Balance wheel wobble: possible hairspring out of flat?

[ifibrin]

After taking apart and putting back together my eta 2824-2 more than 20 times, the balance wheel seems to have developed a slight wobble, which wasn’t present when I first got the movement. I inspected the balance wheel pivots, jewel holes, end stones, and novodiac shock spring, and they all seem fine.

Could it be that the hairspring is slightly out of flat (slightly bent) causing the balance wheel to wobble when running? If the hairspring is slightly off axis it seems like it could cause the balance wheel to wobble when the hairspring “breathes”, but I haven’t found anyone else mentioning that. As far as I can tell, the hairspring collet can’t be removed from the 2824-2 balance wheel, so I can’t test static poise.

The amplitude, beat error, are all healthy in both horizontal and vertical positions (DU, DD, CU, CD, CL, CR).

 

 

 

 

 

 

 

Edited September 9, 2021 by ifibrin

[mikepilk]

If you look at the hairspring side-on as it is running , it should be obvious if it is not flat.

The hairspring can be levered off as usual.

The fact that it runs well in all positions suggests that the jewels/pivots are fine. 

[ifibrin]

5 minutes ago, mikepilk said:

If you look at the hairspring side-on as it is running , it should be obvious if it is not flat.

The hairspring can be levered off as usual.

The fact that it runs well in all positions suggests that the jewels/pivots are fine. 

If the hairspring is slightly off horizontal it might not be possible to see visually. I can only see the slight wobble right at the rim of the balance wheel.

[mikepilk]

4 minutes ago, ifibrin said:

If the hairspring is slightly off horizontal it might not be possible to see visually. I can only see the slight wobble right at the rim of the balance wheel.

If the hairspring is off enough to make the wheel wobble I think you would see it. Sounds like you have distorted the wheel somehow. 

If you have some balance truing callipers - put the balance in, without moving the hairspring, and give it a spin to see where the distortion is. You can put the pointer thing on the side opposite the hairspring. You will need to remove the hairspring if the wheel needs bending.

If this was a watch you weren't just using for practice, and it looks OK in all positions, I wouldn't bother tweaking it. 

[watchweasol]

It sounds odd, if the pivots and the jewels are ok check the balance spring side on as mentioned and align it if required, check also the jewel settings for being secure. If you removed them one or other may be a tad loose. The balance spring must be parallel with the balance wheel rim and be even in its movement

[oldhippy]

If the staff pivots are OK and the jewels are also OK then you need to look at the balance wheel to see if it's true. The hairspring doesn't cause the balance to wobble. 

[Nucejoe]

 Exessive side shake or bent pivot causes balance wheel to wobble, or the wheel itself is out of round or unlevel, Either case exasrebates positional variation.

 If you are sure there is a wobble, your TG reading is not credible then. Two wrongs can make it appear right.

Lighting or colour might make the wheel look as if wobbling.

 

 

 

 

[ifibrin]

13 minutes ago, oldhippy said:

If the staff pivots are OK and the jewels are also OK then you need to look at the balance wheel to see if it's true. The hairspring doesn't cause the balance to wobble. 

If the balance wheel isn’t true how would I test this if the hairspring can’t be removed?

[oldhippy]

You say the hairspring can't be removed? Why not, can you post a photo of the balance complete. 

Here is a photo of one. If yours is the same the hairspring can be removed. You remove it in the same way as others. 

[jdm]

30 minutes ago, oldhippy said:

You say the hairspring can't be removed? Why not, can you post a photo of the balance complete. 

I would advise not to remove an hairspring from the balance unless absolutely necessary. That is, when is demonstrated that it must be done to have the watch work as it should.

[oldhippy]

Ifibrin, is perfectly capable of taking apart the movement and putting it back, I see no reason why removing the hairspring from the balance, providing one is careful which has been proved by the previous work.

[Nucejoe]

 Some collets are laser welded to the staff and are not easily removable , such designs aim to preserve the perfect dynamic poise done by machines at production line.

 If you are sure the collet is welded type, I wouldn't attempt removing it. Some trueing can be done even with the H/S on the balance wheel. 

 

 

[oldhippy]

The hairspring doesn't play any part in trueing the balance. 

It causes the balance wheel to oscillate with a resonant frequency when the timepiece is running, which controls the speed at which the wheels of the timepiece turn, thus the rate of movement of the hands.

I would like to know what you do to the hairspring to get the balance to run true? 

[ifibrin]

30 minutes ago, oldhippy said:

The hairspring doesn't play any part in trueing the balance. 

It causes the balance wheel to oscillate with a resonant frequency when the timepiece is running, which controls the speed at which the wheels of the timepiece turn, thus the rate of movement of the hands.

I would like to know what you do to the hairspring to get the balance to run true? 

I haven’t trued the balance wheel. I was wondering how to do it with the hairspring still on. I was under the impression you had to use the truing calipers with just the balance wheel to see if it was in the round first, before dynamic poising.

I don’t remember the balance wheel wobbling so much when I first got it, so I assumed I must have distorted the hairspring at some point over the more than 20 or so disassemblies and reassemblies.

[oldhippy]

If you are careful you can use truing calipers with the hairspring attached, just be careful.  A I have already said the hairspring will not cause the balance to wobble. When you removed all the jewels from the balance stall are you sure you put the right ones back into their correct places. You didn't put the one from the top on the bottom or the other way round. 

[JohnR725]

1 hour ago, ifibrin said:

I haven’t trued the balance wheel. I was wondering how to do it with the hairspring still on. I was under the impression you had to use the truing calipers with just the balance wheel to see if it was in the round first

usually on modern balance wheels you don't have to worry about whether they are round or not. If somebody had restaffed the watch or was really enthusiastic with how they were handling the balance wheel taking out of flat is possible. Then if you're really careful you can still flatten the balance wheel in your truing calipers with they hairspring. But you also want to be really really careful that you don't make things worse. 

12 hours ago, ifibrin said:

Could it be that the hairspring is slightly out of flat (slightly bent) causing the balance wheel to wobble when running? If the hairspring is slightly off axis it seems like it could cause the balance wheel to wobble when the hairspring “breathes”, but I haven’t found anyone else mentioning that.

probably the reason you haven't found anyone mentioning this is because it's basically impossible.

in order for the hairspring to push on the balance wheel and get it to wobble this would mean that the balance jewels would have to be knocked out of alignment. The same jewels that typically hold the balance wheel rigidly except under an extremely hard impact where they move to allow the balance pivots to remain intact. or basically hairspring camp possibly exert that much force.

13 hours ago, ifibrin said:

I inspected the balance wheel pivots, jewel holes, end stones, and novodiac shock spring, and they all seem fine.

if they seem fine but yet you have a balance wheel wobble and obviously they're not fine? Often times beginners will start to look for bizarre things like they hairspring is knocking my balance out of alignment when it's probably something quite simple.

13 hours ago, ifibrin said:

The amplitude, beat error, are all healthy in both horizontal and vertical positions (DU, DD, CU, CD, CL, CR).

I don't suppose we can have a picture or numbers? Or even whatever your timing procedure is how exactly do you do your timing?

 

[ifibrin]

6 hours ago, JohnR725 said:

usually on modern balance wheels you don't have to worry about whether they are round or not. If somebody had restaffed the watch or was really enthusiastic with how they were handling the balance wheel taking out of flat is possible. Then if you're really careful you can still flatten the balance wheel in your truing calipers with they hairspring. But you also want to be really really careful that you don't make things worse. 

probably the reason you haven't found anyone mentioning this is because it's basically impossible.

in order for the hairspring to push on the balance wheel and get it to wobble this would mean that the balance jewels would have to be knocked out of alignment. The same jewels that typically hold the balance wheel rigidly except under an extremely hard impact where they move to allow the balance pivots to remain intact. or basically hairspring camp possibly exert that much force.

if they seem fine but yet you have a balance wheel wobble and obviously they're not fine? Often times beginners will start to look for bizarre things like they hairspring is knocking my balance out of alignment when it's probably something quite simple.

I don't suppose we can have a picture or numbers? Or even whatever your timing procedure is how exactly do you do your timing?

 

I am currently waiting for cousinsuk to restock the novodiac shock springs to see if changing the shock springs make a difference. I realized that the tabs on the novodiac spring holding the end jewels down seem to be getting more bent outwards with time as I keep removing them and re-inserting them each time I do the servicing. In fact, one time they were so bent they couldn’t press the end jewels down when the watch was running and basically rotated themselves out of the incabloc novodiac seating. I bent the tabs of the novodiac spring back slightly to fix it.

For the timing, I wait 5min in between positions for the reading to stabilize.

DU +4; 291deg; 0.0ms

DD +8; 288deg; 0.0ms

CU +4; 272deg; 0.0ms

CD +9; 271deg; 0.1ms

CL 0; 274deg; 0.1ms

CR +10; 272deg; 0.2ms

 

As an off topic point, I was working on a tiny AS 17 jewels movement yesterday (577.301), and the KIF trior shock spring looked like the novodiac. However, the KIF shock block seating only had one groove to rotate the KIF trior spring edges in, compared to the 3 grooves on the novodiac shock block which makes it much easier to rotate the novodiac spring edges in. That was when I realized the novodiac springs might have started out flat...

Edited September 10, 2021 by ifibrin

[oldhippy]

Usually on modern balance wheels you don't have to worry about whether they are round or not. 

 

WHAT? I'M HORRIFIED 

[Nucejoe]

10 hours ago, ifibrin said:

 I realized that the tabs on the novodiac spring holding the end jewels down seem to be getting more bent outwards with time as I keep removing them and re-inserting them each time I do the servicing. In fact, one time they were so bent they couldn’t press the end jewels down when the watch was running and basically rotated themselves out of the incabloc novodiac seating. I bent the tabs of the novodiac spring back slightly to fix it.

Tab being so bent that it fails to push down on endstones, leaves the jewel and housing free to move by the staff pivot as the balance oscilates so balance wobbles. 

I try fitting the shock spring flipped upside down. 

[Nucejoe]

1 minute ago, Nucejoe said:

Tab being so bent that it fails to push down on endstones, leaves the jewel and housing free to move by the staff pivot as the balance oscilates so balance wobbles. 

I try fitting the shock spring flipped upside down. 

You should see the jewel and chaton moving inside the housing.    

[HectorLooi]

Could you post a short video of the wobbly balance? As the others have explained, it could be due to several reasons. A video would help members narrow down the diagnosis.

Is this the same watch that you had problems with the pallet fork1 and oil drop in the balance jewel?

You could get a complete balance (without the balance cock) from Khatena, which would solve the problem of bent pivots, hairspring problems, balance out of true and deformed balance wheel. But that doesn't solve the problem of damaged Incablocs.

[ifibrin]

17 hours ago, Nucejoe said:

Tab being so bent that it fails to push down on endstones, leaves the jewel and housing free to move by the staff pivot as the balance oscilates so balance wobbles. 

I try fitting the shock spring flipped upside down. 

 

17 hours ago, Nucejoe said:

You should see the jewel and chaton moving inside the housing.    

When I hadn't flattened the tabs on the novodiac shock spring, I did see the end jewels vibrating in the shock block, and the balance wheel wobbling by an extreme amount. After flattening the tabs on the shock spring, the end jewels no longer moved/vibrated visually, but the balance wheel still wobbled slightly. I tried pressing very lightly down on the end jewels with tweezers, but the wobbling of the balance wheel persisted; perhaps the wobbling is due to the end jewels being loose on the opposite shock block, since I can't press down on both end jewels simultaneously.

 

4 hours ago, HectorLooi said:

Could you post a short video of the wobbly balance? As the others have explained, it could be due to several reasons. A video would help members narrow down the diagnosis.

Is this the same watch that you had problems with the pallet fork1 and oil drop in the balance jewel?

You could get a complete balance (without the balance cock) from Khatena, which would solve the problem of bent pivots, hairspring problems, balance out of true and deformed balance wheel. But that doesn't solve the problem of damaged Incablocs.

This is from the same practice 2824-2 movement that I have been practicing more than 20 times on; the pallet fork and oil drop issues have been resolved. I could get the complete balance, but don't have the tools to remove the stud from the balance cock. I don't think the shock block settings, or the end jewels (end stones and jewel holes) are damaged, just potentially the shock springs, which have excessively bent tabs from repeated reinstallations...

 

Edited September 11, 2021 by ifibrin

[ifibrin]

23 hours ago, oldhippy said:

Usually on modern balance wheels you don't have to worry about whether they are round or not. 

 

WHAT? I'M HORRIFIED 

Could you explain why this is so in more detail? Also, what is the exact difference between a balance wheel "in the flat" and "in the round"?

[oldhippy]

This will help you to understand about incabloc and how it works. Watch both.

 

 

 

 

[HectorLooi]

1 hour ago, ifibrin said:

I could get the complete balance, but don't have the tools to remove the stud from the balance cock.

You don't really need special tools to remove an Etachron stud. Some people just slip one tip of an old tweezer into the space between the stud and the arm and gently pry the stud off. Use a finger or a piece of rodico to control the stud, as it can fly out quite forcefully. The key word is gently. Don't distort the Etachron spring or you'll have another problem on your hands.

Good luck!