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Hello,
When you change the scale length from 660 to 650 do you have to change the size of the body from the original plan?
RonaldD

no. if its an acoustic, maybe the bracing would need changes because of lesser tension in the shorter strings. i wouldn't know about that stuff. other than that, i cant see why the body would have to be changed at all.

Acoustic. Steel string and classical.
RonaldD

It's routine to use different scale lengths on the same body. You generally do want to shift the bracing so it is in the same place relative to the bridge placement.

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http://www.chassonguitars.com

On a nylon string, the fixed point for both scales being the 12th fret, the bridge should be moved further up the body by 5mm (a little less than 1/4"). Nothing worth calling your mother... And on an steel string, assuming it's a 14th fret neck joint, the shift should be even smaller than that. As long as the wings of the bridge sit on top of the X brace, I'd say you're good to go.

But definitly no body sahpe changes...

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

Absolutely right Alain. My last was a 640, and I used exactly the same brace placing, body size and sound hole location and dimensions. Turned out great. Even got a full 19th and a piece of a 20th without obstructing the sound hole too much. I might make some minor changes if I was going to change it much more than that though. Also, it's different if it's a steel string.

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Waddy

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