Filament wound airfoils. (again)

Howdy,

I was channel surfing the other day, and caught a glimpse of how they
make rotor blades for the Hind MI-8 helicopter on RT. (Russian News)
Very Interesting. They use small sections of metal (aluminum?)
honeycomb cut to the shape of the airfoil, align it them with the spar
on the leading and trailing edges, and then filament wind the whole
lot together, preesumably with carbon fiber.

I imagine a simmilar technique might be servicable for experimental
aircraft. paper fiber honeycomb is used as packing material and can
probably be had quite cheap. I was thinking, cut it to form, attach it
to the spar, drown the whole lot in epoxy. Then after it cures
filament wind it to make the skin.

Just a thought.

In article ,
" wrote:

Howdy,

I was channel surfing the other day, and caught a glimpse of how they
make rotor blades for the Hind MI-8 helicopter on RT. (Russian News)

Nit: The Hind is Mi-24. The Mi-8 (9/17) is "Hip".

(NATO reporting names begin with "H" for helicopters, "F" for fighters, "C" for
cargo aircraft, etc.)

le dimanche 5 juin 2011 01:17, s'est penché sur son écritoire numérique:

I imagine a simmilar technique might be servicable for experimental
aircraft. paper fiber honeycomb is used as packing material and can
probably be had quite cheap. I was thinking, cut it to form, attach it
to the spar, drown the whole lot in epoxy. Then after it cures
filament wind it to make the skin.
More difficult than layout carbon fabric and require more tools.

I prefer the basic
1 layer bid 0°/90°,
1 layer biaxial ±45°,
1 layer bid 0°-90° in a simple wood mold

--
http://www.youtube.com/watch?v=1ODCf7J8L0o
Philippe Vessaire Ò¿Ó¬

"Philippe" wrote in message news:2876563.GUn9oUikQW@GastonCoute...

le dimanche 5 juin 2011 01:17, s'est penché sur son
écritoire numérique:

I imagine a simmilar technique might be servicable for experimental
aircraft. paper fiber honeycomb is used as packing material and can
probably be had quite cheap. I was thinking, cut it to form, attach it
to the spar, drown the whole lot in epoxy. Then after it cures
filament wind it to make the skin.
More difficult than layout carbon fabric and require more tools.

I prefer the basic
1 layer bid 0°/90°,
1 layer biaxial ±45°,
1 layer bid 0°-90° in a simple wood mold


Yep. And they would need and autoclave (pressure and heat) to cure it all,
and expensive machinery to wind it with the accuracy needed to make a
reliable structure.

Filament winding is definitely not for homebuilders.

-- Jim in NC

wrote in message
...
Howdy,

I was channel surfing the other day, and caught a glimpse of how they
make rotor blades for the Hind MI-8 helicopter on RT. (Russian News)
Very Interesting. They use small sections of metal (aluminum?)
honeycomb cut to the shape of the airfoil, align it them with the spar
on the leading and trailing edges, and then filament wind the whole
lot together, preesumably with carbon fiber.

I imagine a simmilar technique might be servicable for experimental
aircraft. paper fiber honeycomb is used as packing material and can
probably be had quite cheap. I was thinking, cut it to form, attach it
to the spar, drown the whole lot in epoxy. Then after it cures
filament wind it to make the skin.

Just a thought.





why use paper honeycomb, a foam form would be easier to shape accurately and
just as light, though filament winding would require a degree of accuracy
that most homebuilders could not afford.

--
[This comment is no longer available due to a copyright claim by Church of
Scientology International]
"I like your Christ. I do not like your Christians. They are so unlike your
Christ"

"Paul Saccani" wrote in message
...
On Mon, 6 Jun 2011 19:24:46 +1000, "Atheist Chaplain"
wrote:

why use paper honeycomb, a foam form would be easier to shape accurately
and
just as light, though filament winding would require a degree of accuracy
that most homebuilders could not afford.

Indeed.

Getting the building bug?
--
Cheers,
Paul Saccani
Perth, Western Australia.

Had it for a while Paul :-)
Just need to clear some space out in the garage for a start, I have been
reading and researching this for a while now and have even put a dent in the
list of tools required (though we all know that Murphy was an optimist ) The
biggest hurdle I have is the sub 0 temps we get here in winter so laying
down the skins and curing is only a summer prospect here :-).
KR forums are a wealth of information and most times Google is your friend.

--
[This comment is no longer available due to a copyright claim by Church of
Scientology International]
"I like your Christ. I do not like your Christians. They are so unlike your
Christ"

"Atheist Chaplain" wrote in message
...

"Paul Saccani" wrote in message
...
On Mon, 6 Jun 2011 19:24:46 +1000, "Atheist Chaplain"
wrote:

why use paper honeycomb, a foam form would be easier to shape accurately
and
just as light, though filament winding would require a degree of accuracy
that most homebuilders could not afford.

Indeed.

Getting the building bug?
--
Cheers,
Paul Saccani
Perth, Western Australia.

Had it for a while Paul :-)
Just need to clear some space out in the garage for a start, I have been
reading and researching this for a while now and have even put a dent in
the list of tools required (though we all know that Murphy was an
optimist ) The biggest hurdle I have is the sub 0 temps we get here in
winter so laying down the skins and curing is only a summer prospect here
:-).

One could always consider the possibility of alloy and rivets.
Works for me.

--
Jeff R.

le dimanche 5 juin 2011 01:17, s'est penché sur son écritoire numérique:

I was channel surfing the other day, and caught a glimpse of how they
make rotor blades for the Hind MI-8 helicopter on RT. (Russian News)
Very Interesting. They use small sections of metal (aluminum?)
honeycomb cut to the shape of the airfoil, align it them with the spar
on the leading and trailing edges, and then filament wind the whole
lot together, preesumably with carbon fiber.

If you see the French process, blades are made from prepreg layouts and, for the core, a resin
becoming foam during the cure. The mold is a two parts heavy metal machined block and the cure
time one or two days in an oven.

--
http://www.youtube.com/watch?v=1ODCf7J8L0o
Philippe Vessaire Ò¿Ó¬

"Paul Saccani" wrote in message
...
On Fri, 10 Jun 2011 23:15:24 +1000, "Atheist Chaplain"
wrote:


"Paul Saccani" wrote in message
. ..
On Mon, 6 Jun 2011 19:24:46 +1000, "Atheist Chaplain"
wrote:

why use paper honeycomb, a foam form would be easier to shape accurately
and
just as light, though filament winding would require a degree of
accuracy
that most homebuilders could not afford.

Indeed.

I did the sums, and it seems that paper honey comb would come out a
good deal lighter. That might be OK for fixed wing, but no good for
rotary, the original application.


interesting, but accuracy in the forms would be my greatest worry,
especially for a lifting surface,
how would they compare ??

Funnily enough, one of my old students was an engineer on that rotor
fabrication at PZL.

Getting the building bug?

Had it for a while Paul :-)

Excellent.

Just need to clear some space out in the garage for a start, I have been
reading and researching this for a while now and have even put a dent in
the
list of tools required (though we all know that Murphy was an optimist )
The
biggest hurdle I have is the sub 0 temps we get here in winter so laying
down the skins and curing is only a summer prospect here :-).
KR forums are a wealth of information and most times Google is your
friend.

Stinky stuff. I prefer metal myself. It's so easy to have subtle
flaws concealed in that resin based stuff.


considered metal and rivets but early on I came to the conclusion that I can
put a dent in armour plate so working with thinner materials is a dodgy
prospect :-)

I suppose you are thinking of one of those foam cored canards?


KR2 with foam core wings seems to be a good prospect and having learnt
laying down of glass and resin at high school I do have some experience with
it :-)


VH or RAA?

still RAA, not enough disposable income to cross over to VH just yet :-) If
ever, I don't see a need just yet for carrying any more than one passenger
ATM and RAA registered AC that are for sale are still thick on the ground at
reasonable prices if I decide to buy.
My old flying school offers a Jab 160 wet for $140 ph

--
Cheers,
Paul Saccani
Perth, Western Australia.


--
[This comment is no longer available due to a copyright claim by Church of
Scientology International]
"I like your Christ. I do not like your Christians. They are so unlike your
Christ"

On 06/22/2011 12:26 PM, Paul Saccani wrote:

VH or RAA?

still RAA, not enough disposable income to cross over to VH just yet :-) If
ever, I don't see a need just yet for carrying any more than one passenger
ATM and RAA registered AC that are for sale are still thick on the ground at
reasonable prices if I decide to buy.

This is where we have it over the yankees. They have speed
restrictions on LSA, no retractable, fixed pitch airscrews - we've got
much more freedom than they have in this regard.



From what I have read lately, one can get a licence to fly a normal
automobile, without any changes, as an experimental aeroplane in Australia.

Most likely with strict area restrictions

Regards / Cees

PS. Who will be the first te use UTS's graphene paper in an experimental
plane?
http://www.physorg.com/news/2011-04-...ger-steel.html