Last week I marked the curves for the missing top and bottom of the walnut.

Now I am using those puzzle pieces to make the templates for the mid-ship frame. This frame will be 3 layers that look like a donut, glues together. Using 3 layers I will be able to make a very strong single unit close to 11 feet around, from my 4×8 foot pieces of plywood.

Between these 3 layer elements I’ll rout out 1/2 inch rabbets to accept rib supports. These ribs will be radial, instead of the straight horizontal supports in the hemisphere. Good stuff. Very strong, and not a lot of wasted wood. 🙂

So… here is the first step template for the “bottom” of the walnut. You can see the “missing piece” in the center. I save the missing piece so I can unscrew it from this template and use it as a template for the missing piece “bottom” for the existing template.

So… picture….

New Template layer1 (with Dadoes)
Old Template Layer2 (with missing pieces top and bottom)
New Template Layer3 (with dadoes)

Ribs

…then repeat several times.