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Dennis J

Arching Method

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No problem at all Jackson. It's a difficult thing to explain, it confuses me at times. But it's what it is and no more.

 

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11 hours ago, Dennis J said:

I get the impression that some makers think it's a crime to even use arching templates.

The question aside if makers of the most thought after violins used templates or not we should have a clear concept of what the purpose of the templates is. 

If the only goal is to replicate exactly one and the same arching I would say it is easier to CNC the archings by programming the design.

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The purpose of the templates is to produce a predetermined arching shape. Those templates can be varied by the settings put into the geometric layout. The disposition of the DSL lines, the radius of the arc (tangent or not tangent to the DSL lines), and the angle selected for the right angle triangle can all be varied. So the arching shape can be changed. Even using the same outline pattern and exactly the same long arch templates it is possible to change the arching shape slightly.

You might notice that the geometric layout used is the same for the front and back arching. But I selected an angle of 5 deg., 1deg. lower than the top, for the right angle triangle. I did that because the back long arch is lower than the top.

 

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16 hours ago, Dennis J said:

 

I get the impression that some makers think it's a crime to even use arching templates

Not me. As I said, many talented makers use them. I believe M. Darnton is among them, and he is pretty firm about their usefulness. (Please correct me if I'm wrong.)

It's just not a method I find useful or enjoyable. 

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Michael Darnton's use of the half template based on curtate cycloids (as I understand it from his writings and secondhand from Richard Barnes, one of his students) is the most agreeable template method I have encountered due to its overall simplicity and flexibility. 

For me, once I understand some key wood properties like density and some notions about longitudinal and cross grain stiffness, I choose a max long arch height, derive the remainder of the long arch using simple geometry by means of dividers, then derive the cross arching from the long arch to the inflection point (channel boundary) again using a simple geometric rule applied with a dividers. At this point, I can punch a dozen and a half guide marks and get to hogging. Half an hour of brainless math, an hour of carving, and I'm ready to cut soundholes and graduate. I finish margins, purfle, and carve the fluting with the box closed. It's pretty efficient.

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On 9/17/2020 at 10:02 AM, Don Noon said:

If there is one exact ideal sound and all wood was exactly the same, then there might be an "ideal" arching shape.

The fact that there are all kinds of great violins with a variety of archings and different sounds kinda puts the kibosh on the "ideal" idea.

I'm sure that in 300 years some historian will be looking at a catalog from our time and try to make the case that because all of the prices are different, it proves that we didn't use money. :-) 

A sufficiently sophisticated concept can be utilized in more than one way. I don't have to say that the Cremonese used my curtate cycloid crossarches, but I can say that I can make many or most of their variations by using the same set of templates in different ways (specifically by placing the templates less or more inward (scoop placement)  and using them on differing arch heights) and that those templates used that way do in fact fit many APPARENTLY different Cremonese violins. This is similar to what Roger Hargrave suggests in the Biddulph del Gesu books when he says he believes that all of the violins could have been generated with the same set of half templates, which is mostly true. Just extend that outward to Cremona in general.

Further, it's possible to replicate the APPEARANCE of many different Cremonese makers by using those same templates in different contexts (outline, f-hole, edgework of particular makers). So I think the comment that they are different is basically a result of defective observation. Quite a few dealers can easily tell when they're looking at a "Cremonese arch", even if they don't know the maker yet, which is one indication of common features that are different from other schools.

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4 hours ago, Michael Darnton said:

I'm sure that in 300 years some historian will be looking at a catalog from our time and try to make the case that because all of the prices are different, it proves that we didn't use money. :-) 

A sufficiently sophisticated concept can be utilized in more than one way. I don't have to say that the Cremonese used my curtate cycloid crossarches, but I can say that I can make many or most of their variations by using the same set of templates in different ways (specifically by placing the templates less or more inward (scoop placement)  and using them on differing arch heights) and that those templates used that way do in fact fit many APPARENTLY different Cremonese violins. This is similar to what Roger Hargrave suggests in the Biddulph del Gesu books when he says he believes that all of the violins could have been generated with the same set of half templates, which is mostly true. Just extend that outward to Cremona in general.

Further, it's possible to replicate the APPEARANCE of many different Cremonese makers by using those same templates in different contexts (outline, f-hole, edgework of particular makers). So I think the comment that they are different is basically a result of defective observation. Quite a few dealers can easily tell when they're looking at a "Cremonese arch", even if they don't know the maker yet, which is one indication of common features that are different from other schools.

What I wouldn't give for a week in your shop...

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There seems to be three big variables regarding arching:  The height of the arching,  the longitudinal arch shape, and the transverse arch shapes along the length.  Is there some modern or historic commonality that works best?

My guess is that there will be favorites all over the place.

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1 hour ago, JacksonMaberry said:

What I wouldn't give for a week in your shop...

somebody should video a 3d virtual reality tour of say the plowden violin to start.  they could narrate and point out things with a pencil while you spun around it.  3d would be the important part.  i think it could be uploaded to youtube, and you view it on your headset or one of those phone and cardboard arrangements.  totally do-able right now

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