Could someone please either explain or point me in the right direction to read up on the different types of clutch used in Chrono movements? I read this on another thread which was dealing with the question of " should you let a Chrono run continuously?".
"The crux is the type of clutch.
- The traditional engagement is a set of two gears one of which has half size teeth so the misallignment is halved. It does mean that the contact is half als optimal as well so double the wear/tear. This is best NOT left engaged.
- The vertical clutch is dísengaged when not running, ńile declutching a car clutch. Engagement is the ´rest´ position so it is best kept running."
Which movements use the "vertical clutch"? I gather an Omega based 7753 movement doesn't?
Thanks.
Well, not all true what you quote there, as a chrono running will always cause wear, no matter what type of clutch you use. The clutch used determines the 'jump' in the secondshand, and the wear on starting/stopping.
A Rolex Daytona (2000+) has a wear/tear free clutch for instance, these also don't have the characteristic 'jump' when started. All Valjoux-based chrono's will jump (including your 7753).
But why would anyone let the chrono run continuously anyway?
That should read: "A Rolex Daytona (2000+) has an almost wear/tear free clutch..."
?Originally Posted by Henk Hoving
Examples of vertical clutch are LM5100, Seiko 6138/9, ETA 2894-2 modular.
A broad background - http://www.mattbaily.ca/blog/2011/07...h-chronograph/ but there is much discussion on the various types of clutch,hunt around.
(PS - just saw your update Henk - 'almost' is a good word to add!)
Last edited by andy111s; 11th September 2013 at 10:35.
Thanks for all the replies! I don't actually want to run my Chrono continuously. Just trying to learn :-).
If you don't mind, I've another question concerning a valjoux 7753 based movement (Omega 3304). Would it do any "harm/extra wear" etc if you stop the Chrono hand and then not reset to zero, i.e leave it at 6 o'clock?
P.s I apologise for the daft question!
Leaving the chrono hands causes no extra 'harm' or 'wear'.
Thank you. I gather the movement is in exactly the same state regardless of where the Chrono hand is stopped?
Edit: thinking about it, there must be something different as the reset pusher has "resistance" except when the hand is actually reset to zero (12 o'clock).
I need to do some reading!
Because I find a watch doesn't look right with a static second hand and so prefer it to sweep the dial continuously. It may be just me...
Undoubtedly on a three handed watch, but chronographs are a different beast. Most include a constant seconds hand as an indicator that a) it's working and perhaps, more tenuously, b) as an accuracy tool.
The function of a stop watch is to measure elapsed time, which is why the large second hand is the one that's used for the chronograph elapsed seconds function as it's easier to measure elapsed seconds accurately rather than have to use a subdial for this purpose.
Thanks for the info, and yes, my watch has that: Omega 2293.50.00 (link),
Err...yes? As I said, it may just be me. Each to their own...
Of course, I didn't mean to imply otherwise, it's just that sometimes people comment about things like 'I don't like round wheels on a car' and I feel compelled to explain why they are round, but I'm not saying that your judgement/taste or anything else is awry.
It's not only me:
And, having explored the thread I have quoted above and seen your posts, I quite see why you had this on your mind.
Not knowing a great deal about watches, I find threads like this one reassuring, as I too have wondered if I was doing any real damage to my watch. It's great to get opinions from one and all.
Thanks for the link, will have a proper read later.
As I understand it, the brake on a Valjoux 7753 is constantly on (when the Chrono isn't running), regardless of the Chrono hand position i.e it doesn't matter if it's zeroed at 12 o'clock or stopped at 6 o'clock.
The amplitude will always drop slightly when the chrono is running, owing to the marginal increase in friction. However, on freshly-serviced examples this is minimal and is unlikely to affect timekeeping to a discernible extent.
Have to admit, I prefer to see the big seconds hand running, but the purist in me says it shouldn`t unless it's being used as a timer.
As for the wear and tear aspect......I`ve no idea! In theory, I guess there will be some extra wear but I`m not sure this is observed in practice. I don`t have enough experience with 40-50 year old chronos to comment one way or the other.
Paul
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