WatchUSeek Watch Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
305 Posts
Discussion Starter · #1 ·
I just received my new Glycine Airman 9 and was wondering? The Airman 9 does not have a regular seconds hand. But it does have a center seconds hand for the chrono function. So, would running the chrono function 24x7, or at least while I'm wearing it (so I have a center seconds hand) cause any problems? Since the watch has a Val 7754 Automatic movement and when not worn, will sit on my winder, it should never loss it's reserve power. So the watch 'should' run fine all-the-time, right? Just wondering how much excessive wear will I really cause, running the chrono, all day long?

Thanks,
Dave...
 

·
Registered
Joined
·
1,493 Posts
I have seen this debated several times on various fora; the overwhelming opinion was that it is not a good idea. However I have not seen anyone post any hard evidence as to the effects on a Valjoux 775x movement.

Personally I think that its not a good idea as chronographs are designed to time events and not to run continuously.
 

·
Registered
Joined
·
661 Posts
From what I've heard, most chronos are not designed to run continuously. Increased wear rate would be the only issue I guess. But I don't know how significant that would be.
 

·
Premium Member
Joined
·
414 Posts
From the manufactures of horizontally engaged chronographs of which the V23, 72, 730, 724, 7733, 7740, 7750, 775x are:

The wear on the 3 wheels that transmit the constant second motion to the sweep second hand are NOT designed to be engaged constantly. The teeth and bearings (most are not jewelled on these three wheels, there's a good indication of durability!) are not refined to endure constant running and will wear at an increased rate.

Watches with the vertical clutch system (SEIKO, Citizen, Pierce (some) and others) are designed to be engaged continously. Ever wonder why the SEIKO 6139's and 6138s along with the 7016 family do not have a constant seconds, its because Seiko recommends the sweep second act as the constant second until a timing event is required.

For more info google:

"chronograph vertical horizontal watch design" and see where it takes you.

Valjoux 72, 724, 726, and 730 with horizontal clutch:





YOU CAN SEE THE THREE GEARS I AM REFERING TO ON THE HORIZONTAL SYSTEM. TWO ARE ROSE GOLD IN COLOUR AND ONE HAS A STEEL PATINA. THEY LIE UNDER THE TRIANGULAR ARM SHAPED LEVER WHICH IS USED TO ENGAGE THE SECOND WHEEL WITH THE SWEEP SECOND WHEEL. THE TWO GOLD WHEELS DO NOT HAVE BEARINGS.



Seiko with no constant seconds and vertical clutches









 

·
Registered
Joined
·
305 Posts
Discussion Starter · #5 ·
Geoff, thanks for the info. But, as I stated, my Glycine Airman 9, does Not have a constant second hand either? So, did Glycine modify the 7754 for their own use, or just leave the 3rd hand (constant seconds) off? From what I've seen on the net, the 7754 ususally has one at the 9 o'clock postion!

Dave...
 

·
Premium Member
Joined
·
414 Posts
Aero Dave,

The 7754 is a mod of the 775x family and as such has the horizontal clutch system. With this in mind the 4 of the 7754 stands for the removal of the constant second hand which in effect is just removal of the constant second hand pinion.

This then allowed Glycine to change the dial to the vertical 30 minute and 12 hour format giving a balanced dial look for asthetics. It is purely an asthetic modification and not a modification to allow constant running of the sweep second hand

I would still not run the sweep constantly. Having said that, I have a friend with a 1973 Speedmaster pro which he has constantly run the sweep on and has had to replace two of the gears on the chrono function that I pointed out earlier. Of course it lasted 30 years until gear replacement but maybe he was lucky!

Cheers, Geoff
 

·
Registered
Joined
·
305 Posts
Discussion Starter · #7 ·
Geoff, My understanding was, the 7754 is a modified 7750, But, the 4 stands for the 4th hand (GMT) center hand? Which is independently controlled by the crown, in postion #2, turning counter-clockwise! It's not really a big deal. It just 'seems' strange to look at a watch that has 6 hands on it, and nothing appears to be moving!

:thanks
Dave...
 

·
Premium Member
Joined
·
414 Posts
OOPs you are correct, the 4 is the 24 hour option.

Your second point is absolutely correct also, without a constant second hand you can never tell if the watch is still running. That has always been a complaint of watch wearers.

Seiko actually states this in the watch descriptions; for those of you that need to see the watch running use the sweep second as it will not harm or wear.

The constant seconds on the horizontal movements are certainly not there for use IMHO (at my age) due to the smallness of the dial. Glycine just chose to remove it for the the balanced dial look.

So there are two mods to the 7750 on the Glycine, the removal of the constant second / constant second dial / constant second pinion AND the additional 24 hour hand (two reduction gears on the dial side to transfer the 12 hour tube to a 24 hour tube).

Cheers, Geoff

The moral is; the gears and gear teeth were not cut, finished, nor made of a material to allow for constant use. I have not seen Glycines 7754 to know if the actual three gears are jewelled. Typically the chronograph wheels are not jewelled as they were not to be used continously and therefore did not need the wear protection jewelled pivots supply.
 
1 - 8 of 8 Posts
Top