Sicura - BFG 158 31/7 Balance Issues

[SAK335]

Hi all, I have a project that's been in the drawer for quite some time that I recently pulled out.  I bought this over 5 years ago and went strong out of the gates but got stalled looking for parts.  Then life happened and while I didn't forget about it, I was just too busy until recently to complete it.

The subject is a Sicura "Superwaterproof 400" with a Baumgartner 158 31/7.  This is a 25 jewel movement with a pin pallet escapement.  Although I had rebuilt it back in 2016, I decided to do another full service on it since I have improved skills substantially lately.  The watch is now back together but the issue I'm having is that the Timegrapher is all over the place and timekeeping is drastically different depending on what position the watch is in.

Looking at the balance spring, it's canted at about a 15-20% angle instead of laying flat.  Recent experience trying to straighten a balance spring tells me that my skills aren't as far along as my enthusiasm, so I'm leaning towards just replacing the spring.  But unlike other hairsprings that I've messed with, the spring on this balance is not attached with a screw, but instead appears to be pressed in.  Can anybody walk me through how I would go about replacing this spring?  If you have a link to either a video or a post that shows this process, I'd be grateful.

I've attached photos of both the spring installed in the movement, as well as the stud and how it's attached to the balance cock.

As always, any other suggestions are welcome.  The watch is otherwise in good condition for it's age and I'm looking forward to getting it on the wrist after so long a delay.

[noirrac1j]

2 hours ago, SAK335 said:

  But unlike other hairsprings that I've messed with, the spring on this balance is not attached with a screw, but instead appears to be pressed in.  Can anybody walk me through how I would go about replacing this spring?  If you have a link to either a video or a post that shows this process, I'd be grateful.

 

Hello and welcome to the forum. I am well acquainted with this movement and have exchanged the hairspring on a number of them. I don't think I have pictures (maybe on my other computer), but the most difficult part is reattaching the tiny brass "cotter" pin into the stud while holding the proper length of hairspring--all while pressing the brass pin in with enough tension and not distorting the new spring.

There are two techniques: leave the brass stud on the balance cock, and secure with Rodico onto a suitable platform to work from there; or remove the brass stud to have a bit more freedom with inserting the end of the new hairspring and brass cotter pin. of course, removing the brass stud means having to replace it on the balance cock. Take a deep breath, choose your poison, and enjoy!

 

Regards,

J

 

[SAK335]

OK, so you're saying that the new spring will arrive without a stud.  So that I need to pull that microscopic pin out, pull the spring out from the other end, then push the new spring through and reinstall the microscopic pin.

It sounds like I'm going to be glad that I have a donor movement (also with a bad spring) in case something unfortunate happens.  I appreciate the feedback.

[noirrac1j]

If you get just the hairspring, you'll need to do the procedure(s) I've mentioned, yes. In addition to pulling out that microscopic pin you'll need a staking set to tighten the hairspring collet on the balance shaft.

 

J

Edited January 25, 2022 by noirrac1j

[JohnR725]

1 hour ago, SAK335 said:

microscopic pin.

The microscopic pin really isn't that microscopic there known as hairspring pins. Up until relative recent times and relative recent would be the last 50 or so years there were used to hold hairsprings to the balance wheel. They used on both the stud and the collet. Then companies like Elgin started pioneering using glue to prevent distortion and problems but they hairspring. Others are using glue us a laser welding to get away from hairspring pins.

5 hours ago, SAK335 said:

Looking at the balance spring, it's canted at about a 15-20% angle instead of laying flat.

This is where would've been nice to have a picture of the balance wheel in the watch so we could see the problem rather than out of the watch where things tend to look much worse. Then the funny angle when you're putting the balance with hairspring back together it should probably be in the watch. Because otherwise you're going to have a probability of there's nothing that says where the hairspring will go into the whole of the stud a new end up with it being in the wrong place and you have exactly what you have now.

And yes they do make a special tool for holding hairsprings studs and balance wheels so that you can put the pen back in and get it simply flat then you'll still have to adjust it in the watch. This problem comes up with a lot of vintage watches for the stud is pressed in CF to make a choice with the one oppressed the stud out or just pull the pin it's usually just easier to pull the pin.

12 minutes ago, noirrac1j said:

If you get just the hairspring, you'll need to do the procedure(s) I've mentioned, yes. In addition to pulling out that microscopic pin you'll need a staking set to tighten the hairspring collet on the balance shaft.

I didn't realize the sole the hairspring separate?

Just as a reminder usually hairsprings are not separate from their balance wheels. There vibrated together as a pair they're always sold as a pair with the exception of American pocket watches which have over coil hairsprings and is a few Swiss watches with typically it's a pair. Then typically the stud would be attached if you had a hairspring all by itself without timing screws it's never going to be on time.

I've attached what I perceive is probably the parts list it's not quite the way you described the movement number but I think it's the right thing and it has a problem of course.

Now you'll notice in the picture there are two separate balance wheels and yes it looks like the stud is there. As I said that is so it can have the timekeeping perfect that's the other problem underpinning hairsprings from their stud you have to get it back exactly where you found it or you'll have timekeeping issues usually get it reasonably close and regulate it.

In any case there's two separate balance wheels and why is that? Then you go on you look at the parts description and it looks like there's two different types of balance wheels because one has a roller and one has a Finger. The end up with separate balance staffs depending upon which one you have and really weird he only have one pallet fork for the roller? You really should have two separate pallet forks I'm guessing there must've been a transition from one type to the other may be? Then you'll notice on the description of the balance wheel how it says regulated? In other words the stud is where it's supposed to be for the watch to keep time. But if you didn't want to deal with the stud issue you could just unpin the hairspring and put it back where you found it but you still have to make the thing go flat because you're never going to get at the lineup where it's supposed to be.

This is where rather than practicing on live watches you should find something throwaway and practice on those hairsprings and don't try to fix those watches just practice bending and straightening hair Springs because practicing on live watches isn't really the best way.

 

BFG_BFG 1582, 158.31.7, 1582.31.7_Smaller.pdf

[Nucejoe]

The hairspring is pinned to the stud and stud is friction fitted into stud-holder hole. 

 The replacement hairspring you will recieve doesn't neccessarily produces 18000bph with the wheels you have, balance&spring need to be compatible and vibrated to build your balance complete, So,You best bet would be to buy a balance complete.

 Judging by your picture, stud holder seems to bend downward, plus seems just a bit of sorting near the stud to get the spring leveled. 

[noirrac1j]

2 hours ago, JohnR725 said:

The microscopic pin really isn't that microscopic there known as hairspring pins. Up until relative recent times and relative recent would be the last 50 or so years there were used to hold hairsprings to the balance wheel. They used on both the stud and the collet. Then companies like Elgin started pioneering using glue to prevent distortion and problems but they hairspring. Others are using glue us a laser welding to get away from hairspring pins.

This is where would've been nice to have a picture of the balance wheel in the watch so we could see the problem rather than out of the watch where things tend to look much worse. Then the funny angle when you're putting the balance with hairspring back together it should probably be in the watch. Because otherwise you're going to have a probability of there's nothing that says where the hairspring will go into the whole of the stud a new end up with it being in the wrong place and you have exactly what you have now.

And yes they do make a special tool for holding hairsprings studs and balance wheels so that you can put the pen back in and get it simply flat then you'll still have to adjust it in the watch. This problem comes up with a lot of vintage watches for the stud is pressed in CF to make a choice with the one oppressed the stud out or just pull the pin it's usually just easier to pull the pin.

I didn't realize the sole the hairspring separate?

Just as a reminder usually hairsprings are not separate from their balance wheels. There vibrated together as a pair they're always sold as a pair with the exception of American pocket watches which have over coil hairsprings and is a few Swiss watches with typically it's a pair. Then typically the stud would be attached if you had a hairspring all by itself without timing screws it's never going to be on time.

I've attached what I perceive is probably the parts list it's not quite the way you described the movement number but I think it's the right thing and it has a problem of course.

Now you'll notice in the picture there are two separate balance wheels and yes it looks like the stud is there. As I said that is so it can have the timekeeping perfect that's the other problem underpinning hairsprings from their stud you have to get it back exactly where you found it or you'll have timekeeping issues usually get it reasonably close and regulate it.

In any case there's two separate balance wheels and why is that? Then you go on you look at the parts description and it looks like there's two different types of balance wheels because one has a roller and one has a Finger. The end up with separate balance staffs depending upon which one you have and really weird he only have one pallet fork for the roller? You really should have two separate pallet forks I'm guessing there must've been a transition from one type to the other may be? Then you'll notice on the description of the balance wheel how it says regulated? In other words the stud is where it's supposed to be for the watch to keep time. But if you didn't want to deal with the stud issue you could just unpin the hairspring and put it back where you found it but you still have to make the thing go flat because you're never going to get at the lineup where it's supposed to be.

This is where rather than practicing on live watches you should find something throwaway and practice on those hairsprings and don't try to fix those watches just practice bending and straightening hair Springs because practicing on live watches isn't really the best way.

 

BFG_BFG 1582, 158.31.7, 1582.31.7_Smaller.pdf 968.28 kB · 0 downloads

Yes that's correct about hairspring being sold together with the stud. There are two separate balance wheels because Baumgartner (BFG) made balances with a roller "finger" (made of brass, I guess) and a roller with a jewel. In both cases the pallets are always pins.

So....when the hairspring on a jeweled balance is distorted, and a cheaper finger balance is available, one either removes the brass stud (I am sure that will be a whole new post) and the collet or remove the hairspring to do a transplant. It ain't called Watch repair Talk for nothing!

 

J

 

J

Edited January 25, 2022 by noirrac1j

[JohnR725]

37 minutes ago, noirrac1j said:

hairspring to do a transplant

Maybe this watch is the exception to the rule but in general you cannot swap hairsprings. Each hairspring is specifically vibrated to that balance wheel. This means you always have timekeeping issues if you swap hairsprings. The only way to deal with that kind of a problem is if they give you a little extra hairspring in case you're running fast you can pin it farther along. Or if the watch had screws on the balance which I see at least in the picture above it does not.

Yes it's the age-old question on this group swapping hairsprings in general is bad. The only way it would not be bad is if the balance wheel has screws which means you can either add or subtract screws to match the balance to the hairspring. Or if they were nice when they penned the hairspring they didn't pin that at the end like they typically do but they gave you little bit extra to play with.. Otherwise each hairspring only goes on the balance wheel it came on you have timing issues

[noirrac1j]

4 hours ago, JohnR725 said:

Maybe this watch is the exception to the rule but in general you cannot swap hairsprings. Each hairspring is specifically vibrated to that balance wheel. This means you always have timekeeping issues if you swap hairsprings. The only way to deal with that kind of a problem is if they give you a little extra hairspring in case you're running fast you can pin it farther along. Or if the watch had screws on the balance which I see at least in the picture above it does not.

Yes it's the age-old question on this group swapping hairsprings in general is bad. The only way it would not be bad is if the balance wheel has screws which means you can either add or subtract screws to match the balance to the hairspring. Or if they were nice when they penned the hairspring they didn't pin that at the end like they typically do but they gave you little bit extra to play with.. Otherwise each hairspring only goes on the balance wheel it came on you have timing issues

]This isn't kind of watch where exchanging hairspring will be a disaster. If it were a different kind of watch? I would say don't do it. I won't get into the mentality of elitist right vs wrong, which I abhor. Of course there are standards and protocols when dealing with precision mechanics, but this ain't one of those instances. But I am an open minded kind of guy, so if you want to discuss hairspring vibrators and the like, that's fine.

Just for the sake of "qualifying" I have worked on many watches. My personal collection includes an Omega Speedmaster and Constellation, and several good makes. I service all of my watches. I have ONE Sicura jump hour with a fine 158 31/7  jeweled pin lever that is still beating after all these years. They may not be refined, but the Baumgartner is robust and stands on its own merits. As these old timers like to say, the balance and hairspring assembly is the "heart" of a watch. Transplant anyone?

 

P.S. @SAK335 I have maybe 5 or 6 hairspring/balances for this caliber balance wheel, If you direct message me and are willing to pay shipping, I will give you a couple. So go ahead, learn and don't be afraid to make mistakes along the way.

Edited January 26, 2022 by noirrac1j

[SAK335]

OK, so there's a lot to digest up there.  

First off, microscopic was a bit tongue in cheek because it seems that way to a relative amateur.

I should have explained that since I have a parts movement, and the balance was already in the watch and running, I used the other balance I have for the photo to show the stud.  Now, there are definitely different types of balances for this movement because the one in the watch right now has a pin and the the one in the photo above has a jewel.  Each also has a different pallet fork that it works with and so if you switch the balance, you have to also switch the pallet fork.  I tried for hours to get the one that was original to the watch (with the jewel) to work, but it wouldn't.

Also, to clarify, the second photo showing the canted spring is how it sits inside the watch right now.

Finally, I spent hours on the Timegrapher yesterday trying to get this thing to time reasonably, and I finally got it to where I had a relatively consistent number dial up and dial down (I think it was +1 and -11 which from what I've read is good for a pin pallet movement.)  Having done that, I re-cased the movement and put a strap on it and wore it the balance of the day, let is sit on the desk overnight, and went for a 5 mile run with it on the wrist this morning.  It's keeping near perfect time after 24 hours, which is frankly a bit shocking, but a nice surprise.  I'm going to keep wearing it and see how it acts over a week on the wrist.  If it keeps running well, I'll probably leave it well enough alone since it deserves to get some wrist time after spending 6 years in a box in a drawer.  I'm not one to let perfect get in the way of good, and my primary consideration for any watch is that it keeps good time.  If that remains the case I'm going to call this a win.

I greatly appreciate all the advice so far, it's been an excellent resource and I'm learning a ton.  I also appreciate the offer for the extra balances; I'm going to hold off for now if the watch is running well.