Removing hairspring stud being held without a screw (Tissot 784-2)

[RichardS]

Hi I'm a bit confused about how to deal with this since I haven't seen this arrangement before. I want to remove the hairspring from the balance so I can give it a thorough clean in acetone (coils are sticking together and de-magnetisation hasn't helped). But there's no screw holding the hairspring stud in the carrier. Instead it appears to be a set of friction-fit parts holding it in.

Has anyone had any luck in removing these without damaging anything? Unfortunately I attempted to wedge a screwdriver between the outer and inner bits of the stud without success and ended up leaving a few marks, but thankfully without damaging the hairspring. Any advice would be appreciated!

[AndyGSi]

You need to rotate from the underside, probably 90deg, to release the spring.

That's what the slot in your second photo is for.

[nevenbekriev]

First of all, You don't need to detach the balance (the stud) to clean in acetone. Just deep the whole thing together with the bridge.

If You need to detouch it, one option is to press the pin of the stud thru the hole with something that is thin enough and strong. The other option is to grasp the stud from the hairspring side and twist it and pull in the same time.

[RichardS]

20 hours ago, AndyGSi said:

You need to rotate from the underside, probably 90deg, to release the spring.

That's what the slot in your second photo is for.

Thanks for the replies.

I tried rotating the slot, but it also rotated the hairspring with it. It seems to be a way of adjusting the hairspring centering. I think rotating it further would have caused some damage.

20 hours ago, nevenbekriev said:

First of all, You don't need to detach the balance (the stud) to clean in acetone. Just deep the whole thing together with the bridge.

If You need to detouch it, one option is to press the pin of the stud thru the hole with something that is thin enough and strong. The other option is to grasp the stud from the hairspring side and twist it and pull in the same time.

I suppose i could do a quick dunk, I'd be worried about softening the shellac on the impulse jewel. I was planning on giving the hairspring a few minutes in the ultrasonic cleaner. There was some gunk on other parts that I only managed to remove using this method.

Yes that pin in the stud seems to be the key. Maybe by pushing the whole stud just a little out of the carrier, the friction on the pin will be released and it will all just come apart? I just need to find something to support the carrier from underneath, it's a bit awkward.

[Nucejoe]

5 hours ago, RichardS said:

I suppose i could do a quick dunk, I'd be worried about softening the shellac on the impulse jewel. 

 Lay the cock with balance attached on bottom of a glass Jar,  (cock down-balance up).

Pour your cleaning solution in the jar until fluid level reaches somewhat  below the roller table. Tighten( air tight)  the lid of the jar.

Fluid won't reach the impulse jewel, but hairspring is fully immersed in cleaning fluid, and can be left to soak as long as you want. 

Obviously the Jar best be of clear see-through glass, and balance tilts, make sure that impulse jewel  sticks out of the fluid.

Good luck

[Knebo]

8 hours ago, RichardS said:

I'd be worried about softening the shellac on the impulse jewel. I was planning on giving the hairspring a few minutes in the ultrasonic cleaner.

As long as you use benzine/lighter fluid or professional cleaners (waterless), you don't have to worry about the shellac. Just don't use IPA. 

Install the balance complete on the empty mainplate and put it in your ultrasonic cleaner for 5-10min. It'll be fine. 

[Neverenoughwatches]

2 hours ago, Nucejoe said:

 Lay the cock with balance attached on bottom of a glass Jar,  (cock down-balance up).

Pour your cleaning solution in the jar until fluid level reaches somewhat  below the roller table. Tighten( air tight)  the lid of the jar.

Fluid won't reach the impulse jewel, but hairspring is fully immersed in cleaning fluid, and can be left to soak as long as you want. 

Obviously the Jar best be of clear see-through glass, and balance tilts, make sure that impulse jewel  sticks out of the fluid.

Good luck

Interesting idea Joe, sounds a bit like you need some kind of modified upside-down balance tack to achieve this but move the impulse further up out of the fluid's reach.The hairspring would be stretched out assisting its cleaning, it does seem hairspring risky though but definitely worth some trialling 

Edited July 18, 2024 by Neverenoughwatches

[Nucejoe]

Just now, Knebo said:

As long as you use benzine/lighter fluid or professional cleaners (waterless), you don't have to worry about the shellac. Just don't use IPA. 

Install the balance complete on the empty mainplate and put it in your ultrasonic cleaner for 5-10min. It'll be fine. 

If in    ULTRASONIC ,   lighter fluid can remove shellac.

[Neverenoughwatches]

1 minute ago, Nucejoe said:

If in    ULTRASONIC ,   lighter fluid can remove shellac.

That is possible and has been proven with non professional us machines. I use a very cheap machine for this that doesn't use transducers, the machine only vibrates to creates waves so has a more gentle action on the parts its cleaning. It can also be used without water so it just shakes the cleaning container.

Kind of jiggles things around.

[Nucejoe]

Just now, Neverenoughwatches said:

 sounds a bit like you need some kind of modified upside-down balance tack to achieve this but move the impulse further away.

Ya, have had this idea for long, like placing a U shaped spring/wire , under the balance wheel and on top of the cock, but never tried it. 

Like a U spring cut out of  common paper clips. 

Rgds

Edited July 18, 2024 by Nucejoe

[Neverenoughwatches]

6 minutes ago, Nucejoe said:

Ya, have had this idea for long, like placing a U shaped spring/wire , under the balance wheel and on top of the cock, but never tried it. 

Like a U spring cut out of  common paper clips. 

Rgds

Its finding a way to keep the balance wheel up out of the fluid without compromising the hairspring. I did wonder if the solvent fumes might have an effect on the shellac if left too long.

[Knebo]

18 minutes ago, Nucejoe said:

If in    ULTRASONIC ,   lighter fluid can remove shellac.

Is that so? 

Well, I've only always used benzine for soaking (outside any machines) and professional waterless cleaners in the ultrasonic. With those two approaches, I've never had any problems with the impulse pin. Including watches from the 1930s.

But I indeed cannot be sure that lighter fluid in the ultrasonic is safe. So yea, better ignore that part of my advice. 

[Nucejoe]

Just now, Neverenoughwatches said:

Its finding a way to keep the balance wheel up out of the fluid without compromising the hairspring. I did wonder if the solvent fumes might have an effect on the shellac if left too long.

I haven't had any issue with the fumes , but who knows,  reasonable to wonder.

I think Jd richard made a tool which held the balance at about a cm high with the cock laying down at the bottom.  Sounded proud of it actually.

Here is the tool, though might work like you say if metalic, its was made for barrel work.

Just now, Knebo said:

But I indeed cannot be sure that lighter fluid in the ultrasonic is safe. So yea, better ignore that part of my advice. 

Try it with a broken fork in ultrasonic, no shellac left in a few minutes bath.

Edited July 18, 2024 by Nucejoe

[RichardS]

On 7/19/2024 at 3:26 AM, Nucejoe said:

 Lay the cock with balance attached on bottom of a glass Jar,  (cock down-balance up).

Pour your cleaning solution in the jar until fluid level reaches somewhat  below the roller table. Tighten( air tight)  the lid of the jar.

Fluid won't reach the impulse jewel, but hairspring is fully immersed in cleaning fluid, and can be left to soak as long as you want.

Ok I was preparing to give this method a try when I had another look at the hairspring and noticed that it was secured to the collet with glue:

I imagine there's a good chance that acetone could dissolve this so I didn't go ahead with it. Instead I tried Knebo's suggestion:

On 7/19/2024 at 5:46 AM, Knebo said:

As long as you use benzine/lighter fluid or professional cleaners (waterless), you don't have to worry about the shellac. Just don't use IPA. 

Install the balance complete on the empty mainplate and put it in your ultrasonic cleaner for 5-10min. It'll be fine. 

Ran the ultrasonic cleaner for 10 mins using L&R cleaning solution, did the usual rinse cycles and the stickiness now seems to have gone. I usually use an old Elma SE cleaning machine but I think I might need to increase my cleaning time since the 5 mins I'm giving for the 1st jar is apparently still leaving stuff behind.

So anyway thanks for saving me from having to pull the balance apart (which I'm sure I would have destroyed)

I now doubt that Tissot ever intended this balance be fully dismantled. Even if I had managed to remove the hairspring stud from the carrier, that huge collet didn't look very willing to be shifted!

Edited July 20, 2024 by RichardS

[RichardHarris123]

Has the collet got a split in it?

[nevenbekriev]

I doubt that there is shellac on the impulse jewel. They are press fit in contemporary watches, not glued. As the hairspring is glued to the collet, then this for sure is contemporary movement. The glue on the hairspring end should be resistant to acetone , petrol and alcohol.

[Knebo]

6 hours ago, RichardS said:

Ok I was preparing to give this method a try when I had another look at the hairspring and noticed that it was secured to the collet with glue:

I imagine there's a good chance that acetone could dissolve this so I didn't go ahead with it. Instead I tried Knebo's suggestion:

Ran the ultrasonic cleaner for 10 mins using L&R cleaning solution, did the usual rinse cycles and the stickiness now seems to have gone. I usually use an old Elma SE cleaning machine but I think I might need to increase my cleaning time since the 5 mins I'm giving for the 1st jar is apparently still leaving stuff behind.

So anyway thanks for saving me from having to pull the balance apart (which I'm sure I would have destroyed)

I now doubt that Tissot ever intended this balance be fully dismantled. Even if I had managed to remove the hairspring stud from the carrier, that huge collet didn't look very willing to be shifted!

Glad to hear! 

I'm actually relieved that it worked. Had you said that there was glue (which you'd intend to keep in place), I'd have assumed that the L&R cleaner would remove that, too. I'm surprised it doesn't. Interesting! 

Thanks for keeping us updated. 

[RichardS]

7 hours ago, RichardHarris123 said:

Has the collet got a split in it?

Yes I think you're right. I suppose that means I'll have to start looking for a replacement hairspring or whole balance assembly if I were to do things properly.

This is a watch I'm repairing for myself so I might just live with it until I can find a replacement. I can check that the beat error doesn't shift around after I get it back together.

Edited July 21, 2024 by RichardS

[Nucejoe]

 The glue makes your hairspring a suspect.   How come  is it glued on?   Neven  got a point, should be press fitted or laser welded.

Ok, snow is gone, but how does it run now.  Can we see your TG  display.

Rgds

 

 

 

 

[RichardS]

I believe Neven was referring to the impulse jewel when he said that they are typically press fit in contemporary watches instead of being held with shellac. He also suggested that the hairspring being glued to the collet was a sign that the movement was contemporary, it wasn't something unusual.

It looks to me like the glue has been there from the factory. You can just make out in my previous photo that the end of the hairspring passes through the middle of the stud being held in the collet. The top of the stud is open, and this is where some kind of glue has been used to fill the space and lock the hairspring in place. It doesn't look like someone has done this as a quick repair (although correct me if I'm wrong...).

There wasn't any snow on the timegrapher, it was actually pretty good to start with (perhaps all it needed was regulation but the movement and overall watch were really dirty). This was Dial Up before disassembly:

 

 

I'll post an update once I've got it all back together. Cheers.

Edited July 21, 2024 by RichardS
Tried to clarify

[CYCLOPS]

sorry late, if you have a staking set and the proper stump to hold the regulator,  I think a small pin mounted in a punch could push the hairspring stud out of the center of the hairspring adjustment screw, you see the hole in the center and I think the stud is pressed into it....just a thought, some bench blocks have a V and straight notches that could carefully be used also, it wouldn't hurt to see......

Edited July 22, 2024 by CYCLOPS

[RichardS]

Sounds like the way to go but I'll need to find a stump or bench block that would work, I don't think I have anything suitable. I'll give it a try if I decide to remove that cracked collet... In the meantime I'm waiting on a bunch of other parts to arrive in the mail so it might be a few weeks before I can give an update. Cheers.