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 Post subject: brace radius
PostPosted: Wed Oct 13, 2010 1:00 pm 
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Walnut
Walnut

Joined: Sat Feb 09, 2008 3:01 pm
Posts: 15
I actually have two questions. First, I was wondering if most people radius the large lateral brace that is just above the soundhole or is it best to glue it on flat? My second question is that after I had glued on all my braces I noticed a very small gap under one little area of on one of the legs of the x-brace. The gap measured .002 and it is about one half inch long. Is this anything to be concerned about? Tell me your thoughts.

Thanks, Steve H.


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 Post subject: Re: brace radius
PostPosted: Wed Oct 13, 2010 2:06 pm 
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Brazilian Rosewood
Brazilian Rosewood

Joined: Wed Feb 20, 2008 7:15 pm
Posts: 7550
First name: Ed
Last Name: Bond
City: Nanaimo
Country: Canada
Focus: Build
Status: Professional
You can use either a flat or a radiused upper transverse, you just have to know how each style will affect how you build the rest of the guitar. I radius mine.
As for the gap I'd be inclined to think it'll be allright.


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 Post subject: Re: brace radius
PostPosted: Wed Oct 13, 2010 2:38 pm 
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Contributing Member
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Joined: Fri Jan 22, 2010 9:59 pm
Posts: 3624
First name: Dennis
Last Name: Kincheloe
City: Kansas City
State: MO
Country: USA
Focus: Build
Status: Amateur
I'm just about finished with my first guitar, and went with flat for about a 2.5" span under the fingerboard extension, and radius down to the border from there. Idea being to leave a flat surface for gluing, but still get some dome for humidity safety and proper geometry for the extension to lay down on the top with the neck set to the proper angle. Mostly going by Cumpiano&Natelson book, although he does a smooth radius all along the brace.

I draw a line along the brace at the arch height I want, and then hand plane until I get down to the line, being careful not to remove any material from the center. Aim for a spherical curve, but the exact curve doesn't matter so much as the total offset distance. Perimeter of the top is flat (jointed sides before bending, glued straight to the top with individual tentellones). 1/8" arch on the X, 1/16" on the upper transverse, which in my case came out to make the fingerboard extension float just a bit above the surface with the neck set for string height 1/2" or a tiny bit less above the top. Probably a good thing, as it will likely lay down flat under string tension, so should be good after flexing it down and gluing. Having it flat now might result in a "ski jump" fingerboard extension under tension, not so good :)


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 Post subject: Re: brace radius
PostPosted: Fri Oct 15, 2010 7:24 am 
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Brazilian Rosewood
Brazilian Rosewood

Joined: Mon Jan 28, 2008 5:21 am
Posts: 4915
Location: Central PA
First name: john
Last Name: hall
City: Hegins
State: pa
Zip/Postal Code: 17938
Country: usa
Focus: Build
Status: Professional
There is more than one way to establish this neck angle but you have to find what works for you. I have a video on you tube to show how to set the geometry on the side set . There is no one right or wrong way as long as the process you find works and is repeatable . Getting this part right makes the rest fall into place. Get it wrong and you will be working harder than you need to . It is the details that make the build .

http://www.youtube.com/results?search_q ... ing+3&aq=f

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