Anyone know a good way to make a belly baggage pod?

In article ,
Tedstriker wrote:


You could also go with a flat belly pod, like on some Caravans. Basically,
just a taper on front, and back, with flat between. Curved corners, a
door(s) on the side. Easily done with fiberglass with some 1/2" foam for
the core, with some blocks in the corners to give some room to radius the
outside corners. Easy shape to make, lots more storage space than a bomb,
and less wind resistance, I would think.

One thing I wonder about is the exhaust.
A center mounted bomb pod would be between my exhaust pipes, but a
rectangular pod would be hit on both corners by engine exhaust. I
wonder if the heat would eat through the fiberglass?

I have a pod on my Cessna 206. It comes to a point on the front, but
the sides and bottom are all flat sheets and the corners have very
little radius, maybe 1 inch. It wraps up the side of the fuselage about
4 inches, so the bottom is actually flatter than the original. It is
less than 8 inches behind the exhaust. There is no problem with heat,
but when you fly in the rain, the lead in the exhaust mixes with the
steam coming through the cowling and you end up with two lead streaks a
foot wide on the bottom. It is hard to scrub off. It does affect the
air flow out of the cowl flaps and a two inch extension of cowl flap
travel is required.

The AR-5 tapes were advertised in Sport Aviation. I don't know if
Arnold still advertises them there. His address, as shown on the VHS
videotape cover:

The Arnold Company
1203 Wanda St.
Crockett, CA 94525

("Thomas O'Grady" wrote)
[snip]
I have a pod on my Cessna 206. It comes to a point on the front, but
the sides and bottom are all flat sheets and the corners have very
little radius, maybe 1 inch. It wraps up the side of the fuselage about
4 inches, so the bottom is actually flatter than the original. It is
less than 8 inches behind the exhaust.


What's the approx size of your pod L-W-D?
(...forget the ends if that's an easier est. g)

How do you access it?

What did it cost in performance numbers before-and-after? Noticeable?

Oh, what's the back of your pod look like?

Thanks.


Montblack

On Sat, 11 Jun 2005 12:04:35 -0700, Richard Riley
wrote:

On Sat, 04 Jun 2005 15:24:02 -0400, Tedstriker
wrote:

:
:
:On one of Mike Arnold's AR-5 tapes he makes one, and you can watch and learn
:to make one for yourself. Matter of fact, Arnold's meticulous techniques
:are the best I have ever seen. He is a master at it, having trained with
:another master, Burt Rutan.
:
:IIRC, Arnold made a mold for baggage pod production for the RV series of
:aircraft.
:
:
:That's interesting, where can one obtain those tapes?

With the world's most obvious url - http://www.ar-5.com/tapes.html

I ended up ordering one of Gary Hunter's EZ pods. I'm goint to invert
it, so the more curved surface is on the bottom, and shortening the
pylon. With something like this, it's horribly inneffiencent to shape
a pod, glass it, then use it to make a mold, then finally make a
finished pod. He's already done all that, so all I'll have to do to
mount it, is a little fiberglass work. This must me a common issue
with tadem airplanes with two people in them. Side by side planes
really have a baggage space advantage. The RV-8 has the best baggage
space I've seen for a two-place tandem homebuilt.
Thanks to Richard Riley for the good tip on where to buy one, I should
have it installed for Oshkosh. All other advice and tips appreciated.

Is there a web address for these pods?

My pleasure. Did he have the bigger ones available yet?

Sorry to hear about your drinking problem.

Yes, he has a "Mark IV" version that is larger. I ordered that one,
since I will use only one, instead of the 2 that go on EZE's. It's a
little over 13" in dia. and a few inches longer.

Still working on the drinking problem.

Isn't the more curved on top to produce lift to offset the additional
weight?


"Tedstriker" wrote in message
...
On Sat, 11 Jun 2005 12:04:35 -0700, Richard Riley
wrote:

On Sat, 04 Jun 2005 15:24:02 -0400, Tedstriker
wrote:

:
:
:On one of Mike Arnold's AR-5 tapes he makes one, and you can watch and
learn
:to make one for yourself. Matter of fact, Arnold's meticulous
techniques
:are the best I have ever seen. He is a master at it, having trained
with
:another master, Burt Rutan.
:
:IIRC, Arnold made a mold for baggage pod production for the RV series of
:aircraft.
:
:
:That's interesting, where can one obtain those tapes?

With the world's most obvious url - http://www.ar-5.com/tapes.html

I ended up ordering one of Gary Hunter's EZ pods. I'm goint to invert
it, so the more curved surface is on the bottom, and shortening the
pylon. With something like this, it's horribly inneffiencent to shape
a pod, glass it, then use it to make a mold, then finally make a
finished pod. He's already done all that, so all I'll have to do to
mount it, is a little fiberglass work. This must me a common issue
with tadem airplanes with two people in them. Side by side planes
really have a baggage space advantage. The RV-8 has the best baggage
space I've seen for a two-place tandem homebuilt.
Thanks to Richard Riley for the good tip on where to buy one, I should
have it installed for Oshkosh. All other advice and tips appreciated.

On Mon, 13 Jun 2005 01:45:56 GMT, "Cy Galley"
wrote:

Isn't the more curved on top to produce lift to offset the additional
weight?

With a round pod like that, there's no way it could produce any lift.
Any low pressure area that could be generated on the top, would be
instantly neutralized by air from the bottom just flowing around to
the top. To produce lift, it would require large, ugly end plates
along both middle-upper sides of the pod. I'd rather use a wing to
make lift.

Tedstriker wrote:

With a round pod like that, there's no way it could produce any lift.

A very definitive statement, but incorrect. Not only is there a way,
but there's no way for it NOT to produce lift, if placed at the right
angle of attack.

Any low pressure area that could be generated on the top, would be
instantly neutralized by air from the bottom just flowing around to
the top.

Not really. While it is certainly the case that this shape is an
inefficient producer of lift, even a blunt cylinder oriented
longitudinally into the airstream will produce lift if placed at a
positive angle of attack. Dirigibles and blimps produce lift at
positive AOA's.

.... To produce lift, it would require large, ugly end plates
along both middle-upper sides of the pod.

No, it wouldn't. They might make the lift production more efficient
(meaning that the lift curve slope might be steeper, and the Lift/Drag
ratio might be higher), but they're not necessary for the production of
lift.

.... I'd rather use a wing to make lift.

As would we all.

--
Marc J. Zeitlin
http://marc.zeitlin.home.comcast.net/
http://www.cozybuilders.org/
Copyright (c) 2005

On Mon, 13 Jun 2005 22:42:25 -0400, "Marc J. Zeitlin"
wrote:

Tedstriker wrote:

With a round pod like that, there's no way it could produce any lift.

A very definitive statement, but incorrect. Not only is there a way,
but there's no way for it NOT to produce lift, if placed at the right
angle of attack.

Any low pressure area that could be generated on the top, would be
instantly neutralized by air from the bottom just flowing around to
the top.

Not really. While it is certainly the case that this shape is an
inefficient producer of lift, even a blunt cylinder oriented
longitudinally into the airstream will produce lift if placed at a
positive angle of attack. Dirigibles and blimps produce lift at
positive AOA's.

.... To produce lift, it would require large, ugly end plates
along both middle-upper sides of the pod.

No, it wouldn't. They might make the lift production more efficient
(meaning that the lift curve slope might be steeper, and the Lift/Drag
ratio might be higher), but they're not necessary for the production of
lift.

.... I'd rather use a wing to make lift.

As would we all.

A dirigble can produce some lift due to it's size, the air would
have so far to travel to get to the top to neutralize the low pressure
up there. But on 13" diameter cylinder, any lift produced would be so
insignificant, as to be barely measurable.