MikeC

Very interesting to see an actual video of him! What ever happened with his 'successor' and what ever happened to the lady I wonder.

Linseed oil will become soluble in alcohol eventually after it is fully oxydised and polymerized. It's called linoxin. So it makes sense that an oil varnish would eventually be soluble in alcohol. I don't know chemistry though so I can't say why.

Specific Gravity of the maple is 0.64

I just measured the spruce and used the calculator on makingtheviolin.com it comes out to 0.38 There is a 0.40 marked on the billet so that should be about right.

for the maple I have some leftover scraps. I could cut off a centimeter cube and weigh that. I'll have to cut it very carefully though to make sure it's a cubic centimeter. The spruce is still uncut so I can measure the whole billet. That should be more accurate.

I'm not sure what the density is. What's the best way to measure it?

I just weighed the plate, it's 116.3 grams, that may be a little heavy, I may be able to thin it out some more but it's close to where it should be with the graduations. I could still thin it some more near the edges and maybe a little more in the lower bout. Here it is with my drug dealer gram scale. And here's the end block area. No steep drop off but a little thicker than it needs to be, I should have had a little more recurve / fluting near the ends but I'm still learning to do a proper arching.

Lol, I got er done! Spent some time thinning it down today. Here's a link to his website. I don't know if he still sells the mapping software but you could email him and ask. https://www.pluhar.com/ It's been a while since I was in contact with him.

I continued thinning the back plate yesterday. I'm going to use the software that I got from Hans Pluhar to make a map and see what it looks like. I have too many data points, it gets tedious. After looking at the later Strads, the Cremonese, Messiah and Tuscan -Medici, there is a clear pattern, so I went with something like that as a concept. The thickest area tapering off about at the upper corners and extending somewhat past the lower corners. Here's my drawing. Others have said that the thickness in the Sacconi book is not bad, use that and you'll have good results. But I like to explore and come up with new ideas or new old ideas I used the three compass circles from the NMM pattern but positioned higher with the Librum Segretti centers of ocilation marking the upper and lower boundary. There is something about geometry that appeals to my very analytical brain, it gives a sense of structure and reasoning, rather than just winging it. 4.5mm in the center, broad area of 2.5mm in the upper and lower bouts.

looks good!

As Don said about the peg holes. I like to drill them while the block is square on a small table top drill press. I drill them undersize, just big enough to get the reamer in.

They wont laugh, it looks good! I'm an August baby too! A loooong time ago lol

After going over the above mentioned documents, I started marking out some lines. The center of the three compass circles on the violin pattern from NMM as well as on the ones in the Stradivari museum attributed to the workshop of Ceruti, exactly matches the location of the axis of focus described in Librum Segretti. Also when drawing the equilateral triangle at one third the length of the plate, the lower points fall exactly on the outermost of the three compass circles. The centers of oscillation described in Librum are bounded by the outer compass circle and the apex of the triangle in the upper bout and the arc of the triangle in the lower bout. Librum mentions not only the axis of focus but also it's compliment, which I find is exactly at the point where the outermost compass circle crosses the centerline towards the upper bout. So I used that point to draw out three more compass circles. Does any of this matter? Probably not but it's fun to contemplate. All I really need to do is determine where I want the thickest part to be and how much to thin it out. Oh one other coincidence I forgot to mention. During the last build, looking at the CT scan of the Titian I noticed that the thickest area of the back plate on the long axis is kind of flat, which kind of makes sense. If you have a concave surface and then have a thick area in the middle tapering out to the thin area in the upper and lower bouts, the resulting contour would be kind of flattish. Unless you make it really thick then you have a bulge. Well anyway at that time I made a short flat template to mark out that area. Now I notice that template matches the distance between the two small circles that represent the centers of oscillation mentioned in Librum Segretti. That was kind of interesting and unexpected.

looks good, I like how you thinned the blades.

I added a slightly better image but don't remember where I found it. Should have made a note of that.