Can a warped hairspring cause extremely low amplitude?

[GregG]

I have a Bulova 3AK, and I've tried my best to service it.  I disassembled it, put it through the ultrasonic with a degreaser, reassembled and oiled it everywhere that is necessary.  Unfortunately, the amplitude of the balance is extremely low  Changing position is enough to stop it from running.  I can't imagine any weak points in my process, except for the hairspring.  It's not completely messed up, but it's not really spiral-ish anymore.  There are some definite spots where it's warped.  I read that low amplitude issues are usually a result of gear train or mainspring problems, but the mainspring and gears are still working, clean, and oiled.  Can the hairspring be the source of my issues?

Thanks 

Edited May 13, 2021 by GregG

[Nucejoe]

Observe the rate as well,  if it runs real fast along with low amplitude, the coil could have fouled itself. 

H/S coil, should be flat, level and concentric. a warped coil can,

Foul itself,  that is;  a circle riding on top of an adjacent one in which case your oscilator runs noticably fast. 

In case the rate is decent, low amplitude is caused by excessive friction at pallet jewels, faulty pivots, broken jewels to the balance staff, excessive end shake non of which would normally alter the rate drasically.

Check end and side shakes on staff, also see if roller table rubs on the fork.

Did you run the oscilator in ultrasonic? You could easily lost all shelac off of impulse jewel.

Regs 

Joe

 

 

 

 

[GregG]

Hi Joe, thanks for the reply.  Yes, the balance seems to be running fast.  Does a new balance complete sound like the appropriate remedy for this?

[HectorLooi]

Try demagnetizing it first. If that doesn't work, remove balance cock and rinse in lighter fluid or One Dip and try again. Sometimes old oil is really stubborn. 

Did you remove the balance jewels to clean? Did the upper and lower jewels get mixed up?

[jdm]

On 5/13/2021 at 5:50 AM, GregG said:

Changing position is enough to stop it from running. 

Likely because the hairspring is touching in some positions.

On 5/13/2021 at 5:50 AM, GregG said:

 Can the hairspring be the source of my issues?

Yes, absolutely.

[JohnR725]

What was the condition of the watch in before you service? Did you change the mainspring? Then yes if the hairspring is touching anything other than where it's supposed to be you can lose a heck of a lot amplitude. Then a fun not mistaken this is a really tiny watch which means everything has to be perfect especially around the balance.

[GregG]

9 hours ago, HectorLooi said:

Try demagnetizing it first. If that doesn't work, remove balance cock and rinse in lighter fluid or One Dip and try again. Sometimes old oil is really stubborn. 

Did you remove the balance jewels to clean? Did the upper and lower jewels get mixed up?

Hi Hector.  I will try demagnetizing.  Everything was sparkling when I took it out so I don't think it's a gummed up oil issue.  I did remove the balance jewels, but I kept them separate so I don't think that is an issue either.

6 hours ago, JohnR725 said:

What was the condition of the watch in before you service? Did you change the mainspring? Then yes if the hairspring is touching anything other than where it's supposed to be you can lose a heck of a lot amplitude. Then a fun not mistaken this is a really tiny watch which means everything has to be perfect especially around the balance.

I don't think it was running before I serviced it, or if it was, it was barely running.  I don't remember honestly, because I was sitting on it for months before trying to service it.  The hairspring was always in shoddy condition.  Not completely mangled but definitely not in prime condition.

[Nucejoe]

Are you set up to show a close up video of the coil when running.

 

 

[GregG]

1 hour ago, Nucejoe said:

Are you set up to show a close up video of the coil when running.

 

 

Hi Joe, I can try but I can't guarantee the quality.  I'm going to be pointing my phone camera through my loupe.

[GregG]

Video file.  Amplitude is maybe 60 degrees.

[Nucejoe]

Hi,  Clear top and side view of the coil, often helps to spot the issue. 

 Sticking or even badly fouling H/S doesn't normally affect the amplitude this much. 

Acts as though its nearly fluttering at the pallet&escape, As if all the shelac was lost in ultrasonic and let pallet move.  Need more knowledge here.       @HSL  , @JohnR725  .  

[HSL]

I usually put the balance in mounted on the main plate when cleaning in an ultrasonic, it hasn’t affected the shellac so far.
What one can see from the video it appears to be a hairspring shortened by either magnetism/dirt, or it is touching the balance cock/bridge with the spring, hairspring being locked in the regulator pin and boot on the regulator arm due to a poor end curve pushing the spring together, hence the low amplitude. (Also check if the regulator arm is in the middle position when testing and not at any end position, later on when testing one move it to test the end curve.).
 A nice shot from the side will show which of them it is. Hard to say from this video.

[Nucejoe]

2 hours ago, HSL said:

hairspring being locked in the regulator pin and boot on the regulator arm due to a poor end curve pushing the spring together, hence the low amplitude. 

Yes, you might have nailed it. two or even three circles of the coil. this thing runs fast, Indianapolice 500. 

[GregG]

Thanks everyone! I'll post another video today when I get the chance.

[Nucejoe]

 What HSL said is the very likely issue that is;   (two or three  circles of hairspring locked in the regulator slot). 

[GregG]

I will remove the hairspring and check, but here is a video I was able to capture on short notice.  Sorry for the crappy quality.  Not enough light and battling against the autofocus.  And as for the explanation, do you mean that some of the hairspring coils are wrapped inside the impulse pin?

 

Edited May 15, 2021 by GregG

[JohnR725]

48 minutes ago, GregG said:

And as for the explanation, do you mean that some of the hairspring coils are wrapped inside the impulse pin?

If you're not seeing the problem don't remove the hairspring yet. Jumping on a perception of a problem that you can't see and following a course of action because of that may not yield wonderful results.

You need to be able to see the problem yourself before you can fix the problem.

This really is a tiny watch to work on you should find something bigger to stare at. You want to look at the hairspring see how it looks as it looks flat? Basically want do everything everyone above has said the lookout look at the hairspring doesn't look right of it doesn't look right why doesn't look right. Ideally be nice to get us a picture of what doesn't look right. Because the videos really just aren't cutting it we need a really nice decent close-up picture.

1 hour ago, Nucejoe said:

What HSL said is the very likely issue that is;   (two or three  circles of hairspring locked in the regulator slot). 

Then something like this should be really easy to see as I said if you can't see it you can't fix it. Seeing whether it's flat or touching the balance arm that's a little more tricky.

[HSL]

1 hour ago, Nucejoe said:

 What HSL said is the very likely issue that is;   (two or three  circles of hairspring locked in the regulator slot). 

Lol did I really say that must become senile  

But I took a snapshot from your video, although it is not top of the pops and a bit out of focus
one can see more than one parts of the hairspring sticking together.
Have you tried demagnetize it? If not give it a go. In worst case the end curve is slightly out of shape and that is a slightly harder fix, on a small movement like that I would wait until you practiced a bit on slightly larger ones.
As John says a good single actionshot is often better than a shaky video.

[GregG]

Thank you for taking a look at the video. I've had a macro lens adapter on my Amazon wish list for some time now. I guess it's time to pull the trigger!

[Nucejoe]

6 minutes ago, HSL said:

Lol did I really say that must become senile  

 Obviously I didn't understand what you were saying but decided if you are saying it, its must be right which proves you thoughts are as sophisticated as mine. LOL  but serious, its running like two circles are stuck in regulator slot or one behind the boot.

Regards

Joe

 

[JohnR725]

The problem were having with answering the question is an unfortunate classic problem with this group. Which is which one of us gets to have the best guess staring at a crystal ball or fuzzy video? It definitely looks like a hairspring problem would be my guess but without a really decent photograph were all screwed.

 

[HSL]

Well sometimes one has to work with what one has. Not everyone aspires to become the photographer of the year. In this case the balance is supposedly running quite fast, one really doesn’t have to have a crystal ball to make a guess out of experience that something is wrong with the hairspring.  (I might have one in the closet though  )
Even I realize a good shot from a nice angle is a good help, so here is one I took just to document some finished service of an ETA 2824-2. The catch with being able to take shots like this is the cost of the equipment, maybe not something you buy just to begin a new hobby.

[AlexanderToerzs]

Hi Greg,

If it comes to video shooting there a some points which are completely independent of the equipment you are using and you can greatly improve no matter how crappy, old or battered your camera is. Check this for example:

1. Always pick the best perspective to bring your point across. You want to show a sticky balance spring. Raise your camera and  shoot "into" the balance and find an angle that shows all coils nicely  separated. The sticky ones will stick out like a sore thumb.

2. The motion of a balance is naturally a left-right action. This rather calls for horizontal (landscape) framing to fill the frame with as much balance as possible. Check the space you wasted on top and at the bottom of picture by shooting vertical.

3. Even the cheapest tripod or smart phone stand is better then shooting hand-held macro. 

Cheers and all the best. Alex