Official Luthiers Forum!

Hi Guys,

I'm making the workboard by the instruction from the book Guitarmaking by Cumpiano. I can not figure out how to calculate where the center of the sound hole comes.

I'm making a steel string Grand Auditorium Model. Any help on this is appreciate.

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Building my own grand auditorium steel string guitar.

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Decide where you want the top edge of it in relation to the fingerboard end, and put the center half the diameter down from there.

No set rules on the fingerboard relation. Classicals usually have it around half way between the 18th and split 19th frets. Steel strings, anything goes. I tend to prefer the soundhole up high, with the fingerboard end length on the short side. Some people have large expanses of fingerboard wood past the last fret, or a space between the fingerboard end and the soundhole.

Here's one where I put the soundhole edge under the 19th fret, with a very short fingerboard end overhanging the soundhole. Hopefully the short end length won't result in chipping if that last fret ever has to be pulled...

Off topic, but that is THE COOLEST rosette in the history of guitar-making, Dennis!!

Red on black, venom lack; Red on yellow, killer fellow.

....errr...Red-bellied black snake?

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

Most 14 fret necked guitars have a sound hole centred at 5 7/8 or 6 inches, from the top of the body where the neck joins (ie, the 14th fret !!!), on the centreline

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

I was thinking a coral snake:

https://www.google.nl/?gws_rd=cr&ei=Oab ... oral+snake

...still sounds fairly nasty!

I was working in the tool shed the other day and saw the tail of a diamond python just about to disappear under the eaves into the roof of the house. I grabbed it and started pulling....

10 feet later....

Back on topic, the center of the sound holes normally turns out to be pretty close to 6" from the top edge of the upper bout. If you don't get an answer close to 6", have a long think about things and make sure you got your sums right.

And yes, Dennis, nice rosette!

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

The upper part of the X braces are usually pass around 3/8" from the edge of the sound hole. Pencil out where your X braces will be and where the finger board will end. Then you can cut out a paper circle that's your sound hole dia. and position it where it looks right to you. The braces are the only really fixed point for the position. The fingerboard is pretty much up to your taste for how close it is to the sound hole.

When I design a bracing pattern, I start with knowing where the end of the FB is, the scale length and where the bridge will go, and its size, draw in the soundhole .. the X brace is then figured out and positioned from there ... using its angle, the edge of the soundhole, and the bridge wings ...

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

Yikes! LOL I'm not sure Australia was meant to be inhabited by simians. Well on the bright side I'm sure you have rats or mice anywhere near your house.

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I've always just based the sound hole location from the end of the fretboard but mostly I just make sure they are at least close to some of the more traditional plans I have.

My method is simple. First I throw darts at the soundboard and I pick the one that looks like the best location. Then I bust out my sawzall for some precision cutting and hammer that thing out. LOL, I do not recommend this method...

Trevor ... 10 feet later .. Dinner !!!! Just not sure for who !!!!

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

About like my pet moccasin down here at the raw water pumping station. He jumps into the water for joy whenever I go down there, LOL. About as big around as my arm. Like to sun on the concrete. I just make a lot of racket to let him know I'm coming.

Edwin: For a 4" soundhole measure 2" from the edge perpendicular to the diameter and you will have the center Sorry the devil made me do it. Welcome to the OLF, the others have given you the correct idea.
Tom

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A person who has never made a mistake has never made anything!!!