There are two types of Lange Balance Cocks - for regulators, and for freesprung balance wheels

Sep 08, 2019,14:22 PM
 

Before getting into it, let's revisit some theory first to better appreciate the subtleties of why the engraving differences arise.

The 1st gen Lange Chrono uses a regulator to adjust the timekeeping (beat rate). Notice the swan-neck with its screw - it pins a long needle, which is the regulator lever. The regulator is used to control the position of the regulator pins, which determine the "effective length" of the breathing hairspring. The engraving below is meant to be a scale of sorts, to determine the regulator's position. The letters, as dedestexhes stated, indicate the directions for "fast" and "slow". This is why it is called a "swan-neck regulator".

However, there is a modern alternative to using a regulator which is the freesprung balance. This means there are no regulator pins that interfere with the hairspring breathing, thus it is "freesprung". Timekeeping is instead controlled via adjusting the position of masses on the balance wheel - the further out the weights, the higher the inertia and thus the slower the watch beats and vice versa. This, in theory, provides better timekeeping because of better isochronism and less susceptible to orientation/gravity effects. 

Now, if the weights are used to adjust the beat rate for a freesprung balance wheel, then what is the purpose of the swan-neck? The answer is that it adjusts the starting position of the hairspring instead, to ensure that the "tick" and "tock" of the balance wheel swing in equal amounts and are not lopsided. This is called the "beat error". There are occasions where people mistakenly still call this a "swan-neck regulator", when it doesn't apply here and would simply be called a "swan-neck"!

Ideally, beat error only needs to be set correctly once and can be left alone - this is because the geometry of the spring won't easily change over time. Therefore, the balance cocks of freesprung watches do not have a scale engraved into it, instead they use the entire cock as a full canvas for ornate engraving.

Meanwhile, as we all know, a watch may gain or lose time over the years due to many factors. A watchmaker would have to regulate it every now and then for accurate timekeeping. Thus, for the non-freepsrung watches, the swan-neck regulator serves a functional purpose for timekeeping adjustment and thus the scale makes sense.

The differences can be seen in the photos below - the top is from a Lange Sax-0-mat movement, while the bottom of a RL Jumping Seconds. The Sax-0-mat is an older movement, thus retains the regulator and hence the engraved scale. Meanwhile, the RL series of watches are all about chronometric performance, thus it uses a freesprung balance wheel and hence no scale is needed. Most modern mid-high end Lange watches adopt the freesprung balance, including updated movements - the 2nd gen 1815 Chrono and the Datograph U/D for instance.


In short, if your balance cock has a scale engraved on it, it is a regulator watch. If it is fully engraved head to toe, it has a freepsrung balance wheel instead!

Regards,
skyeriding


More posts: 18151815 ChronographDatograph

  login to reply

Comments: view entire thread

 

balance cock engraving question

 
 By: Chromatic Fugue : September 8th, 2019-13:29
I understand that the balance cock (or equivalent) of every Lange watch bears the individualized engraving of the watchmaker who put it together. Indeed, I understand that these engravings enable watchmakers at Lange to know at a glance exactly which of t...  

I think it is N for Nach (slow) and V for Vor ( fast). [nt]

 
 By: dedestexhes : September 8th, 2019-13:35
You just can see part of the V. The pattern is easily recognized of you do a factory visit. They’ll give a small card which states the engraver, not the person who build the watch. Cheers, Dirk

Got it -- thanks! [nt]

 
 By: Chromatic Fugue : September 8th, 2019-13:41

I noticed the same on my ex Datograph movement.

 
 By: amanico : September 8th, 2019-13:37
My Datograph was from 2004. I guess N stands for neutral, and that the other letter stand for slow or fast. ...  

yep, same engraving

 
 By: Chromatic Fugue : September 8th, 2019-13:47
The most distinctive feature of this engraver's "signature," in addition to the "N" (and hidden "V"), is the use of three parallel lines just below the screw, along with the hash marks at a 45 degree angle to those lines. It's an interesting contrast to t... 

There are two types of Lange Balance Cocks - for regulators, and for freesprung balance wheels

 
 By: skyeriding : September 8th, 2019-14:22
Before getting into it, let's revisit some theory first to better appreciate the subtleties of why the engraving differences arise. The 1st gen Lange Chrono uses a regulator to adjust the timekeeping (beat rate). Notice the swan-neck with its screw - it p...  

Many thanks for this!

 
 By: Chromatic Fugue : September 8th, 2019-17:10
Right here is what’s so great about this site: ask a truly obscure question, get an incredibly interesting answer.

Bravo, thanks. [nt]

 
 By: nwk00 : September 8th, 2019-21:15

The balance cock doesn’t show who assembled the watch.

 
 By: russell996 : September 8th, 2019-15:14
It is true they are individual to the engraver and you can find out who the engraver was from Lange. However the engraver and the watchmaker are not one and the same. They had an engraver at the Concours of Elegance at Hampton Court and when I showed him ... 

Got it...

 
 By: Chromatic Fugue : September 8th, 2019-17:06
... curious: does the engraver perform any function other than engraving the balance cock?

They do other engraving as well

 
 By: mj23 : September 8th, 2019-20:04
Like engraving on solid case back if you’d prefer as an example. That’s extra charge of course. 😁