Back radius

Does anyone know what the back radius is on a Georgia Luther supplies 14 friend Tenor ukulele plan.

It's a 3/16 rise across the 8 5/8” width of the lower bout (which an online arc tool says is a 5’ radius). I can’t tell for sure from the PDF if it's the same radius longitudinally but it might be. I had difficulty nailing the contour with a plane and elected to use a 15’ radius dish, which was the shortest I could get my hands on. I kept the same body depths at the heel & neck ... .it's a bit flat but sounds good.

That’s exactly what I did I used a 15 foot radius this I made six of them that way and they all sounded Good but not as loud as I would’ve liked Thank you for the info.

I was wondering something similar, looking at the Grellier Martin Soparano plans. The back appears to arch way out in the drawing. However, using the common 10 - 12 foort radius, it would not arc nearly as much. By my calculations, a 10 foot radius would only cause about a 1/32 of an inch dome on an approx. 6 inch wide back.

For what it is worth, I use a 7 foot compound radius on my tenors and there is a noticeable arch at the lower bout.