Panel compression rib curvatures e.t.c.

[Ron Nossaman]

Hi Dale,

You didn't miss all of it yet, because it hasn't all been posted so far,
but you missed a whole bunch of it. If you don't have better snakes to kill
tomorrow, I recommend cruising the archives for the many, varied, and often
interminable discussions on crowning, ribs, etc. There's a TON of it in there.

I've stuck to Sitka spruce for both panels and ribs, and haven't had any
reason to try anything else. I've thoroughly mutated a scaling spreadsheet
to use for designing rib scales using the string scale. Using calculated
string tensions, bearing loads from specified angles, and assigning ranges
of unisons to individual ribs, factoring in panel expansion lift, I
pre-compute individual rib dimensions and stiffness I want using deflection
and positioning in the scale as guides. I've got it set up so I can change
rib positioning in the scale, width, height, and crown radius and
immediately see the results on a graph. So far, I've found it extremely
useful for the way I do things. I like the strength and stiffness to weight
characteristics of Sitka, and have been able to manipulate rib dimensions
to go in the direction I want to go without throwing in another variable of
different ribbing material. Generally, I try to keep things simple enough
that I can handle them.

You're right, it is interesting that so many versions of re-invented wheels
end up being similar. Too bad more manufacturers aren't doing more
re-inventing of their own. It's surprising what can be learned by breaking
things and pondering on the pieces.
Ron N