New Cherry/Sitka Terz shape

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Dave Bagwill
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Re: New Cherry/Sitka Terz shape

Post by Dave Bagwill » Fri Mar 30, 2018 8:33 pm

Yep it works well as long as one doesn't get the tips of the blade above the table top, or one will get a little bead on top of the radius. One learned that the first time he tried it. :oops:
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Dave Bagwill
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Re: New Cherry/Sitka Terz shape

Post by Dave Bagwill » Sat Mar 31, 2018 10:14 pm

Today I took the first side out of the clamping form - all good, just right. So I stuck the second side in for gluing and will let that cure overnight.

Headblock - I marked the channels for the a-frame and cut them on the bandsaw, then cleaned them up with a chisel, then cut a couple of 1/4" x 1/4" braces to fit into the channels and laid the block and braces on my drawing to make sure it was right.

I liked the look of Lowden's rounded corners on his headblocks, so I scribed an arc on each side of the block top using a high-tech device called a 'washer' ;-). Then trimmed off the sharp edges of the block on the band saw, just to give me less sanding to do, and used a 16" radius sanding block (thanks KenC) to put a slight radius on both sides of the block and then sanded the curve smooth on the belt sander, then by hand. Did much the same thing on the tailblock.

And that's about all I got done today. Lazy bones. But everything is coming along nicely thus far.
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John Parchem
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Re: New Cherry/Sitka Terz shape

Post by John Parchem » Sun Apr 01, 2018 4:22 am

I like how the braces tie into the heel block. The rounded blocks look good as well.

Herman
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Re: New Cherry/Sitka Terz shape

Post by Herman » Sun Apr 01, 2018 4:51 am

Dave,
Why all the work making solid linings?
Is it cheaper then buying kerfed ones, or do you like the looks?
Herman

Dave Bagwill
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Re: New Cherry/Sitka Terz shape

Post by Dave Bagwill » Sun Apr 01, 2018 11:50 am

H - I'm not the only one! John Parchem, Kevin, John J ( think) and others also use/have used solid linings. They make for a very stiff structure, and the sides become rigid enough to not impede string energy.

They are cheaper, as well, but that's not a big deal, really.

Of course: 199,245,624,001 guitars have been made with regular kerfed lining and most turned out just fine. ;-)

Others may want to chime in on this.
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Dave Bagwill
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Re: New Cherry/Sitka Terz shape

Post by Dave Bagwill » Sun Apr 01, 2018 3:12 pm

Bogdanovich:

"Reasons for Laminating Guitar Sides and Linings
-Stiffness – The most important characteristic for guitar sides is stiffness. Laminating the sides of your guitar will produce stiffer sides than a solid piece of wood that is steam bent.
-Repeatability – Steam or heat bending is difficult to repeat accurately and is time consuming. Once the mold is created laminating sides is pretty quick.
-Consistent Shape, Box Volume and Resonate Pitch – Laminating assures a consistent shape and box size from guitar to guitar. If the shape of the guitars sides differs from guitar to guitar, the amount of volume (cubic inches) inside the box changes, and its resonant pitch as well. This may result in inconsistent results acoustically.
-A Way to Bend Un-Bendable Wood – Laminating may be just the trick for bending wood that will break if you try bending it at full thickness with heat. After wood is thinned down to .060 – 070″ it becomes easier to bend without breaking and may be just the solution.
-Sides without Tension – Building any tension into the instrument is also something to avoid where ever possible. This will extend the life of the instrument. Using turnbuckles or other clamping devices to maintain correct shape of the sides during assembly will build unnecessary tension into the instrument. Laminated sides are locked into the correct shape and no force will be necessary to keep them that way.
-Less Weight – If you laminate using the materials I recommend you are removing a heavier wood and replacing it with a lighter wood which will reduce the weight of the instrument. So you have a lighter guitar that is stiffer. Ideal situation for a classical guitar.
-Increased Stability – Laminated sides will be more stable. There will be almost no movement with humidity changes hence less prone to cracking."

After reading this and the like from other top notch luthiers, I just decided to do it.
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Herman
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Re: New Cherry/Sitka Terz shape

Post by Herman » Mon Apr 02, 2018 11:27 am

Ok , I see, Thanks D.
This shows there are several ways to do build.
I stick pigheaded with my way that works for me. I like to struggle with unbendable wood. It is a kind of war that I like to win. Never had collateral damage like cracks.
Herman

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