Hi all, i was just fixing and recovering a wing i've built as an experiment several years ago and thought i'd share her in case anyone is interested.

The wing is 21" and built from balsa LE, TE, and spars with heavy duty Hefty plates as ribs and tip formers. I've had lots of flights with this wing in the past and it's a great performer. I just got back into flying this year, and i'll cover and get it back in the air soon, i'm just waiting on a micro ESC to finish the build.

Great to see you back, Rusty!

Foam ribs make a lot of sense, as the loads in them are minimal.

Andy

Built up foam and balsa ?

Been doing it for years, just some of them --- Single post from a thread on foam wings

Ray.

I've used (depron?) foam salvaged from grocery meat packaging to make ribs on several .40 size planes without any issues...... I did use balsa leading edge sheeting and balsa cap striping aft of the spar both for stiffening the wing and not limiting my finishing choices....... with a thin scalpel blade and ply or formica rib pattern the ribs are easy to knock out.
I once made a Quadra size plane wing using foam core poster board and that worked out well also.

I agree that the ribs are probably the least stressed elements of a wing. A reasonable place to use a lower cost substitute if you want to.

There was a builder/manufacturer a while back who used 1/2" or thicker foam ribs for a light weight build.

Michael in Ontario, Canada

Originally Posted by Rusty Mustard

................... heavy duty Hefty plates..........................

What are these?
From the pictures, they look like Depron.

I have been building with foam ribs for the last two models I have made. The blue foam is slabbed out to the required thickness depending upon the model size, hot glued to a building board at the required spacing, and the top hot wire cut all together.
Top spars are glued in. Then the whole assembly is cut off (bottom airfoil cut), flipped over and the bottom spars fitted.
Very good method: quick and easy.
I have a video on Vimeo that I can link if anyone is interested.

Jim.

Originally Posted by 2michaely

I've used (depron?) foam salvaged from grocery meat packaging to make ribs on several .40 size planes without any issues...... I did use balsa leading edge sheeting and balsa cap striping aft of the spar both for stiffening the wing and not limiting my finishing choices....... with a thin scalpel blade and ply or formica rib pattern the ribs are easy to knock out.
I once made a Quadra size plane wing using foam core poster board and that worked out well also.

I agree that the ribs are probably the least stressed elements of a wing. A reasonable place to use a lower cost substitute if you want to.

There was a builder/manufacturer a while back who used 1/2" or thicker foam ribs for a light weight build.

Michael in Ontario, Canada

Maybe around 20 years ago there was a manufacturer here in San Antonio named Precision Built, it was owned by Mr. Ralph Brogdon, all his giant scale aerobatic aircraft kits were designed with .500” thick blue styrofoam ribs and his airplanes held up very good. I owned both his 1/4 scale Extra 260 and his 1/3 scale Laser 200.

Bob

There are some full size ultra light aircraft that use foam ribs.

Originally Posted by Jim.Thompson

What are these?
From the pictures, they look like Depron.

I have been building with foam ribs for the last two models I have made. The blue foam is slabbed out to the required thickness depending upon the model size, hot glued to a building board at the required spacing, and the top hot wire cut all together.
Top spars are glued in. Then the whole assembly is cut off (bottom airfoil cut), flipped over and the bottom spars fitted.
Very good method: quick and easy.
I have a video on Vimeo that I can link if anyone is interested.

Jim.

"Hefty" is a brand, and they make styrofoam food plates. Their "Heavy Duty" plates are basically just really dense, stiff and thin versions of plain old foam plates. I just looked it up and it looks like they call that product "Deluxe" and their plastic plates are "Heavy Duty" now.

These plates actually have a VERY THIN lamination on them, i think as a moisture barrier, and are about as stiff as balsa, if the 'Deluxe is still the same kind of product, i built this wing years ago and that's what i used.

Link your video, i'll check it out, i was thinking of doing something similar.

Originally Posted by Rusty Mustard

"Hefty" is a brand, and they make styrofoam food plates. ........................

Glad I asked! Who would have guessed?

Link your video, i'll check it out, i was thinking of doing something similar.........................

Video of top cut only. I will do more during my next build..............I promise!..............

https://vimeo.com/manage/390663316/general