Carbon Tube Fuselage?

[tschwartztm]

Has anyone considered utilizing carbon fiber tubes for the main fuselage?

 

[mcrae0104]

Well there are some obscure companies that have played around with it. I think they were called Boeing and Airbus maybe?

Or do you mean substituting carbon tubes in something like a cub fuselage? Search for "black aluminum" here at HBA and you'll probably find something on that.

 

[tschwartztm]

Thinking about my Sonerai project that’s all steel currently. I want to do a rudder enlargement without adding a ton of additional weight. My thought was to utilize carbon fiber wound tubes.??

 

[mcrae0104]

Hmm, possibly you could make the rudder lighter by substituting CF tube for 4130 tube. But you might make it lighter still if the construction were optimized for the material (i.e. thin CF skins and a few very light stiffening ribs). Just spitballing.

 

[BJC]

Has anyone considered utilizing carbon fiber tubes for the main fuselage?

See https://www.homebuiltairplanes.com/forums/threads/carbon-fiber-tube-fuselage.34683/#post-563131


BJC

 

[Rob de Bie]

Has anyone considered utilizing carbon fiber tubes for the main fuselage?

15 years ago, I worked a UAV that a single large diameter carbon fiber tube as the 'fuselage'. I was slightly shocked when I found out that this commercially produced filament-wound tube only had +/-45 degrees and 90 degrees (hoop) fibers, no 0 degree fibers. Therefore the bending strength and stiffness were quite low.

I'm not sure whether you meant this, but nevertheless it's a warning that the tube layup of commercial products could be very different from what you would expect.

Rob

 

[Mr.T]

15 years ago, I worked a UAV that a single large diameter carbon fiber tube as the 'fuselage'. I was slightly shocked when I found out that this commercially produced filament-wound tube only had +/-45 degrees and 90 degrees (hoop) fibers, no 0 degree fibers. Therefore the bending strength and stiffness were quite low.

I'm not sure whether you meant this, but nevertheless it's a warning that the tube layup of commercial products could be very different from what you would expect.

Rob

There are number of Filament winders that make wound tubes with up 90% true 0° layup , so its not a limitation anyore

 

[CdnMedic]

Hmm, possibly you could make the rudder lighter by substituting CF tube for 4130 tube. But you might make it lighter still if the construction were optimized for the material (i.e. thin CF skins and a few very light stiffening ribs). Just spitballing.

Sonerais apparently tend to be a bit nose heavy as it is. Plenty of people have enlarged the tail with 4130.
Currently building one, enlarging the tail and I'm even expecting to mount the batteries in the back.

Not sure how you would integrate carbon fiber tubes to the 4130 either.

 

[CdnMedic]

Hmm, possibly you could make the rudder lighter by substituting CF tube for 4130 tube. But you might make it lighter still if the construction were optimized for the material (i.e. thin CF skins and a few very light stiffening ribs). Just spitballing.

I've looked at skinning my Sonerai project with composite, it's tempting, and I don't mind composite work, but fabric and paint is still lighter.
I wanted to make a removable shell, like a sno-sho. Doesn't seem worth it on a Sonerai.

 

[Victor Bravo]

I've looked at skinning my Sonerai project with composite, it's tempting, and I don't mind composite work, but fabric and paint is still lighter.
I wanted to make a removable shell, like a sno-sho. Doesn't seem worth it on a Sonerai.

Agreed, likely not worth it.

The time, cost, and effort of making composite shells... light weight ones... is going to take a lot of time, money, and enjoyment away from your flying. If flying is the priority, then you might do a cost/benefit analysis.

If you have something else to fly, and/or if a large part of your aviation enjoyment comes from the experimenting and fabricating and developing... then that of course favors the composite shells, have a blast.

But I will guess your Sonerai may not have any better overall performance with the shells (weight gain cancelling out drag reduction).

 

[Airplume]

In France, an individual built a seaplane, the Agrion, (not quite finished) made entirely of carbon tubes.

The landing gear is retractable, the hull and stabilizers are under construction.

I don't have a global view of the plane due to a problem with my camera's memory card. But you will find photos and information on the manufacturer's website :
https://ulminimalist.sitew.fr/Projet_final.C.htm

 

[mcrae0104]

Using carbon fiber that way reminds me of architect Lou Kahn, who said this about using materials according to their nature:

"You say to brick, 'What do you want, brick?' Brick says to you, 'I like an arch.' If you say to brick, 'Arches are expensive and I can use a concrete lintel over an opening. What do you think of that, brick?' Brick says: 'I like an arch.'”

I have a feeling carbon fiber would say, "I like a sandwich."

There's about three minutes of discussion here from 14:52 on that I think relates to this use of carbon fiber.