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Andreas Preuss

Stradivari's secret was a concept?

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@Michael Darnton

How do you explain then the differences in archings which have the same spanning width and the same height from the low points? For the pure mathematics of the cycloid curve there is only one curve possible. Do you take half cycloid patterns and angle them  resulting in a pointed center?

Is the long arch of classic Cremonse work to your experience as well a cycloid arch? In many scriptures we find for the long arch a perfect circle line.

And last not least, Torbjorn thinks that top and back had basically the same arching. Would you agree on that or do you have a different view?

Sorry for those many questions, but learning doesn't work for me without asking questions.

 

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On 7/25/2018 at 10:02 PM, uncle duke said:

I have five half templates and wanted to see how the outer corner radius'' of them compared to one another.  So starting from the neck side purfling line to the middle bridge width,  for compass point location,  I have the following.

Tertis 7/8  -  7.87 mm in front of bridge

My own 7/8 design   11.93 mm

Bagatella 1700's math method   14.478 mm

1709 Stradivari   17.78 mm

Del Gesu 1733    19.3

All measurements figured out on a flat surface with a dull pointed pencil/compass so maybe 1/2 mm variant allowed, if needed. 

Note - the above is for the outer red circle only.  Surprised me somewhat the differences in regards to making workable fiddles.

    

Sorry, I did not understand at all what you were measuring there.

Is this the distance of the bridge center line to the corner circle? I don't see any reason why this distance should be a fixed distance.

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1 hour ago, Andreas Preuss said:

Sorry, I did not understand at all what you were measuring there.

Is this the distance of the bridge center line to the corner circle? I don't see any reason why this distance should be a fixed distance.

 

4 hours ago, David Beard said:

The CCs give smoothly joined concave and convex curves. But I believe that their actual fit to classical work ends with that one feature.

(Your question highlights one of the many reason for my opinion on CCs.)  But still they can be a helpful guide for modern makers to ensure that the channel is concave, and that the connection to the convex arching is smooth.   But the CCs don't provide any real deterministic guide to arching work.  Only a partial tool that's friendly for template oriented folk.  However, if you let the math guide you, instead of contentiously pushing the math around to keep on track, the math will tend to push your channel wider and narrower in an incorrect way.  The channel width should instead run basically constant through each major bout area. 

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6 hours ago, Andreas Preuss said:

 

Aesthetics are very relative and are not so important in the end. I am sure that there still many people who regard Niccolo Amati as one of the major exponents of well balanced aesthetics.

To me the truly outstanding makers 1. create their own model 2. have their own handwriting and 3. make it work for musicians.

Also very true for me !

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3 hours ago, David Beard said:

 the CCs don't provide any real deterministic guide to arching work.  Only a partial tool that's friendly for template oriented folk.

David,

I respect and, most of the time,  agree with your approach, I often find what you say very interesting.

Nevertheless, for me the way one works the scoop and the type of scoop, width and depth of the channel... in the CCs and near the corners ( and so on...) and the way they blend with those in the upper and lower bouts, and the top of the arch , is one of the most deterministic guide to arching work. For me , this is one of the points of departure. Whatever is the style,  what might be true today : was true in the past centuries, in any style, Cremonese or not...

This is the modern approach, methods and techniques which are very different to what was done between the 16 th and 18th century. 

I must add that I am absolutely not template oriented.

And I agree that within the margins there is an infinite possibility of results and personal characteristics . Two persons using the same method won't end up with two identical instruments.

Did I misunderstand something in your statement ?

Dave.

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14 hours ago, Michael Darnton said:

The original A Amati fholes were upright, but far apart. The maker I tag as H-one tilted them and made them more elegant, giving a modern eye spread. Someone else in the Bros A shop (Antonio? Battle of the Brothers?) continued to make the upright form, both types appearing contemporaneously for some time. 

Nicolo's "innovation" kept the form of the stems of the holes vertical, but recognized that H-one's tilted stem had brought the eyes closer and that this was perhaps tonally desirable, so he threw the upper holes inward from his upright stems,  and maybe also brought the stems a bit closer creating an aesthetic problem at the top and bottom which forced the wings to be bent more to follow the new eye layout. The whole f had to be revamped into something of minimal grace to accommodate both the upright stems and the close-together eyes. Awkward to the max, the whole "solution".

 

Thanks very much for your explanation.

Still I must admit I find Nicolo Amati 's instruments aesthetically strongly interesting,  but you made me learn something and in the future, I will pay more attention to what you said.

David.

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1 hour ago, D. Piolle said:

David,

I respect and, most of the time,  agree with your approach, I often find what you say very interesting.

Nevertheless, for me the way one works the scoop and the type of scoop, width and depth of the channel... in the CCs and near the corners ( and so on...) and the way they blend with those in the upper and lower bouts, and the top of the arch , is one of the most deterministic guide to arching work. For me , this is one of the points of departure. Whatever is the style,  what might be true today : was true in the past centuries, in any style, Cremonese or not...

This is the modern approach, methods and techniques which are very different to what was done between the 16 th and 18th century. 

I must add that I am absolutely not template oriented.

And I agree that within the margins there is an infinite possibility of results and personal characteristics . Two persons using the same method won't end up with two identical instruments.

Did I misunderstand something in your statement ?

Dave.

Hi Piolle,

Not sure we talking about the same aspects?  Certainly I respect individuality and style in the final outcome.  And, while I do aim to revive old ways, I repect modern making the takes a different road.

What I mean is CCs don't automatically give appropriate basic radii of curvature.  One has to know what you want and manipulate the CCs to get there. 

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1 hour ago, David Beard said:

What I mean is CCs don't automatically give appropriate basic radii of curvature.  One has to know what you want and manipulate the CCs to get there. 

Saying that, it's obvious, then, that you do not understand how they are used or generated.

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1 hour ago, David Beard said:

Hi Piolle,

Not sure we talking about the same aspects?  Certainly I respect individuality and style in the final outcome.  And, while I do aim to revive old ways, I repect modern making the takes a different road.

What I mean is CCs don't automatically give appropriate basic radii of curvature.  One has to know what you want and manipulate the CCs to get there. 

Various curves that have reversed curvature with infection points can work.  If you study it enough it becomes a serious disease.  An example of this is attached.

Cycloid Savart report.pdf

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I read that when it came out. Unfortunately, he only saw one way. It's like putting a shirt on upside down and then declaring that it doesn't fit. 

A lot of people approach this like an acquaintance of mine approached statistics. What statisticians came up with didn't agree with his own personal views on the world, so he declared that the whole thing was bunk. I offered to explain how it worked (statistics were my favorite college class) and he responded that it was bunk, and he didn't need to understand it because it was bunk. Dissonance solved.

Maybe Mr Beard will explain how scoop is precisely described in his system without resort to indefinite methods so that I don't continue to believe that it's bunk (and Tjorborn is welcome to do the same,  for the same reason.)

Signing out here. Too much Bunk. Someday maybe we can talk about the pernicious effect of the Germans (to be fair, only because they have the schools and the traditionb other makers do the same thing) on f-hole cutting by modern makers and just as with arching, how hard it is to use one's eye when one already has an erroneous belief firmly in place. I'd love to rub some noses in that!  :-P

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16 hours ago, Michael Darnton said:

Sorry, I'll stand by that statement that done precisely that way is not a characteristic Cremonese habit of the historic period. It might happen in isolated instances of course, anything can happen, and you will see something close to it more later than earlier, but it's just not a primary characteristic of the old Cremonese arch. It appears in a lot of modern making, sure, and I see it coming out of the German-based schools. You take it as a diss if you want to--that's your choice. I'm just stating what I see in the majority of the cases I see.

Purfling on the uphill, and usually agood amount of rising scoop inside, is about as good of a rule as you are going to get for this, and that holds for a lot of Italy in that time, too:

1732 del Gesu:

1732DelGesu.thumb.jpg.97f31737c97138aa335eaccdb8875998.jpg

Can't find the Roth at the moment. You're certainly welcome to show me an old Cremonese violins that looks like the Becker, but you won't find one.

I can tell you that we are going to have a lot of disagreement when it comes to talking about f-holes, too.

 

 

Let's see what happens when we place the straitedge parallel with the gluing surface of the plate, rather than at an angle, on that Del Gesu:

image.png.0f4240d2ddf76592c358ed5728830839.png

Hmmm, the purfling might be about the lowest point after all.....

And that's using the existing shadow, without adjusting it for the new orientation of the straightedge. With the correct shadow, it would look even more like the arch rises from the purfling toward the center.

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9 minutes ago, David Burgess said:

 

 

Let's see what happens when we place the straitedge parallel with the gluing surface of the plate, rather than at an angle, on that Del Gesu:

image.png.0f4240d2ddf76592c358ed5728830839.png

Hmmm, the purfling might be about the lowest point after all.....

I don't know. That still looks ever so slightly on the rise towards the edge. But that's just my untrained POV. 

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16 minutes ago, Nick Allen said:

I don't know. That still looks ever so slightly on the rise towards the edge. But that's just my untrained POV. 

Yes, ever so slightly. But my straight line is superimposed on the existing shadow. Had I taken a new photo, with the correct shadow from the repositioned straightedge, the pufling would appear to be at the bottom of the curve, or the arching toward the center of the plate would appear to rise from the purfling. I've fooled around with this a lot on real instruments, but I'm not set up to easily take photos right now, so I drew a line on the existing photo instead.

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On 7/25/2018 at 1:47 PM, Michael Darnton said:

Not quite. You need to measure to the bottom of the final scoop not the rough edge. So, about 9.2mm or so.

Thanks -- would have helped if I actually read the instructions ;). Looks like one can create virtually any style of arch with cycloids - Strad - Guad - N Amati. 

However, I did have trouble getting something that looked similar to the Andrea Amati small violin in the Ashmolean. This arch looks different than the Brothers arch you posted -- the Andrea is fuller and flater through the top of the arch but with a similar scoop at the edge.

1379172035_AndreaAmatiarch.thumb.jpg.5753d9948ccf6e40557aa1643d541b37.jpg

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1 hour ago, Marty Kasprzyk said:

Various curves that have reversed curvature with infection points can work.  If you study it enough it becomes a serious disease.

:D:D

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9 hours ago, Andreas Preuss said:

Sorry, I did not understand at all what you were measuring there.

2.  Is this the distance of the bridge center line to the corner circle? I don't see any reason why this distance should be a fixed distance.

2.  It would be the distance from the exact stop length/middle thickness of bridge to set the compass point.  Then adjust compass so that all of the purfling corner tips would be included in a complete compass generated circle.  I had nothing better to do that morning.   

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3 hours ago, Michael Darnton said:

I read that when it came out. Unfortunately, he only saw one way. It's like putting a shirt on upside down and then declaring that it doesn't fit. 

A lot of people approach this like an acquaintance of mine approached statistics. What statisticians came up with didn't agree with his own personal views on the world, so he declared that the whole thing was bunk. I offered to explain how it worked (statistics were my favorite college class) and he responded that it was bunk, and he didn't need to understand it because it was bunk. Dissonance solved.

Maybe Mr Beard will explain how scoop is precisely described in his system without resort to indefinite methods so that I don't continue to believe that it's bunk (and Tjorborn is welcome to do the same,  for the same reason.)

Signing out here. Too much Bunk. Someday maybe we can talk about the pernicious effect of the Germans (to be fair, only because they have the schools and the traditionb other makers do the same thing) on f-hole cutting by modern makers and just as with arching, how hard it is to use one's eye when one already has an erroneous belief firmly in place.

Isn't it, though? ;)

Personally, I don't have a "belief". I've made archings by eye, from templates taken from historic instruments, from templates taken from curtate cycloids, and can see how each method might work for someone. I don't happen to use a major "scoop" on  my own instruments, because my impression has been that these don't produce the sort of sound or playing characteristics I am looking for. (Though one could claim that this is actually due to that pernicious German effect). :o

I have not tried Beard's or Tororbjorn's arching methods, so would be reluctant to criticize.

I do have one contemporary French violin here (no German training whatsoever), and one contemporary British violin (also no German training), and in that portion of the center bout on both, the purfling is very close to the lowest point, rather like the Del Gesu pictured above. Could that have been by choice, or must it be attributable to  German training corruption, or ignorance?

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I see what you mean David.

But I think I see Michael's point too. 

Years ago, John or Roger, I cant remember which, in one of their articles describing a Strad poster, said that the arching rose straight from the purfling. Studying the poster, I realised that it did, but was still hollow for a good distance, just as in the examples given. This is very important to me. It allows that the outer arch reflects the inner shape, so that the plate section has levelled out to meet the rib gluing surface. This makes for a flexible edge, I think, and a plate that's capable of moving, even if it's left quite strong.

I think Michael achieves this with his use of CCs. I don't know how to fit them right throughout the violin, but in principle I see the point. I think that what happens around the edges is most important for sound. What goes on in the middle is perhaps more about structural strength.

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I too can sort of see both sides, but I have to come in on Michael's side here. I realize that there are Cremona examples where the purfling lies in just such a spot that it could be read as being the lowest point of the channel, especially later, perhaps, but in the work of the founding family and it's strictest adherents (Stainer, the early Guarneri), it's easy to see that Michael has the right of it. 

I don't have many resources, but I have a few and I intend to use them to show support for Michael's assessment in the next day or two.

In the meantime, like Conor said above, it just makes sense - the purfling sits more or less above the lining. In the case of the purfling lying at the lowest point of the channel, it becomes easier for the inside cross arch to terminate abruptly there. If the purfling and therefore the lining sits uphill towards the edge, then the inside cross arch levels as it approaches the lining, more closely mirroring the external CC, or if you can't abide the Cycloid, the external recurve-of-some-kind. 

Try strictly adhering to the published thicknesses of early Cremonese violins in the channel region with the purfling placed at the lowest point of the channel and see how that works out for you.

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Yes, there are examples with extreme trenches too. As I mentioned, they don't seem to have the sound and playing character that I personally am looking for, and since I don't purport to be a copyist, I can handle such things as I wish..

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Fprget t about the lowest point. If it is really on the purfling or a bit  inside the purfling doesn't  really matter.  

It is more about the points of recurves  or where the center arch sectiion meets the concave arch section along the rim. Functionally there could/should be  a difference if they are just aligned on the purfling or at the same level inside the purfling. (or even at a different level on the plate.) If the whole rim has a broad channel the plate should be more rigid than a ' German arching' Defining arching shape for sound properties is an aspect bluntly ignored by makers involved in acoustics. 

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6 hours ago, David Burgess said:

 

 

Let's see what happens when we place the straitedge parallel with the gluing surface of the plate, rather than at an angle, on that Del Gesu:

image.png.0f4240d2ddf76592c358ed5728830839.png

Hmmm, the purfling might be about the lowest point after all.....

And that's using the existing shadow, without adjusting it for the new orientation of the straightedge. With the correct shadow, it would look even more like the arch rises from the purfling toward the center.

I agree David. I've seen plenty of Stradivari tops like this as well. Especially in the C bout. The deepest point of the curve is inside the purfling but the curve rises from the purfling. Is my description clear?

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On 7/25/2018 at 9:29 PM, Carl Stross said:

The cycloid has a couple of interesting properties of which two or three ( one might speculate ) have a direct relation with the functioning of a violin. 

"Strength" is not one of them. There is a book by Richard Proctor on cycloids should one wish to get an analytical grip on the subject. Book is excellent and pretty elementary. 

However wrong Galileo's belief that the cycloid was suitable for a bridge arch, if it was influential enough to determine the shape of a bridge over the Arno, it was influential enough to carry weight with Italian luthiers. The properties which Galileo attributed to cycloids are far more likely to have weighed with Cremonese makers, than are the properties of the curves discovered by more recent investigations?

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20 minutes ago, John_London said:

1. Where the cycloid is strong is not hugely relevant.

However wrong Galileo's belief that it was strong, if it was influential enough to determine the shape of a bridge over the Arno, it was influential enough to carry weight with Italian luthiers.

2. The properties which Galileo attributed to cycloids are far more likely to have weighed with Cremonese makers, than are the properties of the curves discovered by more recent investigations?

1. I think it is "hugely relevant" but that's only my opinion.

2. I've no idea what properties Galileo attributed to cycloids and if those ones are what got the Cremonese makers to start using them. I'd suspect not. Some cycloid properties were known empirically and used long before violins showed up and they were used a lot. Also, if you read the book I mentioned you'll see that most if not all interesting cycloid properties are a matter of or can be reduced to skillful application of rather elementary geometry - 2000 years old stuff. Nowadays, we like to see analytical formulas for everything but they weren't obsessed with that. 

I'm not saying that they could not've used cycloids in a scientifically incompetent manner while still reaping the benefits of some property they weren't aware of. Euler constructed half of the modern mathematics like that, with little concern for what "convergence" really means. In modern times we had an excellent working grasp of electricity without knowing what really is.  

An intuitive grasp of how stuff works was all what was needed until pretty recently. But it had to work.

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