Rock Rolling & Other Easter Chores

To All:

By the time Whatzhiznamez Inter-Plane Winglets had crossed the Pond
they found a buncha Frenchmen just waiting to pounce on them. These
French fellows didn't care for 'tail feathers' nor 'hull' nor any of
them other home-grown Ami Rican definitions and you could bet your
beans they weren''t gonna allow ol' whatzhizhame to call inter-plane
winglets Inter-Plane Winglets for damn sure. Winglets was O.K.
(although the O.K. had to go) but Inter-plane? I mean, come on...
Inter-PLANE? Ain' no Way they were going to allow that. Aviation was
FRENCH, not American. Didn''t matter that them bicycle boys were
flying two-up, graceful as a swan all over Europe and even England
too. But it's best not to talk about that. They already had a form
to fill out. If you wanted to fly in Europe you'd better be ready to
fill out the form. And pay the fee, of course. Always a Fee when you
gotta Form to filll out.

Ailerons. That's what they became, once the French got their
bureaucracy in gear. No mention of Winglets because, as any fool
KNOWS, you can't have WINGLETS unless you've got WINGS. And there was
ol' whatzhizname calling them PLANES! So I guess we showed you, eh?
Didn't we? You Ami-Rican motorcycle man you, eh? Following your
Bicycle Brothers with your pockets filled with Patent Attorneys.

I won't even get into JOYSTICK.

For some time now I've been making perfectly good joysticks outta
exhaust pipe and matching pipe clamps. Heavier than hell but then
you only need a couple inches of the stuff; just enough to give you
enough pipe so's the thing will rotate in your muffler clamps.
(What's that? Yousay I called them muffler clamps in one message an'
pipe clamps in another? Okay, what's wrong with that? You obviously
knew what I was talking about.) Truth is, just about anything that
gets the job done is okay to use.

So... what IS the job, exactly? It's to make the ailerons move, isn't
it? I mean, we got rid of the shoulder frame and the hip frame and
all them other methods and got it boiled down to a simple stick, once
the French jumped in and told us what it was. And then we tied it to
the elevator too. Again,with more help from the French. Push or
pull, the stick... nobody calls it a JOYSTICK any more... push it
left or right to move the ailerons... which have been defined, legally
and otherwise, as a miniature WING. Push the joystick in one
direction, the aileron goes Up, wing goes DOWN and the the whole damn
plane starts to turn into the low wing. Lovely, graceful evolutions
in the air.

Need to make one. Joystick, that is. Kicking around under the
bench... nothing handy comes mind. I've got a whole box of Teenie Two
control sticks. Kinda cock-eyed and sensitive as hell on the elevator
AND the ailerons. (Sensitivity has to do with the input-output
ratios. Input has to do with where you grab the stick, whereas the
output is the distance between the pivot and the rod or cable that is
being acted upon. Teenie Two, the distances is less than an inch,
meaning it's sensitivity is right up there. Not the kind you'd want
to risk passenger's lives upon.

I keep poking around, find some thin-walled SQUARE steel tubing, 3/4"
on a side. Just the thing! Because I've also found the perfect stuff
for bearings. It's a remnant of a kitchen cutting board, half an inch
thick and about a foot long. I whizz it through the band-saw, lopping
off a piece 2" wide. Find the miter gauge and lop the long piece into
a stack of short pieces, 2" x 2" and smelling faintly of kitchen
stuff. It's about 1630 and my back is hurting enough to kick
everybody out soz I can have some time to myself.

Little corner jig goes onto the drill-press table and is adjusted to
make a hole... somewheres. In the corners of each piece and identical
but I haven't bothered to measure anything. Dig around for some
scrap; something I can cut without needing too much strength. Find
some mild steel willing to get sheared. Center-line has to be 4" plus
enough to bend over to give me a ninety degree bend so I can bolt it
to the structure. It's going to be pretty limp so I leave room to
bend the edges. start filing then take a break for chow.

By the l get back to the shop I've got it pretty much laid out in my
head. I use a chassis punch for the big hole and a drill for the four
#10 fasteners. The sheet-metal screws are substituted for the chassis
fasteners and the support brackets are mocked up on a piece of pine
with the precise distance between them. That allows me to mark the
total length of the part and where the aileron connector must go. The
connector must be four inches long and needs to be welded so I get
things all shiny bright, rig a couple of bricks, make the lower end,
which is .090, weld it to the leg and do a bit of grinding to get the
precise four inch length needed by the arm. Tack that then hammer on
it a bit. Do another tack and everything is straight. Weld one side,
then the next, then close each end.

I gave the steel parts a spritz of paint then hung them to dry while I
made the last pieces on the lathe. These were chunks of 3/4" aluminum
plate turned to a diameter that would not interfere with the #10
fasteners securing the cutting board to the brackets. And I was all
done. At least for this article :-) I still had to make the joystick
itself but that was liable to take several tries, filling it with dry
sand, raising it to a red heat then bending it to conform to my
pattern... a piece of welding rod.

And for the bearings, of course. But everyone knows how to make a
bearing for a piece of square tubing, right? Right?

Gotta go see what the Easter Bunny left me.

-R.S.Hoover

wrote:

So... what IS the job, exactly? It's to make the ailerons move, isn't
it? I mean, we got rid of the shoulder frame and the hip frame and
all them other methods and got it boiled down to a simple stick, once
the French jumped in and told us what it was. And then we tied it to
the elevator too. Again,with more help from the French. Push or
pull, the stick... nobody calls it a JOYSTICK any more... push it
left or right to move the ailerons...

-R.S.Hoover


A wrinkle about flying a low power Wright style design.
If you warp the left wing down, or put the left wing aileron down,
which way is the plane going to turn?
....
....

....
....

....

....

Why - to the LEFT of course!
(More drag = more turning effect and more wing down.)

Brian W

A wrinkle about flying a low power Wright style design.
If you warp the left wing down, or put the left wing aileron down,
which way is the plane going to turn?

* Why - to the LEFT of course!
(More drag = more turning effect and more wing down.)

Brian W


Brian,

Ever fly a Wright? Ever really try that? Ever wonder why that rudder-
thingie in the back has to move and not stay fixed. Or why you even
need that rudder-thingie on a Wright in the first place?

Go look up "well-digging". Then come tell me which way a Wright
machine turns when you warp the left wing down. You should have at
least two answers for me.

Harry Frey
Wright 1902 glider semi-pilot

wrote:
A wrinkle about flying a low power Wright style design.
If you warp the left wing down, or put the left wing aileron down,
which way is the plane going to turn?

Why - to the LEFT of course!
(More drag = more turning effect and more wing down.)

Brian W


Brian,

Ever fly a Wright? Ever really try that? Ever wonder why that rudder-
thingie in the back has to move and not stay fixed. Or why you even
need that rudder-thingie on a Wright in the first place?

Go look up "well-digging". Then come tell me which way a Wright
machine turns when you warp the left wing down. You should have at
least two answers for me.

Harry Frey
Wright 1902 glider semi-pilot

I never flew one - and I'm guilty of passing on this snippet from the
folks who did the man powered series at Aerovironment - who were in a
similar situation. If being a glider semi-pilot means you HAVE flown
one - or many another plane that will turn the wrong way if only
ailerons or wing warping is used - I am open to correction! :-)

Regards

Brian W

If being a glider semi-pilot means you HAVE flown
one - or many another plane that will turn the wrong way if only
ailerons or wing warping is used - I am open to correction! :-)

I don't know about Wright flyers or gliders, but "normal" airplanes
(according to my limited experience on Robins and Cessnas) will
actually turn the proper way. That's due to the fact that once you
bank the plane (by aileron), you also have to pull to compensate for
the loss of lift in the vertical axis. This gives you a slight
rotation of the plane around its pitch axis, and the horizontal
component of lift gives you (after some time) a horizontal velocity,
which, on a stable plane, will induce a force on the vertical
stabilizer that makes the plane turn in the right direction. The
resulting moment is usually much greater than the one due to
differential drag on the ailerons.

In short, an airplane (maybe more so for the "truck-like handling"
planes such as Cessnas, and less so for lighter handling planes, which
I've never flown) will fly well on just aileron and elevator; rudder
is only needed for take-offs and landings in crosswinds. But no
serious flight instructor will ever admit that ;-)

Oliver

Oliver Arend wrote:

I don't know about Wright flyers or gliders, but "normal" airplanes
(according to my limited experience on Robins and Cessnas) will
actually turn the proper way...
Oliver


The effect in discussion is called adverse yaw. It takes design effort
to get rid of it. The most popular method is called differential
aileron movement: i.e. more UP than down. If I recall, that's the method
used on those two popular planes. But the early planes had a more
serious problem too. When they flew just above stall as they did, the
wings were already at high angle of attack. If you then deflect the
outboard section down, it stalls. Vividly sometimes. Modern practice is
to use a little washout - i.e. lower AofA towards the tips - that makes
the stall progressive.

Brian W

On Apr 14, 6:12*am, Brian Whatcott wrote:
Oliver Arend wrote:
I don't know about Wright flyers or gliders, but "normal" airplanes
(according to my limited experience on Robins and Cessnas) will
actually turn the proper way...
Oliver

The effect in discussion is called adverse yaw. * It takes design effort
to get rid of it. * The most popular method is called differential
aileron movement: i.e. more UP than down. If I recall, that's the method
used on those two popular planes. * But the early planes had a more
serious problem too. * *When they flew just above stall as they did, the
wings were already at high angle of attack. * *If you then deflect the
outboard section down, it stalls. *Vividly sometimes. Modern practice is
to use a little washout - i.e. lower AofA towards the tips - that makes
the stall progressive.

Brian W



BUT ! ! ! Wright machines AREN'T "normal airplanes". Are they?

BUT ! ! ! Wright machines NEVER had ailerons. NEVER. NONE of them. Not
even one.

BUT ! ! ! Wright machines didn't and COULD NOT fly at an Angle of
Incidence (AOA for you new guys) over 11 degrees.

BUT ! ! ! Wright machines DID have washed-out wings starting in 1902.

So what gives, Harry?

First, semi-pilot refers to the fact that I was trying to keep my
glider on the ground instead of in the air. Why would I do a damn-fool
thing like that? Becuz I was at an airshow and I didn't want my baby
soaring up and into a WC-130. Still had to fly it for nearly three
hours to keep it from rolling or getting airborne. Shoulda seen the
size of the thigh bruises I had from the hip-cradle. (They didn't tell
you about that in the book? Opps.) So when I speak about this subject,
it is with "some" experience.

Adverse yaw IS the modern term for the "well-digging" effect. What
really happens when you warp the wings of a 1900 or 1901 Wright glider
left-leading-edge-down? You roll sllllllooooooowwwwwwwly to the left,
and yaw rapidly to the right. Why, well it is differential drag caused
by differential AOA. Higher drag in the UP-warped wingtip. IT IS NOT
because of a high overall AOA or lack of washout. Its because one
primary factor. The 1900, 1901, and early 1902 gliders DIDN'T HAVE A
CONTROLLABLE RUDDER! THAT'S IT. END OF STORY. On October 19, 1902,
Orville litterally had a dream about the third axis of control. Wilbur
suggested the idea of integrating rudder and aileron control the next
morning. They tried that setup on October 23, 1902 and DAMNED IF HE
AIN'T FLEW!

Flex-wing hang-glider, blah blah B-2, blah blah PPC, etc. Yeah, I
know. We're talking about Wright machines here. So, by 1902 we had
washout, tapered wingtips, and three-axis controls. What about 1903?
Now we've got a little power, refined actuation, and more control
surface area, and one more thing: a pitch stick. Its mounted to the
elevator control-bar, but it IS the beginnings of a joystick. Same
setup in 1904.

Now late in 1905, there is another significant change. A seat. (Look
Ullm, no more criked necks!) Of course, if you're sitting up, you
can't really use a hip-cradle. So now what? Another stick! So now
there's one for pitch, and a second for wing-warping and rudder.

BUT WAIT, THERE'S MORE! In very late 1905, the rudder was uncoupled
from the warp-wires so it could be controlled on its own. Because
sometimes you need more rudder and sometimes you don't. So how to
control it? You add a hinge 3/5 of the way up your warping stick. You
still push/pull fore/aft for warping, but now you BEND left/right for
rudder on the same stick. The easiest place to see this setup is on
the 1908 - Model C machines. And what do you do with your feet? Dangle
them. Put 'em on the foot rest. Chairdance.

So now we have independent three-axis control via 2 1/2 sticks. Is
adverse yaw and spinning still a problem? You bet. That's how Ralph
Johnstone bought it. BUT..... the development of this system, and
equally importantly AROUND THE PATIENT of this system gave us what we
have today.

So to answer the question directly, what happens in a Wright when you
warp left leading-edge down?

1900 - early 1902: You roll left but spin right and/or stall, crash,
or fly backwards.
late 1902 - early 1904: You roll and turn left if you have enough
airspeed, otherwise you stall and crash.
1905-1918: Pilot's choice. Depends on rudder input and airspeed.
Modern airplanes: Depends a lot on design, but you can still spin and/
or stall if you get stupid.
Flex-wings: they don't warp. They don't have ailerons. Way different
mojo.
Stealth Bomber: Computers my friend. The only one that has crashed
went down on takeoff due to a damp 'puter.

BTW Bob, if you're still with me after this rant, I did happen to see
a joystick in a reproduction Spad once that looked an AWEFUL lot like
a sawed-up wooden baseball bat. Food for thought.

Harry

wrote:

Adverse yaw IS the modern term for the "well-digging" effect. What
really happens when you warp the wings of a 1900 or 1901 Wright glider
left-leading-edge-down? You roll sllllllooooooowwwwwwwly to the left,
and yaw rapidly to the right. Why, well it is differential drag caused
by differential AOA. Higher drag in the UP-warped wingtip......
Harry

I tend to switch off when there are too many upper case words and
exclamations for providing emphasis in a discussion. Still, I found this
document written by Culick of CalTech helpful. Perhaps a little heavy in
parts. Here is his discussion of adverse yaw and how the Glider's outer
wing in a turn dropped - the effect the Wrights called 'well-digging'.
Notice that the wing-warping method altered the trailing edges of the
outboard panels.


From this URL:
http://www.wrightflyer.org/Papers/SETP01_Culick.pdf

"With or without anhedral, the glider having fixed tail also several
times exhibited a second problem associated with adverse yaw. As a
gentle turn, having relatively small roll angle, was being connected to
level flight, the outer wing of the turn dropped and struck the ground.
The Brothers called this event “well-digging.” Wald (1999) has best
explained the cause of the problem. Suppose the glider is turning to the
left, say, and the wings are warped, the trailing edge of the left wing
warped downward to increase its lift and stop the turn. Due to adverse
yaw the wing is slowed, the lift is initially reduced and the wing
actually drops. If the glider is sufficiently close to the ground, the
tip of the wind would strike the sand.
In 1902 the new vertical tail, because it provided directional
stability, did help the aircraft turn. But also because it was fixed it
had a serious shortcoming—it was effective only if the aircraft had
translational motion laterally, i.e. slipping.
When a turn was initiated, adverse yaw swung the aircraft such that the
lift (to the side) generated by the tail would correctly compensate the
swinging motion."


Brian Whatcott Altus OK

On Apr 14, 3:51*pm, wrote:
ent down on takeoff due to a damp 'puter.

BTW Bob, if you're still with me after this rant, I did happen to see
a joystick in a reproduction Spad once that looked an AWEFUL lot like
a sawed-up wooden baseball bat. Food for thought.
----------------------------------------------------------------------------------------

Long been the choice of Them Who Knows, Harry. Ash. Well made. Nice
grip. Pull the pin and you'd just equipped yourself with a Training
Aid. Still best choice for Primary Gliders, in my opinion. (Modern
stuff, the joystick usually has to be crooked as a dog's hind leg.)

-Bob

PS -- Not quite a rant. More of a memorial to 'Orville's flight
instructor,' a common topic of discussion between my dad and his dad,
with me allowed to listen in.

Brian,

You've fallen into a trap that is well known on this newsgroup. The
trap is called "conventional wisdom". It occurs when someone who
doesn't really know (you) gains knowledge from someone else who sounds
like he knows and has a bunch of fancy credentials to support his
position, but doesn't really know either (Culick).

Culick is good at writing books and papers and producing lots of fancy
math to prove his theory of what might have happened 107 years ago.
But, Culick wasn't there. His only real experience with an actual
Wright machine is with the AIAA's reproduction 1903. A machine which,
to my knowledge, has never flown. Therefore, even though Culick is
able to produce complex calculations and site lots of "expert" sources
for his paper, he himself probably has zero working knowledge of the
machine in the air. (None that I can document anyway.)

One of the expert sources he cites is "Engler". That would be Nick
Engler of Wright Brothers Airplane Company. Now Engler does have real-
world experience with Wright gliders. How do I know? Because I'm the
one who schleped all three of his gliders from the parking lot out to
his tent on the dune at Jockey's Ridge State Park on Sept 09, 2001.
I've met the guy. He's a nice guy. But, from my experiences, Engler
takes certain liberties when stating facts about the Wrights and their
machines. By that, I mean that he may be right about a point, but
can't prove it. And rather than calling it a theory, he claims it as
fact. That's not something that I do. He also takes certain liberties
in constructing his reproduction machines.

Case-in-point. The upper wing of Engler's 1902 glider calls for two
additional braces that Wilbur didn't need. These braces run diagonally
from the rear spar to the trailing ends of the two center ribs. Engler
claims they're necessary to keep the ribs from breaking if you build a
2-piece wing. (Wilbur's was one-piece and was never disassembled, but
Engler's had to come apart in 2 18' sections be transported.) Well,
somebody else figured out how to build that same 2-piece design into
the same wing without the additional bracing. And in 6 years, he has
never broken those ribs in question. How? That person followed
Wilbur's notes and used a 15-ga solid strand spring-steel wire in his
trailing edge instead of the 7x19 3/32" stainless steel cable that
Engler used. That person's trailing edges are also straight like
Wilbur's, and not scalloped between the ribs like Engler's. See,
Engler was afraid of solid-strand wire. Afraid it might break. And
since "we all know that cable is the only acceptable material to use
in an aircraft", he used it. And introduced a problem and a solution
that never occurred in 1902. Now was he right in doing this? Maybe.
But if you read notebooks "A" - "C", you will never find a single
reference to a wire breakage on any Wright machine. If Wilbur and
Orville never broke a wire, why would I break one? I used the correct
wire and have never broken one.

Second example from Engler. Take a look at his 1901 bicycle-experiment
photos from a few years ago. You'll see a red bike with a horizontal
wheel mounted pannier-style out in front of the handlebars. Look
closely. You'll see that his wheel was mounted to a horizontal support
that connects to the handlebars, and is braced by struts bolted to the
axle of the front wheel. Typical setup for panniers. Also, the test
airfoil and plate look to be about 2"x9". You'll also see this same
design on the replica at Carallion Park. Looks good. Don't work.
Again, go back and read Wilbur's notes. That flat plate is 9"x 18" or
so. And the airfoil is nearly that big too. Second, if you try riding
the pannier-mount bike, you'll see that the test wheel swings from
side to side as you steer, invalidating the test. Third, and this one
is sneaky, Wilbur and Orville drew the description in the book
backwards! How do I know? Because I tried it myself. What would they
have really done? Probably mounted that wheel just like they said, "on
a spar projecting forward". Delivery bikes around 1900 featured a
front basket mounted on tubes that were braised directly to the frame.
(I've seen one.) Is that what the Wright's did? I dunno. But the wheel
is steady that way. Now, about those steel bits that are supposed to
balance. If you look at the drawing in the notebook (or even NASA's
fancy graphic on their site) you'll see the surfaces are mounted on
the leading 1/2 of the test-wheel. But, when you start riding, they
don't stay there for long. Nope, they swing around and smack you in
the face until they reach equilibrium. Wana guess how I know this?
Yea. I tried it myself. Now all of the fancy math still works, but the
fact of the matter is that no one seems to have descovered this little
problem until about a year ago. About the time that I posted photos of
my test-bike on my now-defunct website (thanks AOL). Then, about three
months later, Engler's bike had ditched the pannier-mount for wooden
spars lashed to the bike frame with waxed linen cord. His test
surfaces also grew. And there's Gaffney (or that-other-guy that I met
in 2001) riding down the street on the bike dressed up like Wilbur
showing how the little wing-thingie is balanced in the back 1/2 of the
wheel. Hmmmmmm. Why the sudden change in design? Am I that
influential? If I am, I certainly don't think so.

So, there's what I know about experts that write fancy papers and
claim all sorts of things that they haven't tested and can't prove.
Now I'm not claiming to know what Wilbur and Orville did. I can only
say that I built a machine that is similar to thier 1902 in X-Y-Z
respects and dissimilar in A-B-C resepects. And that my machine
exhibited similar characteristics to those described in the Wright
notebooks, and produced similar test values and results. And, I can
tell you what happens when I warp the left leading edge of MY glider
down in a wind. And that is, it rolls really slowly left until the
right (not left, right) wingtip stalls and falls. That effect is
dependent on airspeed of course. Sometimes it does stall, and
sometimes it doesn't. Sometimes it just wallows around like a pig,
from what I've experienced. But, its not the warped-up left trailing
edge that causes the drag or the stall. Its the right wing. From what
I've experienced.

Take that for what its worth, but do not believe me. Go build a Wright
1902 glider yourself. Then take it to Jockey's Ridge and fly it. Then
come tell me what your machine did when you warped the wings. Then
you'll have a theory to add to the Wright-collective-history and you
can call yourself an expert. Throw in some complicated equations and
you'll be as good as Culick or Engler, or me for that matter.

Bob keeps hitting the nail on the head. Try it, test it, make it
better, fly it. Learn from others, but do not be limited by them. They
may not know what the hell they're talking about.

Harry