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Hairspring too light...see slow motion video...next steps

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Nucejoe Distinguished Member

Nucejoe

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Hi Texas. Merry Christmas and a very happy new year.

 

Shortening the length makes it run faster. 

Adjusting through the balance weights can work to the same effect, but usualy if its only by few minutes a day.

So, how slow does it run? 

What is the diameter of the coil, also measure the  distance from jewel hole in cock setting to the stud, in other words we should take into account how far is the outermost circle of the coil from the stud. we wouldn't want hairspring hitting on stud as it breaths.

I' be happy to work with till you get the right beat.

Joe

 

 

LittleWatchShop Distinguished Member

LittleWatchShop

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15 minutes ago, Nucejoe said:

Shortening the length makes it run faster. 

It is an overcoil, so I will have to shorten it at the collet.  Never tried that!

 

16 minutes ago, Nucejoe said:

Adjusting through the balance weights

I thought that might help...and closer to my abilities at this stage.

 

17 minutes ago, Nucejoe said:

What is the diameter of the coil

I will measure and get back to you.

 

17 minutes ago, Nucejoe said:

I' be happy to work with till you get the right beat.

Great.  I am heading out of town for a week, so will not get back to this until after Christmas.

 

18 minutes ago, Nucejoe said:

Merry Christmas and a very happy new year

Back to you!  I hope next year is better for the whole world.  COVID has managed to suck the fun out of life for a couple of years--thankful for my retreat to watchmaking as it keeps me home!

Nucejoe Distinguished Member

Nucejoe

Posted
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 I just saw your vid, its way too slow, yes this hairspring might be incompatible with this balance, that doesn't mean it can't  produce the required beat, you are likely to end up with a very small  coil which probably osciilates unstable in dynamic state.

 

Marc Distinguished Member

Marc

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You need to sort out the amplitude a bit. Your video is showing somewhere in the region of 180 to 190 degrees so timing is going to be somewhat difficult, you need to be hitting a very minimum of 220 degrees.

Then before you start altering anything irreversibly take a really close look at the balance. Has somebody added any extra weight (timing washers) in the past to slow it down.

If the H/S comes pre-studded for a particular calibre then it should be reasonably close unless the balance wheel has been messed about with. Afterall there would be little point in supplying it studded if you're only going to have to remove the stud and re-attach it having shortened the H/S

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LittleWatchShop Distinguished Member

LittleWatchShop

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All good comments.  After Christmas, I will do a thorough analysis of the balance assembly.  I have more hairsprings, but they are mostly all the same model and for the same model movement.

This was an ebay find many months ago.  No telling what has been done to the watch in the past. It is missing the sweep second pinion, so there is less load on the train than normally would exist.  Hard to imagine that is an issue.

I wonder...could the mainspring be too strong?  I did a full clean and did not notice the mainspring to be out of the ordinary.  I have services several others of this vintage.  Hmmm...maybe swap the balance assy between one of the others...that is a thought.

1 hour ago, Marc said:

If the H/S comes pre-studded for a particular calibre

Yes it was.

rodabod Distinguished Member

rodabod

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Is the terminal curve sitting between the index pins on the regulator ok?

And what is the history of the watch? Knackered hairspring?

Marc Distinguished Member

Marc

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1 hour ago, LittleWatchShop said:

I wonder...could the mainspring be too strong?

If this was the case then you would expect to see very high amplitude or even re-banking (where the balance amplitude is so high that the impulse jewel crashes into the outside of the fork horns). Your problem is the opposite, the balance wheel amplitude is too low, which could be as a result of too weak a main spring, or excessive losses within the train or the escapement, or both.

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Nucejoe Distinguished Member

Nucejoe

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I first tried my best to enlarge the pic and zoom on oscilator but no joy, then I noticed the big amplitude, based on which I think this hairspring is way too long, so way too slow. 

Educational to me as to how did Mark came up with 190 for amplitude. 

Then to test for in beat, start with the oscilator at rest, swing the balance by few degrees like 10 to 15 , if its out of beat by 90 it fails to recieve the impulse so the oscilation dewindles to stop.

Can you show a good close up of the oscilator?

JohnR725 Distinguished Member

JohnR725

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17 hours ago, LittleWatchShop said:

is an overcoil, so I will have to shorten it at the collet.  Never tried that!

Definitely not recommended as they were made in a very specific shape and you weren't supposed to play with the shape.   They were premade for a reason so you don't want to screw your hairspring up playing with it.

19 hours ago, LittleWatchShop said:

Could it be that it is the wrong balance wheel? 

If you look in the Waltham parts book the hairspring you have this for balance wheel number 26116. Which looks like it probably is the right balance wheel so that's definitely the right hairspring but what are you not paying attention to?

Typically with balance wheels hairsprings are not available as a separate component. This is because the hairspring has to be vibrated to every single balance wheels. The only time hairsprings are available as a separate component typically was if they were pre-made too exacting specifications like with an over coil. That means you have to match the balance wheel to the hairspring which is why it has timing screws.  This is where typically when hairsprings were separate like American pocket watches you can also purchase timing screws.

 

LittleWatchShop Distinguished Member

LittleWatchShop

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15 hours ago, rodabod said:

Is the terminal curve sitting between the index pins on the regulator ok?

Yes, appears to be fine.

 

15 hours ago, rodabod said:

And what is the history of the watch? Knackered hairspring?

Got the watch on Ebay and the hairspring was completely destroyed.  I have been waiting for many months to find a hairspring and just found some on Ebay.  This is a new install of a NOS hairspring that is correct for this cal watch.

 

15 hours ago, Marc said:

If this was the case then you would expect to see very high amplitude or even re-banking

Roger that!  The problem, at least first order, was the beat.

 

12 hours ago, nickelsilver said:

From the vid if the roller jewel is 90 degrees from the arms it's massively out of beat too

Bingo.  The collet was off by roughly 20 degrees.  A rookie mistake!!  I have adjusted it and now it is close (I can make it run a little fast or a little slow, but it is still a little erratic. 

 

7 hours ago, anilv said:

Looks like the pivots are gummed up. have you tried running the balance without the hairspring?

I have cleaned the watch fully and both top and bottom jewels were removed and cleaned.  I did not notice any issues with the pivots, but I will go back and take a look.

LittleWatchShop Distinguished Member

LittleWatchShop

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6 minutes ago, JohnR725 said:

If you look in the Waltham parts book the hairspring you have this for balance wheel number 26116. Which looks like it probably is the right balance wheel so that's definitely the right hairspring but what are you not paying attention to?

As noted in my previous reply--the balance was out of beat.  Significant screwup on my part, but hey...I am still on this journey.

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