Saturday, January 31, 2015

Starting on the Belly

I glued up the belly yesterday when I re-glued the back seam. Today I started roughing the inside. My method is to rough the inside close, rough the outside a couple mm's or so thick, and then flatten the bottom. At that point I can start finishing. I figure that is the way the master received the job from the apprentice. I'm doing the grunt apprentice work now. With planes the work is very easy. Here is the first hour:


First I drilled 2 holes twenty mm's deep. I'm making a long arch based on two catenaries, kind of like a back, but with longer arches. I didn't want just a straight catenary, and I didn't want a Strad-like arch. It is more like a del Gesu. The arch is quite flat, so it should work.


It's hard to tell from the phot, but the long arch is all roughed in. I leave it a little short so if I have to take more off the bottom than a mm or so, the arch won't be undercut at the blocks. I write this like I've been doing it for years, but I just found in out when I was doing the cello back. At least I learned something. And I learned how to glue up a long crack.


As you can see the planes leave a big pile of chips in just an hour. But they are nice easy chips. I move the plane in a long motion, cutting the whole arch in one swipe. Sometimes I may have to work on an area to push it down; especially near the block where the arch rises quite quickly; but most of the time the plane bottom defines the cut, and make the job simple.

Now, I have to go to work. Tomorrow is Sunday and I'm off. I'll work on the cross arches then. It is supposed to snow. I've heard anywhere from 5-10 inches. Yuck.

2 comments:

  1. That's pretty good Ken, but why not do the outside arching 1st , flatten the edges next, cut the purfling groove/glue purfling, close finish the outside shaping and then work on the inside. Then, maybe flatten-lower the edges some more before finishing the inside right before final tuning. What do cello plates tune to anyways? It seems to me lower hz and more weight compared to a violin. Yes, snowy weather is depressing no matter where you're at, good luck.

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  2. I think that the entire shape is modeled from the inside arch; at least the convex part of the outside. If I get the inside arch right, I can rough in the outside within a mm or two, and it goes really fast. After I bring the outside shape to size, drop the edge down flat, true up the inside arch, and make the outside arch a perfect circle, I can work on getting the re-curve right.
    I'm not sure what tones the plates have. I do know that the sounds are easy to hear, and are fairly loud; there is 4 x's the surface area.

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