Watch running too fast with low amplitude

[Khan]

Hi

Its a FHF-28 movement that I serviced and replaced the mainspring from another similar FHF movement, and looks like never serviced and used anyway for many years. 

I Also replaced the hairspring from FHF-25, i Guess they use the same hairspring? 

The old hairspring were black and round and the newer one is S-shaped. 

The watch is de-magnetized. 

Now I cant even get the balance to run freely, after re-adjusting the stud screw, so Guess the hairspring is too close to the floor.  Anyone that can guide? Much appreciated. 

 

 

 

 

 

Edited November 16, 2021 by Khan

[watchweasol]

Parts from a similar movement are not always compatible  so we may have a problem there. Check the height of the balance spring and for fouling either the balance rim , the balance cock ,  or even the fourth wheel, It it magnetised , coils sticking , is the spring breathing ok and evenly. all relavant things to check.

[Nucejoe]

 Both hairsprings have same strength, yet the replacement one might be shorter therefore not comptable with the other balance , though its a screw balance, you would be disturbing its static poise as soon as mess with the screws, thence create a bigger problem for yourself. Unpoised  balance wheel would result in excessive positional variation and dynmaic instability on wrist . My vote is not to mess with it until you master static poising at least. 

Replacing the hairspring you created a hefty beat error but amplitude increases once you adjust the beat.

I can't see any other fault. 

Regs

 

 

[clockboy]

Agree with the above changing parts from one movement to another can be problematic. The mainspring could now be too strong also the hairspring is not sitting correctly. The coils should be evenly spaced so when you adjust the regulation arm it adjusts the effective length of the hairspring without altering the hairsprings balance and poise. See pic.

 

[Nucejoe]

Oh I see    now that clockboy spotted it, the coil is not perfectly centered, beat error too alters as you center the coil, can say for better or worse, but will change. 

[Khan]

Hi all

Thanks for quick responses! 

According to Bidfun, I see that the only difference in mainspring is the height which is 0.15 mm higher. Will this make any difference? I was still able to close the barrel. 

I can try adjust the hairspring. Visually, the hairsprings from both movements looks like same and the diameter of both movements is same . By the way, the beat error is approxx. 3-4, when regulator pin os centered. 

 

 

 

 

 

[JohnC]

I would re open the barrel and look for scoring on the lid and bottom. A hundredth of a mm I would say no prob but 0.15 sounds a bit dangerous. If it's scraping that can suck your amplitude.

[JohnR725]

3 hours ago, Khan said:

I Also replaced the hairspring from FHF-25, i Guess they use the same hairspring? 

The problem with hairsprings are there not sort of interchangeable? If were talking about American pocket watch or some Swiss watches typically with an over coil their pre-made to exacting specifications. They were matched the balance wheel by timing screws on the balance wheel to have the balance wheel exactly calibrated to that hairspring. So for these examples the American or Swiss if you look at the parts list it will actually list a part number for the hairspring it was available separately.

Typically with everything else in the universe whether the balance had screws or not almost universally all flat hairsprings are vibrated to each balance wheel. So all the parts are mass-produced but every single balance wheel gets a unique hairspring for that specific balance wheel only. Yes in the factory every single balance wheel was on a machine and got a unique hairspring just for that balance wheel. That means typically on a parts list for watch you will never see the hairspring it's a balance complete.

3 hours ago, Khan said:

The old hairspring were black and round and the newer one is S-shaped.

This can make things more complicated? Like in addition to the hairspring changing what else did they change? Did they make this watch over a span of time with variations? For instance if we look at the parts list like at the link below we find more than one balance wheel then that is a definite problem probably

Once you get your hairspring centered in you get the balance wheel to run it does look like those are screws perhaps I don't know if the unscrew or not. This means you can possibly add weight or possibly add more screws if they have more screw holes which typically American pocket watches did. In other words you could make adjustments if you're lucky. Is working in a modern balance wheel with no screws then that is an issue if you try to swap a hairspring as there's nothing you can do.

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=FF_25

 

[Khan]

Can I re-use the old mainspring if there is No bents and dents on it? I replaced it because I thought it Will increase the amplitude. 

[watchweasol]

Hi  The fact that after servicing and changing parts there are problems it is always  best to revert back to the originals where possible and re analyse the problem from that standpoint.  In your case it the original balance spring was ruined go back to the original mainspring and start from there to see if there are any changes.  The fact that the barrel lid closed doesn't mean a lot other than it fitted in the barrel, it may be binding on the closed lid 0.15 might just be too much.

[mikepilk]

1 hour ago, Khan said:

Can I re-use the old mainspring if there is No bents and dents on it? I replaced it because I thought it Will increase the amplitude. 

 

I wouldn't use that spring - it looks 'set', i.e. lost it's elasticity. And it doesn't look flat. 

[clockboy]

6 hours ago, Khan said:

Hi all

Thanks for quick responses! 

According to Bidfun, I see that the only difference in mainspring is the height which is 0.15 mm higher. Will this make any difference? I was still able to close the barrel. 

I can try adjust the hairspring. Visually, the hairsprings from both movements looks like same and the diameter of both movements is same . By the way, the beat error is approxx. 3-4, when regulator pin os centered. 

 

 

 

 

 

Going higher is always risky. Any rubbing on the barrel lid will effect the performance of the spring. 

[Nucejoe]

I concur with mikepilk, these the old type mainsprings are usually set, you best replace this with a new modern type.

[JohnR725]

1 hour ago, mikepilk said:

I wouldn't use that spring - it looks 'set', i.e. lost it's elasticity. And it doesn't look flat. 

 

1 hour ago, clockboy said:

Going higher is always risky. Any rubbing on the barrel lid will effect the performance of the spring.

For the answer of can you use the old mainspring yes you can but? But as the replies of indicated correctly it's no longer sort of functional? In other words you can wind the spring up the watch will run but it will not run for 24 hours and depending upon how badly the mainspring is lost its spring characteristics it may not run very well at all. As far as it's not being flat that's usually the result of people hand winding the spring in putting a severe distortion on it and then the spring gets set in a inappropriate shape. It could also be wouldn't removing it because it's now soft that could also occur.

If the spring was severely distorted by inserting and you look inside the barrel the bottom and the lid should be nice and smooth and still have the plating it probably has if the spring is distorted you put pressure on those parts and you'll see wearing which is not good. The same thing would occur with putting a mainspring  that is too tall is that you might utter altogether but it's too tight and you're getting no power out of it.

8 hours ago, Khan said:

According to Bidfun, I see that the only difference in mainspring is the height which is 0.15 mm higher. Will this make any difference? I was still able to close the barrel. 

I can try adjust the hairspring. Visually, the hairsprings from both movements looks like same and the diameter of both movements is same . By the way, the beat error is approxx. 3-4, when regulator pin os centered. 

You'll notice in the answer I gave above I gave a link if we look at the link you run down the list we get the mainsprings or in this case just one mainspring and if we click on that we get this link

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=qWLXEs

I snipped out a picture for you depending upon where you're located one number will be more useful than the other the GR number is useful for people ordering from cousins. The number at the very top is a best fit number sometimes that shows up on eBay or particular material house here you can buy it from them providing it's still in stock to do that you have to go to the main webpage enter the number and see what happens and I will do that for you.

In case you don't have at the page where you are look is here

http://www.julesborel.com

It looks like they haven't it's available and this is where you always get a discrepancy between the parts listing which is ancient and the homepage it's $21 but it is available. Here are usually not always but on vintage or older watches mainsprings can be more common like when you look at the link I gave first it shows all the watches that use the same spring more watches on the list the more likely the spring may still be available versus of the spring only goes in one watch then you're probably going to be screwed because nobody will ever have that.

Then if you understand how the numbers work you change the number slightly to something like searching for this on eBay 711P Mainspring I see that one person has it and they'll even taken off for they want five dollars for it. By the packages in its a brand-new white spring exactly what you're looking for. Then you do have to be careful of eBay because later down the page they'll give you other results where they shorten your search term liked the word mainspring because eBay just assumes at all mainsprings will interchange.

For now you could insert the old spring back in knowing that it's not perfect but it's good enough to get the watch running and testing things out it just won't have maximum performance and a run out of energy before 24 hours. But regularly for incoming watches I will do a lot of testing of things with a set spring just because it's there. Then when the watches cleaned and I see how badly set it is I always replace it so it will work with its wound up tight. Which is probably why a lot of people don't change the mainspring is because they don't realize that is going to be a problem hours later when they run out about and then the blame all kinds of other stuff and be really confused over what's going on.

 

 

 

 

 

[JohnR725]

8 hours ago, Khan said:

I can try adjust the hairspring. Visually, the hairsprings from both movements looks like same and the diameter of both movements is same . By the way, the beat error is approxx. 3-4, when regulator pin os centered. 

Oh almost forgot yes they look identical the balance wheels will look identical and they will not be identical. The length of the hairspring is extremely critical because of it wasn't critical the factory would just make them and push them on in their good to go. So yes they will all look identical but they will not be identical which is why every single one is vibrated to the specific balance wheel.

but even with the wrong spring the watch should run the balance wheel should turn. Providing they hairspring as you said looks identical you should build a put it in their put the watch in beat setter they hairspring so it's not rubbing on the balance arm or the balance bridge in the watch should run it just won't keep time it may look like crap on the timing machine because ill be off in timekeeping considerably but the balance wheel should run visually really nice.

It's one of the really really hard things to see by watchmakers if their hairspring really is flat and not touching the balance arm because the clearance is really really close and it just takes a little bit a rubbing on the arm to stop the balance wheel from turn

[Khan]

Thanks a lot to everybody putting time to explain in details, I really appreciate.

Ordering the correct complete balance might be best way to go. 

The "new" mainspring doesnt look too high in my opinion, otherwise there would be scratches in the Barrel "cap"?

Furthermore, I manipulated slightly with the hairspring (I know its not good enough) and the balance runs nice (without sticking together), without pallet fork installed but doesnt turn at all with zero oscillation, what can be the reason?

Edited November 16, 2021 by Khan

[JohnR725]

32 minutes ago, Khan said:

Furthermore, I manipulated slightly with the hairspring (I know its not good enough) and the balance runs nice (without sticking together), without pallet fork installed but doesnt turn at all with zero oscillation, what can be the reason?

If you take the pallet fork out you remove the hairspring from the balance wheel does the balance wheel turn freely all by itself? That is when back in the watch and everything down tight? Sometimes when you're really frustrated watchmaker having an issue you put the basic sin does the balance wheel turn nicely all by itself. To give it up off the air in its spins beautifully you turn it upside down does it still spin beautifully. It's a way of isolating the problem then you put the hairspring in give the balance wheel like one turn let it go does it spin beautifully at least spinning back and forth under control hairspring if not then you've isolated your problem of is that they hairspring a problem is the balance the pivots the jewels it helps isolate the problem as opposed to I have no idea which unfortunately happens a lot in watch repair.

 

[watchweasol]

Hi JohnR725's advice "returning to basics" is sound, check each component on its own, ie Balance and then the Fork/pallet.  with the balance out and power on does the fork/pallet snap crisply between the banking pins, if not investigate by removing power and then the pallet/fork and check the train by applying a turn on the spring. Do the wheels spin down with a little reverse spin at the end ? If no  a train or power fault, if ok re fit the pallet/fork apply a little power and check the action if sticky , fork/pallet problem. if ok re fit the balance does it oscillate well in nt a balance/hairspring problem.  by taking it down in small steps we eliminate sections of the watch. 

[Khan]

Hi Thanks for great guidance.

I changed the pallet fork and now able to run the balance. I couldnt see any visual damage on the old pallet fork but it turned crisply on banking pins, but felt like not sitting horizontally stabile enough, like tilting slightly. The watch runs very slow, as the hairspring is from another family movement. Now so I think I have to buy a new balance.