I have purchased a number of 992b's and one of them has what to me (since still new to hobby) is very odd behaviour. It runs strong (second hand never stops...but every now and again the minute and hour hands quit moving?? The watch doesn't stop...but the hands do...then they start moving again.... It was running perfectly last week but just began behaving like this a few days ago...took me a while to spot it..

Does this suggest a specific problem?? My first thought was to remove the dial and see if there was an issue with the hour/minute/pnion gears there that drive the hands.

Any help appreciated.

Hi Gary,
It is probable that the cannon pinion is loose. It should be initially very easy to verify without any disassembly. If you remove the bezel and take a toothpick and gently, closer to the center (so you don't bend the hand in case this is not the problem) try to turn the hand. If it moves very easily then you likely have a loose cannon pinion.
Mike

Thanks Mike. I tried that, hands are solid, don't budge. I note that when the hands quit moving, the "loss" before they begin to move again is approximately 1/2 hour every time??? For example (after a pause) it reads 2:26 now and time is 2:56. That is what makes me think teeth??

That's a strange one, since your watch was running well before. Does this happen if you do not move the watch around, is it laying face up all the time or are you handling it? If you are handling it, maybe the hour wheel has too much play under the dial and is coming unmeshed with the minute wheel once in a while, and it needs a dial washer. But that still doesn't explain the approximately 1/2 hour loss each time. I would say the next step would be to check under the dial. It would be very strange if it is any wheel/pinion problem. You will also be better able to check for a loose cannon pinion with the dial off.
Mike

Gary,

I would recheck the hands again as Michael suggested it may have a flat spot , losing grip for a half a rotation once in a while I have seen them “D shaped” where someone has tried to crimp the cannon pinion with nail clippers etc whilst still in place !. Pulling the dial is the answer you will be able to quickly check the teeth/wheels etc and engagement, make sure there is a dial washer there also and have a good look at the cannon pinion and the pinion also maybe bent/damaged.

Thx Mike, Chris

I'm not handling it; it is sitting in a Jerry Stand" while observing it.

Chris is confirming what my engineering instinct (since I don't have experience) was telling me to do. The puzzlement is what created the behaviour since it was running so well; and that it loses almost precisely a half hour and then runs fine for the rest of the wind.

Thanks again

Gary, Hamilton Cannon Pinions are (in my opinion) notoriously EASY to loosen up and HARD TO TIGHTEN successfully. When they start "letting go", it can happen all at once in just one "re-set" of the time. I suggest that this watch needs to be inspected.

Thanks Dave, I think mine is another such example.