'evening gents!

All good food for thought. I'm curious though whether a sheet of 1/16 balsa laminated with 1/32 ply weighs more than a sheet of 3/32 balsa once lightened. The 1/32 ply wouldn't necessarily have to run the length of the fuse it could stop just aft of F3 as in the Picorare plans.

In any event, I made some back of the envelope calculations to see how the wing loading changes for different models. Given this thread is about the Nanorare, I'll take some license to post some details on 15 size models - the T10 and the D10. Here are some figures:

T10 (Picorare)

Span: 40"
Mean Wing Chord: 6.56"
Wing Area: 262.4 sq in = 1.822 sq ft

Wing loading @ 28 oz AUW = 15.4 oz/sq ft
Wing loading @ 36 oz AUW = 19.8 oz/sq ft
Wing loading @ 40 oz AUW = 22.0 oz/sq ft

D10 (Deception)

Span: 40"
Mean Wing Chord: 7.71"
Wing Area: 308.4 sq in = 2.142 sq ft

Wing loading @ 28 oz AUW = 13.1 oz/sq ft
Wing loading @ 36 oz AUW = 16.8 oz/sq ft
Wing loading @ 40 oz AUW = 18.7 oz/sq ft

From these figures it would seem reasonable to conclude that the upper weight limit for the T10 should be no more than 36 oz and for the D10, 40 oz. In order to keep the wing loadings under 15 oz/sq ft the targets would be 27.3 oz for the T10 and 32.13 oz for the D10.

Andy, perhaps these figures will help in the project although I'm sure design programs spit this stuff out ordinarily. Having built what I suspect will be a 40 oz D10, my goal will be to find a way to build a 27 oz electric Pico!

... when I get around to it.

David.