wood species question

Can I administer the meds?

Seeing these comments from the peanut gallery brought to mind an interesting
memory from middle school -- eighth grade I believe.

It was a schoolyard scrap between two of the heavyweight contenders -- one
of many matches and rematches in a long line of slugfests among the
slugerati of middle school.

As usual, the fisticuffs attracted a mighty crowd, and as usual the scrawny
nerds were in the front row, cheering and screaming and waving their little
fists. Keeping the crowd back with arms outstretched behind them -- and at
the same time forming a kind of ring for the fighters -- were some of the
other school sluggers.

It was a spirited match that ended pretty much a draw, with both
combatatants slugged out and panting for air. Just as the action was winding
down into general groping and grasping, one of the little hamsters in the
front, eyes glazed over with blood lust, screamed out some kind of comment
to the effect of, "Come on, let's go. You call this a fight?"

Well that turned all eyes on the little rodent, who quickly sprouted a big
"Oops" bubble above his head. One of the big kids who was on crowd control
quickly administered a cuff upside the head, along with some words of
remonstration, to the effect of "who the heck asked you?" -- and then the
mob dived in.

The next instant our little rodent was being tossed around by the angry mob
like an unfortuante rag doll. A monster wedgie was the crowning indignity as
I recall.

Wow. I hadn't thought of that story in years. Thanks to Rich, Lou, and
Hemingway for sparking that memory.

I sometimes try to picture how some of these kids from middle school might
have grown up, trying to picture the kind of people they have become later
in life, how they might behave in certain situations.

I think I have a pretty good picture of what that unfortunate little
spectator would be doing right about now.

Regards,

Gordon.




"Lou" wrote in message
oups.com...
Can I administer the meds?

"Jerry Springer" wrote

Don't give up yet, I want to see how he responds to your telling him you
have never been on a "ragwing" list. :-)

chuckle

Probly got to go see his shrink, ya think?
--
Jim in NC

Why is it that the looser of the fight always says "it was pretty much
a draw"?

My friend,

You misinterpreted the story. That particular fight was in no way a metaphor
for this fight, in which I have quite obviously decimated a feeble-minded
moron.

The metaphor was about the gleeful onlooker speaking out of turn and getting
humiliated for his trouble.

Guess who is playing the part -- or parts -- of the onlooker?

Regards,

Gordon.




"Lou" wrote in message
ups.com...
Why is it that the looser of the fight always says "it was pretty much
a draw"?

On Wed, 20 Jul 2005 21:15:53 -0400, "Gordon Arnaut"
wrote:

My friend,

You misinterpreted the story. That particular fight was in no way a metaphor
for this fight, in which I have quite obviously decimated a feeble-minded
moron.

The metaphor was about the gleeful onlooker speaking out of turn and getting
humiliated for his trouble.

Guess who is playing the part -- or parts -- of the onlooker?

Regards,

Gordon.

Man, are you any relation to Jaun?


"Lou" wrote in message
oups.com...
Why is it that the looser of the fight always says "it was pretty much
a draw"?

Just to wrap up this thread for those who were seriously interested in wood
substitution issues, before the discussion was rudely disrupted by a
know-nothing peon who has since departed with tail between legs -- as soon
as he realized the jig was up.

As was discussed before the rude interruption, the FAA has approved a number
of wood species for substitution for sitka spruce on certified aircraft,
including certain varieties of pine, fir, cedar, and poplar. There is
specific guidance on this is Chapter 1 of AC43.13b.

Since we are primarily interested in experimental aircraft, I think it is
quite prudent to follow what guidance exists for certified craft -- it is a
good standard to adhere to. For example, AC43.13b specifically states that
white pine can be substituted for sitka if the member is appropriately
resized to account for the slightly lower strength (and weight) of pine.

I did not set out to provide a lecture or tutorial on wood substitution as
this is not the appropriate forum for such an exercise. Instead, I urge each
airplane builder to educate himself using good reference material, such
ANC-18 and the many NACA documents that can be easily downloaded.

However, I thought it would be useful to show how easy it really is to
accomplish the calculations necessary for resizing even the most critical
structural member of the airplane, the wing spar.

Subsequently I also worked through a simple calculation for compression,
which may be relevant in parts like wing compression members and drag
braces. (Stress in tension is calculated the same way as compression: force
per area).

The main reason for sbustituting wood is that it allows the builder to buy
lumber locally, where he can inspect it closely and subject it to proper
selection techniques -- assuming he has learned how to do that.

I think personally that shipping aircraft lumber cross country is not a good
idea. Others may have different views and indeed many airplanes are flying
successfully that have been built with mail-order lumber. However, it is
quite conceivable for such small pieces of wood to be placed in awkward
bending situations in transit. And as we have seen, it does not take much
bending at all to cause compression failure that is nearly invisible to the
naked eye.

It is a fact that there have been catastrophic structural failures on
homebuilt wooden airframes. That's not to say that those accidents were
caused by wood damaged in transit. In some cases, accident investigators
have been able to pinpoint the cause of the failure -- and compression
failure in wood members has been one such cause, as have other things, like
improper techniques, materials, etc.

In some of those cases were compression failure was a factor, it may never
be known when or how the wood was damaged. Still it is enough of an issue
for me that I prefer not to buy mail order lumber. It is also quite a bit
cheaper to buy wood locally, which is a nice ancillary benefit.

Another benefit is that I prefer to mill my own boards to size, which lets
me make best use of the grain direction, slope, etc. When you get a
cardboard tube of wood from a mail-order house, it is a fait accompli --
everything is already cut to size and you must use it regardless of how the
grain pleases you.

The fact of the matter is that in every part of this continent -- and indeed
many parts of the world -- there is suitable lumber available locally. In
the Great Lakes region where I live, northern white pine grows tall and
straight, yielding nice long runs of knot-free planks. There is also spruce
locally, but it is difficult to get clear wood because eastern spruce does
not tend to grow very tall, so branches start much lower to the ground than
pine.

In Australia, there is an abundance of hoop pine, which is actually stronger
than sitka spruce, also grows very tall and makes fine wood for airplanes.

So yes, I think it is important to know these things when one is starting
out and considering what to do and how to get started.

That's why I have gone to considerable effort here to silence the noise from
a completely worthless clown who thinks it is okay to completely disrupt an
intelligent and friendly discussion despite the fact that he has zero
knowledge of the subject.

In any case, I think everyone can see that this annoying moron has been
completely discredited, hence his silence.

I just want to address a couple of things and then I will call it a wrap. As
I have shown, making calculations for resizing lumber is not that difficult
or time-consuming, even for complex stresses like bending moments.

And I have also shown that making calculations for compression and tension
is even simpler still. (I gave an example for compression, but tnesion is
calculated in exactly the same way -- stress equals area per force.

Column buckling is not a consideration on any wooden part of an airframe,
there is simply no such structure that has a length to thickness ratio high
enough and that is completely unsupported along its length.

I'm adding this just to clear up the confusion that the irritating moron has
raised -- throwing verbiage out willy-nilly without even knowing the first
thing about what those things mean.

All in all, substituting local wood is a very attractive option for a number
of reasons. It should not be dismissed out of hand because of some erroneous
impressions we may have, or some hangar tales we may have heard -- and above
all, not because of some nut screaming "fire" in a crowded theatre.

Regards,

Gordon.

Just one more quick point about stiffness and elasticity, since this was
another issue that nutjob was screaming about.

As I explained earlier, stiffness of all the species mentioned in AC43.13b
is quite acceptable and does not really vary by a significant degree. Also
stiffness is not a structural concern -- although it can be a factor in
flying qualities.

For example, an airplane built of fir will be stiffer than than the same
airframe built of spruce, and could provide a little crisper control
response. However, the more flexible spruce or pine airplane will give a
little more comfortable ride in bumpy air.

I think that puts to rest all of the dust that nutjob has kicked up.

Regards,

Gordon.




"Gordon Arnaut" wrote in message
...
Just to wrap up this thread for those who were seriously interested in
wood substitution issues, before the discussion was rudely disrupted by a
know-nothing peon who has since departed with tail between legs -- as soon
as he realized the jig was up.

As was discussed before the rude interruption, the FAA has approved a
number of wood species for substitution for sitka spruce on certified
aircraft, including certain varieties of pine, fir, cedar, and poplar.
There is specific guidance on this is Chapter 1 of AC43.13b.

Since we are primarily interested in experimental aircraft, I think it is
quite prudent to follow what guidance exists for certified craft -- it is
a good standard to adhere to. For example, AC43.13b specifically states
that white pine can be substituted for sitka if the member is
appropriately resized to account for the slightly lower strength (and
weight) of pine.

I did not set out to provide a lecture or tutorial on wood substitution as
this is not the appropriate forum for such an exercise. Instead, I urge
each airplane builder to educate himself using good reference material,
such ANC-18 and the many NACA documents that can be easily downloaded.

However, I thought it would be useful to show how easy it really is to
accomplish the calculations necessary for resizing even the most critical
structural member of the airplane, the wing spar.

Subsequently I also worked through a simple calculation for compression,
which may be relevant in parts like wing compression members and drag
braces. (Stress in tension is calculated the same way as compression:
force per area).

The main reason for sbustituting wood is that it allows the builder to buy
lumber locally, where he can inspect it closely and subject it to proper
selection techniques -- assuming he has learned how to do that.

I think personally that shipping aircraft lumber cross country is not a
good idea. Others may have different views and indeed many airplanes are
flying successfully that have been built with mail-order lumber. However,
it is quite conceivable for such small pieces of wood to be placed in
awkward bending situations in transit. And as we have seen, it does not
take much bending at all to cause compression failure that is nearly
invisible to the naked eye.

It is a fact that there have been catastrophic structural failures on
homebuilt wooden airframes. That's not to say that those accidents were
caused by wood damaged in transit. In some cases, accident investigators
have been able to pinpoint the cause of the failure -- and compression
failure in wood members has been one such cause, as have other things,
like improper techniques, materials, etc.

In some of those cases were compression failure was a factor, it may never
be known when or how the wood was damaged. Still it is enough of an issue
for me that I prefer not to buy mail order lumber. It is also quite a bit
cheaper to buy wood locally, which is a nice ancillary benefit.

Another benefit is that I prefer to mill my own boards to size, which lets
me make best use of the grain direction, slope, etc. When you get a
cardboard tube of wood from a mail-order house, it is a fait accompli --
everything is already cut to size and you must use it regardless of how
the grain pleases you.

The fact of the matter is that in every part of this continent -- and
indeed many parts of the world -- there is suitable lumber available
locally. In the Great Lakes region where I live, northern white pine grows
tall and straight, yielding nice long runs of knot-free planks. There is
also spruce locally, but it is difficult to get clear wood because eastern
spruce does not tend to grow very tall, so branches start much lower to
the ground than pine.

In Australia, there is an abundance of hoop pine, which is actually
stronger than sitka spruce, also grows very tall and makes fine wood for
airplanes.

So yes, I think it is important to know these things when one is starting
out and considering what to do and how to get started.

That's why I have gone to considerable effort here to silence the noise
from a completely worthless clown who thinks it is okay to completely
disrupt an intelligent and friendly discussion despite the fact that he
has zero knowledge of the subject.

In any case, I think everyone can see that this annoying moron has been
completely discredited, hence his silence.

I just want to address a couple of things and then I will call it a wrap.
As I have shown, making calculations for resizing lumber is not that
difficult or time-consuming, even for complex stresses like bending
moments.

And I have also shown that making calculations for compression and tension
is even simpler still. (I gave an example for compression, but tnesion is
calculated in exactly the same way -- stress equals area per force.

Column buckling is not a consideration on any wooden part of an airframe,
there is simply no such structure that has a length to thickness ratio
high enough and that is completely unsupported along its length.

I'm adding this just to clear up the confusion that the irritating moron
has raised -- throwing verbiage out willy-nilly without even knowing the
first thing about what those things mean.

All in all, substituting local wood is a very attractive option for a
number of reasons. It should not be dismissed out of hand because of some
erroneous impressions we may have, or some hangar tales we may have
heard -- and above all, not because of some nut screaming "fire" in a
crowded theatre.

Regards,

Gordon.

On Thu, 21 Jul 2005 23:26:33 -0400, "Gordon Arnaut"
wrote:

Just to wrap up this thread for those who were seriously interested in wood


Another benefit is that I prefer to mill my own boards to size, which lets
me make best use of the grain direction, slope, etc. When you get a
cardboard tube of wood from a mail-order house, it is a fait accompli --
everything is already cut to size and you must use it regardless of how the
grain pleases you.

I think you guys forget that shipped wood comes in a protective
packing. it isnt sent with the address in texta and a stamp stuck to
the end of the plank.

Queensland Hoop Pine (QHP) is a wonderful timber to use. I am building
a modified Druine Turbulent in what is called recutting grade. there
are enough flaws in the wood that it cant just be milled and used, you
need to cut to avoid the flaws.
to buy the cut QHP for a Corby Starlet was $aus3,200. it is similar to
a turbulent in volume of wood used. to buy locally in Perth you can
get QHP in 14" x 2" planks up to 5 metres long at $aus 96/metre.
a 5 metre plank is a little under $aus500 and yields enough wood to
build all of a single seat aircraft.
my wood is sourced by the brother in law in queensland and comes over
in his ute when he visits. I've run out of wood for the wing spars but
$aus50 has bought all the wood needed for the fuselage and
tailfeathers. plywood is a little over $aus200
an icom A200 radio is $1,200. it is my target to build the entire
aircraft for less than the cost of the radio.I think it can be done.

tools for the job so far are a table saw, a band saw, a little hand
coping saw (gets a lot of use), a pencil, an engineers square, a steel
straight edge, a stanley knife and about 60 of the black nylon clamps
with the orange jaws that you can buy in Home Depot in the USA or
Bunnings in Australia. I'm using FR100 epoxy.

having the courage, and the knowledge, to select and cut the wood
yourself can save a small fortune.

In Australia we use a 1944 emergency wartime standard as the guide to
QHP. Emergency Standard (E)3D.803-1944

Stealth Pilot
Australia

You have a good list of tools. I replaced my coping saw with a back saw
and started getting better results. I'd like to ad 2 more tools to your
list, a standup belt sander and a pair of reading glasses.
The belt sander comes in handy for over cutting the small pieces and
sanding down to the lines and square. The reading glasses sure help on
the small joint alignment.
Lou