# Seconds Hand Consistently Stopping at the Same Spot



## two40 (Oct 10, 2011)

Bit of a cross-post from the Russian section and this thread - https://www.watchuseek.com/f10/luch-ultra-thin-2209-killed-then-fixeded-638038.html

A quick background update. I took apart two identical 2209 movements and assembled one with the better parts from both. Originally both movements had small issues which is the reason why I merged them.

The watch was working fine for a while but it began to cease up. The second hand stops at around the 30 second mark fairly consistently. Sometimes it does 2 to 3 revolutions but most times it stops after 1.

1/ Magnetic problem? I know there are a couple of screws (ones that hold the movement to the case which are positioned at 12 and 6) that are magnetized. I am waiting on a demagnetizer which is in the mail.

2/ Mainspring problem? Most likely not the issue as it stops at the same position pretty consistently. Last night I did fix the original barrel I wanted to use and swapped it around. There was resistance in winding which is now gone. This barrel is a lot better. The problem is still there though.

3/ Problem in the wheel train or motion works? My guess would be some issue with one of the wheels. What would cause something like the above issue? A missing tooth? An off centre wheel? Some hair/dirt etc causing problems?

I'm going to take it apart again to see what I see but I would like to hear what you think the probable causes are for the second hand stopping at a particular spot each time.

Many thanks.


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## Sodiac (Dec 6, 2008)

The most obvious would be, is the hand hitting something at that point anywhere inside the watch or on the other hands? Or, could it be a gear tooth missing somewhere?


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## two40 (Oct 10, 2011)

I'm checking for missing teeth now. Part way through taking it apart.

The first thing I thought of was the hand rubbing. I moved the other hands in another position but it still stopped at 6 so it wasn't hand on hand.

Could be in the motion works. One of the wheels is missing a tooth like you said or maybe a wheel is off centre? If one of the wheels is rubbing on the plate or one of the bridges?


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## AbslomRob (Jun 13, 2009)

If you remove the balance and pallet fork and wind it a click, does the train spin freely and then backlash a bit or does it spin for a bit and then seem to "slow" to a stop?


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## GeneJockey (Oct 7, 2010)

Schumtz in the 4th wheel teeth? I had one that stopped at the same point every minute, and there was the tiniest piece of stuff in between two teeth.


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## two40 (Oct 10, 2011)

4th wheel looks clean. I checked all the others and they all seemed fine.



AbslomRob said:


> If you remove the balance and pallet fork and wind it a click, does the train spin freely and then backlash a bit or does it spin for a bit and then seem to "slow" to a stop?


What does this tell you? In both scenarios.

I took it all apart and put it back together. It has run without stopping over night. It's not in the case yet. I wonder if it will do the same once in the case. That would have to mean the hands are causing the issue.


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## AbslomRob (Jun 13, 2009)

two40 said:


> 4th wheel looks clean. I checked all the others and they all seemed fine.
> 
> What does this tell you? In both scenarios.
> 
> I took it all apart and put it back together. It has run without stopping over night. It's not in the case yet. I wonder if it will do the same once in the case. That would have to mean the hands are causing the issue.


The former is the desirable state. The "backlash" is caused by the inertia of the train against the mainspring, and it indicates that the train is unencumbered (nothing binding anywhere). Otherwise, you'll see the latter, which tells you that there is something dragging on the train somewhere.

One of my big nemesis is tiny fibers that come up from the carpet. They're clear and nearly invisible unless you're looking carefully, but because they're nylon, they'll stop the works like a brake.


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