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Progress on Phil Lardner's All-carbon CD? 02 Nov 2019 10:24 #1264

I think the skin on the original is structural.....there are nose skid loads, tow hook loads, on a cantilevered forward assembly......


No - the pod skin on the prototype was just a single layer of doped Dacron cloth (same as the wing skins.) Ultra light... and ultra fragile! All the loads were carried by the carbon tow reinforced wooden frame. The foot-launch doors were made a bit sturdier (out of plywood and spruce strips)which gave the pilot a little more protection from sticks and stones when landing.

I agree with you on using kevlar in the pod skin - carbon is too brittle and dangerous to be used on its own. The Swift uses a blended carbon/kevlar twill weave in its pod skin, which seems to work well. I saw one badly damaged (after coming down under its rocket parachute in dry, spiny pine trees in Italy this summer - the pilot was eventually lowered to the ground by the fire brigade without so much as a single scratch. His Swift didn't fare so well - damage to one leading edge and both winglets, and a badly damaged pod skin. The mixed weave carbon/kevlar did its job and there were no sharp carbon shards.

I'm also thinking about incorporating pultruded carbon rod into the pod skin as an option for carrying the loads instead of aluminium tubes. Early days for this thought process!

Phil.

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Progress on Phil Lardner's All-carbon CD? 02 Nov 2019 10:34 #1265

Hi Don,

I haven't come across "Hat/Omega" reinforcement before - can you elaborate or point me to a description and/or demo video?

Is it just composite/fiber encapsulated xps foam framework? Definitely an option, f that's what it is.

Thanks,

Phil.

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Progress on Phil Lardner's All-carbon CD? 02 Nov 2019 13:00 #1266

Hi. Yes. In big boys world it is like this one :


In smaller world like that one :
(working, but quite ugly to me)

And here is my variant:


http://www.fao.org/3/t0530e/T0530E08.htm

Non structural foam, placed each 150-250mm as longerons + former each 400-600mm. With as thin skin as possible. Kind of tube and rag structure. But from composite..

Longerons could be made in one single step, even without flow media under foam. Formers - i do not know. Will have to give it a try.

+ spray glue for dry stacking all frames / fiber.

Here is more on reinforcement fiber placement:

https://eprints.usq.edu.au/32695/1/JCOMA-16-364.pdf

+ have somewhere a video with boat hull with longerons on infusion process.

One goodie : http://antrimdesign.com/put-on-a-black-top-hat.html

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Last edit: by stanislavz.

Progress on Phil Lardner's All-carbon CD? 02 Nov 2019 16:58 #1267

Phil Lardner wrote:

I think the skin on the original is structural.....there are nose skid loads, tow hook loads, on a cantilevered forward assembly......


No - the pod skin on the prototype was just a single layer of doped Dacron cloth (same as the wing skins.) Ultra light.
Phil.


oops when you get old your mind plays tricks

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Last edit: by Don B.

Progress on Phil Lardner's All-carbon CD? 10 Nov 2019 12:41 #1268

Hi all. Some off topic. Got an steal deal on 300gm2 carbon fibre 45/-45 biaxial . 5gbp per kg.. Will take 100kg for myself. Can take more. Or share..

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