Strads not symmetrical

[David Beard]

2 hours ago, francoisdenis said:

Hi David, what do you mean exactly here? The "vesica pisci " was a pythagorean symbol of trinity and symmetry connected to the division of a width into 3 equal parts  "1-1-1" , It has been "recycled"  afterward (for its trinity property) by the catholics (and lately by  the new-age as a feminist symbole of the fertility ).  An upper part of a violin made following this symmetry will look very weird !

A pair of overlapping circles are the basic structure in the upper and lower bouts.  That pattern is generally a vesicca patteren.   The special case of the vesica pisci is when the gap between the centers equals the radius, the 1 to 1 to 1 case ( or 3:3:3 etc).

But bouts don't usually use just the picis type ratios.

In the Strad violin moulds, the upper bout is most commonly a 2:1:2 ratio.  In the lower bout, a 1:1:1 ratio is typical.

But, what is very interesting is that the instruments show a wider range of veisci ratios used than the moulds do.  Things like 7:6:7, 6:5:6, 5:4:5, and 4:3:4 are common in the lower bout for actual violins even though the moulds do not show so much variation in the choice of ratio.

I believe the explanation is that the moulds were made a chosen designs.   But, the actual outline designs were worked out only after building an instrument's actual sides were made and arranged in a disposition on the board for a plate.   The greater range of vesici ratio choices was used to better follow the real sides in the actual build. 

This was also the motivation for sometimes chosing different sizings for treble and bass side C bout main circles.  Once again, to follow the actual disposition of completed sides during the specific build.

In contrast, in all the moulds the main circles for the center bouts are sized symmetrically.  

[francoisdenis]

On 9/17/2022 at 10:05 AM, David Beard said:

The greater range of vesici ratio choices

David, It seems that you definitely don't want to take account that there is only one symmetry specific to the vesica (1-1-1) since this specificity is the reason for its symbolism and moreover the "mandora" never appears in the violin shape....
the other figures you mentioned are nothing more than the interaction of two circles. To use an analogy may be you will grasp that the perfect circle being a specific kind of ellipse it would be very strange to speak of ellipse as "a large range of circles"... I have to say that it's not the first time that I try to draw your attention about this inappropriate use.
May be should try to find a term to nominate this relation between the radius and the centers of two circles "symmetry" "cadence" "series" "rhythm" "division" "partition" even "ratio" would avoid this confusion.

I know this is probably a detail for all readers here but a person as expert as you are in geometry can no longer afford this kind of mistake.

[David Beard]

3 hours ago, francoisdenis said:

David, It seems that you definitely don't want to take account that there is only one symmetry specific to the vesica (1-1-1) since this specificity is the reason for its symbolism and moreover the "mandora" never appears in the violin shape....
the other figures you mentioned are nothing more than the interaction of two circles. To use an analogy may be you will grasp that the perfect circle being a specific kind of ellipse it would be very strange to speak of ellipse as "a large range of circles"... I have to say that it's not the first time that I try to draw your attention about this inappropriate use.
May be should try to find a term to nominate this relation between the radius and the centers of two circles "symmetry" "cadence" "series" "rhythm" "division" "partition" even "ratio" would avoid this confusion.

I know this is probably a detail for all readers here but a person as expert as you are in geometry can no longer afford this kind of mistake.

We disagree on this.  You might desire everything to be 1:1:1 , but the historical examples don't conform to such a desire.

The Cremona lower bout is n:n:n in concept, but actually carried out as n:(n-1):n in many examples.   Cremona upper bout are basically 2n:n:2n in concept.  But actual examples show variations of the ratio choice, 3:2:3 being a popular example in Cremona upper bouts.

It probably is true that a 1:1:1 ratio was the archetypal concept.   But even in archaic examples predating the violin family we see makers using a more diverse range of ratio choices.   In Lira d'Bracci for example we see ratios with the gap between centers is greater than the radius, leading to the typical dimple on many Lira lower bouts.   And then, a more circle upper bout shape has been favored across many instrument types.  So for example, we see rarios of n:1:n common in vielle upper bouts.  And note, the 2:1:2 of Cremona violin upper bouts fits this pattern.

The historical instrument making shows high concept ideals only lurking in the background.   The daily majority of choices show instead a mix of tradition and pragmaticism.

[David Beard]

 As far as terminology, 'vesica' refers generally to the 'fish bladder shape' of overlapping circle.  Only the 'picis' of 'vesica picis' refers to 'twins' and the special 1:1:1 arrangement of the vesica picis.

The more general use vesica is common in mathematics.  No new terminology is needed.

 

The even more general term 'lens' cover circle overlaps when the radii aren't necessairily equal.

[jezzupe]

Well, I wanna know who was the town drill bit maker, all this talk of 1 mm drill bits makes me wonder who was the source for such things, it would seem to me that it would be harder to make good 1mm bits than say 5mm, even with today's hybrid metal compounds they tend to snap all the time, and well based on the shape of the "nail" I would call it much more of a tack I wonder if they even pre-drilled holes?

[JacksonMaberry]

4 minutes ago, jezzupe said:

Well, I wanna know who was the town drill bit maker, all this talk of 1 mm drill bits makes me wonder who was the source for such things, it would seem to me that it would be harder to make good 1mm bits than say 5mm, even with today's hybrid metal compounds they tend to snap all the time, and well based on the shape of the "nail" I would call it much more of a tack I wonder if they even pre-drilled holes?

I haven't seen any original neck nails that are that small in diameter.

[jezzupe]

19 minutes ago, JacksonMaberry said:

I haven't seen any original neck nails that are that small in diameter.

My memory of seeing these "nails" in xray photos is that they are very similar to today's modern carpet tack, that has a needle sharp point that flairs out rather quickly and tapers up to probably 2 to 3mm and vary in length, and also seemingly sqaurish not really round. I've seen some pics of pretty honking nails in lutes and ouds also, which I can't imagine not splitting the wood unless predrilled...And I'm not suggesting the nail is 1mm just the pilot hole, or well smaller than the nail. Do we have any "drills/bits" from Cremona?

 

 

[JacksonMaberry]

44 minutes ago, jezzupe said:

My memory of seeing these "nails" in xray photos is that they are very similar to today's modern carpet tack, that has a needle sharp point that flairs out rather quickly and tapers up to probably 2 to 3mm and vary in length, and also seemingly sqaurish not really round. I've seen some pics of pretty honking nails in lutes and ouds also, which I can't imagine not splitting the wood unless predrilled...And I'm not suggesting the nail is 1mm just the pilot hole, or well smaller than the nail. Do we have any "drills/bits" from Cremona?

 

 

Sorry, I misunderstood. I'd love to see some Cremona drill bits!

[Davide Sora]

52 minutes ago, jezzupe said:

My memory of seeing these "nails" in xray photos is that they are very similar to today's modern carpet tack, that has a needle sharp point that flairs out rather quickly and tapers up to probably 2 to 3mm and vary in length, and also seemingly sqaurish not really round. I've seen some pics of pretty honking nails in lutes and ouds also, which I can't imagine not splitting the wood unless predrilled...And I'm not suggesting the nail is 1mm just the pilot hole, or well smaller than the nail. Do we have any "drills/bits" from Cremona?

 

 

 

7 minutes ago, JacksonMaberry said:

Sorry, I misunderstood. I'd love to see some Cremona drill bits!

These are the ones that are in the Museum among Stradivari's tools, albeit the attribution is uncertain to the Stradivari or Ceruti workshop, they certainly used something like this. Iron lengths from largest to smallest are 170mm, 74mm, 60mm and 51mm.

[JacksonMaberry]

Thanks!

[HoGo]

I remember seeing a video on YT with reconstruction of original Strad or gesu neck attachment 3D printed from CT of original neck and head block. They used some nails to show how the parts would fit. Perhaps Carlson and Canone was it? I couldn't locate the video again. Predrilled hole would be a must or the neck root would crack way too easily with old hand forged nails.

[Davide Sora]

28 minutes ago, HoGo said:

I remember seeing a video on YT with reconstruction of original Strad or gesu neck attachment 3D printed from CT of original neck and head block. They used some nails to show how the parts would fit. Perhaps Carlson and Canone was it? I couldn't locate the video again. Predrilled hole would be a must or the neck root would crack way too easily with old hand forged nails.

I think the work you are talking about is the one done by Francesco Piasentini (TEC Eurolab CT scans) for the Messiah, I don't know if there is a video on Youtube but there is this article published on The Strad.

https://www.thestrad.com/lutherie/ct-scanning-the-messiah/11554.article

[jezzupe]

Thanks for the photos Davide but really they create more questions than answers

https://www.youtube.com/watch?v=B0w4EVpNliA

 

speaking of nails in violins, but really they're staples....such a pleasant tone

 

[JacksonMaberry]

2 minutes ago, jezzupe said:

Thanks for the photos Davide but really they create more questions than answers

https://www.youtube.com/watch?v=B0w4EVpNliA

 

speaking of nails in violins, but really they're staples....such a pleasant tone

 

When bowed, it sounds a lot like a daxophone. Google that at your own peril.

[jezzupe]

3 minutes ago, JacksonMaberry said:

When bowed, it sounds a lot like a daxophone. Google that at your own peril.

a wooden saw..

[JacksonMaberry]

2 minutes ago, jezzupe said:

a wooden saw..

Yeah! Tbh I enjoy the sound of the ordinary musical saw much more. Used to play saw duets with my dad! We'd do a lot of opera.

[francoisdenis]

 

15 hours ago, David Beard said:

You might desire everything to be 1:1:1 , but the historical examples don't conform to such a desire.

Not at all, I'm not defending anything in particular about it - it's just a question of terminology - It is true that, in a restrictive sense, "vesica" can only be understood as a synonym of "lens" referring to the measure of the "mandora". The expression "vesica pisci" is then reserved for the historical symbolic meaning of a 1-1-1 partition relationship.
It remains that when we talk about "vesica" and geometry the reference that comes to mind is the "vesica pisci" (google makes the same mistake) - at least that's what happened to me - Sorry to missed this subtlety.

[David Beard]

2 hours ago, francoisdenis said:

 

Not at all, I'm not defending anything in particular about it - it's just a question of terminology - It is true that, in a restrictive sense, "vesica" can only be understood as a synonym of "lens" referring to the measure of the "mandora". The expression "vesica pisci" is then reserved for the historical symbolic meaning of a 1-1-1 partition relationship.
It remains that when we talk about "vesica" and geometry the reference that comes to mind is the "vesica pisci" (google makes the same mistake) - at least that's what happened to me - Sorry to missed this subtlety.

Yeah.  There is so much popular interest in vesica picis that it tends to obscure all else.

[Davide Sora]

14 hours ago, jezzupe said:

Thanks for the photos Davide but really they create more questions than answers

 

Why? To me they seem more than appropriate tools for drilling wood. Certainly very inconvenient to use for pre-drill holes in the block if you have the back already glued, but with the free ribs they seem perfectly adequate.

[Andrew tkinson]

7 hours ago, Davide Sora said:

Why? To me they seem more than appropriate tools for drilling wood. Certainly very inconvenient to use for pre-drill holes in the block if you have the back already glued, but with the free ribs they seem perfectly adequate.

 A few years ago I made a lute sttepting to use "historically informed" methods. Here I was drilling the neck block for the neck nail using an old shell bit in a home made bit stock/ brace

Being unable to use the brace inside the lute body I then used the same shell bit with a small home made handle, like a small gimlet, to drill the nail pilot hole in the neck holding the unglued neck body joint together carefully while drilling

(If by some strange chance you may want to see and read more about my efforts in this area, see here  https://www.lutesociety.org/pages/building-lute-original-methods )

I reckon a nice square section tapered pointed bradawl - a big version of what is sometimes called a birdcage awl - would have been easily made by an average blacksmith, strong and good enough to make the pilot hole for a similarly shaped neck nail? Perhaps it would have been used to 'ream' a nail shaped hole after the initial boring with a small straight shell bit?

[David Burgess]

On 9/19/2022 at 9:44 AM, Davide Sora said:

Why? To me they seem more than appropriate tools for drilling wood. Certainly very inconvenient to use for pre-drill holes in the block if you have the back already glued, but with the free ribs they seem perfectly adequate.

Agreed.

18 hours ago, Andrew tkinson said:

I reckon a nice square section tapered pointed bradawl - a big version of what is sometimes called a birdcage awl - would have been easily made by an average blacksmith, strong and good enough to make the pilot hole for a similarly shaped neck nail?

Also agreed.

[Andrew tkinson]

I have been thinking that if I was going to nail a neck on a violin maybe I would drill a initial hole - smallish so capable of being reamed later, closer to the shape of the nail - for the nail in the block while the rib assembly was still fixed to the mould. It would be more stable and easier to hold and manage? 

I admit that I am not an experienced violin maker so often am puzzled by things that are obvious to skilled makers so please go easy on me but I wonder if anyone has noticed any traces of drilling on the Stradivari moulds left by over enthusiastic drillbits as they went through the neck block? It would be interesting to see these traces, if they are there, as they would maybe indicate the type of bit used eg shell bit or small gouge used as drill or spiral pointed or centre bit etc?

I hope this talk of drills is not too boring? (Sorry!)

[JacksonMaberry]

14 minutes ago, Andrew tkinson said:

I have been thinking that if I was going to nail a neck on a violin maybe I would drill a initial hole - smallish so capable of being reamed later, closer to the shape of the nail - for the nail in the block while the rib assembly was still fixed to the mould. It would be more stable and easier to hold and manage? 

I admit that I am not an experienced violin maker so often am puzzled by things that are obvious to skilled makers so please go easy on me but I wonder if anyone has noticed any traces of drilling on the Stradivari moulds left by over enthusiastic drillbits as they went through the neck block? It would be interesting to see these traces, if they are there, as they would maybe indicate the type of bit used eg shell bit or small gouge used as drill or spiral pointed or centre bit etc?

I hope this talk of drills is not too boring? (Sorry!)

Good pun! Haha, love it. I'd also be interested to know if such marks exist on the forms. I've only ever seen representations of their flat surfaces. 

My own forms do have such drill marks, but only at the bottom, because I drill the pilot hole for the endpin while it's still on the form.  I while one is at it, I don't think it would be a bad idea to drill the pilot hole for the neck fastener at the same time. 

I've described my timeline before, but in a nutshell, I glue the neck to the ribs while it's still on the form, and the glue is strong enough to keep it there with no issue as I remove the form. Once the neck-rib assembly is free, I drill the pilot hole through the block and ribs into the neck and then promptly drive home the fastener (silicon bronze cut thread boat screw in my case). Then shape the linings and glue to the belly, then the back. 

[Davide Sora]

1 hour ago, Andrew tkinson said:

I admit that I am not an experienced violin maker so often am puzzled by things that are obvious to skilled makers so please go easy on me but I wonder if anyone has noticed any traces of drilling on the Stradivari moulds left by over enthusiastic drillbits as they went through the neck block? It would be interesting to see these traces, if they are there, as they would maybe indicate the type of bit used eg shell bit or small gouge used as drill or spiral pointed or centre bit etc?

 

1 hour ago, JacksonMaberry said:

I'd also be interested to know if such marks exist on the forms. I've only ever seen representations of their flat surfaces.

I have not seen any mark that could suggest holes drilled with the ribs on the form, it is one of the reasons why I think that the nails were placed with the ribs free from the form. I remember that I had looked for them because among the various theories of when the neck was fixed there was one that hypothesized that at least two nails were hammered with the form still glued to the ribs, a rather implausible theory in my opinion.

[David Beard]

18 minutes ago, Davide Sora said:

 

I have not seen any mark that could suggest holes drilled with the ribs on the form, it is one of the reasons why I think that the nails were placed with the ribs free from the form. I remember that I had looked for them because among the various theories of when the neck was fixed there was one that hypothesized that at least two nails were hammered with the form still glued to the ribs, a rather implausible theory in my opinion.

Also, consider that our modern impulse to attach the neck while on the form is an impulse to control things.

We do not have good cause to suspect the old masters shared that impulse, quite the opposite.   Instead, their methods provide an up coming moment to 'adjust in reaponse'.   That is of course the moment when the sides are pinned and twist aligned on the plate board to etch their dispositon, and only then work a final plate outline design.