NH35 Hairspring problem

[Manxcat]

I am new to watch repair, I apologize for getting any details wrong.

I bought an Invicta off eBay advertised as not working that has a NH35A in it.  The symptom was that you could wind all day and it would never start ticking or become wound at all.  I assumed there was a barrel/arbor/mainspring problem and pulled that out.  The mainspring was not engaged with the arbor...but there was no reason...I twisted the arbor and it garbed the spring just fine.  I got to thinking there may be a problem in the train so I was going to pull the balance and the pallet level and when I pulled the balance bridge, the balance wheel stayed in the watch...have not seen that before.

I got out my staking tool which I am not well practiced with, removed the hairspring from the balance bridge, got it restaked on the balance shaft, when to get it mounted to the balance bridge again, and it fell off the balance shaft.  There does not seem to be an adjustment cut in this spring collet.  I know you cant put anything on there (such as glue or thread lock) because it needs to be adjustable, but there is no tension to the shaft.

Any idea why it would just fall off?  I dont think anyone else messed with this previously...but that is a possibility too...it is from eBay.

[matabog]

you took out the balance cock and you just pulled out the HS from the balance? Weird! I suppose it was messed with before.

You could try tightening the collet, using your staking tool, but most likely there is another problem in there...

 

my 2 cents: get a new balance complete from ebay  - you should be able to find one for NH35

[Nucejoe]

7 hours ago, Manxcat said:

  There does not seem to be an adjustment cut in this spring collet.  I know you cant put anything on there (such as glue or thread lock) because it needs to be adjustable, 

If there is no adjustment cut in the collet, then it wasn't build to be adjustable. 

[Manxcat]

Nucejoe, I dont think it was...but I was not expecting that.  The NH35 is a very widely used movement...didnt imaging the hairspring would just fall off the shaft. 

Matabog, without a cut, I had not thought about it much farther...but I suppose I could use a riveting tool to push the metal toward the shaft...might try that.  I am going to order balance, probably a whole movement...but I still wanted to try to fix this one just because.

Thanks for the feedback!

[JohnR725]

1 hour ago, Manxcat said:

.didnt imaging the hairspring would just fall off the shaft.

 

10 hours ago, Manxcat said:

I am new to watch Repair

As you're new to watch repair you need to learn that you should expect the unexpected.

Then typically the hairspring does not fall off. This is where we really need a picture to see how it fell off.

I've also attached the technical bulletin just in case you didn't have one

Then for something like this a balance complete is what you need it be the easiest and the best. But you may find that the balance complete conceivably cost more than the whole movement so it's probably just a movement complete.

 

 

NH35_TG.pdf

[Nucejoe]

NH35 has stud carrier ( beat adjustor) arm, so the need for collet adjustability is redundant so far as beat adjustment. 

Setting the collet about where it was would negligably affect dynamic poise of the oscilator and is not a concern in this case.

So I would glue/peen ... etc   the collet in this case, since as JohnR said you are probably looking at purchase of another movement complete. 

Regs

[jdm]

10 hours ago, matabog said:

My 2 cents: get a new balance complete from ebay  - you should be able to find one for NH35

The issue is that the cheap ones are iffy and have a poor reputation, and an original one is maybe 10 Euro less than a complete new mov.t.

[spectre6000]

I dealt with these Seiko balances a while back, but due to my own failings rather than whatever mystery befell this particular balance. I was 100% only concerned with learning, and didn't really care all that much about the watch itself. In freedom bucks, as I recall (this was not in the current pandemic economic paradigm) the balance was $20 plus shipping (purchased along with a bunch of other stuff from Cousins as I recall), and a complete movement was available to my door for $35 from Ali-X. I went the balance route because I didn't think I wanted another movement just kicking around, I wanted to fix rather than replace, etc. Knowing what I know now, I'd have just gotten the movement. The extra $7, or whatever it would have worked out to after distributing the shipping, isn't enough to worry about, and the spare screws and such come in handy (at least the way I do things).

In your case, it might actually serve yet more utility. Fixing this balance for the purpose of learning obviously has value EXCEPT that this is not the sort of balance you're likely to come into contact with otherwise that might benefit from fixing. It's not the sort of balance that's intended to be fixed (I'm 99.999% sure you can't even buy a balance/hairspring separately unless someone is out there splitting them for some reason on eBay or something), and trying to fix it is not going to teach you how to attach hairsprings to balances so much as how to potentially undo whatever freak accident this particular balance fell victim to that the collective hive mind here has never seen before. The lesson just isn't really all that applicable to anything in the real world, and thus not really worth the brain damage to learn. Sometimes the answer really is to just replace the parts with new (especially when they're as cheap and readily available as these are). I think the old timers would say you then stash the old away for down the road when the parts aren't available anymore, at which point you'll have enough experience to roll your eyes at past you and this weird thing, fix it, replace whatever balance needs replacing at the time, and not think twice about it.

[Manxcat]

Spectre6000, I agree, but I had purchased a staking tool and this was my first chance to try to use it...it did end badly but I learned alot from it.  New parts on the way, specifically a whole movement.  I may circle back to this movement, pickup a balance and hairspring which seem to only be available together which I do see as a good thing and see if there is actually more wrong with this movement that I have not even found yet.

I am not in this to make money or even save money...I like keeping myself busy with things I feel contribute.  Fixing a watch or learning how feels better than a video game or watching a TV show.  I have not been doing this long, I have made many mistakes already and will make many more.  My mistake this time was picking a stake that was too big...the collet got stuck inside it...lesson learned.  I though it was close to the shaft size and didnt want to damage the staff

I think the biggest thing I have learned so far in watch repair is that there are no shortcuts at all.  Not with processes, not with parts, and not with tools.  Thanks to all for the feedback!

[Nucejoe]

4 hours ago, jdm said:

The issue is that the cheap ones are iffy and have a poor reputation, and an original one is maybe 10 Euro less than a complete new mov.t.

Jdm you mean there are cheap chinese parts to NH35 too.  How to tell the diference?  

[jdm]

3 minutes ago, Nucejoe said:

Jdm you mean there are cheap chinese parts to NH35 too.  How to tell the diference?  

If you buy from a reputable seller, and the part is promised as genuine, so should be. In my opinion when it's about this class of watches it's about not wasting money paying more to get less. Even if it's small money.