Testing Vachy's precision... fingers crossed!

Hi all,

After reading stories about how proud people are of their watch's precision, I decided (hesistantly) to start
my own measurement experience. Unfortunately, I don't have any equipment, so I used to US atomic clock
web site. As for 9h23 (EST) this morning, I am perfectly synchronized to it. Due to personal constraints, I can't
check in 24 hours (as it is typically done, it seems)... so I'll check once tonight (in 12-15 hours) and once in
about 30 hours.

I am not going for a perfect score, but I do want to know how precise my piece is. Now the question is,
what kind of time difference would be considered "acceptable" after that time? I see people with chronometer
watches posting about their +/- 2s variation after 24h. I'm thinking I'd be quite happy with +/- 10s...

What do you think? I'll keep you posted with the results tonight and tomorrow.
looking forward to the results! (nt)
08/31/2010 - 17:50
Re: Testing Vachy's precision... fingers crossed!
08/31/2010 - 20:22
I look forward to seeing your results. My watch runs consistently 7 seconds fast per day. I read in a WatchTime special issue that VC considers +0 to +15 seconds to be the acceptable range for non-chronos. I still don't really understand the emphasis on not running slow. It's a bit frustrating in that my watch is pretty much in the middle of that range, so if they had targeted -7 to +7, my watch would have been almost perfectly on time. The only bright side I see is that, along with hacking seconds, it makes it easier to keep the minute hand and second hand perfectly synchronized since one doesn't have to adjust the time to compensate for drift; one only has to stop the watch from running every once in a while for long enough to let time catch up. I doubt that was VC's rationale, but I do keep my minute hand and second hand in perfect synchronization just because I can.
After about 13 hours...
09/01/2010 - 06:45
So I set my watch "exactly" to the US atomic clock about 13 hours ago. After 13 hours of regular use, I'm roughly 5 seconds ahead of it. If things go according to my guess-timation, I should be less than 10 seconds off tomorrow when I check in (which, to me, is good). I figure that, with the power reserve running lower, it should slow Vachy down with respect to what he was during the day. This should slow down my time gain (I think). However, with new technologies, I'm not sure if what I just said still holds. I'll keep you gentlemen posted Tien
After about 29 hours
09/01/2010 - 22:57
So finally, after about 29 hours of normal wearing, I checked the US atomic clock and Vachy is ahead by about 13 seconds. I'm slightly disappointed with the performance result because I would have I liked for it to be competitive with chronometer watches. However, to be honest, it's probably much more precise than I would ever need. And I guess it also invalidates the thought I had that lower power reserve slows down the watch. Well, that's it for now. Tien
test it for a week and see if it evens out
09/02/2010 - 09:23
Re: test it for a week and see if it evens out
09/02/2010 - 18:45
Alex, This is very interesting because this implies that the speed will vary.  With my JLC Reverso Grand Sport I used to have something like +6s a day (24h.), for about the last 6 years. Until lately where the gap has dramatically increased up to 15 to 20s a day.  And it remains so after servicing and revision at JLC. On the other hand, my VC Overseas Chrono 1st gen runs at +1/+2s a day but can have +3/+4s a day during the w-e when I'm more active (sprot, gardening, etc.). Quite naïvely, I had always thought that speed remains relatively consistent over time. Even though it can be a tad faster in the beginning and can slowly decrease with the watch aging. Is the speed of an automatic movement so much sensitive to the behaviour of the one that bears it, as it seems to be the case with my VC? How can it be explained that my Reverso runs now at such a speed? I'd be interested to have your opinion on that matter. thks
I may just do that... keep you posted.
09/03/2010 - 09:11
That's just hoping to be rescued by positional variation.
09/04/2010 - 04:49
A watch that loses ten minutes one day and gains ten minutes the next day "evens out," but it's not a good watch. All watches vary in timekeeping somewhat depending on position and motion, but the better ones are supposed to vary relatively little. I am disturbed by the gaining of 13 seconds in 29 hours, but I would be a lot more disturbed if the watch "evened out" by losing 13 seconds in 29 hours in a different position. A consistent 11 seconds per day of gain can probably be regulated, but a positional variation of 22 seconds in a high-end watch would be entirely unacceptable.
Re: After about 29 hours
09/06/2010 - 07:34
Hi Tien, I recall you bought your watch new in LV in the beginning of the year?  Depending on how long it might have been at the AD, chances are that your watch has "settled" in over the past few months. My experience has been that a watch that has been properly regulated right after a full restoration will run a little bit faster (say 3-8 seconds/day) after a few months - as the oils have become better distributed and any "wear in" has taken place.  If I think it runs too fast, I take it in for analysis and if it is running consistently, have it re-regulated to slow it down a little bit.  Usually the accuracy/precision will last for years and when it finally gets to a point when it runs too slowly, I know its about time for another service. Your watch will also be affected by your lifestyle.  A watch that indicates very well on a timing machine will often run differently when on your wrist. The position you lay your watch at night will also affect the overall rate over a 24 hour period (for example, if it runs fast on your wrist, you may find that there is a position that will run a little slowly when you're not wearing it, therby "balancing" things out over a full 24 hour period). Without a timing machine, you will need to be patient and time the watch the old fashioned way:  wind it up and let it sit in each of the 6 positions for 24 hours to measure how fast/slow it might be (you can try to shorten the time up by timing for 12 hours, but 24 hours is preferred).  Besides these positions, also time the watch when it is on your wrist (which might be 8-12 hours?).  With this information, you will have a better understanding of your watch's current performance.  As MKVC said, 13 seconds over 29 hours sounds a bit too fast for me for a quality VC .  If you don't want to take a week to test Vachy, then see if you can take it to a VC AD or watchmaker that you trust to analyze it on a watch timer.  (My wife bought me one for Christmas last year, she had no idea how much fun I would have with it - so she is very happy that I enjoy using it so much!).  I would say that the most important thing to look for is that Vachy is running well and consistently in each position, ideally with little variation between the positions.  If it is running this way, its a minor thing for VC to regulate the watch for you.  If it is running oddly, Vachy is still under warranty and VC will take care of anything that needs to be done. For a couple of personal examples:
  1. My oldest VC is a 1908 Chronometre Royal pocket watch that has been fully restored by VC.  It runs within a range of +3/+7 on a timing machine when put in all 6 positions.  It runs at +3/+4 s/d when in actual use (in my pocket during the day and resting at night)
  2. My newest VC is a 31-Day retrograde bought in 2006.  It runs within a range of -3/+1 on a timing machine when put in all 6 positions.  I can't tell what it runs at when I'm wearing it because it doesn't have a seconds hand  
Expect the best from VC, I most certainly do.  I hope this info is helpful. Best Regards, Dan
Re: Re: After about 29 hours
09/07/2010 - 07:27
Thanks Dan... that's a great description of the process. I do have a general feeling that Vachy is not performing up to par but not enough to push me to send him away YET. The thought of sending him off to the spa and leaving my wrist naked for 3-4 months is quite terrifying to me. I will be passing by an AD at the end of the week so I'll follow your suggestion and ask them to check his performance on the timing machine. Of course, I'm worried about the outcome and of the hassle that it entails. I'm going back to LV this year (on Vachy's birthday) to count down the New Year. If I find another wrist companion, maybe it will be easier to send Vachy off to the spa. Tien
Regulating a K1072
09/04/2010 - 23:06
I had my cal 1072 watch back in Geneva for a service this summer and, apart from doing great work on the case and dial, they also regulated the escapement - it currently runs at about +2 seconds per day which I think is amazing for a 45 year old watch. By the way, Alex - your Don Corleone better watch out when this guy's about (see left).
The Breguet hairspring makes quite a difference.
09/05/2010 - 08:44
I have found that Breguet hairsprings really seem to make a difference in timekeeping. Your caliber 1072 has one.