The Breitling Watch Source Forums

- on an Omega (Speedmaster 300M GMT), hence posting in the 'General' etc section.

Looking at the watch this morning I noticed that the '16' hadn't engaged fully; it looked like it was about 80-85% round but not fully flush. Using the hacking hours function (crown out at position 2 out of 3) I changed back to the 15th, and then slowly forward to the 16th again, and it snapped into position fine. Where would one put that on the spectrum between 'occasional glitch of a mechanical watch, to be monitored' and 'portent of apocalypse'?

The watch is well within a long warranty so an issue would be an albeit serious nuisance rather than a disaster, but it has unsettled me (coming straight after a weekend when the car left us stranded with a serious engine issue...)

As an aside, am I right to assume that the don't-change-the-date-either-side-of-midnight issue is not material to a GMT watch where you change the date via the hacking hours hand? The Omega manual is skeletal for this model and doesn't mention this. So I assume that a GMT watch is designed to be able to change, for example, backwards from 1am on the 2nd day of the month to 11pm on the 1st day of the month?

I think the death zone either side of midnight is a specific issue to a number of watch movements, but there may be some that do not need this consideration. Yours may be one. I can think of some Japanese movements that do not give this consideration.

I would also have thought that even as a GMT the consideration would still apply in any other case though. My thought, and I am not 100% sure here, is that the GMT function is an add on feature which relies on the main movement for its timing and regulation. So it does its thing as a subset of the main movement. I guess some movements may have this function integrated and possibly therefore the death zone is not relevant, but……... Wow. Bloody good question Tom.

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Jim

"You have Control".

Don't know enough about how Omega modifies the 2892-A2 to know whether it is an issue, but highly doubt it because as you say the GMT wouldn't be very practical. To make sure that there is no issue rotate the date through the full set of 31 days and make sure that it centrally sits in the window on all of them. If it does then I wouldn't worry, but if it ever happens again get it checked out.

Thanks Jim. I've foxed myself actually, the more I think about it.

The calibre is 2628, the GMT version of the 2500 calibre. Amid Omega FAQs on the web I've found this:

"Slow date-change on calibres 1128, 1150-1-2, 1164, 1270, 1379, 1400, 1424, 1426, 1429, 1430, 1432, 1438, 1441, 1449, 1479, 1530, 1532, 1538, 1675, 1866, 2520, 2600, 2628, 3603, 3606. ... [snipped] Avoid changing the date manually between 8 pm and 2 am, since this is the period during which the automatic date-change is in operation."

However:

1] The manual emphatically says nothing about the death zone (good shorthand that) for the 2628 whereas it does for other calibres, clearly implying that it's not an issue on the GMT.

2] Since on a GMT the date change is not by the fast-change method on a conventional mechanical watch, but by the hacking-hours function, in changing the time by hours aren't you merely (safely) accelerating a mechanical process which might be underway, rather than interfering with a separate one?

Thanks Roff (though the calibre is a modified 2500 as I understand it). But anyways yes, I did go fwd through a month of changes, taking care especially to check the 15-16 change, and it behaved. Will watch... In fact, I might set it to the 15th again to see how it changes overnight to the 16th again. Though I'm now scared of winding it backwards to the 15th...

Sorry for posing an Omega question on here. But I didn't want to join another forum just to ask this. I'm happy here.

ETA 2892-A2 = Omega 2500

Well, it changed to the 17th ok...

When I had a GTG recently with a few serious collectors, I asked the 8-2 danger zone specifically, and was told this danger zone applies across brands with only a few exceptions and should be religiously avoided.

If not from reading breitlingsource, I would never have known since no AD ever mentioned any danger zone to me and like you said, it's not written with big bold "WARNING!" in the manuals!

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a few Pams...

Well, I've been monitoring it since, and it's done it again today on the '3'. Slightly closer to what I'd call perfectly aligned this time, maybe 85-90%. But definitely not quite fully engaged - and it went to properly aligned when I tapped the watch gently on the shoulder.

Sticking. Service.

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Jim

"You have Control".

Aye. It's only about three months old, that's what's annoying!

Oh dear, sorry Tom. I had not picked up on that fact. Well, that’s no good at all. I assume its under warrantee, so perhaps a return to the AD will get it sorted.
Could be something getting caught or something sticking. Something could have moved that shouldn’t have. Problem is, It’s intermittent. If your watch had stopped completely, then there is no real question on the next step. I have had similar date wheel issues but they have always cleared themselves. I have never bothered taking my own advice on this and have them repaired, as they have been low cost movements.

My thinking is that although it is intermittent; don’t let that throw you off. Take it back and let the AD do some assessing and adjusting.

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Jim

"You have Control".

Thanks Jim. Yes, the co-axials have a three-year warranty so I'm chilled as they say, just annoying. And of course in respect of demo/ing and probably diagnosing the problem it would be easier if it did it consistently. At the moment all I can say is "on two dates it's not quite fully engaged". Of course it's possibly that if I'd waited it would have done, but certainly as of c8am on those mornings it was only 80-90% engaged. I'll monitor it for the time being.

Without knowing the gearing of the date change mechanism I don't think that we have enough evidence to have confidence in what might be causing it. Two data points 18 days apart may be an indication of an intermittent problem with dirt / dust, but it could be a problem with a tooth in the mechanism - will be interesting to see what happens on the 21st (another 18 days). It could also be something like insufficient torque from the mainspring when the date change engages which would likely be consistent but appear random because it would be dependent on the amount of power reserve in the mainspring.

Regardless of the cause, it's not going to fix itself!