26320 Chronograph Seconds Hand Running Fast

[wlc]

Hi,

I picked up a new 26320 from an AP boutique this weekend, and I've noticed that the chronograph seconds hand is running faster than the running seconds at 6 o'clock. After 30 minutes of running the chronograph, the chrono hand has gained 5 seconds over the running seconds hand. This time was gained evenly over the 30 minute period.

Has anyone seen this before?

Thanks!

[waisoserious]

Take it back....

[srvrf]

I'd be willing to bet that not many have ever tried to look at this or would even notice. You'd have to start it when the running seconds hits 12:00 and then watch it for 30 minutes. It would seem like this shouldn't be possible because of how the gears should work. But I have three watches with the same F Piguet movement and I should be able to run them and post pictures later today.


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[wlc]

Thanks srvrf.

That's exactly what I did - started the chrono when the running seconds hand was exactly at 12. I was also under the impression that this couldn't be possible, but after trying the experiment 3 times, the results are consistent. I could potentially see the chrono losing time vs the running seconds if there was some sort of slippage, but gaining time doesn't make a whole lot of sense.

I'd very much appreciate if you could let me know if you see this behavior on any of your F. Piguet 1185 movement watches.

And if anyone else out there has a better understanding of this movement, and how this could be possible, I'm very curious!

Thanks

[srvrf]

Mine seems to be right on. Here is one just after starting and an hour later. The chronograph seconds hand is about 1 second ahead of the running seconds hand in both pictures.
For the record, I'm not flipping anyone off in the first picture although I have no idea why my hand was like that.





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[wlc]

Yup, seems like yours is working perfectly - thank you for taking the time to check.

For the sake of comparison, here's mine - the first pic is right after starting the chronograph, the second pic is 31 minutes later.

[csi-n]

I wouldn't have thought that what you've described is mechanically possible. I always thought that the time and the chrono functions are run by the same spring/escapement/drive system, and hence would always be in sync.


Sam

[wlc]

I've posted two replies since this morning, and both said they required approval by a moderator. Is that the norm? Sorry, I'm new around here!

In one of the earlier replies, I posted before/after photos similar to srvrf's above, showing the chrono hand gain about 5 seconds over half an hour. Hopefully that post will be approved and you'll be able to see for yourself.

I also would not have thought this to be possible. I'm going to give a call to AP and see what they say...

[wlc]

Well, that post went through, so maybe I wasn't logged in earlier? Anyway, here are the pics...

Right after starting the chronograph - note that both seconds hands are at about 10 seconds...



And here it is 31 minutes later - note that the chrono hand is about 6 seconds ahead of the running seconds hand...

[srvrf]

Originally Posted by csi-n

I wouldn't have thought that what you've described is mechanically possible. I always thought that the time and the chrono functions are run by the same spring/escapement/drive system, and hence would always be in sync.





Sam

I totally agree with you but my pictured ROC used to have a problem that I couldn't believe. It was fixed when they changed the hands. When I started the chronograph, the first 1 min 59 seconds were perfect. But the minutes hand never advanced to 2. The seconds hand continued operating but it never made the minute hand (or hour hand) advance any further. I thought that if the gear made it move to the first minute it would surely make it move to the second minute but it did not. I didn't get a great explanation from AP but they mentioned the possibility of the hand slipping a bit on the pinion. So I'm not sure what's exactly going on here, but it doesn't make sense nor does it sound like normal operation.


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[Sammk]

Do let us know how it goes. I'm curious as my 26320 is coming next month

Originally Posted by wlc

I've posted two replies since this morning, and both said they required approval by a moderator. Is that the norm? Sorry, I'm new around here!

In one of the earlier replies, I posted before/after photos similar to srvrf's above, showing the chrono hand gain about 5 seconds over half an hour. Hopefully that post will be approved and you'll be able to see for yourself.

I also would not have thought this to be possible. I'm going to give a call to AP and see what they say...