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Long Arch Drawing


Dennis J
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9 hours ago, Andreas Preuss said:

Would be interesting to know from which period in Antonio Stradivaris working life the rib came from. I don’t take it for granted that he used all his life the same techniques he use in his youth. As a matter of fact I see the typical past 1700 scroll design as a result of using a jig which also contributed to the highly precise repetition of this pattern over a time span of more than 30 years.(!)

I see the whole working method of Antonio Stradivari as fast, efficient and perfect. Working with a bending iron which has to be reheated in between in an open fire is a sort of more complicated than soaking and binding them over a mould until dry. I might be wrong though. 
 

Note: I find it also a bit strange that if a bending iron was common practice that apparently not one single of them has survived to our times despite that they must have been pretty indestructible hardware items. 

I don't think you need a jig to make scrolls accurately similar and precise, just use the same template (one template, more efficiency) and be very skilled at work (Stradivari certainly was). Knowing several very skilled luthiers, I assure you that it is very possible to do so, even at a level of precision higher than that of Stradivari, if you are sufficiently obsessive/manic as some of my acquaintances.:)

As for the bending iron, heating it on the fire can be done in a perfectly efficient way (I did it at the beginning, before discovering the electric ones with the thermostat). Just have two, one in use on the workbench while the other is kept warm on the hot plate (yes, at the time of Stradivari hot plate existed), alternating them as soon as the temperature drops too much for bending.

Making violins wasn't very different from today, I think imagining strange scenarios or unusual methods doesn't get very far.

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On 5/3/2022 at 1:54 PM, HoGo said:

I tend to think we are grossly overthinking something as simple as the arching (and many other aspects) and Strad, Gesu and company are laughing in their graves. Quite a few examples show that the original intention of long arch shape might as well be simple circle curve done more or less by trained eye with smooth transition at end blocks. Time and tension causes creep that can result in arches similar to what we see today. And of course copying of the past shapes unaware of the efffect might cause severe magnification of the effect.

I posted these pics before but it is another del Gesu that is scarry close to circle... The upper photo is old pic from London exhibition, the lower is recent from Biddulph I guess. The yellow line is perfect circle for comparison.

DiableArchesCurvature.jpg

DiableArchesCurvatureGraphs.jpg

Dear Hogo The upper foto shoe what I can see a radii tha not end at the rib but the block. This means that the scoop shape is wider at least at the neck side. I'm I right? The lower radii ends longer out on the rib at the neck?

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13 hours ago, Andreas Preuss said:

Would be interesting to know from which period in Antonio Stradivaris working life the rib came from. I don’t take it for granted that he used all his life the same techniques he use in his youth. As a matter of fact I see the typical past 1700 scroll design as a result of using a jig which also contributed to the highly precise repetition of this pattern over a time span of more than 30 years.(!)

I see the whole working method of Antonio Stradivari as fast, efficient and perfect. Working with a bending iron which has to be reheated in between in an open fire is a sort of more complicated than soaking and binding them over a mould until dry. I might be wrong though. 
 

Note: I find it also a bit strange that if a bending iron was common practice that apparently not one single of them has survived to our times despite that they must have been pretty indestructible hardware items. 

If no surviving jig for making scroll work has been found ,,, and no bending irons … how do we apply the idea ?

   For what it’s worth,  Iron back in the day was much more valuable relative to today, historically homes were often burnt down to collect the iron nails on the American frontier when the occupants moved , these nails could then be recycled into anything from horse shoes to anvils to guns and knives . In many areas entire homes and churches were built with no iron at all , being reserved for cutting tools that wore down … back in ww2 they melted down millions of anvils and post vice to make ship hulls and anchor chain … 

5 hours ago, JacksonMaberry said:

Can't imagine bothering to remove a burn if I made one. Waste of time.

You ever made one ? I have , I use a torch heated bending iron , and “fixing “ a burn is very simpler and quick , moreover burns are very easy to avoid with even a very hot iron by simply wrapping the rib in a piece of linen cloth or hemp canvas. … Considering the old timers love of the aesthetic and long time commitment in making, as well as client expectations… to my way of thinking taking a few minutes to scrape or rasp off any burn would , both thin the rib and make things look nice and neat . 
years ago on MN there was a discussion of ribs and these mystery marks on the inside curves, I think they were cleaning up burn with a rasp and didn’t quite produce the same surface as the scraper so varnish filled the small scratches producing dark lines that only show when the varnish got worn thinner. image.thumb.jpg.8798cbf77f6c2da9184af21bf48e8ca8.jpg

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2 hours ago, James M. Jones said:

If no surviving jig for making scroll work has been found ,,, and no bending irons … how do we apply the idea ?

   For what it’s worth,  Iron back in the day was much more valuable relative to today, historically homes were often burnt down to collect the iron nails on the American frontier when the occupants moved , these nails could then be recycled into anything from horse shoes to anvils to guns and knives . In many areas entire homes and churches were built with no iron at all , being reserved for cutting tools that wore down … back in ww2 they melted down millions of anvils and post vice to make ship hulls and anchor chain … 

You ever made one ? I have , I use a torch heated bending iron , and “fixing “ a burn is very simpler and quick , moreover burns are very easy to avoid with even a very hot iron by simply wrapping the rib in a piece of linen cloth or hemp canvas. … Considering the old timers love of the aesthetic and long time commitment in making, as well as client expectations… to my way of thinking taking a few minutes to scrape or rasp off any burn would , both thin the rib and make things look nice and neat . 
years ago on MN there was a discussion of ribs and these mystery marks on the inside curves, I think they were cleaning up burn with a rasp and didn’t quite produce the same surface as the scraper so varnish filled the small scratches producing dark lines that only show when the varnish got worn thinner. image.thumb.jpg.8798cbf77f6c2da9184af21bf48e8ca8.jpg

Some clamps made of iron survived. i
 

It’s very unlikely that ALL bending irons were collected to recycle the iron. 

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49 minutes ago, Andreas Preuss said:

Some clamps made of iron survived. i
 

It’s very unlikely that ALL bending irons were collected to recycle the iron. 

Sure … that’s true … some very cool clamps survive , and a few other fun  bits as well …it’s also very unlikely that we know where they all are ..could be door stops and garden markers for all we know 

However the point still stands, iron was extremely expensive  common items were commonly reforged into other items ,and the simple fact that we can’t hold his today doesn’t mean he didn’t have them , anymore than not holding whatever jigs for making exactly scrolls he might or might not have had , certainly the technology for bending irons has been around for a long time , yet the jog ,  for accurate duplication of wood worked scrolls  has no known 17th century counter part , there are examples of jig device for stone sculpture of human forms so the thought can’t be simply ruled out … …   In Addition wrought  iron can not be dated the same as tree rings , if the material is wrought iron any bending iron could be a hundred … or a thousand yrs old and we would not know . Fwiw the absolute best cc ribs I found a quick steaming and roughly shaped rib section applied quickly to a inside counter form  brought up to conform with a heavy leather strap on clamping levers till cool ,,.. the ribs come off exactly and because of the heat involved they stay in the same shape . 

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17 hours ago, Andreas Preuss said:

As a matter of fact I see the typical past 1700 scroll design as a result of using a jig which also contributed to the highly precise repetition of this pattern over a time span of more than 30 years.

That isn't true.  They use highly structured designs yes, but they are not strictly repetitive as you are claiming.  That does not match the evidence.

A jig is unlikely because it would produce literal repetition as you describe.  But that simply isn't what the evidence shows.   Not even for one maker for 30 years.  Certainly not for the community for generations of making.  Not even for one maker for one year.

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Risking sounding foolish, again, this discussion of beautiful functional curves, design and craft tradition makes me think of traditional farm waggons. They are a bit like a violin in that they are mainly made of wood, are curved and many of them have a waist area (to allow the wheels to to turn more to reduce the turning circle). This is a nice example

Somerset "Cocked Rave" Wagon | Wagons, Horse and buggy, Old farm

Their designs, which varied depending on the soil, crops and traditions of different parts of Britain evolved over centuries and they were made by craftsmen who relied on their training, eye and tradition to produce their work. I probably have mentioned this somewhere else, George Sturt in his book "The Wheelwright's shop", Page 18, describes how two old wheelwrights were putting the finishing touches to a new wagon and one was painting the owners Name and address on the name board

" He managed all right until he came to the address, 'Swafham' or 'Swayle,' but this word puzzled him. He scratched his head , at last had to own himself baffled; and appealed to his mate. 'Let's see, Gearge,' he said, 'blest if I ain't forgot how you makes a sway!'

George showed him"

Perhaps some wheelwrights and carriage makers may have studied geometry but I expect most of the best craftsmen and designers, if they could read, the only book they had was the bible - perhaps they were like Dan Brown and could find the geometrical and design secrets hidden in its pages?

I think the beauty and functionality of their creations were largely the result of slow evolution and refinement to solve problems, combined with a human desire to make and own things that look nice?

 

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12 minutes ago, Marty Kasprzyk said:

Of course they studied classic Greek and Roman geometry.  Notice how the waggon's top edge shape is made with five or six compass circle arcs.

But the wheels are certainly just free shaped.

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Just now, Marty Kasprzyk said:

I wasn't there at the time but I suspect the wheel was invented before the compass and that a drawing wasn't needed.

Paper wasn't invented yet either so the compass drawing of the wheel must have been made in mud or sand.  

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Perhaps the waggon's curves may have been caused by distortion under decades of heavy load? Perhaps transporting thousands of German imported violins in the nineteenth century?

Here is a waggon that perhaps is either new or untouched like the messiah violin or has been a bit over restored and had it's curvature/distortions corrected in a large plaster cast?

After restoration.

Restored Newton Farm Wagon - Hansen Wheel and Wagon Shop

Before restoration

Along the road we go - farm wagons in The Museum of English Rural Life

On a more serious note it is interesting to see the difference in design approach between the box shaped utilitarian waggon, perhaps a product of a more modern rational industrial approach, better roads and suitable for mass manufacture  and the extragavant graceful, organic curves and chamfering of this Somerset Bow Waggon.

My apologies for bending the curve of this thread away from the topic of violin arching.

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16 hours ago, reguz said:

Dear Hogo The upper foto shoe what I can see a radii tha not end at the rib but the block. This means that the scoop shape is wider at least at the neck side. I'm I right? The lower radii ends longer out on the rib at the neck?

The two pictures are of the same violin (del Gesu "du Diable") some 130 years apart (the older in 1872, later in late 1990's). They were not taken at the same angle, the first one seems to be with lens more or less in plane with the back and the later one seems to be centered or perhaps closer to top edge plane which makes the curve disappear near ends a bit "sooner" in the first pic. I created these to show that in 100 something years the arching definitely moved a bit (you can also see how f hole shape is distorted).  But definitely this arch has much wider "recurve" area at both the upper and lower blocks than typical Strad violins. You can see that in other pics of the violin in reflections here: https://violinsandviolinists.com/2015/07/15/the-coming-of-the-messiah/

 

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Dear Hogo, looking again to the two pictures and compare we observe CREEP I believe. The action on the end block by string load has "buckled" the length curve shape under the finger board. The higher curve by buckling this is creep. This buckling as it does on every instrument happens between the end block and the structure between the upper F-hole. On the other side of the F-hole location we find a downward bending by the load from the bridge while the sound post has not movement since the sound post is the pivot. Also, the other bout shape which I cannot observe on the images must become forces buckling outward. Principally we thus see two outward buckling structures which chords line become shorter while the structure on the "island" become forced down and a chord line on the outside of the instruments shortens. Increasing forces on the end block thus is the result of this behavior. When string load changes as it does in the playing action the deflecting behavior, we see becomes dynamical structures start flexing. The stiffness quality of that behavior over time produces the creep we observe. Earlier on this tread both Don Noon and I have shown cross sectional images that show what is described above. It is quite easy improving the dynamical behavior by on the outside after the instrument is finished removing either varnish or scraping wood. Increasing dynamical behavior increases the constantly changing of the volume in the box. That result in breathing and sound projection at least by my own experience. In fact, it’s very sensible to do so. Over time we will find the creep we see. Thank you for showing these foto's

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I cannot predict tone or even musical behavior of instrument just by looking at pictures. I meant to illustarte that the long arch at least on some del Gesu instruments is very close to circular arc. How much distortion there is in the block areas of violin on the pics is impossible to tell because we can't see them. We cannot speculate about things we don't see. It's just like guessing the color of David B.'s underwear :-) .

What is obvious to makers is that the old folks used quite diferring archings as the whole even If the main arch is (or started as) circular the width and depth of the scoop area around perimeter (and thus position of inflexion points as some look at it) varies between typical families of Amati, Strad, Stainer, Guarneri, Da Salo etc. This affects tone greatly and possibly also longevity of the arch itself. The STL's as you describe (IF present) generally don't follow past the inflexion points into the scoop so are of very little help explaining the tone differences.

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59 minutes ago, HoGo said:

I cannot predict tone or even musical behavior of instrument just by looking at pictures. I meant to illustarte that the long arch at least on some del Gesu instruments is very close to circular arc. How much distortion there is in the block areas of violin on the pics is impossible to tell because we can't see them. We cannot speculate about things we don't see. It's just like guessing the color of David B.'s underwear :-) .

What is obvious to makers is that the old folks used quite diferring archings as the whole even If the main arch is (or started as) circular the width and depth of the scoop area around perimeter (and thus position of inflexion points as some look at it) varies between typical families of Amati, Strad, Stainer, Guarneri, Da Salo etc. This affects tone greatly and possibly also longevity of the arch itself. The STL's as you describe (IF present) generally don't follow past the inflexion points into the scoop so are of very little help explaining the tone differences.

Thank you for answering. Yes it is very difficult saying this will be the result or this will be better. However some structural condition has impact on how the instrument may deflect and by that the stress condition that has direct influence og the acooustic aout come. STL does not have anything to do to point into the scoop. They are on arching shape. Enclosed an exaggerated arching shape done in the word program.48465012_lenghtarcdeflection20220505.thumb.jpg.881e5f61811326836ef7b7dede38f167.jpg

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Looking at Ho Go's del Gesu pic, at least the older one. The front arch apart from being close to circular is quite low. The neck end seems to dip well short of the upper block suggesting a fairly long recurve there.

The back arch is low as well and definitely off centre so that the lower section is more full than the upper section which shows a very gradual slope to the upper block. The recurve there can't be seen but must be there and it would be quite long. And those features of the back arch are something I've noticed in some instruments before. Not dissimilar to the one in my posted drawing.

I don't think there is anything simple about arching. There are a lot of variations and subtleties involved and it's something that requires a bit of careful analysis.

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3 hours ago, Dennis J said:

Looking at Ho Go's del Gesu pic, at least the older one. The front arch apart from being close to circular is quite low. The neck end seems to dip well short of the upper block suggesting a fairly long recurve there.

The back arch is low as well and definitely off centre so that the lower section is more full than the upper section which shows a very gradual slope to the upper block. The recurve there can't be seen but must be there and it would be quite long. And those features of the back arch are something I've noticed in some instruments before. Not dissimilar to the one in my posted drawing.

I don't think there is anything simple about arching. There are a lot of variations and subtleties involved and it's something that requires a bit of careful analysis.

How is that remotely circular!  Open eyes.

It is flattish, then suddenly turns down toward the ends.   Circles are equal curvature at all points!

Open eyes.  See what is, not what you planned to see.

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5 hours ago, David Beard said:

How is that remotely circular!  Open eyes.

It is flattish, then suddenly turns down toward the ends.   Circles are equal curvature at all points!

Open eyes.  See what is, not what you planned to see.

Of course it is not circular, but if you compare it to the yellow circle, the largest deviation from circle is approximately 0.5mm under the fingerboard. If you look at the pictures alone they will look flatter than they really are because photo lighting makes the top of arch much lighter and it loses contrast with the pure white background of Biddulph book. That second pic shows a bit more bulge under fingerboard and tailpiece than the upper pic of du Diable aged some 140 years which is more reliable in showing original intention of the maker. IMHO, I would expect more than the 0.5 mm of bulge from original arch (whatever it was) under fingerboard even on few years old violin built to "thin" Strad specs.

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1 hour ago, HoGo said:

Of course it is not circular, but if you compare it to the yellow circle, the largest deviation from circle is approximately 0.5mm under the fingerboard. If you look at the pictures alone they will look flatter than they really are because photo lighting makes the top of arch much lighter and it loses contrast with the pure white background of Biddulph book. That second pic shows a bit more bulge under fingerboard and tailpiece than the upper pic of du Diable aged some 140 years which is more reliable in showing original intention of the maker. IMHO, I would expect more than the 0.5 mm of bulge from original arch (whatever it was) under fingerboard even on few years old violin built to "thin" Strad specs.

Seeing what you'd like/expect to see instead of what is plain as day in front of you.

'Circular' was simply not the long arch concept, nor what we actually see in the example.   Even though some of the back's end up close to circular, it's still not the right concept, not the concept that runs consistently across all the breadth of the examples.

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1 hour ago, David Beard said:

'Circular' was simply not the long arch concept, nor what we actually see in the example.   Even though some of the back's end up close to circular, it's still not the right concept, not the concept that runs consistently across all the breadth of the examples.

I'm curious how you think you know that circular was not the long arch concept, and also that it is not the "right" concept.

Hogo's two photos of the same instrument, with one an older photo and the other newer, give a conservative and convenient example of how much archings can distort over time.

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8 hours ago, David Beard said:

How is that remotely circular!  Open eyes.

It is flattish, then suddenly turns down toward the ends.   Circles are equal curvature at all points!

Open eyes.  See what is, not what you planned to see.

I was referring only to the old photograph. To my eye it is a lot closer to circular than most early instruments. Can't see any sudden downturns there.

The newer photograph is quite different, hard to believe it is the same instrument.

 

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