Balance wheel doesn't work while gear train is ok

[BlueHarp]

Hi again,

Here is my first question : I got a pocket watch from the 1920s (very beautiful case and dial), but the balance wheel doesn't work. When I remove it and keep only the gear train, there seems to be no problem at all. But when I put the balance wheel and the pallet fork (more exactly the part that was in use in the 1920s), it does not move.

Would someone have any idea? I attach 2 photos.

Many thanks!

[watchweasol]

Hi  When you say it doesnt move, is it stiff and sticky, does it oscillate if you give it a help with a brush, does it move at all.  You have checked the train and thats ok and the pallet is ok . yes. Check the end shake on the balance for a little movement.  also try powering down the watch removing the pallet and just fitting the balance whilst you work on it as this removes any outside influence, also check the balance pivots are not bent or broken. use a small artist brush or air puffer to oscillate the balance. If it oscillates ok check the beat it may be out.

[Shane]

If you are inexperienced, it is very easy to install the balance in a "overbanked" condition.  The roller jewel or possibly finger (in your case) must be installed beyond the direction/side the pallet fork is pointing in.

If this doesn't make sense to you and you can't find a visual reference, let us know and I'm sure one of us can come up with a photo that explains it better.

Shane

Hold the balancecock over the movement so that the wheel is set with the rooler on the correct side.  Once the pivot is in place (without tripping the fork), rotate the arm until its in its position and set it on its locating pins.

We can get better photos but that's all I have before coffee.

Shane

[BlueHarp]

Hi again,

Yes, the balance wheel moves, and when I give a little push on the pallet I can see that it produces several oscillations. And the balance pivots are not bent nor broken.

Il looks like the movement is "tired", as if it had not enough energy to continue oscillating, and I don't know where it comes from 

[watchweasol]

So we are in the position, that the balance is free and the train is free is this the case without power or with power, whith power applied to the movement there is the distinct possibillity that there is worn pivo holes in the plates and under power they are displacing the wheel pivots to a degree where the intermeshing of the gears is wrong and binding. As this is a pin pallet movement check the pins in the pallet for wear,  The problem may also be related to the fact that the mainspring is set and although delivers enough power to drive the train without the balance its not enough to drive the watch including the balance. So there are several things to check, power delivery, state of mainspring and barrel, pivot holes in the plates and the pallet pins. That should keep you busy.   Be interested to hear the outcome      cheers for now.

[BlueHarp]

My question might seem strange, but could it be possible that the hairspring is no longer able to oscillate both ways? Can a hairspring "tire out"?

[watchweasol]

Hi Not strange at all, any mechaical device can tire out eg mainsprings, the constant winding and un winding can result in a set spring as the forces are quite strong, a balance spring is not subject to those types of force so I would imagine it would be quite impervious, but that depends on the type of metal used in its construction. the most likley causes are those already high lighted and before playing around with the balance I should investigate those before all else. Its a question of elimination. If all the points check out then its another ball game.   By the way It might be prudent to check the balance for a loose collet or finger (roller)   and worn/chipped jewels . I have seen some with brass bearings on the balance.           cheers

[nickelsilver]

7 minutes ago, BlueHarp said:

My question might seem strange, but could it be possible that the hairspring is no longer able to oscillate both ways? Can a hairspring "tire out"?

No. The elasticity of steel is its elasticity. It even doesn't really change with heat treatment, there the point of plastic deformation changes but up to that point its "springiness" remains the same. Heat treatment does change a lot of things though, and hairsprings from steel are 99.99999% of the time heat treated; if nothing else this avoids plastic deformation from simply removing and replacing the balance on the cock.

 

But otherwise hairsprings don't get tired, and certainly don't decide to spring one way but not the other. If the balance oscillates freely with the fork out but not with the fork in, you have a problem with that interaction. If it doesn't oscillate freely with the fork out- not just move back and forth a few times, but oscillate freely- you have a problem with something on the balance.

[Nucejoe]

Always a good idea to purchase a watch  that you have found a donor movement for. 

Problem is if the watch doesn't run, most newbies wont hesitate to instal the donor movement in, just to hear the ticking, a false feeling of success this certainly is.  but this defeats the purpose as  we loose the chance to rebuild a movement and learn. 

I have shared this experience of mine many many times with friends here, only some have heard me. 

 

 

Just now, Nucejoe said:

Always a good idea to purchase a watch  that you have found a donor movement for. 

Problem is if the watch doesn't run, most newbies wont hesitate to instal the donor movement in, just to hear the ticking, a false feeling of success this certainly is.  but this defeats the purpose as  we loose the chance to rebuild a movement and learn. 

I have shared this experience of mine many many times with friends here, only some have heard me. 

 

 

please disregard the above as this was meant to be posted on another thread. 

[Shane]

After looking at your photos again, it looks as if the movement is covered with a fine fuzz.  I would assume that type of contamination would be throughout the entire movement (it certainly doesn't make things better).  The movement should be disassembled and cleaned.

It also may be an illusion but the shaft on the pallet fork does not look to be pointing at it's hole.

I would also like to ask if the absence of oil wells for the pallet fork and escape wheels are common with what looks like a BFG or similar quality movement?  I can't say that this detail has stood out on any of my own BFGs.

Good luck.

Shane

Edited July 7, 2022 by Shane

[Nucejoe]

Did you check fork and balance end shakes?   

Have you lubed the roller finger and pallets?

[anilv]

Check the mainspring. These pin lever movements need a lot of force to get going. Maybe apply some torque on the barrel gear (not the ratchet wheel) and see if that helps the watch run better. If yes then you need a new mainspring.

I assume you've cleaned the movement? Ive worked on something similar which had cone shaped balance pivots. Very robust but easy to get gunked up as the working area is very exposed. The balance needs to be removed from the cock and cleaned thoroughly.

Hope this helps.

Anilv

[watchweasol]

Inessence  its a back to basics job. dismantle and clean the movement, check the mainspring all the wheels amd their pivots and the plates and the pivot holes then re assemble checking all the pre mentioned points,. Not forgetting to fit the balance on its own (Nicklesilver) and check its freedom and oscillation, check the pallets. Then once all has been proved two turns on the mainspring and now see if it runs, If so dismantle again oil the pivots etc and re assemble and see if it runs, If not deeper investigation is required.        good luck.      Cheers

[BlueHarp]

Waaaoowww! I wasn't expecting so many answers. Thank you for all your comments! At the moment, the watch is disassembled, and I have started reassembling it slowly and carefully.

[Shane]

16 hours ago, BlueHarp said:

could it be possible that the hairspring is no longer able to oscillate both ways?

I read this after a long day but if it is overbanked, you will have more freedom of movement in one direction than the other.  It can happen in either direction depending on how it was assembled or where and what mechanical damage that caused it may exist.

Does the pallet fork move back and forth when the balance is rotated through what you are perceiving as oscillation?  If not the escape wheel is never unlocked to release the power from the mainspring to continue it cycling.

Best of luck.

Shane

[BlueHarp]

Watch reassembled ... and it works! Just a little problem remaining : it stops when being put on a table, but works well in a vertical position. 

Thank you all for your precious advice 

[JohnR725]

23 hours ago, BlueHarp said:

Il looks like the movement is "tired", as if it had not enough energy to continue oscillating, and I don't know where it comes from

in your background history did you service this watch? In other words you receive the watch was not running or was running and then you service did and now it doesn't run at all? Did you clean the watch how did you lubricated and did you change the mainspring?

On 7/6/2022 at 1:57 AM, BlueHarp said:

(more exactly the part that was in use in the 1920s),

then the wording is interesting other words you put back the parts that were originally in the watch or you replace them?

22 hours ago, BlueHarp said:

My question might seem strange, but could it be possible that the hairspring is no longer able to oscillate both ways? Can a hairspring "tire out"?

typically no hairspring seemed to last forever.

12 minutes ago, BlueHarp said:

Watch reassembled ... and it works! Just a little problem remaining : it stops when being put on a table, but works well in a vertical position. 

most common reason for something like this is problems with the balance pivots. Or the balance jewels if there are any at all in this watch.

[Shane]

5 hours ago, JohnR725 said:

typically no hairspring seemed to last forever.

From my experience a spring properly manufactured, sized for the expected force, range of motion, installed correctly and "protected from corrosion" should last indefinitely.  A spring's Achilles heel is corrosion.  It creates points of increased and uneven stress that eventually will cause it to fatigue and fail.  If it was not corroded, I would argue that a spring that is allowed to approach or pass it's yield point in normal operation was actually incorrectly selected for that installation or purposes.

Shane

[BlueHarp]

Watch works now in every position. I used a needle to clean the hole that receives the balance pivot and I put some oil.

Now I have an "elderly lady" which works .

Thanks for your help!

[Neverenoughwatches]

35 minutes ago, BlueHarp said:

Now I have an "elderly lady" which works .

 

Sounds very wrong  lol

8 hours ago, Shane said:

From my experience a spring properly manufactured, sized for the expected force, range of motion, installed correctly and "protected from corrosion" should last indefinitely.  A spring's Achilles heel is corrosion.  It creates points of increased and uneven stress that eventually will cause it to fatigue and fail.  If it was not corroded, I would argue that a spring that is allowed to approach or pass it's yield point in normal operation was actually incorrectly selected for that installation or purposes.

Shane

Very thorough and articulate Shane. You should write books  

[watchweasol]

Hi nice to hear it all up and running. Welldone

[Shane]

3 hours ago, BlueHarp said:

Now I have an "elderly lady" which works .

That's great and a sharp looking watch as well.  How does you feel (as if I have to ask)?  Hooked yet?

Shane

[Neverenoughwatches]

13 minutes ago, Shane said:

That's great and a sharp looking watch as well.  How does you feel (as if I have to ask)?  Hooked yet?

Shane

I bet you didnt need to ask Shane. Its not a first experience of hows your father, a getting married or a baby arrival feeling, but its pretty good for us mancave dwellers.

[BlueHarp]

It is so gratifying to see that little wheel moving again after a few hours of effort and to realize that it all started one century ago. The thing is that I'm not usually very patient, but this hobby is so interesting that I have accepted the challenge.

I won't try any longer to get watches in good repair on eBay, but rather watches which are good-looking but which need a look inside.

And that is a good way to make progress in English as well as getting the vocabulary about watch making. I have the habit of watching a You tube programme which is called Chronoglide (animated by a Dutch watchmaker). Wonderful! 

Yes, I'm really hooked  I

[watchweasol]

Chronoglide is a  very good instructional site contains a lot of useful and easy to understand information well worth a look.  Have a look at watchfix.com there are courses to be had and also some good information. The fact that it is run by our own administrator, even better.