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Old Apr 13, 2008, 03:11 PM
Anyolmouse
Guest
n/a Posts
Re: Flying wing design


"BCRandy" <RMAHEUXR@bellsouth.net> wrote in message
newsgtMj.32659$dT.9300@bignews1.bellsouth.net...
| I'm new to RC. Looking about the web brought up a question
| perhaps someone more knowledgeable can answer. What would
| happen if you built a flying wing with a small amount of
| dihedral? Would it be more forgiving for beginners?
| Wouldn't inverted flight be unstable? TIA.
|
| Randy
|
|

Bill Evans designed and built several flying wing models called
Simitars. I built one of them from plans called the Zippity Do Da. It
has a small amount of dihedral and he also designed some with anhedral.
All fly well. The main thing that makes them fly well is the reflex
airfoil design. Setting the airplane up requires the elevons to be up
approximately 1/8 inch from the hinge line. Also the angle of attach
must be approximately plus 1/4 inch as it sets on the gear. Otherwise it
makes taking off difficult. Here is a link to his autobiography
http://www.modelaircraft.org/museum/bio/Evans.pdf

--
Anyolmouse

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Old Apr 13, 2008, 03:36 PM
BCRandy
Guest
n/a Posts
Flying wing design

I'm new to RC. Looking about the web brought up a question
perhaps someone more knowledgeable can answer. What would
happen if you built a flying wing with a small amount of
dihedral? Would it be more forgiving for beginners?
Wouldn't inverted flight be unstable? TIA.

Randy


Old Apr 14, 2008, 09:11 AM
Ed Paasch
Guest
n/a Posts
Re: Flying wing design

Most flying wing designs are surprisingly stable and relatively easy to fly
one an RC pilot has mastered his basic trainer aircraft. Electric flying
wings like the Great Planes Slinger/ Mini Slinger, the Thunder Tiger
Velocity EP, or the Parkzone Stryker are very popular as second aircraft
because they look cool, can fly fast, and aren't too difficult to control so
long as one remembers to turn down the throttle once in a while.

The Zagi family of aircraft from Trick R/C is another very popular family of
flying wing. Some models like the Tazz w/ brushless outrunner motor can be
very high performance, however, and are better as a "next step up" after a
pilot has flown something more tame and wants another challenge. Several of
the "brushed" motor Zagis are available that are good choices for the
budding pilot, however, and the EPP wing cores used in the Zagi models have
a reputation for being very hard to damage.

Part of what makes these planes easy to fly is the lack of dihedral. They
fly as well upside down as they do right side up. Spinning them around
quickly and getting comfortable with inverted flight help newer pilots
acclimate to faster manuevers that will be commmonplace as they learn to fly
scale IMAC aerobatic planes and/or 3D models.

If you've mastered your basic 4-channel aileron trainer and you want to move
up to something faster that looks cool but is still easy to fly, one of
these electric flying wings is a terrific choice.

Ed P.
a.k.a. bigedmustafa

"BCRandy" <RMAHEUXR@bellsouth.net> wrote in message
newsgtMj.32659$dT.9300@bignews1.bellsouth.net...
> I'm new to RC. Looking about the web brought up a question perhaps
> someone more knowledgeable can answer. What would happen if you built a
> flying wing with a small amount of dihedral? Would it be more forgiving
> for beginners? Wouldn't inverted flight be unstable? TIA.
>
> Randy
>
>



Old Apr 14, 2008, 06:04 PM
MJKolodziej
Guest
n/a Posts
Re: Flying wing design


"Doug McLaren" <dougmc+usenet-20080414@frenzied.us> wrote in message
news:1208198782.22288@frenzied.us...
> In article <2KIMj.65924$y05.64161@newsfe22.lga>,
> Ed Paasch <bigedmustafa@hotmail.com> wrote:
>
> | Most flying wing designs are surprisingly stable and relatively easy
> | to fly
>
> I'm going to have to disagree with you.
>
> I've flown several, powered and unpowered, from various manufacturers.
>
> They generally are not stable and have significant bad habits (such as
> a tendancy to tip stall.) They're also very sensitive to the correct
> CoG location -- off by a fraction of an inch and you can go from a
> plane that can barely keep it's nose up to one that's almost
> unflyable.
>
> However, they're generally resiliant, and that is what makes it work
> -- you can crash them repeatedly and they'll probably survive.


Doug is talking about EPP foam wings here. There are balsa built up flying
wings that don't crash as well.
.

Doug, again what is that zagi copy that you like with the X in the name?
mk


Old Apr 16, 2008, 12:37 AM
Doug McLaren
Guest
n/a Posts
Re: Flying wing design

In article <Wn7Nj.61684$yk5.47652@newsfe18.lga>,
Ed Paasch <bigedmustafa@hotmail.com> wrote:

| The three that I mentioned initially - the GP Slinger/Mini Slinger, the TT
| Velocity, and the F-27 Stryker

I have a Slinger (along with my 10 or so other various flying wings)
-- it does not come with a battery, and the battery compartment is
large enough to let you move the battery around a lot.

(It's also made with really crappy foam, I might add -- not very
stiff, and even adding bunches of CF wouldn't fix mine adequately.)

| The Zagi XT, the only one I've personally gotten to see close up for any
| period of time, also had a similar compartment and was bundled with a NiMH
| flight pack for near-foolproof balancing so long as the instructions were
| followed.

With that cavaet (all instructions were followed), all the flying
wings will be perfectly balanced all the time!

| I have no doubt there are plenty of poorly designed flying wings available

They're not `poorly designed', they just require that you follow the
instructions and be careful about the CoG, and you put the battery in
the right place every time, because the margin for error is much
smaller than with typical planes.

| With regard to the GP Slinger in particular however, I've seen pilots who
| could barely fly their glow trainers by themselves have no problem flying
| the Slinger around and actually look good while doing it. Sure, they can be
| tip stalled or put into the flying wing "death spiral,"

They're prone to it, and have no banking stability. This makes them,
all else being equal, harder to fly than planes with dihedral and your
typical `plane' shape. And since the CoG is so much more critical,
it's that much more likely that sombody will get it wrong (even with
an RTF, after a few repairs, modifications or battery changes.)

| but these planes do generally bounce pretty well.

Yes, but I was pointing out that they're harder to fly. Not
impossible, but harder.

| I can only relay what I've seen, and I've seen several pilots who weren't
| particularly proficient with other aircraft fly Slingers and Strykers like
| they were expert pilots.

Then they were better pilots than you gave them credit for. In any
event, people can and do learn to fly on planes that are hard to fly.

--
Doug McLaren, dougmc@frenzied.us
There is too much sex and violence on TV...well, too much violence anyway.
Old Apr 16, 2008, 01:49 AM
Ed Paasch
Guest
n/a Posts
Re: Flying wing design

OK Doug, I will recommend that folks avoid these finicky death-spiraling
disasters henceforth. Thank you for showing me the error of my ways.

"Doug McLaren" <dougmc+usenet-20080415@frenzied.us> wrote in message
news:1208319976.13538@frenzied.us...
> In article <Wn7Nj.61684$yk5.47652@newsfe18.lga>,
> Ed Paasch <bigedmustafa@hotmail.com> wrote:
>
> | The three that I mentioned initially - the GP Slinger/Mini Slinger, the
> TT
> | Velocity, and the F-27 Stryker
>
> I have a Slinger (along with my 10 or so other various flying wings)
> -- it does not come with a battery, and the battery compartment is
> large enough to let you move the battery around a lot.
>
> (It's also made with really crappy foam, I might add -- not very
> stiff, and even adding bunches of CF wouldn't fix mine adequately.)
>
> | The Zagi XT, the only one I've personally gotten to see close up for any
> | period of time, also had a similar compartment and was bundled with a
> NiMH
> | flight pack for near-foolproof balancing so long as the instructions
> were
> | followed.
>
> With that cavaet (all instructions were followed), all the flying
> wings will be perfectly balanced all the time!
>
> | I have no doubt there are plenty of poorly designed flying wings
> available
>
> They're not `poorly designed', they just require that you follow the
> instructions and be careful about the CoG, and you put the battery in
> the right place every time, because the margin for error is much
> smaller than with typical planes.
>
> | With regard to the GP Slinger in particular however, I've seen pilots
> who
> | could barely fly their glow trainers by themselves have no problem
> flying
> | the Slinger around and actually look good while doing it. Sure, they
> can be
> | tip stalled or put into the flying wing "death spiral,"
>
> They're prone to it, and have no banking stability. This makes them,
> all else being equal, harder to fly than planes with dihedral and your
> typical `plane' shape. And since the CoG is so much more critical,
> it's that much more likely that sombody will get it wrong (even with
> an RTF, after a few repairs, modifications or battery changes.)
>
> | but these planes do generally bounce pretty well.
>
> Yes, but I was pointing out that they're harder to fly. Not
> impossible, but harder.
>
> | I can only relay what I've seen, and I've seen several pilots who
> weren't
> | particularly proficient with other aircraft fly Slingers and Strykers
> like
> | they were expert pilots.
>
> Then they were better pilots than you gave them credit for. In any
> event, people can and do learn to fly on planes that are hard to fly.
>
> --
> Doug McLaren, dougmc@frenzied.us
> There is too much sex and violence on TV...well, too much violence anyway.



Old Apr 16, 2008, 02:23 PM
Doug McLaren
Guest
n/a Posts
Re: Flying wing design

In article <jsgNj.8901$3N1.4926@newsfe17.lga>,
Ed Paasch <bigedmustafa@hotmail.com> wrote:

| OK Doug, I will recommend that folks avoid these finicky death-spiraling
| disasters henceforth. Thank you for showing me the error of my ways.

Ok, but that's not what I said ...

`Do we still carry those flying wings?' `You mean the widow makers?'

--
Doug McLaren, dougmc@frenzied.us
A truly wise man never plays leapfrog with a unicorn.
Old Apr 16, 2008, 02:29 PM
Max George
Guest
n/a Posts
Re: Flying wing design

In message <Wn7Nj.61684$yk5.47652@newsfe18.lga>, Ed Paasch
<bigedmustafa@hotmail.com> writes
>The three that I mentioned initially - the GP Slinger/Mini Slinger, the TT
>Velocity, and the F-27 Stryker - are ARFs with very specific battery
>compartments designed to make balancing on the CG almost automatic if you
>

If you want to know more about flying wing design then go to

http://www.b2streamlines.com

I am surprised that no one has mentioned this before in this thread. It
is a very informative site
--
Max George
Old Apr 17, 2008, 05:55 AM
Daniel Krier
Guest
n/a Posts
Re: Flying wing design

I've had alot of experience with rc flying wings, so maybe some of this
info can help you.
I have a foam covered with balsa swept wing called a Javelin, it has a
symetrical airfoil and no wash-out ( wing twist). It is very fast but
has a terrible tip stall and really no low speed handling at all. Swept
wings of this type depend on a slight reflex at the rear of the airfoil
for stablity, this creates a slight down-force at the back sort of like
a tail. It helps, but doesn't seem to get the job done by itself.
I also have a couple of Klingberg wings which are actually models
based on the Horten 3 sailplane. They use an actual Horten airfoil with
several degrees of wash-out. I've never measured the wash-out but it is
probably about 6 degrees. These planes fly great both slow and fast, but
there is a noticable drag penalty for having the washout.
Most full size swept flying wings used the wash-out method: Northrop
used a symetrical airfoil and 4 degrees wash-out. The Hortens always
used semi-symetrical and and at least that much wash-out.
I recently built a scale model of the Horten 229 v1 using all the
best plan data ( A.L. Bentley) and it flys best of any I've built.
This one uses semi-symerical with some reflex toward the root,
transitioning to symetrical at the tip. This minimizes the amount of
twist needed, which was 4 degrees.
It is also true that Flying Wings are sensitive to C.G. location. It
should be forward of 25% of the Mean Aerodynamic Chord. Basically, start
nose-heavy.

Old Apr 17, 2008, 11:52 AM
Doug McLaren
Guest
n/a Posts
Re: Flying wing design

In article <fu0ke4$bsm$1@registered.motzarella.org>,
MJKolodziej <mjmwcsREMOVEKILLERCHAOS@htcomp.net> wrote:

| Doug, again what is that zagi copy that you like with the X in the name?

XE2 probably. http://www.combatwings.com/

Though there's really a ton of clones out there and most of them are
pretty similar. Zagi may have really made these sorts of planes
popular, but then other vendors started putting out stuff that was
significantly better than what Zagi was doing. I haven't really kept
up with them in the past few years so I don't know if Zagi has caught
up, but upon looking at their current offerings, I'm guessing not.

Things that make these sorts of planes better --

-- good airfoil (alas, `good' depends a lot on how the plane
is meant to fly, but in general flat bottom airfoils are
not very good.)
-- stiff, light foam
-- foam that is CA and goop safe.
( See http://www.yourzagi.com/abuse_small.jpg for an
example of what can happen. )
-- CF spars as needed to stiffen things
-- no canopy, things buried in the wing
-- cooling for the battery and motor if there is one
-- padding in front of any electronics or battery to protect
it in an accident. Also, it's nice to put the battery in
front of the RX rather than in back, so it doesn't crush
the RX in a crash.
-- pushrods buried in the wing rather than exposed.
-- covered with ultracote rather than packing tape

Some of these have to be done by the manufacturer of the kit, and some
can be done by the end user.

--
Doug McLaren, dougmc@frenzied.us
No, no, you're not thinking, you're just being logical. --Niels Bohr
Old Apr 17, 2008, 11:56 AM
Doug McLaren
Guest
n/a Posts
Re: Flying wing design

In article <1156-48071EA4-61@storefull-3174.bay.webtv.net>,
Daniel Krier <Djkhm4@webtv.net> wrote:

| I have a foam covered with balsa swept wing called a Javelin, it has a
| symetrical airfoil and no wash-out ( wing twist). It is very fast but
| has a terrible tip stall and really no low speed handling at all.

Good point, I forgot about that ...

Flying wings do tend to have wash-out to help reduce the tendency to
tip stall. The problem with that is that in inverted flight, wash-out
becomes wash-in, and so the plane becomes even more prone to tip stall.

In general, most flying wings fly inverted poorly (though from what
Daniel described, his Javelin should fly as well inverted as right
side up, thanks to no washout and the symmetrical airfoil -- but this
sort of setup is rather rare.)

--
Doug McLaren, dougmc@frenzied.us
No, no, you're not thinking, you're just being logical. --Niels Bohr
Old Apr 17, 2008, 06:13 PM
Morgans
Guest
n/a Posts
Re: Flying wing design


"Daniel Krier" <Djkhm4@webtv.net> wrote

> It is also true that Flying Wings are sensitive to C.G. location. It
> should be forward of 25% of the Mean Aerodynamic Chord. Basically, start
> nose-heavy.


For the Gremlin RC Combat wing, I seem to recall the CG is something more like
15% to 17%.

25% would be at the most rearward range of CG, I would think.
--
Jim in NC

Old Apr 17, 2008, 07:13 PM
Robert Dorsey
Guest
n/a Posts
Re: Flying wing design

I'm part of a small team of ME university students that just finished
competing in a DBF competition with a flying wing.
The wing we used in competiton was our first prototype. Due to the
design requirement of a fairly large payload bay, it ended up being a
tractor with 20 degrees sweep, reflexed and 4 degrees washout. Had the
CG set for 10% in front of the AC. It flew very well, very stable.
Handled 45 degree turns with ease, even in very windy conditions.
Looked way cool too.
There were many that said our design would not work and tried to scare
us into thinking we were going to have our hands full, but they
couldn't have been further from the truth. Not sure if its because we
performed good design analysis or were very lucky.
It was a fantastic experience.
Robert
Old Apr 17, 2008, 10:03 PM
Martin X. Moleski, SJ
Guest
n/a Posts
Re: Flying wing design

On Thu, 17 Apr 2008 16:13:08 -0700, Robert Dorsey <be35@cox.net> wrote in <85mf04tiu7qgaks3gh6ofrpafqgbre6ghu@4ax.com>:

>I'm part of a small team of ME university students that just finished
>competing in a DBF competition with a flying wing.
>The wing we used in competiton was our first prototype. Due to the
>design requirement of a fairly large payload bay, it ended up being a
>tractor with 20 degrees sweep, reflexed and 4 degrees washout. Had the
>CG set for 10% in front of the AC. It flew very well, very stable.
>Handled 45 degree turns with ease, even in very windy conditions.
>Looked way cool too.
>There were many that said our design would not work and tried to scare
>us into thinking we were going to have our hands full, but they
>couldn't have been further from the truth. Not sure if its because we
>performed good design analysis or were very lucky.
>It was a fantastic experience.


Congratulations!

Have you got a website about your team & design?

An article about the competiton?

Marty
--
Big-8 newsgroups: humanities.*, misc.*, news.*, rec.*, sci.*, soc.*, talk.*
See http://www.big-8.org for info on how to add or remove newsgroups.
Old Apr 18, 2008, 07:57 AM
dan
Guest
n/a Posts
Re: Flying wing design

On Apr 18, 2:13=A0am, Robert Dorsey <b...@cox.net> wrote:
> I'm part of a small team of ME university students that just finished
> competing in a DBF competition with a flying wing.
> The wing we used in competiton was our first prototype. Due to the
> design requirement of a fairly large payload bay, it ended up being a
> tractor with 20 degrees sweep, reflexed and 4 degrees washout. Had the
> CG set for 10% in front of the AC. It flew very well, very stable.
> Handled 45 degree turns with ease, even in very windy conditions.
> Looked way cool too.
> There were many that said our design would not work and tried to scare
> us into thinking we were going to have our hands full, but they
> couldn't have been further from the truth. Not sure if its because we
> performed good design analysis or were very lucky.
> It was a fantastic experience.
> Robert


Hi
sound interesting can send some pictures so ee'll all enjoy??
 


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