I called master watchmaker Martin Braun some minutes ago and asked him to give Sidney some additional information about “the stud and knee”. Please read Sidney´s question and Martin´s answer …
>> Sidney posted this comment:
“I’m not a native speaker but a watch lover,Mr.Alexander. I don’t get the meaning of “the stud and the knee” that you mentioned in your article. Could you kindly explain it to me,please? Thanks. Sidney from Shanghai”
>> Master watchmaker Martin Braun gave me this answer:
“Dear Alexander, many thanks for your inquiry about the technical description for the Slow Runner.
We have to apologize for the wrong word used in the description, brought in from our translation office, who is not that deep in watchmaking and we oversaw it.
The word “stud” stand for “Impulse Pin” or “Ellipse”
But coming back to your question: The system of a Balance Wheel with Hairspirng works perfect, if all angles are in the numbers.
That means, the angle has to be correct between Impulse Pin, and Outer Fixation Point of the Hairspring (Piton) and the Inner Fixation Point of the hairspring.
With “normal materials you will always have some tolerances we do not have with silicium material.
Basically it has two reasons why it has to be.
First of all to center the beat: We have no moving arm to adjust it. But it is so well calculated, that if we build in the system, the center beat is 0.0 ms.
The second thing is, that if the Inner Fixation Point is in the right angle, we reach a small running deviation to + if the amplitude become smaller what cause normally an anisochronism mistake to a minus deviation.
Finally we could optimize the outer curve of the hairspring. We have a Free Sprunge System and do not need a center radius curve at the end of the hair spring. So we could make a curve which allows the hairspring to “breath” during swinging more in a centered way. The complex curve shape is much more precise to produce that it can be done with an normal hairspring.
I hope that answers your questions. It is very difficult to explain in my not mother tongue.
All the best
Martin Braun”
Please do also read my article about the watch presented in Basel at Baselworld HERE
