brandon1
842
The reason for the RL swan neck...
as far as i know is that it adjusts the stud holder...much like the new GP Microvar setup. This is used to control the beat. Many (most?) watches that have a free-sprung balance have an adjustable stud holder of some kind.

B
Not entirely alone.
By: mkvc : February 16th, 2010-00:28
I certainly have a preference for variable-inertia regulators, of which the most typical examples are free-sprung. However, I have a particular soft spot for the old IWC system that combined a variable inertia balance for large adjustment with a regulator...
Explanation....
By: BDLJ : February 16th, 2010-04:49
Hey Graham, In a (very small) nutshell, a free-sprung balance is where the balance spring length is fixed and the adjustment is via the polar moment of inertia of the balance...hmmmm. Bit techy, sorry. From the other direction: On a balance with a regulat...
free sprung vs. regulated
By: tee530 : February 16th, 2010-05:59
Also no expert, but the basics as I understand them: Free-sprung balances vs. regulated balances reflect two different ways of adjusting the rate (fast/slow) of the oscillating timekeeper. Free-sprung have a fixed-length hairspring, and thus the rate is a...
Not always high end
By: nickd : February 16th, 2010-10:33
Elgin produced the Durabalnce free sprung balance, though I don't know if it was ever used in production. FHF produced a free sprung production movement the FHF 72 www.ranfft.de . You see it from time to time on ebay in various watches around the $150 mar...
elgins
By: eterna-fan : February 16th, 2010-11:49
elgin produced tens of thousands of durabalance grade watches. the finishing was spartan, at best, but the movements were excellent time-keepers. i believe the free-sprung caliber 730a was the first wristwatch approved for US railway service. they were no...
More...
By: nickd : February 16th, 2010-13:18
The index pins of a watch with a regulator don't grip the spring perfectly tightly, otherwise you'd have to slacken them to adjust the regulator. Classic theory says the balance is isochronous due, in part, to this gap. As the balance spring oscillates it...