Drawing lesson

Danhux asked me how I got dimensions for my drawing of the Guadagnini violin. Well, I kinda, sorta, made them up, and kinda sorta scaled them off of photographs, and kinda sorta used ratios that are used to draw up outlines on all violins. Each maker may use different ratios, or different starting points. The fastest and best answer to Dan might be to buy a Stad Poster. That wouldn't be a bad idea, I might suggest The Titan (Titian) Strad and then you could follow the same arching I used on the one I made at the beginning of the blog. It will give all the measurements you need except the neck and fingerboard, those are just made standard. Many people will recommend that you just make the mold for the ribcage by tracing the outline of the back on a 1/2" piece of wood, and cutting it 3.5mm or so in from the line. This will allow for the overhang (2.5mm or so) and the 1mm thick ribs.

Yeah, that will work. But it wasn't the way they did it. And your outline might end up pretty whomped out. The Titan is a good poster, but it is not very symmetrical. There aren't many old violins that are. It's from the way they are constructed. The ribs are build on an inside frame, and when they are released from the frame they may not stay where they were. The outline was traced on to the back and belly using a washer to get the overhang, and then they were cut out. There could be quite a difference in shape. The frame, or mold was made fairly symmetrical, so the ribs started out symmetrical. Why not start out the same way?

Well I thought my mold for the Titian, (I thought it was Titan, Titan sounds better, who makes this stuff up?) was off. It was another mold for one I started a long time ago. The delGesu is OK too, it's a little different. But here's a lesson on how to draw up a P mold for a Titian Strad.





Draw a centerline, mark the center of it, and then mark it out 173.5mm from the center to make it 347 long. Mark it again at .8 and .6 of the length from the top. That will mark the lower bout and lower corner. Mark a point 4/7 of the lower corner for the upper corner. The point for the upper bout can be located where the distance between the bouts will be .618 of the total length. Yeah, you have to do some math for that. That gives you the lengths.

For the widths you can use 160/101/200. I only draw one half, so divide them in half. I used 78mm and 88mm for the upper and lower corners. For the arcs at the top and bottom I chose a point 5/8 up from the bottom. That point happens to be the apex of the triangle drawn between the f holes. A line 5/8 down from the top bisects the lower holes.

You can find radii to make the shape right, but you'll have to have the poster to make it to your liking. The poster also give every measurement you need to make it. Thicknesses, f hole measurements, arch height vertically and horizontally. It also has the ct scans of the arching and ribcage (thats where you want to check your drawing.

The one I just drew up is pretty close to my mold. The f hole at the bottom could be pushed out a mm or so further, but it's pretty close. It's closer than the one I made!