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Long Arch Drawing


Dennis J
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3 hours ago, notsodeepblue said:

 

 

 

Mr Zuger,

Putting aside the error-strewn nature of your highly misguided amateur pseudo-analysis, have you ever stopped to consider that it might be the utter contempt you show for other people that stops them engaging with your crackpot ideas?

Its you that do not understand. Its a pity because when you do you can start a discussion. As it is now you only can say as you do. Read the master dissartaion and try to understand. Also as I asked you give your opinion on the spectra recorded

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6 hours ago, reguz said:

Its you that do not understand. Its a pity because when you do you can start a discussion. As it is now you only can say as you do. Read the master dissartaion and try to understand. Also as I asked you give your opinion on the spectra recorded

Your recorded spectra is of little value, since so much depends on the recording path, the microphone positioning, the pressure, speed and position of the bow on the string, the room acoustics, etc.

That's why Joseph Curtin tried to come up with a standard setup which pretty much anyone could put together, so spectral data from different violins, made by different people would actually have some comparative value.

It is you who does not yet understand some of even the most elementary things.

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22 hours ago, James M. Jones said:

Of course I’m not David, but this is a public forum. I have No problem with intelligence per say , however on any cognitive level there’s multiple facets to intelligence, for instance a mathematical savant might smell complex equations but not know how to play a tune, or order a pizza q . The “problem “as I see it ,  is violins fall within a fairly narrow scope of definition, that scope of definition doesn’t seem to include that what Robert describes.

the goal of violin making ,as I understand it, is not to create a wood structure that resist deformation to the greatest extent possible, (Robert seeming approach.) , although a consideration, it is not the goal , rather quite the opposite, it seems to be that the actual goal of making a great violin( easier said than done ) is to create a structure that, while strong enough to not simply collapse, but is is rather weak enough to respond to the slightest input possible and vibrate across a wide spectrum, for tonal color , and, with as much “out of plane “movement as possible within reason,  for amplitude… equal tonal projection. Or something like that .. walking the thin edge as it were. 
 

 

21 hours ago, Marty Kasprzyk said:

That seems like a good understanding of what a violin is supposed to do.

It might be helpful to get some opinions on how long a violin is supposed to last.  I've heard somebody say there are only about fifty great Strad violins in still in use so it would be nice to be able to make a violin sound that good and last that long.  On the other hand maybe the other ones which died early even sounded better.

I hope (as a retired mechanical engineer) that my instruments last a little longer than me so I don't have to witness their demise.  So as I get older and older they can last shorter and shorter time which allows me to make them lighter and lighter which makes them louder and louder to make up for my hearing getting worse and worse.

One thing to consider? Sometimes the "smartest people" are super focused on one particular narrow thing.

On a public forum they might look like idiots, but meet them face to face and you might be embarressed by your own ignorance. I have worked with people so inelligent that I have had problems grasping the extent of it.

Not saying Robert is one of them, we haven't met.

Quite often they also are very, very humble in person, but they don't have the ability to write "humble", because it's a skill to write objectives in a humble way.

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8 minutes ago, David Burgess said:

Sure, there are lots of different ways to define smarts. What is your definition?

Luckily we don't have to define this on MN. There is a spectrum divided into 7 intelligence areas. Leonardo D. might have had top scores in all areas.

(If you want to know I can tell you yours and after that I'll tell you mine)

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One quick "skill/intelligence" you and I have in common is correcting our writing mistakes, so fast, logging in and out of MN, before someone have a chance to qoute our posts. Not that smart actually....

We are both exposed for what we really are --- wannabes that are craving for attention.

You are cheating because I have to switch back and forth to Google translate, lets do this sometimes in Finnish?

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3 hours ago, Peter K-G said:

Luckily we don't have to define this on MN. There is a spectrum divided into 7 intelligence areas. Leonardo D. might have had top scores in all areas.

(If you want to know I can tell you yours and after that I'll tell you mine)

Why would someone who is, or who aspires to be a violin maker care about your intelligence assessment, since your professional area of expertise is in the trucking industry, not in violin making ?

How is your trucking supply-chain thing going right now?

I will however acknowledge that there is one thing that the two loosely have in common: When the wheels ain't turning, you ain't makin' money. ;)

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Dear All. Why is it that still no one seem to understand that all I say and write has to do with a structure I found. I do not say this is what your instrument is. So, when you read is is up to you understanding what the structure I show can or cannot. How it functions or function not and compare with what you know about the instruments you make. Thus far NO ONE has written a word about his own instrument. What I do is giving you the ability of coming to an understanding how MY instruments work. It is for sure not what was written above " a wood structure that resist deformation to the greatest extent possible, (Robert seeming approach.)". Total misunderstanding. What my research is about is understanding how all area participate. When that happens it technically becomes possible reducing thickness just to reach that state. Participating does not mean that some structure is excluded in that sense that it makes it possible to reach that optimal condition like to gain. For me this is stress on all structure. Some of you write about the problem that creep destroy the instrument. The reason is Wrong arching shape and wrong graduation. STRAD could. Yes, his instrument has creep but they still work and are amongst the greatest. WHY? yes just the Why I like to understand. That is my research about.

For that reason, I started studying arching shape and found a simple geometry that can explain. It holds STL-bar structure and I found that these do not deflect but structure on both sides do and you are able to make the plate thinner so they work easier. Isn’t that we all like to achieve? So, when you read my papers, it is that you must try to understand. The problem thus far is no one has said any negative word. No one say you are wrong. Do that if you can and express what is wrong.

Dear David you say some word about sound testing. Yes, J Curtin has a special equipment That over time has looked different. All however do not use the STRING producing sound. So, the energy the mechanical behavior that arises improving buckling/bending behavior so vibrating on structure arises producing sound we DO SEE.

When you say Audacity recording is not good. It is good at your service. It will be difficult comparing a recording at your home. The conditions are unlike mine. But using the audacity when you as I do improve the instrument is a great help.

I make after adjustment of stress condition on arching shape on the outside. I free so to say the buckling stress to increase so it participates better, that is what I use audacity for. You probably do not work like that simple because you do not understand they quality of your arching structure. Where should I start you ask yourself? I know where to start and improve. But again, and again you write like “it is you who does not yet understand some of even the most elementary things." DO YOU? Let us know. I have a red line in my research and what is published I stay for. If you believe you understand where it is wrong WRITE NOW an answer so everybody can learn from you.

So, come out of your trench and start discussing instead of shooting.

Enclosed some photo that show some of my profound research.

Dear David you say some word about sound testing. Yes, J Curtin has a special equipment That over time has looked different. All however do not use the STRING producing sound. So, the energy the mechanical behavior that arises improving buckling/bending behavior so vibrating on structure arises producing sound we DO SEE.

When you say Audacity recording is not good. It is good at your service. It will be difficult comparing a recording at your home. The conditions are unlike mine. But using the audacity when you as I do improve the instrument is a great help.

I make after adjustment of stress condition on arching shape on the outside. I free so to say the buckling stress to increase so it participates better, that is what I use audacity for. You probably do not work like that simple because you do not understand they quality of your arching structure. Where should I start you ask yourself? I know where to start and improve. But again, and again you write like “it is you who does not yet understand some of even the most elementary things." DO YOU? Let us know. I have a red line in my research and what is published I stay for. If you believe you understand where it is wrong WRITE NOW an answer so everybody can learn from you.

So, come out of your trench and start discussing instead of shooting.

Enclosed some photo so you can see of my profound research.

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On 4/24/2022 at 7:44 AM, reguz said:

Enclosed some photo so you can see of my profound research

Dear Mr. Zuger;

Please do not title your documents with my name. I wouldn't want someone to think that I wrote them, and I do not want to be associated with them.

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Dear Dennis. Yes, I will try. At the answer to David Burgess, you find the document with his name. It should be titled FOR David Burgess. The last image on the page show how you find what I call "Straight Tangent Line" (STL) You will find them with a ruler. On the page I also show a figure with iso-lines on which the computer program has calculated where the are located. The intersection of the STL on the iso-lines has equal distance thus the sloop on the surface like a topographic map touch (intersect) al the iso-lines.Dear Dennis. Yes, I will try. At the answer to David Burgess, you find the document with his name. It should be titled FOR David Burgess. The last image on the page show how you find what I call "Straight Tangent Line" (STL) You will find them with a ruler. On the page I also show a figure with iso-lines on which the computer program has calculated where the are located. The intersection of the STL on the iso-lines has equal distance thus the sloop on the surface like a topographic map touch (intersect) al the iso-lines.

 You find all about this on www.zuger.se

 

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50 minutes ago, Dennis J said:

Well I can't quite see that being a feature of normal arching, but I'll have a good look at it.

 

 

ED03711E-87C7-4868-ABBA-3B17D3495BD6.thumb.jpeg.cee0c159a0f43ea9e39ef15d6cd92702.jpeg246FA866-5D33-46E2-B8F2-515AA214AB75.thumb.jpeg.18db249b7a53304675485d1ff42bad00.jpeg91D1B4FC-0B52-421D-81FC-5B56B1EAC6D2.thumb.jpeg.e168608e63d32c6d215078f7eac3efba.jpeg6261C274-5523-4906-907B-BE9FF1697247.thumb.jpeg.b0da2436307655fb606aca16f3bd6cb7.jpegMaybe going out on a limb here , and certainly am not claiming expertise on what can or should be done with arching for tone! But  … here are  a couple shots of what I think Robert is referring to , on two versions of different yet very normal arches , both very closely copied from classical pattern, a Brechian Magini viola last set ,and the Delgesu “plowden, first set …as I see them , STL as a necessary phenomenon, as the transition of shape gives way from concave to convex because of the anti clastic curve involved, there’s always going to be a straight line somewhere in the transition, same as going from the edge trench to arch , the inflection point as some reference it will have a very small straight section as both curves flatten where they meet , we also see this effect moving from cc corner to upper and lower bout , a very small section right at the transition pretty much in noticeable at the edge work , and short for sure …. I think the big debate about STL … is not if they exist or add strength, they do , but rather the value of them , the violin body need room to vibrate and the rounded shapes give that room . Imadgine flat planes strung between the STL and how the tone might shift due to the heightened structural capacity that would cause. At least that’s my opinion. They are there they are structure , but there is no “equilibrium “ and arch structure can vary quite a bit and still have them . 

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I haven't read even half of this. I read some, and my eyes glaze over, so I go somewhere else. A long arch is a long arch. I get mine just from the model, and arching height. I just brought the Montagnana model upstairs to look at while I was eating lunch. It's ready to glue onto the ribs, and then finish up the edge work and purfling. I noticed the long arch, and thought about this post. Is it still going? Yes? Wow.

I just looked, and I can find STLs on the arching of this almost 20" arch. 3 out of 4 quadrants have them on the diagonals. One has a dip near the sound hole. Oh well. They are just a result of the arching. I'd rather have better arching, than have perfect STLs. I've never looked for STLs. You could make an instrument with a cubist approach, and make a Picasso violin with flat sections all over; but it wouldn't really look like a violin.

Anyway. Here is a long arch. That's what it looks like. I've made 2 others of this model. It works fine. It rises fast, is basically flattish between the corners. I don't use any arch templates. It is what it is.

IMG_0766.thumb.jpg.acdebcd67788fd3d218ead4abff48981.jpg

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23 minutes ago, Ken_N said:

I just looked, and I can find STLs on the arching...

I think that unless you make a really screwy arch, you'll find some diagonals that are pretty flat.  I found that on my "carved by eye" tops, and also my CNC'd tops as well.  The CNC shape was generated using a long arch and several cross arches, and the computer skinned them into a 3D surface without specifically including anything about STL's.

If you look hard enough, I think you can find features in any complex shape that might appear to be important.  The hard part is proving that the features ARE important, and not just an artifact.

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I'm aware that the anticlastic nature of the arching can lead to areas where a straight or near straight surface might occur but it would be very limited in the areas specified by Reguz. I don't think it is of any significance. Changes in curvature across most of the arching are very slight.

The only practical way to manage arching is to locate inflection points on an arc and make arching guides based on that.

As far as the long arch goes small differences in height at any given point can alter the overall shape quite markedly, at least on a drawing. Probably not so noticeable on a finished instrument.

So as difficult it might be to make sense of arching I find it strange that makers would just put it in to too hard basket and rely on long arches supposedly copied from old instruments. I've spent a few weeks looking at both the front and back arch from time to time. I've settled on the front arch specs. and I'm just about there with the back which is more complex. It's probably something I should have looked at before I got involved with cross arch geometry.

 

 

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5 hours ago, Dennis J said:

I'm aware that the anticlastic nature of the arching can lead to areas where a straight or near straight surface might occur but it would be very limited in the areas specified by Reguz. I don't think it is of any significance. Changes in curvature across most of the arching are very slight.

The only practical way to manage arching is to locate inflection points on an arc and make arching guides based on that.

As far as the long arch goes small differences in height at any given point can alter the overall shape quite markedly, at least on a drawing. Probably not so noticeable on a finished instrument.

So as difficult it might be to make sense of arching I find it strange that makers would just put it in to too hard basket and rely on long arches supposedly copied from old instruments. I've spent a few weeks looking at both the front and back arch from time to time. I've settled on the front arch specs. and I'm just about there with the back which is more complex. It's probably something I should have looked at before I got involved with cross arch geometry.

 

 

Glad you are aware of anticlastic phenomenon... I love the word anticlastic ... it’s fun ...

Put this way , I don’t know your background in this field , but it seems you might be reaching a bit . Most makers I’ve talked with and from my own direct experience ,  most makers seem to take a bit of liberty with arching -kind of that one place a maker can really have any hope of self expression...  the underlying reason ?

is that rarely do cross arches and long arches of classical work , line up due to deformation of the corpus .in general, over time ,

some years ago Sam Z wrote an article in Stad , or not , could be a different publication,the Arizona group , vmsaa? ...anyhow , the article ,  describing several forms of movement and the potential causes, it’s well known that what we see is not what they made ,and each maker will need to make decisions as to the actual arches and how they lay , I personally enjoy pretty much completing  the long arch , and then use half templates for the cross , of course the whole thing is done in concert , always a little of both, but on the whole the long arch gets sorted first, then cross arch details to finish up. On the whole ,very few of the makers I’ve met and talked with , (not a few, several are gold tone winners, ) dry few of them seem to simply accept a rote copy , and almost always have their own ideas,  even in a sort of “bench copy” where the actual original is sitting on the bench next to the copy being produced- I think it was , Michael Fisher? Out of calli, ? he did some intense copy work , building on the back so the corner blocks all take off at the exact proper skew ... dude was a master work in his own right . Short f this approach, Most makers  (Including myself ) it seems , are perfectly happy accepting a flat rib surface to work off ( the classics are all warped , twisted , bent into smiling, or laughing shapes, re graduation, re arched, re built  ect...,  )  most makers talk a bit  loosely of making a “copy “ or closely copied,. Therefore, we all need to produce our own rendition of the long arch , and not without much consideration.

There no “to hard basket” the issue is what basket , of the millions of violins made , 

 I think on of the best pieces of advice I ever got was “” make lots “ .....” make a hundred then you will know something “ Francis Whitaker Master Blacksmith. While not violin making specifically the message must hold true . It’s craft , not art . image.thumb.jpg.f13c5e059ade8d099ce7d385358b52d2.jpgth 

 

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6 hours ago, Don Noon said:

I think that unless you make a really screwy arch, you'll find some diagonals that are pretty flat.  I found that on my "carved by eye" tops, and also my CNC'd tops as well.  The CNC shape was generated using a long arch and several cross arches, and the computer skinned them into a 3D surface without specifically including anything about STL's.

If you look hard enough, I think you can find features in any complex shape that might appear to be important.  The hard part is proving that the features ARE important, and not just an artifact.

Comforting in a way to hear you say this , I trust your  overall judgment even if we see things from a different perspective. 

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Dear James M. Jones. I hope I can give you some understanding what STL condition can bring about in a positiv as well a negative condtion. Read the document that explain.For James M Jones20220426.pdfFor James M Jones20220426.pdfFor James M Jones20220426.pdfFor James M Jones20220426.pdfFor James M Jones20220426.pdfFor James M Jones20220426.pdf

For James M Jones .docx

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Yes James, I didn't want to use the anticlastic word, but I was thinking about it. It is probably why beginners have such a hard time carving plates. Concave on the horizontal axis and convex on the vertical.

So straight lines on the diagonal quadrants do exist. I reckon it probably occurs somewhere whatever method is used to form the arching. It's not something you have to aim for.

What you say about Sam Zygmuntowic's comments is interesting. I think it's arching reality.

I've just about finished my exploration into arching methodology. What I have posted seems to have attracted a lot of attention, not all good,  and that is why I have continued to post it. But I do realise it would take a lot of time and effort to take on what I have laid out. And making a set of arching guides manually is a big task, but there are other options there.

What I like about it is the ability to plan and control arching and the synchronisity of front and back arches using the same inflection surface arcs. That can be achieved even with their differing long arch profiles.

Well I'm going to make a small adjustment to my latest back long arch and I'm finished. I had drawn up a profile in pencil which looked ok. But then I decided to draw one with a fine tip black pen. Just doing that made the lower bout curve look too high. So I think it shows what an arching profile looks like is as import as anything else.

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13 hours ago, Dennis J said:

I'm aware that the anticlastic nature of the arching can lead to areas where a straight or near straight surface might occur but it would be very limited in the areas...

The straight lines happen where the long arch and cross arch are both convex, i.e. a synclastic surface.  You wouldn't get straight lines anywhere on a perfectly spherical surface, but violin plates are not spherical.  It probably has something to do with the complexity of constraining the surface to meet a flat plane at the ribs and the difference in curvature between long and cross arching... but I see no benefit to spending time digging into this.

What I do know is that my CAD design was generated from convex curves (except for the recurves), and the CNC'd plates have those straight diagonal lines on them, even where both archings are convex.  It is what it is, and it works good.

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