# Balance Wheel Issue



## James Walker (Apr 25, 2020)

Hi all

I'm new to horology namely pocket watches. I have acquired a few movements on eBay to practice on. I have managed to get some going again. However there are some that I managed to get the balance wheel swinging albeit a low amplitude. But I'm flummoxed as to why when I turn them 180 degrees, the balance wheel stops. Is this to do with gravity and/or not enough torque from the barrel spring?

Thanks

James


----------



## nevenbekriev (Apr 21, 2019)

Hi James,

Probably You have a cylindre movement... In cylindre escapement, there is a pin on the balance rim and another pin under the balance bridge, they together limit rotation of the balance wheel to 180 degr. This is to avoid locking... Usually, amplitude is less than 90 when cylindre/'scape wheel pair is worn and no more than 120 when everything is perfect...

As for the amplitude, it depends on many things. If one wants good amplitude, then he must minimize all looses in balance/hairspring itself, escapement, train and mainspring in the barrel. In cylindre escapement, looses because of friction in cylindre/esc. wheel pare are most significant... When the pair is worn or even not correctly lubricated, increasing the torque in train leads rather to slowing down and even stopping of balance, than to increasing of amplitude.


----------



## James Walker (Apr 25, 2020)

Hi nevenbekriev

thank you for the reply. Very interesting. However, what I am referring to is when the watch is face down, the balance wheel rotates, but when i turn it on its back (180 degrees) it stops. This is what I was referring to when i mentioned gravity - Why should the balance wheel rotate when its face down but stop when its on its back? I have a number of movements that do this, thats why I thought it may be a common problem and possibly rectifiable?

Many thanks for your input. Nice post

James


----------



## nevenbekriev (Apr 21, 2019)

Now I see...

Yes, this happens sometimes. But first I need to know what kind of movement is it. Is it with no jewejs, with cone shaped balance pivots, that seat in steel cup bearings? Or, it has normal balanse staff pivots in hole stone and cap stone bearings? If You are not sure what I am asking, just show a picture of the movements...


----------



## James Walker (Apr 25, 2020)

As far as I can see it has 11 jewels 2 for the minute wheel 1 for the seconds wheel 2 for the escapement and 2 for the balance staff. it has normal balance staff pivots in hole stone and cap stone bearings yes - Will an eccentric hairspring have anything to do with it?

Thank you for your help


----------



## nevenbekriev (Apr 21, 2019)

Hi James,

OK, the most frequent reason for which a watch will work face down but stop face up or vice versa, this is a broken balance pivot. When one pivot is broken, if this pivot is down, the friction in balance increases and watch stops. This is easy to check - usually balance wobbles like on this video.

Of course, there are another possible reasons, but first, we need to check this one. Is that Your case?


----------



## James Walker (Apr 25, 2020)

Thanks for that Neven

Yes I did check the upper pivot and it was bent over at an angle.

I guess this was the cause

Thanks for the help

James


----------

