Wrinkly flat panels

I saw a set of rollers with the corrugation profiles in them, and the 2024 was 'simply' hand cranked between them. Once
you have the rollers is should be pretty easy, but getting the rollers...

They crank out roof gutters from the back of vans on the building site, maybe someone knows someone who has an old
gutter rig...

--
Dan D.



..
wrote in message ...
In article , "Blueskies" wrote:
ala TriMotor - corrugations

I kind of like the idea of corregations. Any ideas on how to accomplish them?

thanks,
tom

How about cork? Probably too heavy...

--
Dan D.



..
"Tim Ward" wrote in message ...

wrote in message
...
snip of misunderstanding

Sorry I wasn't clearer on my intention. I'd only spray about an inch
on the
panels. Not much weight, and still get significant damping.

tom

Balderdash, tom.

I think you are blowing in my ear.

First, just how do you expect to "spray on" a 1 inch thick layer
of foam INSIDE a wing? I can't do it, and I can do anything
(with Duct tape!).

Second, a 100 square foot wing is 14,400 square inches.
One inch thick is 14,400 CUBIC inches, or 8.3 cubic feet.
Top and bottom skins give 28,800 cubic inches or 16.6 cuft.

At the mythical 3 lb/ft^3, that's 50 pounds.

Sorry dude, that boat don't float...

Yeah it will. 8^) I was talking about flat panels on the fuselage. The
Zenith CH701 I would like to build has about 60 square feet of fuselage
area
behind the cabin. At one inch, that amounts to 5 cubic feet. One website
I
visited that made fire retardant spray urethane foam says 1.75 pounds per
cubic foot, so the weight of this addition would be less than nine pounds.

If the panels are really flat, then why spray it on? Low density foam is
available in sheets. I'll bet the consistency is better than you can get
from a can. Bond it on before you rivet. It shouldn't have to go all the
way to the edges to prevent the oilcanning.

It looks like for the 9 lb weight penalty you could increase the thickness
of just those panels by about .010 inches (.15 lbs/sq ft). That would make
it less likely to oilcan and stronger.

Does the foam really need to be continuous? Why not just bond some foam
stiffeners to the inside of the panel every six inches or so? The HP-18
sailplane wing is made from 1/2" foam on four inch centers. That technique
might be more anechoic than a smooth continuous foam surface, too. You
could taper the stiffeners to be thicker in the center of the panel, and get
more stiffness/unit weight that way.

An interesting way to bond the stiffeners might be to use 3M VHB (Very High
Bond) double stick tape. It's used to bond side panels on truck and trailer
bodies. Fast and no goop.

Tim Ward

Blueskies wrote:
How about cork? Probably too heavy...

And absorbs water. If it wasn't heavy when you put it in, it will be
after you fly through the first cloud. Whatever you use, make sure it is
HYDROPHOBIC

(a word I learned about in RAH)

--
http://www.ernest.isa-geek.org/
"Ignorance is mankinds normal state,
alleviated by information and experience."
Veeduber

Why not just buy a better headset? That ought to take care of any noise
from the sheetmetal and it won't add a bunch of weight and potential for
hidden corrosion to form under the deadening material.

I thought this discussion was about a bush plane? All of the serious
bush pilots that I know strip all of that crap OUT of their airplanes if
possible.

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

Del Rawlins wrote:

Why not just buy a better headset? That ought to take care of any noise
from the sheetmetal and it won't add a bunch of weight and potential for
hidden corrosion to form under the deadening material.

I thought this discussion was about a bush plane? All of the serious
bush pilots that I know strip all of that crap OUT of their airplanes if
possible.

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

I thought it was about a Zodiac, but i've been wrong before...

But a Bush plane with rattle padding?


File under Hard Lessons Learned:

How important it is - and how hard it is -
to keep excess weight OUT of an airplane.

Temper foam is a great example.

This is for sure and certain the most comfortable stuff imaginable
short of free fall,

but the WEIGHT!

Padding a pair of bucket seats can add 30 pounds to the empty weight
of the airplane.

Ed Heineman would tell it loud and clear...
Simplacate rather than complicate.
Add lightness rather than heaviness.


Richard

In Richard Lamb wrote:

I thought it was about a Zodiac, but i've been wrong before...

Could have sworn they was talking about a CH701 STOL.

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

In article , Del Rawlins wrote:
In Richard Lamb wrote:

I thought it was about a Zodiac, but i've been wrong before...

Could have sworn they was talking about a CH701 STOL.


I was talking about a CH701 rear fuselage. I agree that you should lighten
and simplify whenever possible. One reason not to do anything is that the
panels make quite a racket as buffeting occurs near stall. Maybe this is just
another genius of Chris Heinz?

thanks everybody for the discussion

tom

massophobic?

--
Dan D.



..
"Ernest Christley" wrote in message . com...
Blueskies wrote:
How about cork? Probably too heavy...

And absorbs water. If it wasn't heavy when you put it in, it will be
after you fly through the first cloud. Whatever you use, make sure it is
HYDROPHOBIC

(a word I learned about in RAH)

--
http://www.ernest.isa-geek.org/
"Ignorance is mankinds normal state,
alleviated by information and experience."
Veeduber