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Anyone have any idea what kind of radius the back of a stauffer / austro-german martin would be?

I have the plan from stew mac but it is not written on it... i can tell it is smaller than 15' as my 15' template does not match up.

Any help would be great.

Best.

G.

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www.leddingtonguitars.com

I did a quick measurement on a couple of old German guitars from that period. Laying a straight edge across an 11 1/2 inch wide back the gaps on either edge measured about 1/4 inch.

Thanks... now the question is how to figure out what radius that translates as.

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If you are less concerned about having a circular curve and go with a spline curve you can just bend a thin batten 1/4 inch below a line drawn through two nails spaced 11 1/2 inches apart. Although it won't tell the radius it will give you a curve that the wood will conform to more easily and minimize problems with end point stiffness.

Using those figures I have just drawn it in Autocad and the measured radius is 1682mm or 66.22" or 5.5ft.

For those interested i found this - https://www.mathopenref.com/arcradius.html

Using this and measurements from the plan i found it to be 8.7ft.

Thanks for the help guys!!

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www.leddingtonguitars.com