Omega Seamaster

[jim1228]

Hello, I serviced a mid 1950 Omega sea-master men’s wrist watch. The watch is self winding. It was cleaned in a ultra sonic cleaner and the main spring was also removed inspected cleaned greased and put back in it’s barrel. The movement was reassembled and oiled and the hair spring was rinsed in (one-Dip). I manually wind it, then after about 3 to 4 hours it loses about a minute. No mater how much I adjust the regulator nothing changes. Does the fact that it is self winding have anything to do with this issue?

Thanks
Jim

[Bob Tascione]

Hi Jim,
Since the regulator is having zero effect you may want to check that the hairspring is sitting between the regulator pins and not on the outside. If it is then check that the pin gap (space between the pins) isn’t too wide. Under high magnification and while the balance is oscillating, make sure that the spring is vibrating between both pins and is moving all the way across the gap and making contact with each pin. If it’s not hitting the pins or is hitting only one then you’ll have timing problems. One minute in 4 hours is pushing the limit for a regulator problem. I think somewhere around 5 mins per day is as much adjustment as you can get but I could be wrong so checking the hairspring position is worth a try. Also you might check that the hairspring is flat and not tilted off the plane of the balance and/or dragging on the balance arm or making contact with anything else. If it’s losing at a steady rate such as 1 minute in four hours and losing 30 secs in 2 hours or 15 secs in one hour (might want to check that) then diminishing power probably isn’t the problem. If it’s losing most of that 1 minute in the last hour or so then loss of power might be the culprit.
After checking the hairspring please let us know what you find out Jim,
Bob

[jim1228]

Hi Bob, The hairspring is right where it should and touching both pins while in oscillation. I did notice that the balance cock didn’t seem to be seated flush. So I removed it and made sure there were no debris underneath. Re-assembled it and made sure it was properly seated. I will let it run and check the time later this afternoon and then give you an update.

Jim

[Bob Tascione]

Thanks for checking Jim,
I’m curious to hear how the test results turn out and to know whether it’s losing at a steady rate or if the rate loss is accelerating towards the end of its run as the power drops off.
When you get a chance please post the results when you get them.
Enjoy it over there on that beautiful island today Jim,
Bob

[jim1228]

Hi Bob, Well it seems to me that it’s losing time gradually from the end of it’s run as the power drops. There is nothing else that I can find that would hinder it’s power. I should have just replaced the main spring when I had it apart. A new one is on it’s way.

Jim

[randy]

JIm,
You say that you are winding it, and then it starts losing after about 3-4 hours, correct ?
I have a 56′ Seamaster w/ the 491 calibre movement.
At the risk of offending you ( as I do not know your level of expertise), can I offer the following ?

Did you use chronogrease between the mainspring bridle and the barrel, so that the mainspring is “dragging” the right amount on the outside wall, thereby tensioning ( winding ) the spring properly ?
Are you wearing the watch after you wind it ? The manual says something like only winding them about 10 turns initially, and then assume that you will wear them right away to keep them winding further.
Not doing either of these could contribute to your loss of time…

Thanks for entertaining my ramblings,…hope you get this sorted out.

Regards,

Randy

[jim1228]

Hi Randy,
No offense taken here. Those of us that have been working on time pieces for an extended time, weather clocks or watches are always open for suggestions and new ideas . The movement is a 470 and yes the mainspring bridle and barrel outside wall was properly greased. I only worked on but a few self winding watches but never ran into this issue. Your suggestion is well noted and I will wear the watch to see if it will maintain it’s time. But first i must get a band for it. I will keep the forum updated.

Thanks again Randy
Jim

[randy]

Hope it’s the answer !!
Best regards,

Randy

[jim1228]

Hello,
Sorry it’s been a while since my last post. (Busy) Update: Put in a new main spring and a new watch band, wore it around for a couple days. Minor adjustments were made to the regulator and it’s keeping good time.

Jim

[randy]

That’s great !!!!!

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