Today's Message Index:
----------------------
1. 12:15 AM - Re: Silencer box (Christopher Armstrong)
2. 04:08 AM - Re: wings (Ted Cowan)
3. 06:41 AM - MKIII CLASSIC KIT WITH JABIRU ENGINE FOR SALE (Jim Ballenger)
4. 07:42 AM - Re: Weight & Balance on Firestar II (James and Cathy Tripp)
5. 08:45 AM - Re: Re: wings (Christopher Armstrong)
6. 09:28 AM - more wing (Bob Bean)
7. 11:56 AM - Re: more wing (snuffy@usol.com)
8. 01:10 PM - Re: more wing (Bob Bean)
9. 01:26 PM - oopps (Paul Petty)
10. 01:44 PM - Re: more wing (snuffy@usol.com)
11. 01:58 PM - apoligy (Paul Petty)
12. 02:25 PM - Re: more wing (Richard Pike)
13. 03:04 PM - Re: more wing (John Hauck)
14. 04:25 PM - Re: more wing (snuffy@usol.com)
15. 04:27 PM - Re: more wing (Richard Pike)
16. 05:12 PM - Re: mo' n mo' wing (Bob Bean)
17. 05:12 PM - Re: more wing (Thom Riddle)
18. 05:27 PM - Re: Wing Mod Weights (Don Gherardini)
19. 05:58 PM - Re: Re: mo' n mo' wing (Christopher Armstrong)
20. 06:01 PM - Re: oopps (Christopher Armstrong)
21. 06:21 PM - Fabric attachment (Andrew Gassmann)
22. 07:13 PM - enclosure question (ZackGSD@aol.com)
23. 07:29 PM - Re: oopps (Denny Rowe)
24. 08:01 PM - Re: Wing Mod Weights (Richard Pike)
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 |
|
--> Kolb-List message posted by: "Christopher Armstrong" <tophera@centurytel.net>
Who is up for a SWAG. ( newbys SWAG stands for Scientific Wild Ass Guess.)
If you put a hole in your nice finished box right in front of the current
outlet you would have a short path and a long path.
The differences in length are equal to a time when you devide by the speed
of sound. ~1000 feet per second. If that distance is equal to n+0.5 ( n=0
or any positive integer ) wave lengths at the frequency that you want to
squash then you will get the canceling effect that you are looking for.
So if you want to squash say 11000hz (5500 rpm times two cylinders sucking)
then you have (~1000ft/sec)/(11000/sec)= .091 feet (1.1 inches) peek to
peek.
If I did any of this right if you set your length to (n+0.5)*1.1 inches you
should get some wave canceling effect. This will squash all the frequencies
that are multiples of the target frequency as well, 22000hz 33000hz etc.
What you have to do is get the magnitudes of the two waves that same so that
they can completely eliminate each other. Most likely the short path is
louder then the long path so they cant completely cancel each other. By the
way if you end up at an n*1.1 inches length you double the noise, and you
would double the noise at every frequency that has this length, in this case
the half multiples of 11000; 5500, 16500, 27500 etc.
So .55, 1.65, 2.75, 3.85, 4.95, 6.05, 7.15, 8.25 inches would cancel your
primary frequency and all the whole multiples while boosting all the half
multiples. So you need to know the sound spectrum of the noise and pick the
length based on which frequencies to squash and at the same time avoiding
the ones that you can't be doubling.
Course I could be FOS cause it is just a SWAG.
Topher
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 |
|
--> Kolb-List message posted by: Ted Cowan <tcowan1917@direcway.com>
a related story here brings up a what I believe to be a good question. If
the Firefly does well, as does the SlingShot, as does the Kobra, then why
wouldnt shortning the Original Firestar wing (removing the added materials,
i.e., 12 inche extension on each wing) provide a lighter, more efficient
wing than the standard 27 footer. I have the original firestar, five rib,
been flying it for over seven years, and cannot think of any improvement
that I would make to it. It is probably the best flying Kolb ever built.
Performs like a dream and if you learn to fly it well, will get you in or
out of just about anything. Notice I did not say without bumping around.
But -- being five ribs, wouldnt reducing the length of the wing have very
profound good benefits; speed, efficiency, weight and still have pretty much
the soft, slow landings I have come to know. I would think that would be
better than adding beef to the dead cow. Of course, I might be wrong cause
shorter might give you more speed easier and thus needing the beefing. I
have had mine up to and including the 80 - 85 plus that I have heard about
without any flutter -- just feels like it is really fast and gets real light
on the controls. Just my thinking. Am rebuilding the ole white lightning
from ground up and just getting to the wings. Not going to make any changes
in the original design. Cant improve on something this good. (not and sell
it too). What do you say about that. ted cowan, alabama
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: | MKIII CLASSIC KIT WITH JABIRU ENGINE FOR SALE |
--> Kolb-List message posted by: "Jim Ballenger" <ulpilot@cavtel.net>
Kolbers
Dave Stroberg near Edenton, NC has his MKIII for sale. He has most of the instruments
and a 16/19 gallon aluminum fuel tank. It needs covering and I think he
has the material to cover it. Dave is terminally ill and can not finish the
kit. He does not want to sell any item separately. If you are interested, please
contact his wife at phone number 252-264-2240 for more information. He
is asking $23k but you can probably get it for $19k.
Jim Ballenger
Flying a FS KXP 447
Building a MK III X
Virginia Beach, VA
DO NOT ARCHIVE
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: Weight & Balance on Firestar II |
--> Kolb-List message posted by: "James and Cathy Tripp" <jtripp@elmore.rr.com>
7.5 inches which should equate to 9 degrees.
James Tripp
FSII
DO NOT ARCHIVE
----- Original Message -----
From: "Vic" <vicw@vcn.com>
Subject: Kolb-List: Weight & Balance on Firestar II
> --> Kolb-List message posted by: "Vic" <vicw@vcn.com>
>
> I need to update my weight and balance on my Firestar II but I don't have
my
> plans with me. Can someone supply me with the measurement for leveling
the
> plane. What I am looking for is the number of inches from the leading
edge
> to the level.
>
> Vic
>
> Do Not Archive
>
>
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 |
|
--> Kolb-List message posted by: "Christopher Armstrong" <tophera@centurytel.net>
If the Firefly does well, as does the SlingShot, as does the Kobra, then why
wouldnt shortning the Original Firestar wing (removing the added materials,
i.e., 12 inche extension on each wing) provide a lighter, more efficient
wing than the standard 27 footer.
Shorter wingspan means lower aspect ratio and reduced wing efficiency. But
oddly enough that does not necessarily mean worse performance across the
speed range. Airfoils are optimized for lift to drag at a given lift value.
The designer try's to size the wing so that at his chosen airspeed the wing
is operating at that most efficient lift coefficient. On the FSII with
their generous wing area the airspeed where the wing is operating at that
lift coefficient is fairly slow. As you speed up each foot of wing needs a
lower lift coefficient because there is more wind and you get farther and
farther away from this optimum lift coefficient. By reducing wing span the
wing area is reduced and the speed where the wing operates most efficiently
increases. At any given lift coefficient the wing is less efficient but at
points that were above the target speed before the trim job you can end up
with a net improvement, below it you end up with a reduction. If you get
carried away the performance goes down everywhere and you feel real bad
about your choices. If you add wing span the performance goes up below the
sweet spot and down slightly above it. If a plane gets heavier and you add
wing span you can often gain back the initial performance because you are
getting back to the original sweet spot( less the weight penalty). If you
decrease the weight you also are reducing the Lift required and shifting the
plane below the sweet spot. Part of my decision to clip my wings is that I
am fairly light (160 pounds on a bad day) and I plan on putting a bare
minimum of gear on the plane, keeping it light as well. I will need lower
lift coefficient then some of you big boys with lots of in plane toys, and I
am willing to give up a bit of the short field capability for a small
increase in cruise, so a bit less wing should be a benefit for me. Of course
it could backfire and my plane might suck!
Topher
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 |
|
--> Kolb-List message posted by: Bob Bean <slyck@frontiernet.net>
High lift airfoils like kolb and piper cub can get away with clipping better
than more symetrical shapes. You may be able to reduce the loss of aspect
ratio by using a fence. -I doubt that a winglet would help much on a short
stubby wing. After sleeping a bit on what I'll be doing to mine....I knew
I was going to put fences on my open wing roots and now will extend them
both top and bottom. Even on a stock MkIII, unless it had a completely
enclosed rear like John H's, I would try to stop the air from sliding
inboard from the wing bottom. The accelerated air from the prop suction
causes a lot of pressure loss under the wing. Mine must be missing a
good 20% of lift as it is right now. I have flown (just for
experimentation)
other general aviation aircraft with the root fairings removed....very
noticeable. -BB, dormant MkIII, N3851E, dusty tool box do not archive
Message 7
| 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 |
|
--> Kolb-List message posted by: snuffy@usol.com
. The accelerated air from the prop suction
> causes a lot of pressure loss under the wing. Mine must be missing a
> good 20% of lift as it is right now.
So what happens then in a case like Richard Pikes parasol wing? I think
his lift is improved. It still has the accelerated air from the prop
suction. Does it have something to do with the turbulance caused by the
air spilling off the wing into the center section? Kirk
Do not
archive
Message 8
| 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 |
|
--> Kolb-List message posted by: Bob Bean <slyck@frontiernet.net>
hmmm, good question Kirk. After revisiting the ambitious mr Pike's
website here's my take: He has reduced his drag by frontal area reduction,
commendable. Increased lift?? To get lift one has to deflect the air
downward somehow. I doubt whether the air going around all that
stuff in the center section is going to be cranked downhill, especially
with the big baloney slicer chopping it up. That kind of effect is better
accomplished by tractors the likes of the Dyke Delta , Wittman Tailwind
and Bellanca Viking. It is fun to imagine the results of what could be
done and I'll sure letcha all know if I get any improvement with my
eventual configuration. -BB do not archive
snuffy@usol.com wrote:
>--> Kolb-List message posted by: snuffy@usol.com
>
>.. The accelerated air from the prop suction
>
>
>>causes a lot of pressure loss under the wing. Mine must be missing a
>>good 20% of lift as it is right now.
>>
>>
>
>So what happens then in a case like Richard Pikes parasol wing? I think
>his lift is improved. It still has the accelerated air from the prop
>suction. Does it have something to do with the turbulance caused by the
>air spilling off the wing into the center section? Kirk
>
>Do not
>archive
>
>
>
>
Message 9
| 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 |
|
--> Kolb-List message posted by: "Paul Petty" <Lynnp@c-gate.net>
Ok guys, Here is one for the shark tank. Last night I got busy on the second wing
and after drilling the first set of holes in the top of the spar I removed
the steel root and turned around with my back to the saw horses and spar to debur
and then heard what appeared to be a Cessna 150 crashing into the work area!!!
The spar ever so slowly rolled off the saw horses and did a baton dance on the
shop floor for what seamed to be eternity!!!!! That's right, I dropped the spar.
I said I dropped the spar...I DROPPED THE DAMN SPAR!!!! The noise was so tremendous
it scared the living daylights out of me and I threw the wing root and
deburring tool into the air and ran for my life!!!!! I thought the building
was caving in on me. Well once I determined the source of the excitement I rushed
to evaluate the damage. Surprisingly there was only one small dent in each
end.
So here is the question of the day. Can I fix the ding and move on? My thoughts
say yes. I'm thinking about cutting a plug, if you will, out of 3/4" plywood
and bevel it ever so slightly and drive it in the end. Or get my machinist buddy
to machine a piece of steel pipe with a slight taper to resize the end. The
root end dent will come out when I rivet the steel ring into place. The wing
tip end must have been the first to make contact because it is a bigger ding.
I have to be the first idiot to have pulled this off. Bet even Beauford hasn't
went this far into stupidity land. What about it Beauford? Got any scrapped spars
in your monument of foul ups? If I decide to scrap the spar I still have
the damaged tail boom I can use if it is the same material. On another note, not
Kolb related, however somehow ties into this post on the OOOPPS scale index.
Have you guys and gals, if there are any, ever seen the videos of the F-16 that
crashed at an air show in Idaho? If you haven't check them out. The pilot
punched out .8 seconds before impact!!!
http://www.f-16.net/f-16_photos_album04-photodis.html
http://www.f-16.net/f-16_news_article842.html
http://www.f-16.net/PhotoGallery/album44/aby.mpg
http://www.f-16.net/PhotoGallery/album44/acb.wmv
Bet the noise level was close to what I heard.....
Paul Petty
Ears still ringing
Building Ms. Dixie
Kolbra/912UL/Warp
do not archive for heaven's sake
Message 10
| 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 |
|
--> Kolb-List message posted by: snuffy@usol.com
. I doubt whether the air going around all that
> stuff in the center section is going to be cranked downhill, especially
> with the big baloney slicer chopping it up.
I think with his parasol configuration that more air is directed to the
lower half of the prop arc . So I would assume from this that there
must be some pressure on the underside of the center section of his
wing. ????????
Do not archive
Message 11
| 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 |
|
--> Kolb-List message posted by: "Paul Petty" <Lynnp@c-gate.net>
Bob Dalton,Bryan,Duncan,Craig,Bean, and all,
I was half asleep when I posted "Last Post" I was not planning on bailing out.
Just toning back. This Internet stuff has become a very time consumer and affecting
me at work and home as well. Not to mention cutting into my Kolbra constuction.
No one has ever offended me with humors jabs. Hell I'm a big target for
that! I love it. John Hauck is the only one that has made me tuck my tail a
few times but well needed and well taken. I tend to respect those who have "been
there done that got tha T-shirt"
Thanks to everyone that has put up with my goofy side of life. Remember I'm from
Mississippi. Heck I even learned how to correctly use the ' thingy from one
member who had a interest in my grammar. Uncle Craig had me on the floor laughing
with his post...
I guess I'm hooked someone toss me a lifesaver.....
pp
do not archive
Message 12
| 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 |
|
--> Kolb-List message posted by: Richard Pike <rwpike@charter.net>
I have wondered the same thing. I know that performance has improved, but
is it primarily because the prop is getting fed more and somewhat less
turbulent air, and especially in a way that the thrust is not all from the
top half of the disc? (pushing the nose down) Or is the wing doing more?
And how would you know which?
I agree that if there was some way to further clean up the whole area, it
might get better. The two clunkiest things that need to be removed are the
radiator and the muffler.
Daydreams follow... (Thinking outside the box here) (1) Redo the exhaust
system to put the muffler out in front of the engine, inside my current
streamline section between the parachute launcher and the engine. Now the
only part of the exhaust hanging out would be the expansion cone, which
would now be in line with the airflow, plus the manifold itself.
(2) Eliminating the radiator by using the lift struts instead. Don't know
how Kolb is currently doing it, but when I got my kit with the streamlined
extruded aluminum lift struts, there is a 1" or 1 1/8" tube that runs full
length down the middle of the lift strut. There is room to run two 5/8"
thinwall aluminum tubes through the length of the lift strut. One ahead of
the 1 1/8" tube, and another one behind it. Slip fit/epoxy them in place,
(so that they will heat transfer to the lift strut) and connect them
together at the top of the strut with a joint around the actual lift strut
fitting. Replumb your cooling system so that the hot coolant runs up the
front of each strut and down the back, and then back to the engine.
I have not pursued this because it gives Murphy's Law too many
opportunities, and also because every time you need to take the airplane
apart, you would have to drain all the coolant and that would be a major
hassle, I would rather give up the efficiency. (Sob) Also, would it work
well enough to keep the engine from overheating while you were sitting
still on the ground with no airflow? Maybe not.
Not to mention the whuffo that comes up and grabs a hot strut and takes a
handful of hide off their palm, and then wants to sue you...
Back to the topic - I think the improvements come mostly because of better
airflow to the prop and slightly because of more pseudo-wing available. But
that is an area that would benefit from more improvements, and I have
certainly not exhausted the possibilities.
One place where I really missed the boat - When I set my wing incidence, it
is by the plans, but the inboard rib bottoms do not line up correctly with
the perimeter sub-frame that comes welded from the factory for the center
section. Redoing it now is more trouble than it's worth, but if I had not
already built my center section gas tank, I would redo that area to match
the steel tubing to the bottom of the wing in alignment. That would allow a
gap seal along the bottom of the wing.
Richard Pike
MKIII N420P (420ldPoops)
At 04:09 PM 2/7/04 -0500, you wrote:
>--> Kolb-List message posted by: Bob Bean <slyck@frontiernet.net>
>
>hmmm, good question Kirk. After revisiting the ambitious mr Pike's
>website here's my take: He has reduced his drag by frontal area reduction,
>commendable. Increased lift?? To get lift one has to deflect the air
>downward somehow. I doubt whether the air going around all that
>stuff in the center section is going to be cranked downhill, especially
>with the big baloney slicer chopping it up. That kind of effect is better
>accomplished by tractors the likes of the Dyke Delta , Wittman Tailwind
>and Bellanca Viking. It is fun to imagine the results of what could be
>done and I'll sure letcha all know if I get any improvement with my
>eventual configuration. -BB do not archive
Message 13
| 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 |
|
--> Kolb-List message posted by: "John Hauck" <jhauck@elmore.rr.com>
> I have wondered the same thing. I know that performance has improved, but
> is it primarily because the prop is getting fed more and somewhat less
> turbulent air, and especially in a way that the thrust is not all from the
> top half of the disc? (pushing the nose down) Or is the wing doing more?
> And how would you know which?
> Richard Pike
Richard/All:
Since I am not an engineer or mathematician, I must look at "stuff" with the
little bit or "horse sense" I have left.
Was thinking about the statement above. My question is: Would it make any
difference on nose pitch down, whether the top or bottom of the prop is
creating the thrust, since the prop is attached to the aircraft by the prop
shaft in the center of the prop?
Not trying to be a wise ass, but trying to learn.
Thanks,
john h
Message 14
| 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 |
|
--> Kolb-List message posted by: snuffy@usol.com
My question is: Would it make any
> difference on nose pitch down, whether the top or bottom of the prop is
> creating the thrust, since the prop is attached to the aircraft by the
prop
> shaft in the center of the prop?
I know that if I put the prop in a vertical position on my Minimax I can
grab the top end and lift the tail of the plane off the ground. Of
course it's a Warp Drive and I wouldn't do it with any other prop. ;o)
Do not
archive
Message 15
| 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 |
|
--> Kolb-List message posted by: Richard Pike <rwpike@charter.net>
I came by my theory by visualizing pushing it - say you could have a model
MKIII and the wing was the main source of drag, and you could push on it by
pushing on the prop with your finger. If you had a two blade prop, and you
pushed on the back side and end of the top blade, the thrust vector would
go through the hub, but the push would tend to push the nose down. But if
you pushed on the back side and end of the downward pointing blade, then it
would tend to push the nose up, the force still going through the hub.
Anyway, that is how I picture it, but in high school physics class, I had
to sit on the back row.
(The better your grades, the closer to the front you sat, and vice versa...)
(The problem was I was trying to be a wise ass, but the test scores usually
pointed more toward the dumb variety)
Now what we need is a reality check by one of the listers who didn't sit on
the back row.
Guys?
Richard Pike
MKIII N420P (420ldPoops)
At 05:03 PM 2/7/04 -0600, you wrote:
>--> Kolb-List message posted by: "John Hauck" <jhauck@elmore.rr.com>
>
>
> > I have wondered the same thing. I know that performance has improved, but
> > is it primarily because the prop is getting fed more and somewhat less
> > turbulent air, and especially in a way that the thrust is not all from the
> > top half of the disc? (pushing the nose down) Or is the wing doing more?
> > And how would you know which?
> > Richard Pike
>
>Richard/All:
>
>Since I am not an engineer or mathematician, I must look at "stuff" with the
>little bit or "horse sense" I have left.
>
>Was thinking about the statement above. My question is: Would it make any
>difference on nose pitch down, whether the top or bottom of the prop is
>creating the thrust, since the prop is attached to the aircraft by the prop
>shaft in the center of the prop?
>
>Not trying to be a wise ass, but trying to learn.
>
>Thanks,
>
>john h
>
>
Message 16
| 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: mo' n mo' wing |
--> Kolb-List message posted by: Bob Bean <slyck@frontiernet.net>
John, you're an old rotor head....remember precession? Swash plate input
90deg before
reaction. Should be the same with a prop. If you feed it more air at the
top the reaction
should be to turn left or right depending on rotation. Shoot me down if
I'm wrong.
-BB do not archive
http://search.netscape.com/ns/boomframe.jsp?query=precession+helicopter&page=1&offset=0&result_url=redir?src=websearch&requestId=f0fc17a23e51eae8&clickedItemRank=1&userQuery=precession+helicopter&clickedItemURN=http%3A%2F%2Fwww.cavalrypilot.com%2Faerodynamics%2Fgyro.html&invocationType=-&fromPage=NSCPResults&remove_url=http://www.cavalrypilot.com/aerodynamics/gyro.html
<http://search.netscape.com/ns/boomframe.jsp?query=precession+helicopter&page=1&offset=0&result_url=redir%3Fsrc%3Dwebsearch%26amp%3BrequestId%3Df0fc17a23e51eae8%26amp%3BclickedItemRank%3D1%26amp%3BuserQuery%3Dprecession%2Bhelicopter%26amp%3BclickedItemURN%3Dhttp%253A%252F%252Fwww.cavalrypilot.com%252Faerodynamics%252Fgyro.html%26amp%3BinvocationType%3D-%26amp%3BfromPage%3DNSCPResults&remove_url=http%3A%2F%2Fwww.cavalrypilot.com%2Faerodynamics%2Fgyro.html>
Message 17
| 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 |
|
--> Kolb-List message posted by: "Thom Riddle" <jtriddle@adelphia.net>
Mr. Pike's analysis is correct. For those who understand moments (anyone doing
weight and balance should be familiar with the term) and or torque(same thing
really), what is happening with asymmetrical thrust(more on top compared to bottom),
a moment (or torque) is created about the lateral axis (think wing span)
resulting in a nose down pitching force(moment).
I sat in the front row but mostly because I've been hard-of-hearing to stone deaf
and back to hard-of-hearing over the years. But being in the fron row there
was little I could do to avoid learning something occasionally and this sort
of stuff stuck with me for some reason.
Thom in Buffalo
Message 18
| 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: Wing Mod Weights |
--> Kolb-List message posted by: "Don Gherardini" <donghe@one-eleven.net>
brother Pike
a post you made caused me to think of a time WAAAYYY back,,,,back at Spartan
when I was in the Airframe classes...
snip<<<<Everyone agrees that Kolb ribs are probably the weakest link in the
whole
wing structure, yet SOP is to drill them full of unnecessary 1/8" rivet
holes all down their top & bottom surface to secure the fabric, (when they
could be just as easily rib stitched, and probably with less weight) then
>>>>snip
I can vividly remember the day I pondered this same question...not about a
Kolb of course...but of the Idea of riveting fabric to ribs...vs rib
stitching.
now...he may not have been right...but the instructor went into a long
speech about which is better...when you do..when you dont...an so on...
but basically here it is....a round top or tubing rib should never be
ribstitched ... to keep from "puckering" or "dimpleing" the fabric...and
when heat shrink type fabric is used...just about never.
A flat top or cap'ed rib should/may be rib-stitched..
Still....all them holes just cant help...I'lll betcha if Homer didn't have
to pay Dennis and John them danged high wages, he probably could have
afforded a big ole press with some nice rib forming dies and we would have
Kolbs with nice stamped ribs in em today!!!!
(...grin....!)
Don Gherardini
FireFly 098
http://www.geocities.com/dagger369th/my_firefly.htm
Message 19
| 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: mo' n mo' wing |
--> Kolb-List message posted by: "Christopher Armstrong" <tophera@centurytel.net>
John, you're an old rotor head....remember precession? Swash plate input
90deg before
reaction. Should be the same with a prop. If you feed it more air at the
top the reaction
should be to turn left or right depending on rotation. Shoot me down if
I'm wrong.
Well that won't be necessary but...
Precession refers to a gyroscope that reacts 90 degrees off from any input
moment. What we are talking about here is where the center of force on the
prop disk is. The rotor heads might remember that as you speed up from
hover the advancing blade starts making more lift then the retreating blade
rolling you to the retreating blade side so you have to move the collective
to the advancing bade side.
Similarly p factor is when you are nose up the right side of the prop has a
reduced AOA and less speed and the left side has an increased aoa and has
more speed. The left blade makes more lift and yaws you to the right.
If the top of a prop is making more lift it will indeed pitch the nose down.
How it is hooked to the plane is not important. If the rotor disk of a
ridged rotor helicopter couldn't move its center of lift and use the
horizontal moment arm to generate a moment then the pilot could not control
it. Flapped rotors work more like a weight shift trike, tilting the rotor
disk and generating a side force with a vertical moment arm to the cg, with
the same results.
I think I am meandering way off topic... oops
Topher
Message 20
| 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 |
|
--> Kolb-List message posted by: "Christopher Armstrong" <tophera@centurytel.net>
Well I would put a couple of stops on your saw horses/work table right
now... that was the first thing I did, so I had to ding my spar the old
fashioned way, by dropping tools on it.
Message 21
| 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: | Fabric attachment |
--> Kolb-List message posted by: Andrew Gassmann <a1929gassmann@earthlink.net>
This was mentioned many moons ago, using the HIPEC system:
No stitching or rivets..read more:
http://www.sirius-aviation.com/hipec.html
Andy
Message 22
| 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: | enclosure question |
--> Kolb-List message posted by: ZackGSD@aol.com
i'm new to the list, so forgive me if i do not get this just right. i just
bought a one-owner 95 kold firestar in mint condition w 90 hrs. 503, single
card. i am a ga pilot and have had two ul in the past. two questions..1.. has
anyone enclosed an older firestar before with lexan? at least back to the
bulk-head, right before the 5 gal. tank? 2. has anyone every placed a small
extra tank right behind the seat, i.e., a 3 gal tank? would this change the cg
to
do so, or is that right on the mark?
alan
Message 23
| 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 |
|
--> Kolb-List message posted by: "Denny Rowe" <rowedl@highstream.net>
Paul wrote:
Surprisingly there was only one small dent in each end.
> So here is the question of the day. Can I fix the ding and move on? My
thoughts say yes. I'm thinking about cutting a plug, if you will, out of
3/4" plywood and bevel it ever so slightly and drive it in the end. Or get
my machinist buddy to machine a piece of steel pipe with a slight taper to
resize the end. The root end dent will come out when I rivet the steel ring
into place.
Paul,
I would feel comfortable with working the dents out and using the spar,
being they are on the ends, they should not be under much load, especially
the tip end, and as you said the ring takes care of the root end.
See what others think, but I say its probably fine.
The spars and tail boom are the same tubing.
Denny Rowe, Mk-3, PA
Message 24
| 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: Wing Mod Weights |
--> Kolb-List message posted by: Richard Pike <rwpike@charter.net>
Good point, riveting the fabric has to look a lot better than putting a
knot on top of an already round rib. (Which is why I tied my knots off to
one side of the rib - minimize the visual damage).
But the question is not appearance but rib strength.(If you can tolerate
"Homer Bumps" on the trailing edges, rib stitch bumps might seem less awful)
Richard Pike
MKIII N420P (420ldPoops)
At 07:33 PM 2/7/04 -0600, you wrote:
>--> Kolb-List message posted by: "Don Gherardini" <donghe@one-eleven.net>
>
>brother Pike
>
>a post you made caused me to think of a time WAAAYYY back,,,,back at Spartan
>when I was in the Airframe classes...
>
>
>snip<<<<Everyone agrees that Kolb ribs are probably the weakest link in the
>whole
>wing structure, yet SOP is to drill them full of unnecessary 1/8" rivet
>holes all down their top & bottom surface to secure the fabric, (when they
>could be just as easily rib stitched, and probably with less weight) then
> >>>>snip
>
>I can vividly remember the day I pondered this same question...not about a
>Kolb of course...but of the Idea of riveting fabric to ribs...vs rib
>stitching.
>now...he may not have been right...but the instructor went into a long
>speech about which is better...when you do..when you dont...an so on...
>
>but basically here it is....a round top or tubing rib should never be
>ribstitched ... to keep from "puckering" or "dimpleing" the fabric...and
>when heat shrink type fabric is used...just about never.
>
>A flat top or cap'ed rib should/may be rib-stitched..
>
>Still....all them holes just cant help...I'lll betcha if Homer didn't have
>to pay Dennis and John them danged high wages, he probably could have
>afforded a big ole press with some nice rib forming dies and we would have
>Kolbs with nice stamped ribs in em today!!!!
>(...grin....!)
>
>Don Gherardini
>FireFly 098
>http://www.geocities.com/dagger369th/my_firefly.htm
>
>
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! --
|