Devfus foam

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Vigilant1

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It would be a shame if some acetone hit that EPS left behind and you ensured a path for the resultant liquid mess were made to ensure it dripped out...

😉
I think the squirrels might make less mess, even if they raised 3 generations of squirrel pups in those wing rib bays. :)
 

berridos

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Are chordwise tensions strong? Arent chordwise tensions solved by the skin?
 

stanislavz

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Example for d nose. You cut you d nose mold from eps, mold some composite inside between two foil, remove internal foil, and put currugated ribs preformers. And mold rib. Outside caps in image. Minus - it will need a vacuum bag to hold it..

Or you wrap you corrugated ribs former with composite, and use it as a clamp and former. Inside caps. Remove eps with local mouse of you choice. Or acetone. Or just wrap it with strech film..

For both solutions you need extra temporary formers at you future spar place, to ensure correct placement of rib chord vise.

Pluses are: only wet/dry bonds, no extra glue, no extra time for mold preparing.

And minimum cutting and sanding
 

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stanislavz

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Are chordwise tensions strong? Arent chordwise tensions solved by the skin?
I think we have different terminology. In foam ribs - caps are around rib, at it perimeter. Working only in tension/compression. On no foam rib - you replace foam with 45/-45 composite with corrugations.
 

berridos

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Shouldnt the corrugations by from top to bottom of the airfoil instead of chordwise as i think i interpret form your picture?
 

stanislavz

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Shouldnt the corrugations by from top to bottom of the airfoil instead of chordwise as i think i interpret form your picture?
What for ? They are to divide shear field and protect against buckling.
 

Vigilant1

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Shouldnt the corrugations by from top to bottom of the airfoil instead of chordwise as i think i interpret form your picture?
FWIW, I too expected the rib corrugations would be up-and-down. When I've seen stiffeners in metal ribs of stressed skin aircraft, that's the way they are oriented.
What for ? They are to divide shear field and protect against buckling.
As I understand it, the ribs are there to prevent the skins from buckling. They can do that best if they prevent the skins from moving to or from the airfoil's mean chordline, keeping the top and bottom skins exactly the same distance apart (like a spar web). If the corrugations are chordwise, the rib "accordion" can open and close in response to skin pressures on the large flat areas of the wing surfaces in the middle of the airfoil, reducing the rigidity of the wing.
Things would be different if we had a non rigid fabric skin and the ribs were gathering all skin forces and transferring them to the spar. In the case of a stressed skin, I believe the skin does that . .. if skin buckling is prevented by the ribs.
I could well be in error.
 
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