This is strange to me but I would like to do the question anyway, so other people read this later, and know.

I sold a omega speedmaster automatic recently . The caliber is 1152.
The buyer claims that the watch keeps perfect time but the chronograph is slow... can this happen? Is the chronograph running independently? Can sb please explain if this is possible at first and then how can this happen?

 

Can't happen. You may have a hard time convincing the buyer of this, as he may just be looking for an excuse to return the watch.

 

Thanks for your reply.
So it’s sure that this can’t happen.
I will just tell home to make a video starting the chronograph from zero second of the seconds dial and wait until one minute passes

 

Sort of...

Under normal circumstances, the rate of the watch and that of the chronograph will be the same. However there is a chance that if the watch were to receive a knock, the teeth of the horizontal coupling between the chronograph wheel and the oscillating pinion could momentarily loose engagement, and the chronograph wheel/hand could move. However this would be a one time event, and not be repeatable generally.

The idea of having him make a video is a good one. Have him make sure the watch is fully wound, and laying flat on a table when he takes the video.

Cheers, Al

 

Thanks Al!!
I will surely follow your advice fully !

 

Oddly enough, I had a recently acquired Flightmaster out yesterday and noticed that the chrono was noticeably slower than the main movement in less than an hour. I had the watch serviced by a watchmaker friend after I bought it, and since then the main movement has been keeping excellent time (+5 on average). Obviously he missed something in the chrono movement, so it is going back to him today.

 

That looks like the same situation. mine was serviced also two months ago. Please let us know what was the problem if you are so kind ?

 

I have had a couple of chronos over the years that did this. What was happening was the minute counter would not click over to the next minute, it would move half way and then fall back. Sometimes it would click through, but not always. So it would appear to be running slow relative to the main minute/hour hands. Needed an adjustment.

 

Thanks for your comment.
Yes that’s a good reasoning of what’s happening ..

 

Did the buyer provide details? Is the sweep hand is staying synchronized but the minute counter is falling behind? Or is he claiming that the sweep hand itself is running at a different rate than the running seconds hand?

 

My first idea was that it was running at a slower rate , but when I said that this is impossible he admitted that it was strange for him too but he said in his second message that it’s 2-3 minutes slow .
After that I kindly asked him to take a video of one minute duration as @Archer said above ...
I am now waiting for the video but I guess the video will prove me right... so don’t really know what to do .

 

If the sweep hand is moving correctly, but the minute counter isn't accumulating properly, it's still a legitimate problem for the buyer IMO, as @Evitzee noted. However, this isn't something that would show up in a single minute.