watch winders and fully wound main spring..

[HAL330]

So it occurs to me (and I'm no watch maker, but I do hold a mechanical engineering degree) that keeping your watch wound all the time, either by winding it manually constantly or keeping it on a wonder so that the main spring is at max tension has to have a negative effect over time ... vs allowing it to wind down either partially or all the way to a stop and then winding and wearing it a week later (this assumes you're rotating watches and not wearing the same watch every day)..

Anyone ever do a study on this or has anyone finally decided whether watch winders can do more harm than good by both keeping the main string fully wound and / or not allowing the gear train to stop when not worn for a prolonged period of time and thus wearing down the gears faster for no reason?

Thoughts?

[favre12rodgers]

Originally Posted by HAL330

So it occurs to me (and I'm no watch maker, but I do hold a mechanical engineering degree) that keeping your watch wound all the time, either by winding it manually constantly or keeping it on a wonder so that the main spring is at max tension has to have a negative effect over time ... vs allowing it to wind down either partially or all the way to a stop and then winding and wearing it a week later (this assumes you're rotating watches and not wearing the same watch every day)..

Anyone ever do a study on this or has anyone finally decided whether watch winders can do more harm than good by both keeping the main string fully wound and / or not allowing the gear train to stop when not worn for a prolonged period of time and thus wearing down the gears faster for no reason?

Thoughts?

This has been discussed 100x on here. Both sides have good arguments. Who really knows whether using a winder damages it more or keeps it from being damaged. I keep my watches in a winder but the winder hasn't been on for years.....it makes sense to me that constantly using it might wear stuff out quicker...but that's my opinion (it very well could be wrong). Either way, watches aren't like cars....they won't normally just stop working in 5 years regardless of how you treat them.

[HAL330]

got any links to good threads on this discussion?

[Tools]

Originally Posted by HAL330

. . .

Anyone ever do a study on this or has anyone finally decided whether watch winders can do more harm than good by both keeping the main string fully wound and / or not allowing the gear train to stop when not worn for a prolonged period of time and thus wearing down the gears faster for no reason?

Thoughts?

As an engineer, we know that a constantly running machine is incurring wear. A watch that is wound down and stopped is incurring zero wear.

Winders are mis-named as they aren't really there to "wind" the watch, but to keep it at a relatively constant state of wind. Ideally, you would set the turns-per-day to equal the amount of wind used during that day. A winder shouldn't damage a watch, but again, the watch is always in motion (running and spinning)

Machines that are running continuously usually have a predetermined maintenance schedule to keep them in proper condition. Does wear = damage? If it is routinely maintained (serviced), does it matter?

[HAL330]

Originally Posted by Tools

As an engineer, we know that a constantly running machine is incurring wear. A watch that is wound down and stopped is incurring zero wear.

Winders are mis-named as they aren't really there to "wind" the watch, but to keep it at a relatively constant state of wind. Ideally, you would set the turns-per-day to equal the amount of wind used during that day. A winder shouldn't damage a watch, but again, the watch is always in motion (running and spinning)

Machines that are running continuously usually have a predetermined maintenance schedule to keep them in proper condition. Does wear = damage? If it is routinely maintained (serviced), does it matter?

this makes sense... but more over, doesn't it also seem like keeping the main string at max tension or there about also harmful? If the main spring isn't aloud to drain it's power reserve ever, that seems like it would cause issues.

[Tools]

Originally Posted by HAL330

this makes sense... but more over, doesn't it also seem like keeping the main string at max tension or there about also harmful? If the main spring isn't aloud to drain it's power reserve ever, that seems like it would cause issues.

Mainspring "set" is a known phenomenon, much more common in older mainsprings than the newer miracle compounds.

Because mainsprings do lose tension and elasticity over time, as well as when compressed for too long, they have a limited life cycle. Best practice is to change a mainspring when servicing/overhauling the movement.

Mainspring life is likely extended when allowed to unwind completely from time to time. Manufacturers likely have fatigue and degradation tables before they put their trademark products into use. FAR Nivarox and Rolex Parachrome and Silex hairsprings have all been stress and longevity tested and last a log longer than mainsprings, but I'll bet the companies won't give us that information or mainspring info either.

[HAL330]

Good stuff Tools.. all makes sense.. like I said, I studied engineering 30 years ago, but have not worked a single day in the field.. so I appreciate your expertise..