Hi All,
I just got a new 2017 Speedmaster Professional. 4 days old and I was trying to sync the watch to the atomic clock in order to check its accuracy. On my Seamaster, when I pull out the crown the second hand stops allowing me to sync exactly. My watch dealer told me that it doesn't work this way on a Speedmaster and that you can't stop the seconds hand..
But I found out that if I gently roll the crown rearwards, it will actually cause the second hand to move in the counter-clockwise direction slightly, and if I just maintain very slight pressure in the rearwards direction it will cause the second hand to stop moving altogether, allowing me to sync it exactly.
Will doing this cause damage to the movement of the watch?
So far, loving the watch.

 

Welcome aboard

Once in a blue moon should be no drama but all the time I think @Archer commented a few weeks (months) ago as not being a good idea.

Sounds like your going to be here a bit so show us your watch and set yourself a avatar

 

From the manual (so presumably OK )

2 Operating instructions Manual-winding chronograph

CALIBRES 1861, 1863, 3201

The crown has 2 positions:

2. Time setting: hours – minutes – seconds. Pull the crown out to position 2. Turn the crown forwards or backwards. Synchronise the seconds by pushing the crown back to position 1 to coincide with a given time signal.

Note: calibres 1861, 1863 and 1866 do not have a ’stop-second’ mechanism. To synchronise, the crown should be gently turned backwards and pressure maintained to stop the seconds hand. Release when the display corresponds to the timing signal and push crown back to position 1.

 

Stopping - fine.

Running backwards - not fine...

 

Good to know Archer.

I guess the laws of physics still applies huh? Slowing down (to the point of stopping) time is fine...but you can't go back in time.

 

Yes, laws of physics indeed...



I can't say for sure this is from running backwards, but the geometry of the escape wheel tooth and pallet fork jewel works far better going forwards, rather than backwards...

Cheers, Al

 

Although I understand the logic that forcing the seconds hand to move backwards a significant amount is not a good move, my personal experience trying to set my Speedy XI-45 (which is not very often, as I usually can't be bothered) is that you can sometimes see slight movement with the seconds hand in an anti-clockwise direction, as it is not easy to judge the exact amount of pressure you need to apply to stop the watch.

If the 1861 is so sensitive to these slight movements, which for me are an inevitable consequence of trying to set the watch with some degree of precision, then I for one will downgrade my previous perception of a robust, user-friendly movement.

I know that this is not a sign of watch health, but my XI-45 just kept +0.2 sec/day during a four day run in May (max -0.3 / +0.4) .

 

You are making a lot of assumptions. First, the pallet fork in question is not one from a Speedmaster - I was simply using it as an example of the sort of damage running a watch backwards a lot can do to the pallet fork jewels.

Second, this is not unique to the Speedmaster - all lever escapement watches can be subject to damage from running backwards.

Cheers, Al

 

OK, then all lever escapement watches are subject to damage from running backwards, which includes the 1861. I just had no idea that this was the case, and I always assumed (incorrectly) that the 1861 was more robust in its hacking procedure. I imagined that NASA probably wanted to keep all mission watches in sync and that hacking would have been quite common. I for one will now avoid making any attempt to hack either my Speedy XI-45 or future Speedy Tuesday.

Cheers

 

Wow guys, EXTREMELY helpful response. Guess I have to finally crack the manual. I also purchased a new lawnmower so reading that took precedence!

 

OK. another question. I've used the 'hack' feature to set to the atomic clock. In 4 days, the watch is running over a minute fast. When I tried to use the hack feature (gentle rearward pressure on the crown after pulling it out 1 stop, the second hand didn't stop movement at all.
Any ideas?

 

It may depend on the state of wind - if the watch won't hack when fully wound, let it run down for a day and try again. Less torque coming from the mainspring means less friction on the cannon pinion required to hack the watch.

 

My advice -- if your watch is running fast (like yours is, around +15 seconds per day), just set it to the nearest minute and don't worry about it too much. You can pull the crown out and let the time catch up to your minute hand whenever you need to. Mechanical watches aren't meant to be accurate to the second anyway.

 

Since the watch doesn't hack, the minute hand won't stop, so time will not "catch up" simply by pulling the crown...

 

'Doh. My Speedy runs slow so I have to set it ahead by a minute occasionally, which is less of an issue it seems.

 

On my 105.012-65, last service in the 70', 3 seconds a week.

 

Your 105.012 hasn't been serviced since the '70s?

 

Nope, I bought it to the first owner's son, he told me that.
Tuned last monday :

 

If you wear it often or at all I would recommend biting the bullet and getting it serviced (preferably at STS). I know we sound like a broken record here but 321 parts are not easy to come by so wearing an unserviced 105.012 is pretty risky.

 

Again, excellent news. I was getting worried the watch wasn't working correctly, but I let it sit a day without winding, and it 'hacked' the next morning fine. Great advice again Archer. Many thanks.