Badland Carbon Fiber F5 Fujita?

[Badland-F5 Pilot]

How about not only a titanium Badland F5 Fujita, but also a carbon fiber rod framed F5? With the connectors this company uses with their carbon fiber rods, I think it would be possible to build a frame. Take a look at this and let me know what you think about the idea?

https://www.youtube.com/watch?v=opdxeUMiYS0

It would certainly be super light. As light as the titanium F5? I don't know, but it sure would be interesting to see what could come from it.

[Kaveman]

I just spent way too much time writing out a reply to this rather old question, and then my phone deleted it. So here's a shorter version, just to try to get the discussion going.

A younger me would absolutely use carbon fiber tubes to build something like a quick silver. After an unknown number of hours, if it was holding together well, I'd try for something like an Airbike. Kinda work my way up in sophistication, so to speak. The big issue I see with "Dragon Plate" is that the rod to rod connectors make for lumps, which would make skinning the Badlands a PITA. Not to say it can't be done. Heck, someone should get on it, Carbon Fiber and Ultralight Aircraft are a relationship that's destined to happen, the problem is cost. A carbon UL would likely cost double the F5. Also, carbon fiber is arguably more suited to monocoque construction, rather than tube frame, so maybe a Carbon Merlin Lite?

[Badland-F5 Pilot]

I just spent way too much time writing out a reply to this rather old question, and then my phone deleted it. So here's a shorter version, just to try to get the discussion going.

A younger me would absolutely use carbon fiber tubes to build something like a quick silver. After an unknown number of hours, if it was holding together well, I'd try for something like an Airbike. Kinda work my way up in sophistication, so to speak. The big issue I see with "Dragon Plate" is that the rod to rod connectors make for lumps, which would make skinning the Badlands a PITA. Not to say it can't be done. Heck, someone should get on it, Carbon Fiber and Ultralight Aircraft are a relationship that's destined to happen, the problem is cost. A carbon UL would likely cost double the F5. Also, carbon fiber is arguably more suited to monocoque construction, rather than tube frame, so maybe a Carbon Merlin Lite?

I think you may be right about carbon fiber for something more like the Merlin Lite. The concern I have is that carbon fiber has more of a tendency to break when it reaches its max stress, where metal (aluminum, titanium...etc) seems to have more give. Your thoughts?

Todd

[LA F2 Flyer]

Hmm...Why rod rather than tube? I believe the video stated that carbon rod was 1/3 the weight of an aluminum rod...but an aluminum rod of a decent diameter for UL construction likely isn't all that light. Of course that presents the question of "what diameter should it be?".

As for the covering, Oratex would have no problem shrinking around the fittings, but it would certainly be a bit more unsightly than the legacy welded frame.

And yes, I'd rather have my aircraft bend a little than have it shatter.

[Kaveman]

Oh Lord, here we go. Steel, aluminum and titanium and in fact most metal alloys, are "mixed" to a certain formula, governed by industry standards. No such standard exists for CF. Breaking that down a bit further, there's nothing dictating, exactly, the formulation of the fiber itself, and it's purity. Then there's about a zillion different epoxies and glues to soak the stuff in. This makes looking at the Young's Modulus charts of the stuff as meaningless as a topographical map of an alpaca.

As common place as Carbon Fiber has become in our bold new world, it's actually more of a since experiment in action than a standardized material, common and similar across industries. I can say that I found a number of YM graphs showing exactly what you describe, essentially a sudden complete failure. For our uses, it would be great, right up to the point when it becomes a debris field looking for a location to settle down.

Couldn't find much info on fatigue, or flexibility, but I know it's really only a super material in tension, that's why it has to be oriented in different directions and layers for optimal strength. As a finished material it doesn't deform well. For example, a dent in the door of my old Ford could be pulled with a toilet plunger, a dent in our proposed CF Merlin Lite, is actually a just an incomplete hole, since in order to make the dent, fiber had to tear/break. To affect a repair, the damaged section must be cut away, back into "good" material, and then the surface prepped and patched. The area will never have the integrity and strength before the damage. This could mean that a minor oopsiedoodle that would take a few hours drinking beers with a friend to fix on your Merlin, could be a completely trashed airframe for a CF Merlin. There's some nightmare fuel for anyone with a CF aircraft!