The 'three inch rule' for scallop peaks - O'Brien

Wood choice logic, brace shapes, braces patterns -- what and why for the "heart of the guitar"
Herman
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Re: The 'three inch rule' for scallop peaks - O'Brien

Post by Herman » Thu Jun 04, 2015 11:18 am

You lazy Bagwill! Give me a moment.

Herman
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Re: The 'three inch rule' for scallop peaks - O'Brien

Post by Herman » Thu Jun 04, 2015 11:24 am

Here I drew the position of the upper tonebar, according to what Arnold wrote.
(Explanation for lazy Dave: It is the black line, you have to look for)

Image

Dave Bagwill
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Re: The 'three inch rule' for scallop peaks - O'Brien

Post by Dave Bagwill » Thu Jun 04, 2015 11:35 am

I would thank you, but I'm too d**n lazy....
-Under permanent construction

Herman
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Re: The 'three inch rule' for scallop peaks - O'Brien

Post by Herman » Sat Jun 06, 2015 8:41 am

No one an opinion about this early tonebar position?
Seems to me it weakens the lower bout. Less resistence to raising behind the bridge.

ken cierp
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Re: The 'three inch rule' for scallop peaks - O'Brien

Post by ken cierp » Sat Jun 06, 2015 9:47 am

The "X" intersection on those older Martins was much closer to the sound hole -- about an Inch.

ken cierp
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Re: The 'three inch rule' for scallop peaks - O'Brien

Post by ken cierp » Sat Jun 06, 2015 9:57 am

I am not sure of John's exact measurements for that specific year and model but you can look here and see that the tone bar angles on the pre-wars were different than the modern "D" --- Don't forget that the reason Martin changed the design was indeed to reduce failure incidence -- not to improve sound quality.

http://www.cncguitarproducts.com/templa ... encil.html

Herman
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Re: The 'three inch rule' for scallop peaks - O'Brien

Post by Herman » Sat Jun 06, 2015 11:08 am

Sorry Dave, a bit off topic, but:
Did they change those things also in OO models?
I ask, because my new "customer" wants a foreward shifted X on his OO 12 fretter.
Herman

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