Can I use different material for stringers?

[LuckyFox]

I bought a kit that is missing the stringers. It’s a IV 1050 and the original stringers are supposed to be wood, but I noticed the new kit looks like they use aluminum. Could I use aluminum instead of the wood and what size tubing is it?


Thanks
Robert

[alexM]

Are you talking about the wings or the fuselage? The wing ribs are different. The newer style ribs have round holes for the 3/8" tube (0.028" wall if I recall) in place of the D shaped wooden moulding of yesteryear.
I'm guessing it's possible to create some plywood shapes to fill the gap. Be really careful about what that does to your false rib position though.

True story: I attempted to source that aluminum tube at my local Metal Supermarkets, just like I did for my fuselage stringers. I got a case of sticker shock when my quote came. It turned out ordering it from Kitfox and paying the trucking company was still way cheaper (dang near half if I recall) than my local will call.

[LuckyFox]

Stringers for the fuselage is what I need I believe the original was a hard wood.

[alexM]

Gotcha. I can't speak for the series 4 but the 5 had a wooden stringer on the belly and aluminum on the sides (and several cross pieces which have since been done away with).

Using the aluminum on the bottom required no changes. Those side stringers are 1/2" 6061 with 0.028" wall.

[LuckyFox]

Thank you!!

[taff]

On the IV I built, that came with wooden stringers, all around.
Sides, belly and wings.

Maybe contact Kitfox, they may still have them.

[motortommy]

I have the same question. Stringers are not structural (to the airframe),but certainly help regarding nice appearance of covering and have to handle cloth tension, am I right?
Therefore my plan is to replace welded in steel stringers (previous expert ) on my project IV with full length 1/2" carbonfiber tubes, because of availability...
Any concerns?

[Maverick]

On the IV I built, that came with wooden stringers, all around.
Sides, belly and wings.

Maybe contact Kitfox, they may still have them.

As I was building my current V, I did not recognize that I had the wooden stringers stored away so I contacted Debra about getting some. She told me the no longer furnished wooden stringers and to use aluminum tubing like the current model and further suggested that I buy the aluminum tubing locally rather than buying from Kitfox Aircraft due to the low cost of the material and the high cost you would pay for them to ship it to you. I did find the tubing locally but, then as Murphy would have it, I found the original wooden stringers.

[taff]

As I was building my current V, I did not recognize that I had the wooden stringers stored away so I contacted Debra about getting some. She told me the no longer furnished wooden stringers and to use aluminum tubing like the current model and further suggested that I buy the aluminum tubing locally rather than buying from Kitfox Aircraft due to the low cost of the material and the high cost you would pay for them to ship it to you. I did find the tubing locally but, then as Murphy would have it, I found the original wooden stringers.

Murphy is good sometimes, buy him a drink :^)