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JohnS.

Guarnerius Il Cannone measurements

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That is some seriously good advice, which is borne out by the fact that, until relatively recently, I've made more forms than instruments.

By the way, the Cannon has an unusually wide edge overhang, especially at the corners of the back (in the Cannon between 4.0 and 5+ millimeters!). In the Biddulph book the variability of the overhang is discussed (Roger Hargrave I think) and is thought to be part of the reason we see Guarneris with different overall dimensions but still with a likelihood of having been made on the same form.

The purfling line, as you know will give you a good indication of the outline of the front or the back prior to wear. I would not however use the purfling as a reliable reference for the corners because of the huge overhang. It appears that 'del Gesù', once he had roughed out the corners didn't pay too much attention to the actual curves of the corner or the end of the rib mitres. If he felt the corner looked better, even with a large overhang, he left it as such.

Bruce

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Just to give you an idea of how far off it can be, here is a shot of the overhang at the upper bass side corner of a 1744 'del Gesù' ex Rose-Hennel (illustrated in the Hill book). Sometimes it is not always easy to say that it was like this when it was new but I can't imagine that it could ever have been very close.

Bruce

post-29446-1263128658.jpg

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Thanks for all the great posts. Let me add a little more to my original question. I'm also concerned about the thickness of the ribs on this model. They vary from 1.3 to 2 mm, not counting the linings. Also, the f-holes on this instrument are different from one another. Were these differences a specific intention of Guarnerius, or was it due to restoration or some other factor? I'm mainly interested in reproducing that dark, rich sound of this model, not so much the appearance.

On many 'del Gesù' violins there are deep, heavy marks left by a toothed plane blade. The Hacklinger gauge cannot get down in between deep grooves and could be giving you spurious results. See the photo that I uploaded some time ago on Maestronet.

F-holes are pretty free in style so you see a lot of variation from one instrument to another.

Bruce

post-29446-1263129230.jpg

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Just as a suggestion when making a new model.

I like to make preliminary drawings or sketches of the body and scroll. ...Just try free hand sketches of the f-holes, corner shapes, purfling joints, head profiles or of other basic features you would like to see and keep at it until you get it right. It's great to have a clear mental image of where you want to go before you pick up the knife.

..

Bruce

Great photos as usual, Bruce. I really enjoy seeing the tool marks.

And a really fine idea, drawing, and something I’m not good at. I’ve been meaning to draw f-holes for sometime now, and this is just more incentive to do so.

The fold-over method of mould creation has seemed a bit shaky to me, though I’ve heard people get good results from it -- and I haven't tried it. Seems a good way to eliminate character -- though the builder always will introduce their own.

Here’s the steps I see in that method.

Violin 1.

Create a mould, mostly symmetric.

Make blocks and ribs, mostly symmetric, mostly tight to mould, mostly square to the plane of the mould. Or maybe not, depending on the day.

Build top and back, with edges mostly following the rib outline.

Channel for purfling, mostly following the edges.

Age for 300 years.

Violin 2.

Trace photo of purfling of violin 1, usually the back.

Fold tracing in half, average out differences, or choose best half, or best pieces of.

Make mould, symmetric as possible. Follow building steps as in violin 1, only with high precision.

I think it would be surprising if violin 2 turned out looking like violin 1. But maybe I’m missing the point of that technique. I'm more interested, right now, in step 1 of the first violin -- how'd they create that first mould?

Ken

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Ken - If your goal is to recreate a particular instrument's original mold, then most people are going to introduce symmetry at some point, whether they try to recreate the geometric formula or the mold directly. The paper fold over method can be as sophisticated as you like in terms of making choices about what to follow and what to change.

I don't think there is an option that isn't fraught with opportunities for wrong turns. :)

Bruce - I love the drawing idea. I have often thought that violin makers would benefit from learning to draw, but I've always skated over the idea of drawing a new model first as part of the development process. Your post makes me realize the rewards very likely justify the time spent.

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Great photos as usual, Bruce. I really enjoy seeing the tool marks.

And a really fine idea, drawing, and something I’m not good at. I’ve been meaning to draw f-holes for sometime now, and this is just more incentive to do so.

The fold-over method of mould creation has seemed a bit shaky to me, though I’ve heard people get good results from it -- and I haven't tried it. Seems a good way to eliminate character -- though the builder always will introduce their own.

Here’s the steps I see in that method.

Violin 1.

Create a mould, mostly symmetric.

Make blocks and ribs, mostly symmetric, mostly tight to mould, mostly square to the plane of the mould. Or maybe not, depending on the day.

Build top and back, with edges mostly following the rib outline.

Channel for purfling, mostly following the edges.

Age for 300 years.

Violin 2.

Trace photo of purfling of violin 1, usually the back.

Fold tracing in half, average out differences, or choose best half, or best pieces of.

Make mould, symmetric as possible. Follow building steps as in violin 1, only with high precision.

I think it would be surprising if violin 2 turned out looking like violin 1. But maybe I’m missing the point of that technique. I'm more interested, right now, in step 1 of the first violin -- how'd they create that first mould?

Ken

Hi Ken,

I think it depends upon your goal. That is, just how close do you want to get to reproducing the original?

Andres is suggesting a method like this if you are intent on eliminating some of the asymmetry shown in the original and at the same time to be able to incorporate what you consider to be the best features of the instrument; or for that matter, of various instruments.

As JohnS., who originally started this thread, said; "I really don't like the idea of ending up with a crooked violin if I don't have to, and yet I don't want to sacrifice sound quality. Any advice?"

Asymmetry or crookedness has a tendency to creep in anyway, even when you're careful.

Stewart Pollens wrote an interesting book on the Stradivari Forms and how Stradivari may have made modifications to them and Francois Denis has written another giving a method for drawing the outline from scratch. There's plenty of material out there.

I don't know how many instruments you have made but I would suggest not getting too hung up on the form. The making is a lot more fun. Hans Weisshaar once said to me about a viola I was making and had not yet completed; "Bruce, if you're not careful, you're still in time to ruin it."

Bruce

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In the interests of fair disclosure though, the last time I made a mold I imported the outline of the original into Photoshop and did all the work there right down to the final mold outline and block templates. :)

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Hi Ken,

I think it depends upon your goal. That is, just how close do you want to get to reproducing the original?

Andres is suggesting a method like this if you are intent on eliminating some of the asymmetry shown in the original and at the same time to be able to incorporate what you consider to be the best features of the instrument; or for that matter, of various instruments.

As JohnS., who originally started this thread, said; "I really don't like the idea of ending up with a crooked violin if I don't have to, and yet I don't want to sacrifice sound quality. Any advice?"

Asymmetry or crookedness has a tendency to creep in anyway, even when you're careful.

Stewart Pollens wrote an interesting book on the Stradivari Forms and how Stradivari may have made modifications to them and Francois Denis has written another giving a method for drawing the outline from scratch. There's plenty of material out there.

I don't know how many instruments you have made but I would suggest not getting too hung up on the form. The making is a lot more fun. Hans Weisshaar once said to me about a viola I was making and had not yet completed; "Bruce, if you're not careful, you're still in time to ruin it."

Bruce

Hi Bruce,

I'm a novice at violin-making. I have been doing repair work for a while, though, and am still working my way through the difference between factory instruments (my bread and butter work) and the classical instruments. Your photos are great for that.

Andres and I have attended the same workshop (http://jbviolin.com/workshop/) and he well knows that I am quite capable of ruining many aspects of a violin. I know that I can create all the asymmetry I want while trying to be symmetrical. :)

Personally, though, I think that the folding technique has a strong possibility of eliminating certain elements of the design -- because asymmetries are not uniform, not symmetrical. How's that for a tautology? :) But will also agree that it is a good way to understand a model. I've tried it on a few outlines, and archings, and suddenly asymmetries I hadn't noticed pop out.

And having a math background, I'm certainly interested in Fr. Denis' method -- invested in the book -- and currently reading up on Renaissance architectural design.

But as you say, none of that builds fiddles. Back to the bench!

Thanks,

Ken

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But will also agree that it is a good way to understand a model. I've tried it on a few outlines, and archings, and suddenly asymmetries I hadn't noticed pop out.

I think this is key. Foldover (or similar processes) immediately presents you with choices to make. The amount of information and thought you apply to those choices has a big effect on the outcome.

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Andres and I have attended the same workshop (http://jbviolin.com/workshop/) and he well knows that I am quite capable of ruining many aspects of a violin. I know that I can create all the asymmetry I want while trying to be symmetrical. :)

I think that's the way it was done.

Sadly, when I try to create symmetry, that's what I get. :)

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sORRY TO bring it back up but arnt ribs 33 ?

Any ribs or the Cannon's ribs?

The Cannon block heights, in the Biddulph book are listed at:

Neck block near the neck mortice: Bass - 31.1 mm Treble - 31.6 mm

Upper corner blocks: Bass - 32.3 mm Treble - 32.7 mm

Lower corner blocks: Bass - 32.8 mm Treble - 32.8 mm

Lower block: 32.8 mm

In a well preserved instrument of the classic cremonese school, the instruments can show equal or near equal height for the lower block and the four corner blocks; only the upper block being lower.

Some modern makers would consider these to be on the high side.

Bruce

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