francoisdenis

I can't speak about what's going on with the frequency of AO.... but I noticed that rounded edges appear spontaneously as soon as you used knifes and gouges to cut the "f hole"...

So many advises! Somebody ask me a picture . My client just breaks a string yesterday .

That true , this one seems to be in the average, I ask for a picture

I was away from my laptop since a couple of days and I thanks you all for your advices. I think that the answer could be connected to the pressure and time of playing and acidity. The player damaged the fingerboard very quickly (attached picture) and I had to plan it after only few month of playing. I have some femal players which don't reaches a such result after 20 years....So; wash the hands with high PH soap and less pressure on the fingerboard are my first advise. I will say later how it works .... PS: I have to say that neither brand of the strings, their lenght and instrument are in cause

The strings break between the nut and the bridge so the pb is not related to theses points. Right now, I have the pb with a viola player which can break C wolfram in two (often under the annular finger) only the D string (often in aluminum) seems to escape. It's a reason why I 'm thinking to a kind of chimical reaction with the sweat and seeking a way to thwart the effect. I thought that an ointment could help but it should to not make the playing more difficult. It's not a commun pb but a real handicap for the player.

Typically , a young man (between 17 and 20) playing several hours a day who breaks the strings after a few days only. I have encountered this case several times in my career with the only response "it will pass with age". Does anyone have a more immediate proposal to solve this problem?

Yes, you divide it in 8 units . Speaking of "relative measurements "unit" is a kind of equivalent of "the part of a ratio" You have a "unit" each time you use a ratio which can be the same...or not (Actually in this case you set all the measurement of the width using twice the section 3-5) and you do that using the Thales theorem

Interesting, I didn't know this book yet....

That matchs our empirical experience , perfect circles and perfect straight lines are an abstraction (all of us have had this experience trying to glue our first cello joint...) . So you have this gap between the reality and the ideal - which is an old philosophical issue. circle and straight line are an ideal conception of a reality which, at the end, is more the euler spiral. you will find the same kind of issue with the way the Ancient dealed with integers and irrationals - The beauty is a reality close to the ideal. It is this way that Ancient Ideals were made - the perfection was only the gods domains David you are on the god side and Marty, on the weak humain side

One may also consider (perhaps in a more constructive and realistic way) that it is not one or the other but the one and the other

indeed....

Yes for example, but I am not the only one, the proposals of David and Kevin require only simple measures too (and some others before us, as well). As far as I am concerned, I consider myself more as a historian of the concept of measurement. I read and sometimes studied closely all that I could on the subject. The violin is for me only one example among hundreds of others, the organ buffets interested me, viola da gamba etc ... and since the beginning of this discussion I studied 4 guitars and I am gathering documentation to study 4 others. I reacted to your post because you were saying a common untruth - If someone uses (presumably without knowing it) complex maths it's us, much more than a fifteenth century craftsmen whose methods of measurement are not not so mysterious as that. Above all, I try to defend in this thread the importance of the research method to appreciate the quality of a result.

I do not know the IQ of A Amati (and I admit that this subject is of no interest to me) but if you admit that he knew how to count until 12 it is more than enough to make a violin. We are very far from complex mathematics ....

You seem to be unaware that this work has and continues to be done...

a glance ... I have the book if you want to dig in