Shaping the Corners - a tutorial

[MANFIO]

Hi all! I have noticed that shaping the corners properly is a problem for newcomers. Corners are a tough test for newcomers, they may be too long, too short, too narrow (rendering the appearence of the instrument too weak), too wide, too hooked, etc.

So I decided to make this small tutorial about this subject. I'm not a schollar in violin making and my approach here, again, will be practical, and it's the method I'm currently using for my violas. Again, it's not an "official" method, it's my personal method.

The final appearence of the corners will depend heavily on the ribs form that are bellow them, so I'll start with the ribs. It's a good thing following good plans, such as those published by THE STRAD magazine and try to copy the forms of the instrument that is inspiring you

Based on the Strad poster, I use the dividers to mark the end of the corners over my corner blocks:

and transfer the measuments for my back:

[MANFIO]

Now, using a rule, I'll project this line to get the angle in which my corner will be cut:

[MANFIO]

Here I'm controling the corner overhang with a caliper. I don't like too long corners, they play havoc with the players bow hand and, with some time, too long corners will get damaged by accidental bow impacts.

[violins88]

Manfio,

Thanks again for your generosity. This was very timely information for me. I am doing the corners just now. Thank you.

[MANFIO]

Thanks!

I'll repeat the process with the 4 corners.

Now I mark a point in the end of the corner aligned with the rib mitre:

Now I draw a line from this point to point in the centerline (I find it by eye):

With the divider centered in the centerline I draw an arch that will touch the first line:

Then I trace another line like this. These two lines will give me a visual orientation of the corners:

[Tim McTigue]

Wow, this is fantastic! I hope you'll continue it into the final shaping with the channel. Trying to get the channel to look right in the corners has given me fits lately. It's good to see that there is a simple and practical method to make sure all the corners are properly aligned and shaped, right from the beginning. None of the books I've read so far (all two of them, admittedly) has mentioned anything except copying a template, or judging by eye...

[MANFIO]

Hi Tim, thank you! Unfortunatly I hadn't taken pics while carving the channels...

Now I will draw two parallel lines, one above and one below this line, with the same width of the corner I'm intending to make, here about 8.5 milimeters.

Some years ago now I would cut the corners with a knive, observing it carefully as the work developed, in order to get good, harmonious corners.

Well, now I'm using this hetherodox method (ok, some will frown upon me...). First I choose a round object that has the same radious of the model that is inspiring me. Here I chose a small bottle for the lower part of the C bouts, it conforme to the outline of my model:

[M_A_T_T]

Nice work and good photography.

........you plan on doing a varnish tutorial?

[Tim McTigue]

Poor Luis. Didn't know what he'd signed up for. Too late now, the requests are piling up. It strikes me that if Tony S. had been able to share his methods in similar fashion, the world would be much richer now - violins of Strad quality would be the norm...

[MANFIO]

Hi! Thank you! A varnishing tutorial would be much more difficult... I've just applied my ground and my hands were sticky all the time, it would be difficult taking pictures in such conditions. The varnishing process is much more dynamic too, it's a bit different in every instrument. Ciao!

[tomroth]

cool

[Doug Rice]

Luis: Thank you so much. This is so logical and systematic compared to what I have done in the past. You are a great teacher. mille grazi. Doug

[kubasa]

Wow, yet another tutorial. Thank you Luis!

[MANFIO]

Thank you all!

The corner may be left "square" or may be slightly rounded, I've done mine square in the past but now I'm making them slightly ronded.

For a reference, here a template of a Strad cello corner in the Museo Stradivariano di Cremona, with Strad's autograph "misura per le punte alli violioloncelli" (or something like that). The photo is by Melving, if I'm not wrong, he posted it here:

All the following pics are from the site of the Shrine to Music Museum.

Here a Strad violin corner with some wear:

Now a Girolamo Amati violin corner:

Here the beloved Andrea Guarneri viola tenore corners, this instrument is a favorite among many makers, including Michael Darnton. Notice that apparently he left the corner "square" instead of rounding it. Notice also the cut lines left by a "grafietto tagliente" to mark the limits of the channel over the purfling:

[COB3]

Luis, thanks for the comparison, side by side...that is very helpful...do you happen to know which Stradivari instrument that corner photo is from?

Chet

[Tim McTigue]

I especially find the last example helpful, it clearly shows how the channel in the corners should look. Thanks!

[MANFIO]

It's the 1693 Harrisson Stradivari, here is the link, just click on any major structural area of the instrument to see a close-up of that area:

http://www.usd.edu/smm/Violins.../3598StradViolin.html

This site is fantastic, with many instruments, and free, you don't need to get an expensive violin book to study some instruments in detail.

[MANFIO]

And here quite nice photos and work by Michael Darnton, as usual:

http://www.mindspring.com/~mdarnton/Corner.jpg

[Tim McTigue]

quote:

---

Originally posted by:

MANFIO

This site is fantastic, with many instruments, and free, you don't need to get an expensive violin book to study some instruments in detail.

---

Wow, you're not kidding! I guess it's true, there really isn't a whole lot under the sun that isn't available on the Internet...

[Andres Sender]

ah never mind.