Scroll widths

[HonestEngineer]

I'm currently trying to design a viola scroll and have been looking for inspiration but have found very little. There seems to be lots of discussion about the side-on view of the scroll but very little on the widths of each part of the scroll. I've found a few templates for the first turn. I've also found lots of references to a 'cremonese' approach that involves transferring circles from a pattern to the various parts of the scroll to form the widths. But while I've found one example of the actual radii of these circles for a violin, I can't find any for a viola. I really want to design this from geometric first principles but I've found no discussion at all as to the mathematical approach to developing the scroll widths.

Can anyone shed any light on this area?

[Torbjörn Zethelius]

Hi, I've written an article that I think covers your question. My latest attempt at establishing the scroll width ended with me making it one Cremonese oncia wide, i.e. ≈ 39.1mm. For a viola I might use a scroll width which is a 1/9 fraction of the viola's body length. 

 

[HonestEngineer]

Hi Torbjörn, that sounds really interesting, but the dropbox link doesn't work unfortunately.

 

[Nick Allen]

9 hours ago, HonestEngineer said:

I'm currently trying to design a viola scroll and have been looking for inspiration but have found very little. There seems to be lots of discussion about the side-on view of the scroll but very little on the widths of each part of the scroll. I've found a few templates for the first turn. I've also found lots of references to a 'cremonese' approach that involves transferring circles from a pattern to the various parts of the scroll to form the widths. But while I've found one example of the actual radii of these circles for a violin, I can't find any for a viola. I really want to design this from geometric first principles but I've found no discussion at all as to the mathematical approach to developing the scroll widths.

Can anyone shed any light on this area?

I've measured and measured, and it has never turned out the way I measured. 

I've found that the best way for me to do my scrolls is to more or less shape the inner turns as I go. Whatever is pleasing to my eye at the time is usually the prevailing determiner. 

Have you tried playing around with the scaling of the violin measurements?

[Julian Cossmann Cooke]

The width on the da Salo viola which is the subject of a Strad poster is 48 and change.  I can't bring myself to leave it that wide.  I'll go for aesthetics instead.  Wanted to reduce the weight of the head anyway.  

[David Burgess]

12 hours ago, HonestEngineer said:

I'm currently trying to design a viola scroll and have been looking for inspiration but have found very little. There seems to be lots of discussion about the side-on view of the scroll but very little on the widths of each part of the scroll. I've found a few templates for the first turn. I've also found lots of references to a 'cremonese' approach that involves transferring circles from a pattern to the various parts of the scroll to form the widths. But while I've found one example of the actual radii of these circles for a violin, I can't find any for a viola. I really want to design this from geometric first principles but I've found no discussion at all as to the mathematical approach to developing the scroll widths.

Can anyone shed any light on this area?

As an engineer, maybe you are overthinking this? Unless you are trying to copy some specific historic viola, enlarging a favorite violin scroll has worked well for me.

You could enlarge a front and/or back photo, and take measurements from that, or you could look at them, study and digest them, and use that as inspiration for something which might not turn out exactly the same. Maybe better, maybe worse. What is your risk tolerance level?

[Janito]

As DB says - I use 110% of a Cremonese violin scroll as a starting point for all dimensions.

So width for viola = 42 + 4.2 mm approx.

 

[David Burgess]

15 minutes ago, Janito said:

As DB says - I use 110% of a Cremonese violin scroll as a starting point for all dimensions.

So width for viola = 42 + 4.2 mm approx.

Same here, except that I will vary that increase, depending on whether it is a 15 1/2", or a 17" viola. I don't think my 17" viola scrolls would "hang together" very well, on a 15.5 inch viola.

[Torbjörn Zethelius]

6 hours ago, HonestEngineer said:

Hi Torbjörn, that sounds really interesting, but the dropbox link doesn't work unfortunately.

 

https://www.dropbox.com/s/gp7p73a3ybx7clg/Carving a scroll using angular templates.pdf?dl=0

Hope this works.

[HonestEngineer]

10 minutes ago, Torbjörn Zethelius said:

https://www.dropbox.com/s/gp7p73a3ybx7clg/Carving a scroll using angular templates.pdf?dl=0

Hope this works.

Great thanks. That looks like just the kind of article I need. Bed-time reading for tomorrow evening I think.

[HonestEngineer]

1 hour ago, David Burgess said:

As an engineer, maybe you are overthinking this? Unless you are trying to copy some specific historic viola, enlarging a favorite violin scroll has worked well for me.

You could enlarge a front and/or back photo, and take measurements from that, or you could look at them, study and digest them, and use that as inspiration for something which might not turn out exactly the same. Maybe better, maybe worse. What is your risk tolerance level?

Yes, I'm almost certainly overthinking this... but that's the way my mind works and I've learnt over the years to roll with it. I've really enjoyed designing the body of my viola using a mathematical approach. Something about having a viola that follows a mathematical pattern appeals to the nerd in me. I could have just used one of the many existing designs out there, but it feels more of a sense of achievement if I've created everything, including the overall shape of the instrument. Having studied engineering drawing many years ago, I also love the idea that the entire instrument shape can be created with nothing more than a pair of compasses and a good understanding of geometrical construction. Hence I got rather frustrated when I couldn't find any pointers on how to do this with the scroll.

As for risk tolerance, I'm building this instrument for myself so I can do whatever I like so long as I'm prepared to live with the results!

Thanks everyone for your responses... I need to go away and process it all now.

[Janito]

1 hour ago, David Burgess said:

Same here, except that I will vary that increase, depending on whether it is a 15 1/2", or a 17" viola. I don't think my 17" viola scrolls would "hang together" very well, on a 15.5 inch viola.

Indeed - I should have specified that's for my ~16 3/8" viola model (it was on my mind as I have just been mapping a scroll to an enlarged Milanollo).

 

[David Burgess]

8 hours ago, Torbjörn Zethelius said:

Hi, I've written an article that I think covers your question. My latest attempt at establishing the scroll width ended with me making it one Cremonese oncia wide, i.e. ≈ 39.1mm. For a viola I might use a scroll width which is a 1/9 fraction of the viola's body length. 

 

Torbjorn, while i am probably as fascinated as anyone with construction ratios and principles, I was mostly trained "by eye". For my violas, I mostly enlarged violins, and then erased and re-drew various parts to suit my taste. But gotta say that you do make some very nice scrolls. Different approaches, for different people. Nothin' wrong with that.

[Conor Russell]

I make my violin  heads a little  under 40, because  they look a  bit too heavy at the 'standard' 42.

I've just  finished  a viola whose head is about 43. I think  viola heads should look light, wide enough  that they don't  look scrawny over the pegbox but no more. 

[Jim Bress]

As my betters above have already written, I have been taught that measurements are a good starting point. However, eye should be the final guide.  As the saying goes, everything must hang together. 

-Jim 

[Torbjörn Zethelius]

10 hours ago, David Burgess said:

Torbjorn, while i am probably as fascinated as anyone with construction ratios and principles, I was mostly trained "by eye". For my violas, I mostly enlarged violins, and then erased and re-drew various parts to suit my taste. But gotta say that you do make some very nice scrolls. Different approaches, for different people. Nothin' wrong with that.

Hi David, I also like to work by eye. But at the same time I think it's a good practice to establish ratios. It makes the finished work more complete IMO. BTW where does the 'standard' 42mm come from? Few Cremonese violin scrolls are that wide.

[Julian Cossmann Cooke]

2 hours ago, Torbjörn Zethelius said:

Hi David, I also like to work by eye. But at the same time I think it's a good practice to establish ratios. It makes the finished work more complete IMO. BTW where does the 'standard' 42mm come from? Few Cremonese violin scrolls are that wide.

42mm=good German "robustness".  On a serious note, though, it would be interesting to compare the standards taught at the schools outside the US -- the US school curricula having been based on Mittenwald (though even those may have evolved to something else).  Not definitive by any means, but an interesting data point.

Any alums care to pitch in?

[Janito]

12 hours ago, Conor Russell said:

I make my violin  heads a little  under 40, because  they look a  bit too heavy at the 'standard' 42.

I've just  finished  a viola whose head is about 43. I think  viola heads should look light, wide enough  that they don't  look scrawny over the pegbox but no more. 

The width of the bouts can make the width of the scroll (and volutes) appear 'wimpy' when the whole is observed face-on.

[Moroni Larson]

On 12/2/2018 at 7:21 AM, Julian Cossmann Cooke said:

 

 

[HonestEngineer]

Thanks everyone for the interesting discussion. I've gone with scaling the Cremonese circle template up by 10% and a total width of 46mm. I've just roughed one out of softwood and offered it up to the body, and it looks nicely balanced, so I'm happy.

I'd still be interested if anyone has any thoughts on how the original Cremonese template was generated?

[Torbjörn Zethelius]

21 hours ago, HonestEngineer said:

I'd still be interested if anyone has any thoughts on how the original Cremonese template was generated?

I believe that Stradivari made his scrolls in a similar way as I described in my article above, with varying proportions and ratios. He then made circle templates so that they could be reproduced by his  apprentices.