Wow....glad you're on board, Johnny (or walrus, if you prefer). :-)
Been waiting for you (or someone) to come along and help with some of the questions that often vex us Rolex owners.
So, I'd like to begin with a question that I've had for a long time now but haven't been able find the right person to ask.
We know that Rolex is always striving to bring us a more accurate watch, and up 'till now they've done a remarkable job, but why don't they employ something like a
remontoir, instead of simply relying on an overcoil termination of the balance spring?
I mean, you and I both know that a balance spring isn't perfectly isochronous because it doesn't obey Hooke's law. Hooke's law states that the force in the spring is proportional to the angle through which it turns, but this isn't true for a spiral balance spring of a watch.
We also know that if the inner point of attachment were at the very center of the balance staff and the outer point of attachment wasn't at a fixed distance from the center of the balance staff with the end of the spring making a fixed angle to the radius, then it could be isochronous, as the restoring force for all angular rotation would be the same. As this isn't the case, the traditional flat balance spring is inherently isochronous.
Further, as the spring is wound, a restoring force is created. However, the portion of the spring closest to the fixed outer point of attachment creates an additional force that acts against the restoring force. The imperfect inner point of attachment creates a similar force. The result is that the spring isn't centered. The mechanical result is that the restoring force in the spring is not proportional to the amount it's been wound up, or, to put it another way, the force required to wind it up varies with amplitude.
Now, we also know that an overcoil balance spring compensates for this effect by making the main part of the spring think that the outer point of attachment isn’t fixed. Essentially, the effective outer point of attachment is at a point that varies with the angular displacement of the spring, so compensating the inherent anisochronism to a certain extent.....
....but that's exactly the rub....'To a certain extent'.... meaning that Rolex could do better with the addition of a constant force train, and my vote would be for the traditional
remontoir set-up.
What say you, Johnny?
(Boy, am I glad you're here...no more hologram questions, just good 'ol meat-and- potatoes horology chat) :-) :-)
