Saw a Cello Back

I got a saw tooth setter for Christmas, so I sharpened up my rip saw I got a garage sale, and put it to use. The first try had a negative rake on the teeth, and the blade just skipped. I filed it back to perpendicular, and it works better. It still does not have the same nice feel that a Japanese Ryoba does; but I got through it.

The blade probably isn't sharpened right. I heard a couple teeth sound like they cracked, and sure enough I'm missing one. There were already two where it looks like an automatic sharpener slipped, and cut into the tooth on the top.

After about 3 hours I had it cut 3/4 of the way through, and extended the cut around to the other end, to work at it from that end. At least the cut is straight! The Ryobas I've used never seem to have enough set to cut through a wide board. Two or three inches is fine; but get to five of six, and it is a problem. This one cut straight, but is just not nearly aggressive enough.

Ten minutes, and it is only down this far. It took 45 minutes to free it up.

I've thought about buying the frame saw from Highland Woodworker http://www.highlandwoodworking.com/classic400framesawwithturbocutblade.aspx
I already have the narrow blade. I could use it to cut out the cello plates. I doubt my coping saw is up to the task. I don't know how the wide blade would be for rip cuts, and it would only have about 3-4 inches of travel. It also has 15 teeth per inch, so I'd probably be cutting sawdust.

OK, I've just thought of something. Was that a real rip cut? I know it was with the grain, but it was across the grain as well, as I cut across the quartered wood. The blade has 5 teeth per inch, but doesn't feel aggressive at all; you have to push it.

Any suggestions?

New way to work

I am going to try a new way of finishing up an instrument. I think it will be more like the original way they were made. I have the plates finished on the inside, and mostly finished on the outside, except for the edge work. I made maps of the thicknesses so I don't have to try to remember where some low spots are, and will glue them up, and tune them from the outside as a unit. Seems reasonable to me. We will see how it goes. This is what I have on a violin, and a viola that I'm trying this on. First the viola:

It is the model I drew up that is in between a Gagliano cello, and a Gagliano violin. It looks like a Grancino. As such, I gave it a thick center 7.5 mm, and the wood seems to like it. I wrote the free plate tap tones on the chart as well. I can keep the charts for my referance, and note areas where I took stock off after gluing up, and maybe the tap tones when glued up, and then after tuning. The belly has no bass bar yet. The archings are very low, 16.5-17 mm. Like a del Gesu viola.

The other is a del Gesu violin. The belly is very stiff, even at 63 grams and no bass bar. The back seems fairly stiff as well, and has a maximum thickness of 5.1, but I cn't get a real ring tone out of it. Maybe an Eb.

This one I didn't put the purfing in, or the undercut. Besides in the corners, there really isn't much of a recure in it. The edges are quite thin, and just a scant overhang, I'll do the purfling when it is assembled. It won't be exactly Cremonese; I won't nail the neck on first; but the procces should be close to what they did.

Today I cut two bass bars, trimmed them close to size, and glued the little guides for fitting them. Took about an hour. I found an easy way to rough the bottom out. Clamp a board on the belly so the bar will lay flat on it when in the right spot. Mark the bottom with a washer, and trim. Do it again and it makes a mark on the shallow del Gesu. Remove the board, and place it the other side, and mark it the same way. Trim both sides to the same distance from the line, and you are close enough to start chalk. The viola needed two roughings, and then both side. Really easy. I also found that the extra length of the bar was easily sawn into guides. Why didn't I think of that before.

Tomorrow I'll start fitting.