veedubber what do your ribs weigh?

I applaud your experimental rib building but I wonder how much the
work achieves.

I weighed two of my truss ribs.
one in alaskan yellow cedar and one in queensland hoop pine.
naca23012 aerofoil in 4ft chord with all the gussets but not all the
strengtheners in place. unvarnished.
they are for the druine turbulent, the plans I sent you.

in QHP the rib weighs 134 grams. in AYC the rib weighs 143 grams.
143 grams is 5.044 avoirdupois ounces.

for all your experimental work on ribs you've never mentioned the
resulting weights?
ok what are they? I'm curious.

Stealth Pilot

On Dec 25, 11:38*pm, Stealth Pilot
wrote:

for all your experimental work on ribs you've never mentioned the
resulting weights?
ok what are they? I'm curious.
----------------------------------------------------------------------------------------------------------------

Hi, Stealth,

Yes I did, but you'll have to read everything I wrote to find it. So
here's some current weights:

5 of the BIG ribs,that finish-out to a about a 60 inch chord, weighed
586 grams (for five) or 117.2g each.
4 of the SMALL ribs, the ones that finish out to about a 50" chord,
weighed 454 grams (for 4) or 113.5g each

I'm assuming the small ones I've measured here are the ones you're
interested in. I have some similar ribs which measure 25.25" between
the spar holes, whereas the ones I've measured above are exactly
24.00" and are intended for use with the 'Chugger' project.
----------------------------------------------------------------------------------------------------------------------------

Checking through the shop, I have examples of the Chugger's rib, ribs
for a modified Teenie Two, some old Primary Glider ribs and so
forth.

Using a conversion factor of .03527 to convert grams into ounces, the
big ribs with their paper gussets AND the section aft of the rear
spar, weighs 4.133 ounces per rib, where as the short ribs (113.5g
each) come out as 4.003 ounces... but of course that's without the
trailing edge. That is, there is NO structure aft of the aft spar
(because the entire trailing edge is meant to move. One reason for
the extra weight is that the short ribs use gussets made of 1/8" thick
doorskins (!). (They are what you would call 'sturdy' ribs :-)

-Bob Hoover

PS -- Neither of the ribs shown includes the leading edge structure.
In one version the leading edge detaches and is in fact, a fuel tank.
In another, the leading edge contains a portion of the wing folding &
latching mechanism.

But in most cases the Leading Edge consists of a single piece, routed
from 1/8" plywood, with notches to accept longitudinal stringers. In
most cases the leading edge itself is fabricated from 1/32" or 1/16"
aviation-grade plywood. In another experiment it is urethane foam
covered with fabric or... whatever.

I've posted some pictures of the ribs on my blog.

-Bob

To All:

A couple of private messages commenting on the significant WEIGHT
difference between the big ribs, which weigh less than the little
ribs.

I believe the most significant difference is in the gusseting
material. The little ribs are gusseted with 1/8" doorskin material
whereas the big ribs use 'fiber' gussets... that is, heavy-grade of
CARDBOARD (as has been previously discussed). This rib is meant for a
PRIMARY GLIDER. Very low total weight and not much in the way of
forward speed. Plus, the big ribs are made of REDWOOD, each piece
selected for its light weight. The small ribs are meant for the wing
of a SINGLE-PLACE VW powered parasol. Other than for the methods of
rib construction, there is virtually nothing in common between the two
wings. The small ribs are made from much heavier PINE, and use
heavier wooden gussets.

-Bob

PS -- If you've comments, I'd appreciate you posting them here. It
isn't convenient to copy them from the blog area.

On Fri, 26 Dec 2008 21:12:22 -0800 (PST), "
wrote:

To All:

A couple of private messages commenting on the significant WEIGHT
difference between the big ribs, which weigh less than the little
ribs.

I believe the most significant difference is in the gusseting
material. The little ribs are gusseted with 1/8" doorskin material
whereas the big ribs use 'fiber' gussets... that is, heavy-grade of
CARDBOARD (as has been previously discussed). This rib is meant for a
PRIMARY GLIDER. Very low total weight and not much in the way of
forward speed. Plus, the big ribs are made of REDWOOD, each piece
selected for its light weight. The small ribs are meant for the wing
of a SINGLE-PLACE VW powered parasol. Other than for the methods of
rib construction, there is virtually nothing in common between the two
wings. The small ribs are made from much heavier PINE, and use
heavier wooden gussets.

-Bob

PS -- If you've comments, I'd appreciate you posting them here. It
isn't convenient to copy them from the blog area.

I've been away.
It looks to me as though the experimenting should continue (after the
morning hack up of course) the weights are pretty well on the money.

this all leads to a comment for the impecunious.
(impecunious = as poor as a church mouse )
I saw this commented years ago but never believed it at the time.
most people build the fuselage first because it builds quick. then it
gathers dust as the other bits get worked on and often the project
stops there because life's demands push the boring bits to the
background.

if you build all of your ribs first, and honestly they are a little
tedious, you still have the fuselage to go so the project has an
exciting bit ahead.this helps you get through the tedious bit.
in the case of the druine turbulent there are 20 ribs made from about
2 kilos of 6 x 9mm stripped up wood and ply ( about 4 and a half
pounds of wood) they are trusses made on a building board template.
you make one rib ready for gussets every day. so it amounts to a month
or so's work.
the cost is actually five eighths of stuff all because the techniques
of ignoring the knots and stripping up the wood that veedubber writes
about actually do work. you just cut away any part of a strip with a
knot and dont use it.
but in building your ribs you have actually assembled over half the
joints that will be made in the aircraft.

the benefits of getting on and doing your ribs first are that you
develop all your fine dexterity skills in woodwork that will be hidden
under the wing fabric. when you come to do the woodwork that will be
visible your skills and fluency with the techniques are just so much
more refined and practised.

you wouldnt think that building a rib could be done in too many
different ways but bob and I have totally different approaches to rib
making. bob's is a time honoured traditional method. my approach uses
no nails.

if anyone is actually interested I'll write up a narrative on how I do
them.

btw if anyone wants a copy of the druine turbulent plans I can share
legible photos of the plans gratis via email. I dont know that anyone
actually enforces copyrights on these plans. from australian
experience there is no money to be made from them and the plans
originators are more interested in seeing turbulents being built.
turbulents fly really well behind a converted 1600cc vw engine just
bolted straight to the firewall.
this works because the vw is an unbelievably smooth running engine.
from what I've read of bob's conversions to date he is doing a pretty
good job with them.

Stealth Pilot

(if you need to quantify what 'five eights of stuff all' means try
half of two tenths of a brass razoo's worth. it's a lot less than a
'penny for your thoughts' :-) )

On Dec 28, 3:18*pm, Stealth Pilot
wrote:


if you build all of your ribs first, and honestly they are a little
tedious, you still have the fuselage to go so the project has an
exciting bit ahead.this helps you get through the tedious bit.
-------------------------------------------------------------------------------------------

Dear Stealth,

I hate to pee in your campfire but to build ALL of your ribs first is
to fly in the face of proven wisdom (as opposed to Conventional
Wisdom, which I believe is the package you are trying to tie on your
pony). And just to prove it, if you'll kindly take a seat, I will
showz you how it's SUPPOSED to be done.

See that big balk of timber over there? (Of course you can't, but
work with me here.) You wanna build a plane. So you go looking for
some WOOD, as in Sitka Spruce wood or Western Hemlock Wood or Red Wood
Wood. (Red can't. But he would if he could.)

Sometimes your ideal piece of wood is growing right up outta the
ground! Yeah! Like that tree-thing over there. So before you build
your aeroplane you gotta chop a notch in the side of that three,
making sure the center of the notch is perfectly perpendicular to the
line upon which you wish the tree to FALL. And here is a trick that
will serve you all your life here in the Gulag. See that notch? All
the eggheaded boys sent to the gulag think the notch must proscribe 90
degrees, and they are correct, but their failure as a Forester is in
that seemingly simple supposition, because if you want the tree to
fall where you are hoping it will, which is precisely atop the head of
Mikhail, the trustee and a rotten ******* if ever there was one...

So yes, a 90 degree notch is good. But No! The notch must NOT be 45
degrees below and 45 degrees above. The notch must be only 35 degrees
below and 55 degrees above! Or even more, if the diameter of the tree
is greater than one meter... or if its height is greater than thirty
meters. But you are what, an accountant? To preserve your innocence
you may make it 45/45 if you wish and hope God (or your friend Ivan)
will nudge Mikhail at the proper time.

Look at the earth upon which your tree will fall. Is it flat? Does
it slope up or down? Are there boulders? Does it span a gully? Are
there other trees of substantial size in the way? If so, you must
take those things into account or your tree will contain an unfaithful
heart; it will suffer Compression Fractures when it strikes the
ground. The fall has given your tree a considerable amount of
energy. As the branches touch the ground the truck of your tree will
tend to bend like an archers bow, generating a curve that would hold
water if it could. But since it can't, the end nearest you will TRY
to spring into the air, but if it can't do that, because of improper
notching OR because the trunk represents substantial mass, or because
the terrain upon which Your tree will fall is below the horizontal,
thus pumping more energy into the tree... because it's falling, you
stupid person you! It is accelerating by the SQUARE of the TIME. You
have given it more time, IF the ground is sloping downward.

But enough of that. Odds are you'll forget it anyway by the time you
get to the tree and talk Mikhail into position and find the fellow
with the saw (yes, the SAW. We are Foresters here, not Accountants).
SO IF... IF any of those things are present, you must put the brakes
onto your tree. You must prevent it from falling too fast. How? Yea
gods, man! You're in a forest! How do you think we'll slow it down?
(With... trees? He asks. Of COURSE WITH TREES! [and me with still
forty years to go...]) You must build a cradle for your baby of a
tree. A beautiful bed into which your love may fall with a smile and
extended limbs.

Do all those things and your beautiful tree will NOT suffer the
Compression Fractures to lie hidden in its heart of wood.

Cut the notch. Then take up the saw (and weld two together if one is
not long enough). And just ABOVE the apex of your notch, begin your
cut, keeping it even and true. That is, even meaning each side will
progress at the same rate as the other, and true in that however it
starts out, it continues. Level is good but the ground is often
crooked and your cut may be up or down but whatever it is, keep it
that way for its entire length. Otherwise your tree will think it's a
member of the Bolshoi and spin around and turn you into a bloody pulp
before you can "Jack Robinson." (Don't ask! It could cost you twenty
more years.)

The part of the tree that flys the best begins the height of a tall
man above the ground. NOT above the felling cut, but above the earth
which nurtured your beautiful tree. You may cut the fallen tree
there. The flying portion of the tree will extend to about two meters
BELOW the first limb of substantial size. The resulting stick may be
as long as twenty meters or more but if you have such a tall
candidate, select your flying portion from that nearest the ground.
How LONG that piece may be is determined by which Camp you are in.
See if you can find Mikhail and ask him (the silly ******* seems to
have disappeared again).

-------------------------------------------------------------------------------------------------------

Got your balk of timber? Try to. It works best.

A good balk is a Bridge Timber that is a Quarter-sawn cut. And you
may have to bribe someone to get that. Or go over to the Flybaby
Group and ask around amongst the builders who know Vancouver Island.

Get a balk of timber that has been properly cut then allowed to dry,
well supported, for as many years as it takes. (Stop your
complaining! You'll be here until you die anyway so what's a few
years?)

A Useful size is seven meters in length, 20centimeters in thickness
and 30centimeters in width. Or if you are in a Canadian Gulag, about
22'x 8"x12"

What you want first are your Spars. There will four of them in a Real
airplane. Then comes your Fuselage stringers and finally your smaller
stringers.

Somewhere along the line you will have built jigs for your ribs and
your tail group. As you cut the longer pieces out of your balk of
timber the cuts will yield some Waste. Set your saw to produce Rib
Stock from the waste.

Your ribs will have two long pieces and a myriad of shorter pieces.
Your task is to know the length of all of these pieces and whenever
the opportunity presents its self, to cut your Rib Stock into the
sizes you will need to produce your ribs. Sort the pieces. If you
put them in tin cans, be sure to poke holes in the BOTTOM of the
cans. If you don't, you'll find out why you should.

----------------------------------------------------------------------------------------------------------------------

And now we have finally arrived at Making of the Ribs.

Do NOT tackle this job as a Death Race. (Yeah, I know, but that was
a Varriviggen or whatever so it doesn't count.)

In producing your spars and stringers and diagonals and intercostals
and all the OTHER pieces of wood needed to build your airplane, you
will have AUTOMATICALLY produced enough pieces to fabricate all of the
ribs in your airplane! (In effect, your ribs are free!!) But you
will only produce those ribs as time permits; when you have finished a
More Important task. That's when you will REWARD YOURSELF by making a
rib. One at a time. Each one a perfect example of the wood-workers
art. Building ribs is NOT a chore nor task to be avoided; building a
rib is a REWARD for doing all the millions of other ****ty Little
Details that insist on being done before the airplane can fly. Why is
that so? Because the Secret is in the Wing.

You'll need to ponder on that so I'll leave you to it. Ponder away.
It is because your Life -- and the Life of anyone else who flys in
your machine depends upon your skill and dedication in making a
Perfect Wing, which itself depends upon a whole ****-pot full of
Perfect Ribs, made one at a time.

Why such emphasis? You will answer that question yourself as your
SKILLS accumulate. And because you would not believe me NOW no matter
how skillful you think you are.

-Bob

Thanks for this info. As well, I wanted to see if an ammonia solution
could be used instead of bicarbonate, so I did some googling, and found
a discussion of the chemistry involved. Turns out that various bases or
basic salts can be used resulting in, I suppose, various chemical
properties of the casein glue since it specifically mentions that casein
glue formed using lime has a known assoiation with aviation related wood
gluing. Here is the link
http://www.dotapea.com/english/chap03casein.htm

There's another article on casein linked from that page, but needs
translating from French.

A.L.

On Wed, 31 Dec 2008 00:11:01 -0700, wrote:

Thanks for this info. As well, I wanted to see if an ammonia solution
could be used instead of bicarbonate, so I did some googling, and found
a discussion of the chemistry involved. Turns out that various bases or
basic salts can be used resulting in, I suppose, various chemical
properties of the casein glue since it specifically mentions that casein
glue formed using lime has a known assoiation with aviation related wood
gluing. Here is the link
http://www.dotapea.com/english/chap03casein.htm

There's another article on casein linked from that page, but needs
translating from French.

A.L.

casein if protected from fungal attack is still an acceptable glue for
some aircraft work. typically gliders in dry climates that are not
left out in the rain.

the chemistry of the glue is one thing but what really matters is the
long term stability of the chemistry in the overall joint.

resorcinal formaldehyde, invented in the early 1930's, is the oldest
glue for aircraft use. the need for near perfect joint gaps, 70psi
jointing pressure and about 70degrees F jointing temperature make it
more difficult to use than the new boy on the blocks Epoxy Resin.
(dont sue me on the numbers, they're from memory)

some glues have disgraced themselves along the way by failing in
service.
acid catalysed phenolics like Selleys 308 are not usable for aircraft
because too much formic acid in the joint gradually destroys the wood
layer abutting the joint leading to in service failures.
PVA glues become thermoplastic at high temperature and will fail
underload.

just be carefull with aircraft glues. what you want is a glue that
forms a chemically stable compound after achieveing the joint
strength. it is never just a matter of sticking stuff together.
Stealth Pilot

Dear Stealth, et al,

Some of the people who have written to me asking for assistance are so
far behind the financial power curve that it's difficult for others to
appreciate. At least one correspondent is/was in China. (He vanished
just when things were getting interesting.) Others have been in
India, where disposable income appears to be less of a problem. One
was in Afghanistan, A number in Pakistan.

In most cases they seek explanation of a single term or phrase, the
next most common is those seeing information regarding adhesives,
which lead to a lengthy exchange covering the making & testing of
casein glue.

It is difficult for me to imagine having to make my own glue; more
difficult to imagine riding a bicycle 60 kilometers each way for the
mere CHANCE of getting on the internet to see if I have responded to
his last message.

Language can be a problem, as are perceptions. In most cases I am
wealthy in their terms, whereas we're barely scraping by relative to
American standards.

These people are heros to me. Imagine having to learn another
language, then how to TYPE in that language, then riding 30 miles on a
bicycle to play work-up, hoping to get even a few minutes of computer
access --- then to find I've suffered a medical problem that kept me
away from the computer for several months.

Making acetylene gas the Old Fashioned Way (ie, carbide pellets into a
tank of water). Using 'bicycle tubing' to fabricate a fuselage. Four
bicycle wheels as your landing gear. Having to make your own rib-
stitching needles.

Most of these people are better educated than me, often asking
questions that are far over my head. I am forced to solve problem
empirically -- to make a part then test it to destruction. They do
not have that option; they must do their calculations so that they can
make the thing ONCE... and hope they get it right.

I worry about the glue... and most everything else. I wonder if the
wiser course would be for me to stuff a sock in it; to let them find
another source of information.

-Bob