original A Schild package, hence the surprise.

About poising, I thought it was done without the hairspring so the balance itself is supposed to be well poised ?

 

1 hour ago, Nucejoe said:

neither cutting hairspring affets the grade,  to get rid of the stud. Cut as close to the stud as you can, use a nail clipper.

The original hairspring was attached close to the end of the attachment point on the balance cock.

 

If we look at the original someone else did, it's the same way with the hairspring getting a bit further than the stud :

https://watchguy.co.uk/cgi-bin/media?image=IMG_3313.JPG&email=&wat_id=2270

Posted

To be clear, the left is the old one and correct while the right is the new one with the terminal curve already too short.

The other way is to buy a balance staff but i don't have a staking set and the poising issue would not be resolved (i don't have a staking set or poising tool).

Posted
22 minutes ago, Xilikon said:

It's not an aftermarket, it's the original A Schild package, hence the surprise.

I am not sure original A Schild package is a guarnty that Chrono grade is inside.

I would unpin the hairspring-stud and pin the new spring into it, if you think you want longer terminal curve, shape one on the new hairspring.

Poising anulare balance wheel in no easy task.

Good luck.

 

 

 

Posted
5 hours ago, Xilikon said:

I noticed that the GP 440 have the hairspring without a stem, just a long terminal curve and the balance cock have the "plates" to pinch the hairspring while the new balance have a stud attached

we really need a decent picture of your watch located above the balance. But as a guess your watch has a micro regulator adjustment which probably also adjusts the beat. His so they can get really really good timekeeping imprecision beats of the watch as a guess without seeing it.

Normally we would not recommend swapping the hairspring is but it might be easier just to swap the hairspring if you somehow lucky it might work probably won't but it would be worth a try.

Then for the wording of the link below I'm guessing the watches are identical except? Except yours has a fancy probably patented micro regulator where the other one does not. The problem with cutting the hairspring at the stud is if you find the hairspring is too short you're screwed but I guess is worth the try.

It really would be better if you can find somebody to put a new staff in

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Girard-Perregaux_440

3 hours ago, Nucejoe said:

Hairspring off of one might not produce the right beat with the other wheel.

You also degrade the perfect poise each balance complete already has.

yes the classic problem hairsprings are vibrated to each balance wheel with some minor exceptions. So swapping a hairspring from one identical watch to another isn't usually going to work. The poise probably shouldn't be an issue in except? If both watches are chronometer grade it may not be an issue but if there chronometer grade they spend way way more time making sure everything is perfect. This means conceivably they dynamically poise the balance wheel that is with the hairspring and call it in place and putting a different hairspring and call it would affect the poise but if you don't care about your chronometer grade then and you don't want to do it staff replacement which would be the best thing to do. Yes want to be real careful not to damage or destroy the original balance wheel in case none of this works because then the only option down the road would be to put a staff in and if you destroy the hairspring on the original you're going to be in big trouble.

1 hour ago, Xilikon said:

About poising, I thought it was done without the hairspring so the balance itself is supposed to be well poised ?

static poise without the hairspring dynamic poise with the hairspring both of them statically should be so close it really doesn't matter.

1 hour ago, Xilikon said:

The other way is to buy a balance staff but i don't have a staking set and the poising issue would not be resolved (i don't have a staking set or poising tool).

the poisonings not going to be an issue this is a modern balance wheel it have to try really hard the screw the poise up. So typically people will staff these they won't worry about the poise you just need a staking set and knowledge of how to get the old balance staff out without destroying the balance wheel and of course putting the staff back in and being careful of what everything exactly where you found it otherwise you are going to have a poising issue.

1 hour ago, Nucejoe said:

I am not sure original A Schild package is a guarnty that Chrono grade is inside.

one of the ways we get a clue about this kind of thing is if you look at the manufacturing information sheets that eta has. Chronometer grade they just took way way more time to make sure everything is perfect. But they're also conceivably will be material differences. The balance wheel metal could be different and they hairspring most definitely would be different. the problem with the hairspring being different if it is different like different metals then its characteristics will be different visually they could look identical but if they're not identical in you cut the stud off but you don't care about the stud anyway seem I would go for it might as well try it out. But there is a possibility that typically as we pointed out you can't swap hairspring users always issues and if the characteristics are dramatically different there will definitely be issues but short of putting a new staff on or swapping the hairspringis not much else you can do.

 

 

 

 

Posted (edited)

Thanks @Nucejoe and @JohnR725for the detailed explanations. To avoid confusion, here is the edited photo of both balance (added identification to differentiate which is which) as the reason is that on the old, the bottom pivot broke off :

IMG_1790.thumb.jpg.d12909f137c136b0c916c7bb1c2c0cdd.jpg

As asked, here is the photos of the balance cock in all angles to show the regulator and such :

JPG00005.thumb.JPG.f2d9b091288adc4d15e910893f31f17f.JPG

JPG00006.thumb.JPG.4a66f15ccde472d1ef1829d8f8275ef8.JPG


JPG00007.thumb.JPG.6aad439ad075a9037b4746fdcae89371.JPG

JPG00008.thumb.JPG.86885d391437e75c925f24187ce11f4b.JPG

As you can see, it's not a fixed stud and when i unscrewed this stud screw, the hairspring just fell off like that so I think it's pinched between the brass plates. 

The new balance complete has a attached stud and a different terminal curve. The AS 1920 can be found on many high beat watches from Mido, Longines, Zodiac, Girard Perregaux and others. If we go to the website of a GP 440 disassembly and reassembly, we can notice the end of the hairspring going over the stud.

If I understand the implications well, the best course of action is to keep the original balance wheel and restaff it instead of trying to swap the hairspring to the new balance wheel ? If yes, it mean I must either buy a staking set or send it to a watchmaker to restaff it (main problem is that i don't know anyone willing to do that without requiring the whole watch to be sent for hundreds of dollars).

 

Edited by Xilikon
Posted

If I correctly understand this, you have a broken pivot on GP440 shown above.

Best course of action is to unpin the hairspring from AS 1920.

Shaping the terminal curve of your choice on 1920 hairspring is a bit tricky. 

Note you do not want to remove the hairspring.

 

Posted

In the end, I think the best course of action is to restaff the original balance wheel. However, I don't have a staking set yet (it's in my plans but not ready right now) so I need to find someone who is willing to do that.

I tried reshaping the terminal curve on the new balance but then the problem is that the length isn't the same and there is no much room for the regulator pin. I reshaped it back to the original curve and put it aside (maybe for another AS 1920 or resell).

  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • I was wondering because of the alum idea. 
    • just a reminder about this test is it's not a perfect test it's a quick test. In other words you can adjust the banking pins that are both the same and visually this test will pass everything looks the same but both banking pins can be in the wrong place. although the majority of time when people are playing with banking pins I don't put them in the same place. one of things have to be careful of is I believe some of the pallet fork measuring tools that actually give you the roller jewel size are actually size so that I get confused? What I mean by this is if you inserted a whatever size in and are always told to go a slightly smaller I thought that the gauge itself its number corresponded to give you the exact number. So a lot of it depends upon the gauge itself I think you do want the roller jewel slightly smaller because it does have to fit in the slot and it does have a little bit a play. But if it's too small you will lose energy so does have to be sized right. Oh other things to check is? I'm attaching an Elgin sheet on checking the escapement I've seen references in the past to making sure that the slot in the four corn is nice and smooth and apparently you can end up with a rough slot and then the recommendation is to polisher clean that up. Not sure how well that's really going to work even if it has been the recommendation of other reference materials. yes art full plate watches fun when they don't work. This is where it's nice to have another set of eyes sometimes as maybe they'll find something you didn't  although that can add other issues. The owner of the shop provides himself on his skills of so now two of my watches have relocated to his bench to solve problems both real and imaginary I'm sure that will get fixed eventually hopefully. But still sometimes another set of eyes might see something that you're not. yes this sort of thing can be quite frustrating. Also makes for an interesting problem unless of course you're the one trying to solve the problem that it's a Escapement Elgin setting up the escapement.PDF
    • I’m not to sure mate! I’ve sent a picture! The crown is off a Tissot 1853 automatic limited edition T115427 A GP19 moto go watch!   
    • For years and I'm still using it I've been using something called SeaMonkey? It's a Mozilla product Basically outscore its Firefox plus an integrated email program. But not the same problems here a lot of times when things are upgraded they tend to be now aimed at very specific browsers like Firefox so I've had to switch to Firefox to respond to any of the messages on the group. So yes they do seem to be getting more browser specific and that may be a reason for others having complications especially if whatever you using hasn't been updated. So yes the world is getting more browser specific perhaps for security reasons. Even though I use a product that is updated on a regular basis is still has problems. So whatever you using for browser should be up to date and if is not recognized it's going to be a problem.
    • I did remember to ask at work and minor complication? Well I suppose technically two separate complications. First off glass mineral glass versus Seiko's Hardlex Glass. Don't know if other companies have their own class or not and a basic class for crystals is probably not the same as window glass it would be more transparent. It becomes obvious if you're looking at a sheet of flat crystal glass versus window glass it's definitely more transparent you can see it when you look at the edges of it window glass looks green. No idea how that changes physical characteristics other than optical. Then we also have thickness like the Seiko five's there crystals are really sick compared to other things and I'm guessing that makes things different. In the first link it talks about Sapphire versus mineral glass. One other thing is bothering me though when I'm reading this is where is the source material? What I mean by this is could we end up with multiple generations of salespeople quoting the same sales tactic or information and we don't actually know because you don't have a source reference? Let me quote something off the website it's brittle oh dear I was sad? Except it's not immune to damage it can crack where shatter under extreme force or impact. So what is the definition of extreme force or impact? Then is that more or less extreme then mineral glass?  Then regarding the price difference while back I had asked the owner where the Sapphire came from and basically wherever he can get the cheapest. So typically ordered from a variety of online supply watch parts in the US and  aliexpress China.. Then yes it does make a difference because we go through a lot of glass crystals and sapphire https://thehorologylab.com/sapphire-crystal-vs-mineral-glass-which-is-best-for-your-watch#google_vignette Then I guess one is glass not glass when it goes by another name? Hardlex Looks like it's purely a Seiko product but now I wonder if other watch companies have their own special glass? I didn't remember from past experience my favorite was people exposed to welding you can find little blobs a metal stuck to the watch case the crystal still intact but there's little burnt holes were bits of metal had actually burnt into the crystal but it was still there. Okay website below starts off with Sapphire sounds good but Apparently it can shatter easier then Hardlex. https://theslenderwrist.com/hardlex-crystal/ One other thing is what I'm reading to websites would be back to I want to see the test results? Often times weren't looking for a subject will find websites where I basically called them these are better than that by the way but sometimes I'll find websites that I will call book review websites were basically the review other websites other material and don't really introduce anything new to the subject. As I said these websites look quite nice which is why I'm giving you a link but where's the test results the definition of extreme how extreme to break a sapphire versus a glass or Hardlex?  
×
×
  • Create New...