I WAAANNNNA See it FLY !!
Bille

Bille, after seeing your post, I've got no complaints!

I can see you don't, either. Full steam ahead and good luck with all your projects.[sm=thumbup.gif][sm=thumbup.gif]

Hii, has anyone found any composite landing gear at Graphtech RC that is a great fit with the same scale shape as the stock aluminum one??? The closest I have found there is the #922, found in the extraspecial saving category.
Also thinking of getting a composite wingtube. 3/4" is the diameter for this plane right?

If I remember right it's 19mm....

ADD TO WISH LIST:
***If you had a choice;is the stock one tall enough to acomidate
most props?

***Would you want it wider,or is the stock with fine?

***It would be Stronger if a slight airfoil was added;Cheaper if
it was flat.

***How much would you be willing to pay ???

I Plan to build a mold and make one for myself. The stock
one is TOOOOOO bendy and bouncy.
BUT-I don't want to take out the air-frame ethor ; with one that is too stiff !!

Tipically Carbon is Stiff but kinda brittle. Kevlar is Strong,but not stiff.
Carbon takes Sun-shine Kevlar Dosen't
SO- the proper balance of Kevlar in the middle and Carbon on the
outside is what i would look for.
The Lightest way to do that is to make a slight airfoil because,((stifness increases
by the cube of the thickness)).
So i would take an airfoil shaped mold and place ( 1 ) layer of woven carbon 5.7oz
on the outside at (+ - )45-degrees to keep it from twisting, then place
uni-tows,(or strings ) of carbon and kevlar inside with foam coar on a light plane or
nomex honneycomb on a heavy plane.
Naturaly the Nomex is REAL expensive and hard to work with.

Here is the Deal... it's a $140 ARF how much Ya willing to spend ?

Bille

Wingtube: I didn't measure mine because its too cold out.... but 3/4" = 19.05mm so a 3/4" tube would probably work just fine in a 19mm setup(the metric is just 0.002" thinner- literally a hair!).

Landing gear option (easy, ~$50) Maynardrupp got TNT to do a special for this plane in "real" aluminum a year ago.... says it works great.
Posts 1230-1233 here:
http://www.rcuniverse.com/forum/m_47...50/key_/tm.htm
I think both kit to kit and pilot to pilot variations make for a variety of experiences. My Phoenix stock gear only bends ~one in 20 flights, and in those cases I am usually glad it did, so I just bend it back cheerfully. I also happen to use 10-15mm of spoilerons on days where wind exceeds 10 knots, so the landing speeds up and therefore it doesn't tend to drop a wing as it slows down in a crosswind. My Phoenix is <<7 lbs though, so especially on windy days, it needs some help getting out of the sky, where it is very happy!

Wing area: somewhat of a personal choice here, but manymost of the people I talk to would include the fuselage between wing roots in any wing area calculations. The reason is that the entire fuselage actually provides some lift, so by including that widest part of the fuse in wing loading calculations you are at least nodding at (probably underestimating) the very real "lifting body" fuselage contribution. I measured 5.5" fuse width, so that would add ~90 sq in to the 700 sq in actual wing area for 790. The goal of calculating wing loading is usually to estimate where in the "rock to feather" spectrum a given build ends up. Helps a lot to compare it to some old plane you've flown before when you are doing a maiden flight and landing. For this purpose I would always include the area between the wings as lifting area... so that a profile fun fly and a GeeBee can be compared on the same page.... with fairly accurate prediction of flight characteristics.

PS if you use this calculator:
http://www.anything-rc.com/wing-load-calculator.html
you get 768 sq in. That's because this calculator calculates average chord and applies it to the 28 +5.5+28 = 61.5" wingspan. Using this, my 6#11oz plane is right at 20oz/sqft.
I would generally use the 16.375 root chord across the 5.5" wide fuselage, which adds 22 sq in. and drops the loading calculated a tad to 19.5 oz/sq ft., a 2.5% (minor) difference.

Guess i got away from THAT when i started designing a Hang glider
with an actual,((Lifting Body)),with an airfoil that protruded out in front
of the main wing so as to dampen pitch And enclose the pilot for reduced
drag.The curent ,"Tails" they are including on gliders like the ATOS,are
not far enough behind the CG to have any Real effect,and if they were
back further then they would make the craft statically tail heavy.

The fuce of airplanes does contribute a bit of lift but it is directaly proportional
to the shape Not the aria, and that is Why i don't include it.
The C/L max for a NACA 0015 airfoil will be MUCH greater than that of
the fuce on the Extra 330. The Fuce would more resemble the C/L produced
by that of a Brick at an angle of attack of 3 deg, so (( I )) think it's kinda pointless
to include it.

The body of an F-35 or Sr-72 is another matter entirely ...!!
Bille

Ps: can anyone tell me Why my spell check dosn't work on this forum?
I.m using FireFoxThere is usually a red line below misspelled words
and there is usually a LOT of them.
I'll need to start ,( copy/past ), if i dont figure it out.

I will post a video of the maiden flight.

Thanks Bill

I Forgot to say Thanks for that info.

Noticed you were from Idaho

My avatar is me jumping off King Mt Idaho last July,(( on my Hang glider));
got to 14,000ft ASL that day,Too bad i didn't bring oxygen
cause the wave window was open and some contestants
went to 19K.
Wouldn't mind moving there BUT Vegas is going to be:
Sunny, with a high near 67. Light east northeast wind today
and i'm gunna go fly my RC; if i lived in Idaho i would be Cold instead !
Bille

I understand your point, debating the value of fuselage lift because it isn't a NACA airfoil, but keep in mind that in Knife Edge, especially for a lighter plane that can hold KE at less than hovering throttle, all you have is fuselage lift. Now any Extra needs a lot of throttle to hold KE at "normal" CG settings, because the side area is relatively low up front-so it is definitely in the direction of your "ignore the fuselage area" leaning vs a big, fat GeeBee- but I still hold that the nice smooth cowl makes a much better leading edge than the front of a brick! The fuse is a very low aspect ratio wing (gliders are High aspect ratio, which is more efficient). By ignoring the ~5.5" x ~30" belly of the front half of this fuselage you are neglecting some real lift. I don't think the back half does much if you ignore the tailfeathers.
I would hazard to guess that if you hung the fuselage in a 15 knot wind with the tail feathers off, it would lift a good 8 oz or more at 30 deg AOA. An ex-NASA aerodynamics expert speaking at our club pointed out that the lion's share (60% rings a bell) of lift is NOT from the celebrated Bernoulli effect of "faster on top" air sucking the wing vertically, but actually due to the conservation of momentum due to the simple deflection of air downward by the tilted (AOA) airfoil. There is a considerable downwash behind the lifting wing of even a glider. This, and very low weight explains how a flat airfoil works so well on those millions of foamies out there. The tilted fuselage does deflect air downward and thereby delivers some significant lift(say 5-10% of total)especially at 10deg AOA, just like putting your hand (or a brick) out a car window and tilting it. Neither the hand or brick will fly due to its weight, but it will be lifted some by diverting air downward.
Again, assuming that the purpose in doing a wing loading calculation is to understand the basic charachteristics of flight for a given model, like landing/stall speed, a profile fun fly and a big wide body GeeBee need the fuselage included in order for this calculation to be meaningful. The funky looking GeeBee is an extreme case, with fuselage area that is at least 1/4 of the wing area, probably 1/2.
On these Pheonix Extras it is more like 1/10 of the "actual" wing area that you use, so the fuselage area is proportionately less important.
You are still doing a good relative comparison of similar or identical planes' oz/sqft numbers without accounting for fuselage lift, but by ignoring fuselage lift, you will have a less valuable wing loading value when the fuselages vary significantly in fuselage planform area as a % of "actual" wing area.

PS I haven't found the chell specker yet on this site/forum either. Most of my posts get edited a day or two later when I re-read them. Other than when the odd argument gets nasty on some forums where the flame shields go up, we tend to just overlook each others typos and figure out what you "ment"!!!
And welcome to the forum, BTW- we're havin' a blast.

PPS: Looks like I was typing when you posted- U R welcome, and that's a cool avatar. Its a shame we can't post higher res avatars! Mine's half Bach, half the robot from the terminator. So "I'll be Bach" needs to be said with a certain (Austrian) California governor's accent. I'm not at all musical, just thought it was funny! I put Idaho, Michigan for my magical location- but we're below freezing here, too!

Excellent explnation on the Fuce lift and from now on
i will include it as part of the aspect ratio on All discussion.
I'll Need to figure another way of looking at models like my new
F-35 though.That will be a fun project and will post a New Topic on it
when completed.

In the mean-while i will copy/past for spell check.

I'll Be Back...

Bille

CARBON LANDING GEAR:
That's NEXT !!


Bille

After pulling the Hacker motor and all the components out of
my Phoenix Extra 330 .61-.91
i had to patch all the air holes and the hole i made so the electric
motor would fit.
Even though it cost me 1/2 oz in glass and epoxy; I'm Real glad i did !!
There are two tabs on the very front of the firewall that secure the side
of the fuce to the fire-wall and also double as a attachment point for the
cowl.Can see good in link below:
http://www3.towerhobbies.com/cgi-bin...?&amp;I=LXNCT4&amp;P=Z

I cut them off so as to wrap glass and epoxy to strengthen the fire-wall.
There was hardly any glue in the hidden joint,and i'm betting that the
DLE-20 would have pulled the mount right off the front of the plane !!!
2 hr of work and glass later-It's not going anywhere now. But if you
have this airplane,be SURE to check this before mounting a DLE-20 to it !!
Bille

After >100 flights with a lighter Saito 91 (22oz vs your DLE-20 at 33 oz), I made a turn back to the runway after a low altitude deadstick and landed on my "chin", flattening the main gear and cracking the firewall loose. After digging in to the front of this airframe, I would agree that something as heavy as a DLE-20 would do well with some extra support.... maybe hard balsa or even maple tri-stock behind the firewall. Having essentially removed and replaced the firewall, I noticed that its really only supported by the fuselage sides- the top and bottom surfaces are such light ( thin and soft) balsa that I doubt they lend any structural support. What's more, mine was glued to the flat fuse sides well enough, but the firewall itself split open to reveal that its made of layers of those "tropical hardwoods" commonly found in Kmart furniture- not real birch or lite-ply. I'd consider putting some gorilla glue around the back of the firewall or replacing it with 1/4 Birch ply for a big engine. This is a very lightly built plane that fly well light, but...
Hard landings can easily put 3-5 G's on the engine, so that can can become 6-10 lb load with that 2lb honkin engine and I'd hate to see it fall off during a hard touch and go! Then it would be called a touch and "Doh!".

The front end of my fuselage basically disassembled when I landed in high grass. The tail and wings were mostly fine. I didn't even break the prop or mess up the landing gear, but the forward half of the fuselage resembled match sticks. I fixed the minor damage on the wings and haven't bothered with that fuselage at all yet. Maybe I will someday. I was very unhappy with the way this plane is built. The wood is sub-standard and they used very little glue.

during initial build I applied epoxy glue and CA glue on different joint area's. I even added 1/4 ply on the inside corners of the firewall, along the base, and where the landing gear area sits. cross my fingers, so far nothing has come off or blown off. I did go with magnets for the canopy - it made getting to the inside a piece of cake. I was worried about radio interferance but someone told me that magnets will do nothing to radio waves. so far with my DX7 and AR7000 RX no glitches. So far my landing gear has been holding up. our runway is all hard compact dirt. some areas are rocky and uneven. Ya, maybe a little bend but not bad - yet. I have put about 30 flights on this plane. It's a fun plane and a learning experience for me since this is my first stunt plane.

question: how do you go into a flat spin?

OK, a FLAT SPIN: I do them occasionally and here's what works for me. Hopefully someone else will enhance this initial input (thats Man-talk for correcting me!).
Zeroth step: check all hinges and linkages on your ele, aile, and rudder at full throw to make sure there's nothing binding, loose or broken. Flat spins are a tad violent and tend to test your hardware.
First, a spin is tricky because you have to stall one wing (inner) while you still fly with the other. You essentially fly around the stalled wing, ideally I think you pivot at half the span of the inside wing.
Make it a bit tailheavy- that helps get it into the spin. This also helps it to stay in the spin, most planes I see flat spinning well are naturally a bit nose high. I personally can't spin if it isn't tailheavy.
Have a lot of elevator throw, like 40+ degrees, on your high rates switch. Set your rudder to at least 40 degrees, too.
Set your idle a bit high- stunting tends to foam the fuel and cause deadsticks without a high idle. You also will idle for most of the spin- so the high idle helps prevent loading up.
You need your engine at the end of a spin to get out sometimes, so hi idle (=live-stick)is good. Many of my buds set an "idle up" switch and flick it on for stunts like flat spins.
Now grab a gallon of fuel- it will probably take that much to get your first good spin or two. Took me 2 gallons but I'm a heavy drinker!!
Climb waaay up. Higher than the three mistakes high that instructors want where you can barely see what its doing. That buys you some time to jack around getting it into the spin. At the end of the climb, you are ready to spin. Level out, pull back on power to idle, and keep increasing elevator to hold it level (in pitch) as it slows down, but not so much that it porpoises. When it porpoises both wings are stalling.. that's too slow.
Now watch the plane.... it will eventually choose a side/direction to drop toward as the plane slows toward a stop with what is probably full up elevator by now- throw the rudder in that direction while still holding the up elevator. The wing that drops has stalled...and now you are using the rudder to rotate around that stalled wing.
Once the plane starts rotating, you can work the ailerons to either go with the rudder direction, essentially pushing it to roll inward heading toward a nose down roll, or pushe the ailerons opposite the rudder, countering the tendency to roll in and holding it flat. Obviously the goal is to keep the plane flat, and on this Extra usually that means using opposite aileron- but not at first, in my experience.
I usually have to go ailerons with the rudder a bit to initiate the spin, and tighten it up a bit (spinning faster)- then go the other way with aileron, about half throw, to flatten it out, and 1/4 opposite aileron keep it flat. Each plane will be different, depending on incidence, CG, throws and weight.
This is not a "jam the sticks in the corners" manouver, you have to work with it as the spin develops. Just keep trying and trying until it suddenly cooperates.... then it may take another 10 tries to get it to do "THAT" again, but stick with it. Its worth the trouble.

Remember to watch your ALTITUDE... start high and have a buddy watching where the ground is. You exit the (upright) spin by relaxing the controls back to neutral and adding some power if you are at or near idle. If that doesn't do it, Use down elevator to point the nose at the ground and count to 3. This gets you back to flying speed and all is back to normal controls wise. Start nice and high, as the all important exit takes a good 50-100 feet and needs to finish before your altitude reaches zero.... you'd be amazed how many planes pancake in while the pilot is saying "check out that flat spin I got it to do"!!! Sometimes the plane almost acts like you are having radio trouble as you exit the spin... because you have stopped flying at that point. Leave lots of room for spin recovery at first.

On this particular plane, I find that I usually have more down than up elevator, and therefore it prefers to enter & hold the flat spin inverted. If you try inverted flat spins, you will have to reverse elevator and aileron inputs, if you think about it. For instance, you will use DOWN elevator to enter the spin and probably go ailerons opposite the rudder at first, then ailerons with rudder 1/2- 1/4 throw as the spin develops & then at the end you may need UP elevator to get the nose down to exit the spin. I know its a bit confusing, but a real blast when you get the hang of it.

After your first gallon or so of near-flat spinning, when you know how to enter and exit the spin and its a bit routine if not polished, you might try adding some power, say 1/4-1/2 throttle, (while maintaining the full rudder throw). This will sometimes help to "flatten out" the spin, i.e. slowing the rate of descent while it is spinning = more joy time.
Inverted, where mine likes to spin best, I can actually get it to hold altitude and occasionally climb while in flat spin.... my particular build needs full throttle for that.
Most planes have a preferred direction for flat spinning, where they enter and maintain the spin better, and the myriad of variables that set that direction mean its a try-it-and-see proposition.
I would guess that a right rudder upright flat spin is most commonly easier on these , because of the built in right thrust of the firewall and 2 degrees right fin setting.
whew, sorry it took so long- lots to tell there! Have fun, wheels down!

Wow, thanks for the info. I'll give it a try this coming weekend. yes, I will go HIGH.

Good explanation !!

On that part where :
"it will eventually choose a side/direction to drop toward as the plane slows toward a stop with what is probably full up elevator by now- throw the rudder in that direction "...

Sometimes this indicates that you have more wash-out in one wing than the other.
The wing with LESS washout will stall first.

Sometimes this i also indicates you have one wing HEAVIER than the other.
The heavy wing will stall first.

SO before you start, set up your plane the night before and set it levle on a table.
Now, Turn on the radio and center your trims, then go to the other side of the room and look at the trailing edges of your wings
down the side if the fuce.
You will see if one wing is warped a bit more than the other.
I usually set a min of (1 degree) of washout at the tips.
This makes inverted spins easier, and landings easier also.

Next we balance the wings.
Turn OFF your radio..
Pull the wings and wing tube out and then push the the wings back on the tube
and measure the center and mark with a felt pen.
i will set something like triangular wood stock on some books and set the wings
on where the center mark is.
The easiest way to counter balance is adding weight at the tip of the light wing
but to insure a mas moment of inertia the weight Should be added where each wing
balances by itself in the center.

All this work will ensure that your plane flies nice and level for landings and
when a stall is induced,(( nether wing will have a tendency to drop)) !!
So the work is worth your time since we Land once on EVERY flight.
Sometimes i land twice. (sigh) !

Bille

I Forgot to say :
To get rid of a warped wing , you can use an iron.
Start with a lower setting and gradually increase the heat untill the iron
is hot enough to get rid of wrinkles.

Next we grap the tip if the wing you want to twist and apply some force
opposit to the warp...
till you see wrinkles appear on the top and bottom of the wing.
use the iron to get rid if the wrinkles on Top And Bottom.

If you go Too far; just do the reverse by applying force to twist the wing the opposit of the warp,
and re-apply more heat till you get it right.

DO NOT let the tips go UP at a higher angle of attack than the root,(near the fuce), this is called
wash-in and the plane will fly like guarbage and tip stall at will. This is Very Bad !!

When viewing the set-up plane from the other side of the room; you should see a tad
more of the underside of the wing at the tip than you do near the fuce.

Another thing you can do is purchace a wing insidence guage to do this then you
know Exactly what you got. I bin flying gliders so long i can tell by looking.

Bille

From the beginning my extra has been quirky in the air. I had a flying buddy fly my plane - maybe he can tell me what he thinks. He said during vertical the plane wants to pull to the left. Even with Right Rudder he had difficulty maintaining straight climb. Also, at the end of the loop the plane wants to drop its right wing. And this happens everytime. During level flight the plane tracks straight both upright and inverted. Since the plane favors to pull to the left on a climb it does a nice hammer head to the left. It struggles to the right. He brought the plane back down and inspected it. All moving surfaces are ok. The elevator he said is a tad off. the right is 1/8" higher at full up elevator and 1/8" lower during down elevator. but he didn't have an explanation why the plane was behaving as it was . He looked at it from the tail and he said the vertical stab is right on. Wings are all straight. He looked at my servo's. he suggested maybe I should swap the elevator servo's and see what happens.

After he told me all that - I took the plane up again. sure enough - during vertical the plane pulls to the left. I thought it was the wind all this time. When I enter a loop the plane tracks nicely. going over to the top and she goes nicely. coming back down and she is tracking nicely. right at the bottom I give it a tad bit more elevator to complete the loop and right at the bottom the Right Wing drops. I'm thinking perhaps at the end of the loop I dropped airspeed and that wing stalled momentarily. My loops are generally big and round - usually flat at the top - And I try to maintain the same airspeed all the way around.

what do you guys think?

nrad2000,

are you using a y-connector or are you using servo mixing from the rx (putting the servos on 2 and 6 channels) for the elevator servos? In the case you are using a Y-connector, it is common to have the the elevator halves deflecting at different angles for the same input and you cant correct this mechanically. With the channel mixing from the RX, I am told there is a slight difference between the time the left and right elevator servos react. This lag is because the RX reads through the channels one by one. Both of these could be causing the snap you notice at the end of the loop. For the record, I am using the rx mixing setup on all my airplanes so far without noticing this problem. But for my new Funtana, I was recommended to go for a match box (just search MSA-10 on Tower for Futaba, JR has an equivalent) so as to get rid of the lag.

With respect ti the tendancy to pull to the left in the vertical, I noticed the same problem on my Topstar which is a 3D airplane from Phoenix. I noticed that as soon as I applied throttle to enter the hover or to control altitude in the hover it would pull left. What it required was more right thrust- hence I added a couple of washers under the LHS engine mount and the next time the tendancy to drop to the left was gone. You dont notice this in straight and level because of the rudder trim that you may have. Also, I suggest you balance the model laterally if you have not already done so

Hope this helped

Ameyam

I had all of those problems and un-requested snap rolls during some maneuvers. I tried different CG positions, and yes, I balanced the airplane laterally when it was new. I have also re-checked that. I tweaked the elevator travel and they are together at all times. I used an OS 75 AX which was not overpowered for sure. The final issue was a slow speed landing in 1ft. tall grass. I didn't break the prop or bend the landing gear, but the whole front half of the fuselage came apart at the glue joints and the tube broke out of one wing. Those tubes sure don't go very far into the wings. I have repaired the wing, but I haven't found the ambition to fix the fuselage. If this airplane was a better flier, I would spend the time and do it right. I just never enjoyed flying it.

I'm running the elevator on 2 separate channels. I have a DX7 and I thought I can correct that travel independantly but for some reason I'm having trouble doing that. for some strange reason when i make changes it affects the other channel. I'll lookk at it again. I'll check lateral balance. I haven't done that yet.

# 1 Doesn't the DX-7 have servo match ?

First thing i would do is install 2 digital servos on the elevator then borrow
a programmer from a buddy, or purchase one and program the servos the SAME !!
1/8" up + 1/8" down is a difference of 1/2" total.
THAT'S (("more")) THAN A TAD OFF !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
are you sure the link is attached in the same hole ?

Then go to a Y harness.

# 2 You MUST use rudder for different speeds on the aircraft.
Pick a speed you like and adjust your motor's right thrust angle to match;
i use 2 degrees. when you speed up you'll need Less right rudder, when you
slow down, (( In the vertical)), you need More right rudder,because of More power.
Dead stick you should need O !

# 3 A wing WILL stall at ANY speed if you add Too much angle if attack.
The trick is to get them to stall at the same time.
Your elevator Must be evened out first,then check wing weight balance, and
last,( but Most importantly) the wash-out or wash-in at the tips Must be identical.
I posted that earlier on this page.

# 4 After you get the Y harness installed with two servos of Equal travel with the
same holes utilized on the links and balance is correct and wash-out at wing tip
is equal.Next i would install these to help cut down on the frustration a bit, Just
till the problems are worked out. This was posted on page 63 post # 1567
http://www.rcuniverse.com/forum/fb.asp?m=10185225

That's My recovered Extra with sheeted wings.
What these devices do is increase the effective span and increase the amount
of efficiency in the ailerons,and makes the wing LESS prone to a tip-stall, at the expense
of a Lil drag. That drag makes the airplane REAL stable.

These were made with 10mil Mylar.
You can't even see them when it is flying !

One another note:
My DLE-20 is installed and ready to fly, I'm just waiting for my AMA membership
card to arrive.

Bille