Cellos are bigger. You would think that I knew that right off the bat. I did notice that, but I didn't realize what it might mean. My back needed to be sawn, and that didn't go too bad. It cut straight, and even on both sides. The problem is that the outside of the board was only cleaned up in the middle from the plane, and the ends were still rough. I didn't think about how much off they were. I'm going to have to glue some shims on the ends of the back on the gluing surface to get it so they don't rock, and then we'll see if I need to do more after they are joined.
I'm trying for a 24 mm back. That's what I figured I could get out of the stock. It will go with a 27-28 mm belly. The pieces will make it, but only with the doubling. I guess that is the proper term for my wedgelike shims. If this happened on a violin, it would be an easy fix. Rub it on the diamond dust wheels that I have, and see where the low spots are, and glue on some stock. The cello back is not that simple. I don't have anything that big to grind it on, and it is hard to hold it in a way that keep s it flat all the time. One side I only needed doubling on one side to stop the rock, and the other needs it on both ends. Hopefully the ones I have glued on now will be enough so I can join them tomorrow after the glue dries, and I flatten them out.
I'll show pictures when I'm done.
I'm putting the purfling groove in the del Gesu violin today. The plan for it and the viola is to glue the belly on the ribs. Cut the recurve and tune them. Get the mortice cut, and get the neck set and glued in, and then glue the back on. I will cut the recurve, and tune the backs on my boards I cut out.
I'll have to get the scrolls done; I never did finish them, and rough out the radius by the botton on them.
And then they will only need to be strung up and tested, and then get finished off with some varnish.
how much lower than 24mm can you go before you realize it won't work as a cello back?
ReplyDeleteHow much easier is it to set the neck without the back vs setting the neck into a complete box?
ReplyDeleteAh, how low can you go? I think I can add thickness to the center to counteract the flatter arch. 8-9 mm in the middle doesn't bother me at all. Even 10 if it worked. The bouts can still be normal. Don't you think?
ReplyDeleteYes I think Ken, I did the same on a back for a violin and ended up losing 3-4 mm heightwise. I'll make it work but it will make me think more while working it. You could say I was hinting that your cello arch height may not come out as you would like it to. It seems you way of setting the neck before the back offers more precision. How much does the neck block move when clamping the back? I guess that won't matter because the fingerboard hasn't been made yet.
DeleteAs for the neck; I have never done the neck with a back on. It just seems so ridiculous to do that. I can saw the sides pretty close, and I know they will be straight. I can slide the neck in , and be sure it fits perfectly. I can cut, and plane the bottome flat with the ribs, I don't have to guess. I can put the back in place, and markt the button out, and then finish the heel before gluing it in. I can glue the neck in place, and use a clamp from the heel to the block if I feel like it. It usually fits so good I don't bother with any clamps at all. Why complicate things by having the back in the way?
ReplyDeleteI should add that I have a pin in the back so I'm not moving the neck block around while gluing the back on. That , I'm sure, would cause trouble.
ReplyDelete