Omega cal 1861 query - twitchy chrono seconds hand when chrono started

[AKM]

Hi everyone,

I thought I might celebrate a new job with a watch - first Omega in space . I've looked at a couple and really like the smaller case, compared with the moon watch, and the vintage feel which is much more noticeable in person than in photos. I'm glad I don't feel that I should have 'bought a moon watch sooner' as the FOIS actually feels like the better model for me.

However, I have question - of the two that I have looked at in ADs, both have had chrono seconds hands that jump ahead 2-3 seconds then hesitate when the chrono is started. One watch did this once out of around five presses of the chrono start pusher; the other did it every other time the chrono was started. My friend who isn't interested in watches, spotted the 'jumping and hesitating' straight away and she wears a plastic fashion watch. She was somewhat more pragmatic about it however and just sees these as higher-priced fashion watches.

I've seen this before the modular ETA 2894 movement, though the Dubois Dépraz module in my Dynamic Chrono has never done it and always gets a smooth release. My CWC with a Valjoux 7753 does it occasionally but is usually pretty good.

I know the 1861 doesn't have a column wheel and a cam lever chronograph isn't as smooth, I've heard it said it can be to do with the position of the cam when the chrono is released.

So I guess my question is: does what I have described sound normal, or should I hunt for another example? Does the calibre 1861 usually get a smooth start to the chrono or is a stuttery start and a little jump quite common?

[RaulGonzalez]

Perfectly normal. One moving wheel is put into engagement with a stationary wheel so depending on the position of the sets of teeth when they meet, the hand might jump forward slightly.

That's the advantage of a vertical clutch system as one part of the chronograph seconds wheel is in constant engagement. The clutch then releases the top part of the wheel and allows it to turn so you don't get a jump when the chronograph is started.

Hope this helps.

Luke

[AKM]

Perfectly normal. One moving wheel is put into engagement with a stationary wheel so depending on the position of the sets of teeth when they meet, the hand might jump forward slightly.

That's the advantage of a vertical clutch system as one part of the chronograph seconds wheel is in constant engagement. The clutch then releases the top part of the wheel and allows it to turn so you don't get a jump when the chronograph is started.

Hope this helps.

Luke

Cheers Luke, that explanation does sound familiar. I trying to work out whether it's 'a feature' which is sounds as though it is. I'm also wondering whether some individual watches perform better than others and it's worth being picky.

[RaulGonzalez]

Here is a good article from a fellow watchmaker- http://omegaforums.net/threads/chron...coupling.5539/

I was going to give you some more detail but that explains it well and with some pictures.

Luke

[AKM]

Cheers, I'll get a coffee and have a read

Many thanks

[anemo]

Here is a good article from a fellow watchmaker- http://omegaforums.net/threads/chron...coupling.5539/

I was going to give you some more detail but that explains it well and with some pictures.

Luke

Thanks for the link - very informative.