I had the same problem with 2409 movement , working in all positions , except face up ( stoping after few hours). I have inserted second shim under balance bridge , and that solved problem. Tovarish Oddessa200 is pointing in right direction.
Last edited by Utva_56; June 10th, 2019 at 12:44.
Always eager to learn; can somebody please explain me what is mend by; the balance is touching the bridge?
What is understood under the "balance"? The balance wheel, the balance staff, the hairspring, the roller-table or the whole balance assembly ?
What is touching the bridge; exactly?
Apart from increasing the end-shake, what is an extra shim going to do about that?
Hope for some enlightening
Last edited by EndeavourDK; June 10th, 2019 at 18:13. Reason: Spelling
I do not know. If my post after all. but I looked at some pictures and it looks like the wheel is hit or interrupted by the bridge? Am I catching this right.
All this should NOT be needed if the parts of the watch are done a bit more precise. 😞
I've been reading your post and it is clear to me that you pulled quite a few watches apart; highly appreciated and the forum has need for watch-repairers
In your last answer we come closer to my questions; not the "balance", but the hair-spring.
Reason why I wanted it to be a bit more precise is that people understand the problem, and don't halve-way jump to conclusions.
Now, and please understand this is not meant as to offend either, but more as a brain-storm together and for my own education; the distance from the hairspring to the balance bridge (assuming the balance-staff pivot is resting on the cap-stone) is the length of the balance-staff pivot + the length of the balance staff till the center of the hair-spring collet. This is a fixed distance to the bridge.
The hair-spring stud is connected to the bridge, this is also a fixed distance.
When the watch is Dial-Up, the balance staff pivot is resting on the bridge cap-stone and so whatever the bridge does, moving it lower or higher (by adding or removing shims) the balance assembly moves with the bridge and distance between the balance assembly and the bridge stays the same.
It may well be, due to gravity, that the hair-spring doesn't touch the underside of the bridge with Dial-Down and touches the bridge when Dial-UP. In my perception adding shims doesn't make a difference. The balance assembly moves equal distance with the bridge; adding a shim doesn't alter the distance between the bridge and the balance assembly. To me it's the hair-spring which doesn't run in a horizontal plane and therefor needs sorting.
Does that make any sense
Edit; another more plausible possibility is of course that something is up with the bridge anti-shock or the pivot; been dropped; partially broken or bent pivot
The story also goes that the watch was bought new, but never been thoroughly tested (?). Was it a lime right from the factory ?
Last edited by EndeavourDK; June 10th, 2019 at 20:35. Reason: Added more fault options, rem.errors
I am sure you know this but just adding an image. B is the bridge. H is the hair spring. What you said that the spring is attached to the stud and to the bridge is correct. But this is what happens. As shown, face down, hair spring will hang down away from the bridge. Also, the balance wheel pivot will rest on the opposite to bridge jewel. The distance between the jewels is a bit larger than the length of the balance pivot to prevent jamming. If you flip the watch face up, the balance will move a bit closer to the bridge (pivot will rest on the bridge jewel). Also the hair spring will hang a bit closer to the bridge and may touch it. Makes sense? To avoid this, you need to put a shim under the bridge. Bridge will move further away from the hair spring. Right?
Another issue that happens: you take the balance off (lets say to clean), there is no shims, when you put you back the watch does not work. The issue is, that the previous watchmaster, instead of adding a shim, slightly ‘scarred’ the space under the bridge using a screwdriver or something like that. That ‘scar’ lifted the bridge a bit. During your service, you cleaned and flatten the scar (maybe by tightening the bridge too much). Look for the ‘scars’ under the bridge 🙂 it maybe a quick solution when a shin is not available. But it really should NOT be done. 🙂
It's the same as when you have the balance assembly, bridge down & balance assembly on top, on your work-desk. Picking the bridge up and moving it up or down doesn't change the distance from the hair-spring to the bridge. That's a fixed distance.
By adding shims all what changes is the end-shake and indeed the distance between the hair-spring / bridge increases only in the dial-down position. It wasn't the dial-down position which was causing the problem, it was the dial up.
Of course, if the hair-spring touches the bridge it must have done so from factory.
As I understand the story, it isn't fully known whether the watch ever ran correctly from new. If it did, then the hair-spring is likely not the culprit but perhaps some damage to the balance staff pivot. A partially broken pivot could also cause the same symptoms; a hair-spring touching the bottom of the bridge dial-up?
If the watch was behaving weird from factory, other causing could be misalignment of the bridge (due to folded / damaged shims), something with the bridge anti-shock, something with the pallet-fork and the impulse-jewel, etc, etc.
Yes, I know about poor watch repair methods, however in the old-days making indentations was more common / "accepted". I've seen it in pocket watches and antique clocks
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