my daytona lose 5 minutes a day after changing dial

[rmfnla]

Originally Posted by MonBK

Like David already adviced you the problem most likely is with the hands.

Use a loupe and study the movement of the hands and see if they catch or rub somewhere.

I missed that; it does make sense...


[Edit: Oh no, the dreaded second page!]

[Welshwatchman]

The watchmaker is seemingly in denial.

5 mins a day is 12.5 seconds per hour.

Take it back to the AD, synchronise the watch witnessed by staff.

Wait there two hours, get them to see the near-30secs drift.

THEN KICK ASS.

[FeelingTheBlues]

Originally Posted by SearChart

If it's too loose wouldn't it then gain time instead of losing time?
If the watch loses time it might be too tight which causes friction, or am I missing something?

Not necessarily Bas, the cannon pinion on a Daytona would, if I'm not mistaken, be like the one below.



The large wheel underneath (with the two small arms) holds the pinion and makes it turn (along with the minute hand) as another wheel in the movement makes it turn. However, if one wants to set the time only the pinion on top would move. The arms need to be tight enough to allow the pinion to move correctly when you want to set the time (if it's really too tight there's a risk that you may make the main gear train move and some teeth could be damaged in the process), if they're too loose, the big wheel would turn but the pinion wouldn't follow (or not always), thus causing the watch to lose time (or "gain time" if you shake it as it would rotate by itself).

Originally Posted by MonBK

Like David already adviced you the problem most likely is with the hands.

Use a loupe and study the movement of the hands and see if they catch or rub somewhere.

When I put hands back on one of my watches, if they're touching each other or rubbing on something the movement usually just stops moving but I must admit I haven't experienced that enough times to see all the types of problems this could cause.

To the OP, it would indeed be wise to take a close look at the hands as well in case they aren't rubbing on the crystal or the dial or if they're touching each other (try to set the time and make the minute hand go over the hour hand, if you see them hitting each other you may have found your problem). As well, allow me to ask if you let the chronograph function on your Daytona run all day long or if you only let the watch run, using the chronograph can make the watch lose a bit of time over a certain period of time (though five minutes could be a bit much, perhaps your watchmaker didn't test it with the function on).

[Ticking_Sonata]

yes i did to use the chronograph for long time and stop it but after several hours my watch start loosing the time. it only happen when i used the chronograph and stop it.

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[FeelingTheBlues]

Originally Posted by gabriel.sw9

yes i did to use the chronograph for long time and stop it but after several hours my watch start loosing the time. it only happen when i used the chronograph and stop it.

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Test the watch without using the chronograph function at all for a complete day, you'll have a better idea of how accurate the movement is.

Did you try setting the time? How did it go with the hands? Was it very easy to adjust the time or did you at least feel a bit of resistance?

[richard371]

I second what Carls says. Try setting the watch to www.time.gov for 24 hours without the chronograph running and see how much it deviates. Then run the chronograph for 24 hours at see how it deviates. A modern Daytona should be running no more then + or - 3 or 4 seconds a day with or without the chronograph running. 5 minutes is way off. My Vintage sundial does better then that :)

[SALTY]

If the watchmaker (I'm being kind) thinks that -5 minutes/day is OK maybe he just misunderstands the whole +6/-4 COSC thing; thinking, you know, that it was MINUTES! Then again, even that would be out.

[FeelingTheBlues]

Originally Posted by Nimrod

If the watchmaker (I'm being kind) thinks that -5 minutes/day is OK maybe he just misunderstands the whole +6/-4 COSC thing; thinking, you know, that it was MINUTES! Then again, even that would be out.

I think you may have misunderstood what the watchmaker did and meant by "the watch is okay". The OP said that the watchmaker's equipment is in the back of the office so he couldn't show him but my guess (as it is what watchmakers usually do) is that he took the watch, put it on a timegrapher and tested it to see how the movement was. The machine most probably showed him that the movement shouldn't lose more than 2 seconds per day.

I find it strange that this machine isn't plugged to a printer, usually the watchmaker should be able to have the information regarding the watch's accuracy in all the tested positions on a piece of paper to show it to the customer. Still, the fact remains that this man probably tested the watch and noticed that it's supposed to run well according to the movement's test, hence our theories about the hands, the use of the chronograph function for a long time or the cannon pinion (the watchmaker could test the watch after starting the chronograph to see how the results change but the two other possible problems cannot be checked on that machine, it works with the sounds made by the watch).