Today's Message Index:
----------------------
1. 12:06 AM - Re: Re: Riblett to Spar Fit (Clif Dawson)
2. 03:57 AM - Re: "copper" prop edging (helspersew@aol.com)
3. 04:55 AM - Re: "copper" prop edging (JERRY)
4. 05:10 AM - Re: "copper" prop edging (M W Stanley)
5. 05:33 AM - Re: "copper" prop edging (Glen Schweizer)
6. 08:07 AM - Re: Riblett to Spar Fit (jarheadpilot82)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Riblett to Spar Fit |
Ah yes, but aluminum is some 5.6 times heavier than spruce.
Divide that 42000 lb by 5.6 and what have you got? 7500 psi.
Hmmmm. Your Al spar is going to be heavier except for
some judicious hole cutting in the web area.
Clif
You cannot escape. Every day
a part of you turns to shit.
>
> Terry; thanks for the pix of your rib-to-spar interface. And just to add
> one last bit to what I wrote about spar strength, changing the material
> from wood to metal makes a vast change in the strength, other things being
> equal. Spruce has a modulus of rupture (or bending strength) of about
> 9,400 psi whereas (to use a metal that is familiar to builders) for
> 6061-T6 aluminum it is 42,000 psi. If someone were to take the time to
> carefully route, dado, rabbet, and otherwise shape a spruce spar into the
> same dimensions and modified "I" configuration as your metal spar, not
> only would it be uselessly flimsy, even properly restrained it could only
> carry about 1/5 the bending stress that yours can.... Riblett or no
> Riblett.
>
> --------
> Oscar Zuniga
> Medford, OR
> Air Camper NX41CC "Scout"
> A75 power, 72x36 Culver prop
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=466632#466632
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
>
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: "copper" prop edging |
Thanks Mark. No English wheel, just a rubber hammer against a shot bag and against
anything convenient to get it to roll over at the edges. Here some close shots
of copper on a prop I saw at OSH a couple of years ago.
Dan Helsper
Loensloe Airfield
Puryear, TN
-----Original Message-----
From: M W Stanley <mmrally@nifty.com>
Sent: Mon, Feb 27, 2017 8:42 pm
Subject: Re: Pietenpol-List: "copper" prop edging
Hi Dan,
That is beautiful work!
I was just wondering if you you used an peening hammer/bag, then an english wheel
to get the shape? Whatever you did, it looks great!
Mark Stanley
Piet build in progress.
Japan
From: helspersew@aol.com
Sent: Tuesday, February 28, 2017 6:57 AM
Subject: Re: Pietenpol-List: "copper" prop edging
Yes, according to my historical research, copper was used early on as a prop tipping
material. Here you can see my early attempts at forming the brass tipping
material I was playing around with. I never had the guts to actually start drilling
holes though. As much as I would like to, I have never felt like I was
in a position to go through with it, being close to Brodhead time and only having
one prop to rely on. Gary Boothe has also been known to be playing around
with this. Maybe he can chime in with more.....
Dan Helsper
Loensloe Airfield
Puryear, TN
-----Original Message-----
From: Douwe Blumberg <douwe@douwestudios.com>
Sent: Mon, Feb 27, 2017 1:23 pm
Subject: Pietenpol-List: "copper" prop edging
I believe Dan Helsper posted his experiments with sheathing his prop LE with brass
on the FB page. Never seen copper used.
He can probably chime in.
Douwe
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | "copper" prop edging |
That is very cool. I might try that on my Model A prop when I get to it.
Jerry
Prairie City, IA
From: owner-pietenpol-list-server@matronics.com
[mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of
helspersew@aol.com
Sent: Tuesday, February 28, 2017 5:57 AM
Subject: Re: Pietenpol-List: "copper" prop edging
Thanks Mark. No English wheel, just a rubber hammer against a shot bag
and against anything convenient to get it to roll over at the edges.
Here some close shots of copper on a prop I saw at OSH a couple of years
ago.
Dan Helsper
Loensloe Airfield
Puryear, TN
-----Original Message-----
From: M W Stanley < <mailto:mmrally@nifty.com> mmrally@nifty.com>
pietenpol-list@matronics.com>
Sent: Mon, Feb 27, 2017 8:42 pm
Subject: Re: Pietenpol-List: "copper" prop edging
Hi Dan,
That is beautiful work!
I was just wondering if you you used an peening hammer/bag, then an
english wheel to get the shape? Whatever you did, it looks great!
Mark Stanley
Piet build in progress.
Japan
From: <mailto:helspersew@aol.com> helspersew@aol.com
Sent: Tuesday, February 28, 2017 6:57 AM
Subject: Re: Pietenpol-List: "copper" prop edging
Yes, according to my historical research, copper was used early on as a
prop tipping material. Here you can see my early attempts at forming the
brass tipping material I was playing around with. I never had the guts
to actually start drilling holes though. As much as I would like to, I
have never felt like I was in a position to go through with it, being
close to Brodhead time and only having one prop to rely on. Gary Boothe
has also been known to be playing around with this. Maybe he can chime
in with more.....
Dan Helsper
Loensloe Airfield
Puryear, TN
-----Original Message-----
From: Douwe Blumberg < <mailto:douwe@douwestudios.com>
douwe@douwestudios.com>
list@matronics.com>
Sent: Mon, Feb 27, 2017 1:23 pm
Subject: Pietenpol-List: "copper" prop edging
I believe Dan Helsper posted his experiments with sheathing his prop LE
with brass on the FB page. Never seen copper used.
He can probably chime in.
Douwe
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: "copper" prop edging |
Thanks Dan,
Yes, truly great work!
I have a long way to go before I need a prop but I do like the look of a
well built wooden prop!
Thanks for the pic's!
Cheers
Mark Stanley
Japan
From: helspersew@aol.com
Sent: Tuesday, February 28, 2017 8:56 PM
Subject: Re: Pietenpol-List: "copper" prop edging
Thanks Mark. No English wheel, just a rubber hammer against a shot bag
and against anything convenient to get it to roll over at the edges.
Here some close shots of copper on a prop I saw at OSH a couple of years
ago.
Dan Helsper
Loensloe Airfield
Puryear, TN
-----Original Message-----
From: M W Stanley <mmrally@nifty.com>
Sent: Mon, Feb 27, 2017 8:42 pm
Subject: Re: Pietenpol-List: "copper" prop edging
Hi Dan,
That is beautiful work!
I was just wondering if you you used an peening hammer/bag, then an
english wheel to get the shape? Whatever you did, it looks great!
Mark Stanley
Piet build in progress.
Japan
From: helspersew@aol.com
Sent: Tuesday, February 28, 2017 6:57 AM
Subject: Re: Pietenpol-List: "copper" prop edging
Yes, according to my historical research, copper was used early on as a
prop tipping material. Here you can see my early attempts at forming the
brass tipping material I was playing around with. I never had the guts
to actually start drilling holes though. As much as I would like to, I
have never felt like I was in a position to go through with it, being
close to Brodhead time and only having one prop to rely on. Gary Boothe
has also been known to be playing around with this. Maybe he can chime
in with more.....
Dan Helsper
Loensloe Airfield
Puryear, TN
-----Original Message-----
From: Douwe Blumberg <douwe@douwestudios.com>
Sent: Mon, Feb 27, 2017 1:23 pm
Subject: Pietenpol-List: "copper" prop edging
I believe Dan Helsper posted his experiments with sheathing his prop LE
with brass on the FB page. Never seen copper used.
He can probably chime in.
Douwe
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: "copper" prop edging |
Water will get between metal leading edge and wooden prop and cause prop to r
ot. (Please don't ask how I found this out)
> On Feb 28, 2017, at 5:09 AM, M W Stanley <mmrally@nifty.com> wrote:
>
> Thanks Dan,
>
> Yes, truly great work!
> I have a long way to go before I need a prop but I do like the look of a w
ell built wooden prop!
> Thanks for the pic's!
>
> Cheers
> Mark Stanley
> Japan
>
> From: helspersew@aol.com
> Sent: Tuesday, February 28, 2017 8:56 PM
> To: pietenpol-list@matronics.com
> Subject: Re: Pietenpol-List: "copper" prop edging
>
> Thanks Mark. No English wheel, just a rubber hammer against a shot bag and
against anything convenient to get it to roll over at the edges. Here some c
lose shots of copper on a prop I saw at OSH a couple of years ago.
>
> Dan Helsper
> Loensloe Airfield
> Puryear, TN
>
>
> -----Original Message-----
> From: M W Stanley <mmrally@nifty.com>
> To: pietenpol-list <pietenpol-list@matronics.com>
> Sent: Mon, Feb 27, 2017 8:42 pm
> Subject: Re: Pietenpol-List: "copper" prop edging
>
> Hi Dan,
>
> That is beautiful work!
> I was just wondering if you you used an peening hammer/bag, then an englis
h wheel to get the shape? Whatever you did, it looks great!
>
> Mark Stanley
> Piet build in progress.
> Japan
>
>
> From: helspersew@aol.com
> Sent: Tuesday, February 28, 2017 6:57 AM
> To: pietenpol-list@matronics.com
> Subject: Re: Pietenpol-List: "copper" prop edging
>
> Yes, according to my historical research, copper was used early on as a pr
op tipping material. Here you can see my early attempts at forming the brass
tipping material I was playing around with. I never had the guts to actuall
y start drilling holes though. As much as I would like to, I have never felt
like I was in a position to go through with it, being close to Brodhead tim
e and only having one prop to rely on. Gary Boothe has also been known to be
playing around with this. Maybe he can chime in with more.....
>
> Dan Helsper
> Loensloe Airfield
> Puryear, TN
>
>
> -----Original Message-----
> From: Douwe Blumberg <douwe@douwestudios.com>
> To: pietenpol-list <pietenpol-list@matronics.com>
> Sent: Mon, Feb 27, 2017 1:23 pm
> Subject: Pietenpol-List: "copper" prop edging
>
> I believe Dan Helsper posted his experiments with sheathing his prop LE wi
th brass on the FB page. Never seen copper used.
>
> He can probably chime in.
>
> Douwe
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Riblett to Spar Fit |
Clif,
Here is a repeat of a discussion that I posted on the Pietvair Forum a while back.
My reason for using aluminum spars was not weight, not exclusively. There
were other reasons far more important to me than that.
(FWIW, I sent all of this to BPA a long time for inclusion into a newsletter article,
but some how, it never made it to print.)
-----------
Here is a comparison of the weight of each type of spar. The aluminum weights come
from the Carlson Aircraft website. It is assumed that the D&E spars are of
a similar weight. The weights of the wood come from the current online Aircraft
Spruce Catalog.
-Aluminum spars weigh between 0.93 and 1.00 oz per linear inch. Therefore, using
the 1 oz. weight times the total length of the 2 front spars (2 x 158.5) and
0.93 oz. weight times the total length of the rear spars (2X158.5) is 317+295,
or 612 ounces. 612 ounces equals 38 pounds, 4 ounces. You will be using 30 each
5/16 X 1 X 5.5 plywood slats and 30 each 5/16 X 1 X 4.5 slats for attaching
the ribs to the spars (more on that later). A 5/16 X 24 X 48 plywood sheet weighs
30 pounds, or 1.33 ounces per cubic inch. The slats would weigh approximately
33 ounces or 2 pounds 1 ounce, for a total weight of 40 pounds, 5 ounces.
The weight of any T88 epoxy used to attach the slats to the aluminum spars is
not included.
(Note - I later weighed the following wood pieces - Blocks to fill the spaces between
the top of each spar and the bottom of each rib upper capstrip - 331 grams,
Front spar spacers to go between the shear web of the spar and the vertical
of the rib - 645 grams, Rear spar spacers to go between the shear web of the
spar and the vertical of the rib - 504 grams, wooden Wing tips added to the
end of the aluminum spar for attaching the wing tip bows - 710 grams, and Wing
Root spacers to fill the space at the wing root where the three piece wing attach
fittings bolt to the spar root - 803 grams. That all added up to 2992 grams,
or 6.5824 pounds. roughly 1 pound more per spar than I had originally calculated.
I had forgotten to add the four wing tips and the wing root spacers in
the original article. Oops.
That made the total calculated weight of the four aluminum spars to be 44 pounds,
13 ounces. Good thing I am a pilot and not an engineer.)
-Spruce weighs 27 pounds per cubic foot. so a 1 X 6 X 158.5 solid spruce spar weighs
14 pounds, 14 ounces, while a 1 X 5.5 X 158.5 spar weighs 13 pounds, 9 ounces.
2 of each spar has a total weight (before any routing is done) of 56 pounds,
14 ounces.
-If you decide to use the 3/4 solid, unrouted spars, each 3/4 X 6 X 158.5 spar
weighs 11 pounds, 2 ounces, and each 3/4 X 5.5 X 158.5 spars weighs 10 pounds,
4 ounces. the four spars together weigh 42 pounds, 12 ounces.
-If you build up your I-beam spars, a sheet of Aircraft grade plywood (7 ply) in
the size noted above weighs 50 pounds. If you add 631.5 cubic inches of spruce
capstrips for the flanges (1/4 X 1 X 2526 inches [158.5 X 4 flanges per spar
X 4 spars]), the flanges weigh 9 pounds, 14 ounces. The built up I-beam, therefore,
weighs roughly 59 pounds, 14 ounces. That does not include the weight
of the T-88 used in the assembly.
So what does all the math tell me? It tells me that aluminum spars are slightly
heavier than 3/4 spars and lighter than 1 inch or built-up I-beams. At most the
difference is roughly 12 pounds. If you are looking for lighter, then the aluminum
is among the lighter of the bunch. A little bit lighter compared to some,
and a lot lighter compared to other methods.
___________
YMMV.
--------
Semper Fi,
Terry Hand
Athens, GA
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=466756#466756
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|