watch losing time..

[GL08]

Hey guys, just curious.. for manual wind watches, specifically speaking the P.999/1 movement.. if you don't wind it everyday since its a 60 hour wind.. do you guys find you -/+ time when it gets around 48 hours mark?

Usually by the 48 hours mark without wind, and 12 hours remaning, i lose a minute or two.. is this abnormal?

[jvo300]

Losing or gaining ten or more seconds I'd expect over a couple days, but a couple minutes is not right in my experience with PAM manual winds (though I don't know about that specific movement).

[Nucengineer]

I don't know about the magnitude of your timing loss, but it does make sense that a manual wind will lose time as a function of unwind or spring detentioning. That is why you don't see COSC manual wind watches. The Omega Speedmaster comes to mind. Nasa would wake the Astronauts every morning and have them wind their speedy's, I presume to keep them at maximum spring tension and most likely at their peak accuracy. With Automatics, the counter weight, or rotor, keeps the watch wound at some nominal tension and allows for the accuracy to be maintained. I would expect that if you set an automatic down and let it unwind, it too would become less accurate as spring tension goes to some minimal value. I am not a watch maker, but this is what my engineering education/training tells me will happen. Hope this helps. For manuals keep them wound tight every day you wear them and this shoudn't be a problem.