Violin Forum/Message Board

[Mat Roop]

Is there a mathematical formula for the basic shape of the scroll? I have heard of the golden mean spiral, but apparently that is not quite it... thoughts?
Thanks, Mat

[Michael Darnton]

I'm certain there's a plan, but I don't know what it is. I took a very clean and typical Strad scroll and blew the photo up, then marked every cm (which would have represented every couple of mm on the life-size head) in the image along the outline of the whole thing, from where it leaves the eye to to bottom of the back, and mapped out the widths on a straight line--what you would see if you "uncurled" the head. You can see the result here, next to the photo:



The interesting thing is the relatively level spots, followed regularly by a quick jump. A simple spiral would result in a steadily increasing line. I believe the line is built in a series of circular sections, but I don't know what section of a circle they include, nor where each section starts. I suspect the junction points may not be where we'd normally suspect, and there may be fewer separate arcs than we'd suspect.
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[Dave Chandler]

Here's a simple demonstration of drawing an ionic volute. I think it will get you where you want to go. Watch it a couple times, it starts to make sense.

http://www.slideshare.net/ozi/drawing-an-ionic-volute
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Dave in the Blue Ridge
Southern Violin Association

"Success is the ability to go from one failure to the next with no loss of enthusiasm" Winston Churchill

"I took the road less travelled, and now I don't know where I am." Marco Polo

[DonLeister]

How did you do that!? That's an interesting investigation of a scroll outline.

I was doing a scroll yesterday (thinking I really need to go to scroll school) and thinking I wish I had a better selection of gouges because it seems the size gouges I have determine a good deal of the look of my scrolls. I use about five gouges to establish the spiral shape, a few more to do the cleaning up of the undercutting and smoothing.
They seem to come out a certain way since I pickup the usual gouge for certain sections of the scroll. Now that I see what happens, repeatedly, I am thinking about what I would rather have happen.

[Michael Darnton]

[Dave Chandler]

Michael:

You're right -- using the scroll you presented above, and plugging it into the table using the formulas on the ionic volute construction at the mentioned website, the ratios between turns is slightly different after the first two circles, the third turn is smaller in your photo by about 14% and your "eye" is larger by about 12%.

Not a heck of a lot of difference, but maybe just enough that it becomes more artistic, and less academic!
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Dave in the Blue Ridge
Southern Violin Association

"Success is the ability to go from one failure to the next with no loss of enthusiasm" Winston Churchill

"I took the road less travelled, and now I don't know where I am." Marco Polo

[Michael Darnton]

The other problem is that Cremonese scrolls don't decrease in an orderly fashion.
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new blog at my site! http://darntonviolins.com/blog
my work sites: http://darntonviolins.com and http://darntonhersh.com

[mikemolnar]