Will Sgarlat

This contraption of a plane is based on a paper airplane that I found in an April 1984 issue of Omni Magazine. I know only 3 basic types of regular paper airplanes, but this is by far the very best for flying straight and far.
The upper surface of the paper airfoil is flat and the undersurface is angled downward and has a dihedral angle. Some people know why this airfoil works, but I really don't. The more you "open out" the undersurface, the more lift is produced.

It uses the Kline-Fogelman airfoil, and this model uses twin vertical stabs with elevon mixing. It's made of cardboard and is only a concept model! If it works, I'll make more out of foamboard
and "fuelproof" it with thinned, water base urethane.

I will also shield the servos from the 049 muckandgoo, so I guess it's not done.

Thanks for checking it out!
Will

Lynn S

Will, Did you try to post a picture?
If you are having problems posting the picture, you have to wait until it gives you the uploaded OK button, then you can click the post OK button.

Will Sgarlat

Pictures didn't post! Sorry all, trying again:

ajcoholic

My Feedback: (10)

Thats wicked looking... how does it fly?

My cat Rudy likes chewing on cardboard, I dont think I would be able to have that one lying around my house!

AJC

Will Sgarlat

Hey AJ,
I haven't tossed it yet! It's too snowy and wet. Even though I shouldn't care if it flies twice, straight cardboard just isn't straight anymore after it's been wet! I have an idea that it will be draggy and sluggish in climb, since it's modestly powered, but cruising at 25 ft will be really neat!
I'll try an .09 or a .15 if it can't get out of it's own way with an .049.

Hey this is a grat forum guys! I'm probably the only one in my club who likes .049's. Too bad cause I love the little, agile planes that you can have a blast flying no matter how much wind there is! The other guys are just missing out.

Bipe Flyer

What a cool looking plane! I'm no expert on V tails so forgive me if this is a stupid question, but how much angle do you need for pitch control?

WINANS

I have built and flown a huge number of planes made of cardboard. I joined a 4-H aerospace project group as a kid and the leader introduced us to cardboard as a great building material. We were all to poor to be able to buy balsa and kits and much of anything else, and dumpsters were full of good cardboard in those days. It works great. Cardboard, pine motor blocks, Ambroid, cloth hinges cut with moms pinking shears, and a Baby Bee seved me well in many applications. We did a number of FF and CL models in profile shapes and flying wing type platforms.

I have such fond memories of those days, they made me what I am today in large part.

Good luck with your project, it looks fun.

Scott

Will Sgarlat

Hi Bipe Flier,
I'm hoping that the lift produced by the angle of bottom portion of the wing will be enough to keep it level at the natural speed at which the plane will fly. I can use a shim to increase the angle as require during test flights.
The actual deflection of my elevons/vee tail surfaces is about 1/2" either way. I'll set dual rates for half the travel and see which setting will be best.
We just got hit with more snow, so it will be a while before I send it off! Darn!
Regards,
Will

Will Sgarlat

Hi again Mr. Bipe Flier,
Now I understand your question! How much angle "away from vertical" is needed for the control surface to act like an elevator?
The closer the surface is to horizontal, the more efficient it will be in pitching the airplane. Probably 45° from vertical or horiz. would be the best angle for a vee tail for overall pitch and yaw response.
Regards,
Will

Bipe Flyer

Thanks Will.

Will Sgarlat

Scott,
Thank you for your comments! I used some ambroid on this one, too! It's fun to design your own planes in 1/2-A size and see how they work (or flop!).
I made one something like this about 20 years ago and flew it as a teather model (on a snowy day) in an open field. It flew OK until it started porpoising! I tried like crazy to get it to get back to level, but the kite string broke away from the wooden handle! It sailed off at an ambling pace and I ran after it and stamped on the line to keep it from flying away! It jerked and went into a death spiral and crashed.
Luckily nobody's person or their property was hurt! I was a complete newbie then.

Red_barron419

Dude!!!!!!!!

that thing is the most ghetto rc plane i have ever seen!!!!!!!!!!!

how does it fly???

i might try it!!!

MR Flyer57

There was another one that I saw, I thought it was so cool and easy to build that I grabbed a pic or two of it.
I don't know who built it or exactly where I got the photos, so if you see your plane here speak up and take credit.
Hey Will I hope I remember to give you credit later for yours!!

MR Flyer57

Clean

If'n it flies well, you might make the next one out of 2millimeter Coroplast. It's just like your cardboard but plastic and therefore, fuelproof. to order some you can go to www.harborsales.com and get the phone number, then call in an order. Also, gead over to the [link=http://Spad forum]http://spadworld.net/[/link] for hints, kinks and info on working with Coro.

As far as the Vtail, you might consider going with coupled ailerons and just leaving the ruddervators alone. 120 degrees is what I remember for the Vtail spread. With your angle you'll have good yaw control, but little pitch control.

combatpigg

My Feedback: (3)

HI MR57! Now THAT'S a paper airplane that could put your eye out!

MR Flyer57

sure looks dangerous to me CP!!
I do like the idea of making something from just the stuff laying around.
I started saving cardboard from cereal boxes, the thin stiff kind. I was thinking I could glue and layer it over curves and it would dry and form wings. I got the cardboard, but never got around to making it happen,,,,, yet!!
MR Flyer57

Beeza

My Feedback: (1)

Hi Will,
I built a paper-airplane looking plane about 5 yrs ago, the plans came out in 1988 June RCM I believe. Some kind of a design contest winner. Pusher reed valve engine, the article says it won't stall, merely sink. It wasn't made of cardboard, but was a built-up fuselage and lower fin. I have been working on it this winter to try for a Speed 400 conversion. 20" by 40" delta, 18 oz with cox .049 and 2 channels. Elevons didn't work.

If I get a chance, I'll send in a pix.

I also built cardboard wings and profile planes a long time back. I read about it in a modeling magazine. It's cheap and easy.

My dad had a radio station years ago and we threw away (I burned) hundreds of record albums and would be sent to the station with hopes for air time. I flew these 33 lp records on control lines in our club. When we didn't have, we still found a way. I like that.

Beeza

MR Flyer57

I happened on a very strange bird about 10 years ago. I am an Locomotive Engineer (train driver) and an Engineer friend of mine said while hauling a empty coal train, he spotted a radio control airplane in one of the cars. He knew that I was into flying them and kept it until he could give it to me.
What he delivered was the strangest plane I have ever seen. Who ever had built it was a genius and as frugal as anyone I have ever met.
It was an electric glider, made out of balsa sheeted cardboard, it had the engine on a pod. the pod was made from music wire and not only held the engine but also transfered the power from the batteries to the motor.
It had the strangest hinge material I have ever saw. I kept some of it and no one has ever identified it. It is a thin medal that has some strange properties. It is very strong but will flex with out creasing.
The plane was in very poor shape from it's ride across the country in a coal car, so it never flew again.
There wasn't a stock wire or plug in the whole plane and even the servos had been glued in and painted over.
I had forgotten all about it until you started talking about the paper plane.
I would sure like to talk to the guy who built that plane, and I ofter wondered what the story was behind it.

MR Flyer57

FrankEscalle

I you go on Model Airplane News's website and go to how to there is how to build a glider out of cardboard that looked like it was just begging for a little engine.

combatpigg

My Feedback: (3)

It looks like it would weigh a ton, but the shape looks worth exploring. If it was built out of carbon tubing, or 3/16 birch dowels and TYVEK building paper, it might turn out light enough to be a good flyer.

Mavi91

I'm in the process of building a cardboard model. For what it's worth, the fuel proofing isn't a big problem if you follow Chuck Felton's idea of treating the cardboard with polyurethane varnish.

Mix 1 part polyurethane (oil based, not water based) with 3 parts cheap hardware store paint thinner. Put it liberally on both sides of the cardboard before you start cutting out parts and let it dry for a minimum of 48 hours. It won't add much weight and you won't believe how strong it makes the cardboard. You can cut and sand it like balsa. I took the attached pictures as I built my wing. All of the ribs are cardboard and I sawed out a stack of them on the bandsaw without a problem. I used carpenter's glue as CA didn't hold well at all.

When you're done, take printer paper and cut it into 2" strips. Smear carpenter's glue (alaphetic resin like Titebond, not white glue) on the paper strips and cover any raw cardboard edges with the tape. When the glue is dry, go over it with a monokote iron or household iron set on wool. The heat will polymerize the glue and make it water and fuel-proof in the process. It will also make the paper really tough as well.

I'm finishing up with a coat of lacquer-based sanding sealer. That doesn't add weight and allows light sanding to get a smooth finish. I'll spray Krylon (which is lacquer based) for color and then hit everything with spray can clear polyurethane gloss. A great finish and it is totally fuel proof.

You do have to use thinner cardboard for smaller planes. The 3/16" refrigerator box stuff isn't a good choice for a 1/2 A plane!

Will Sgarlat

Hi all,
What a great bunch of replies and comments, thanks very much for your input! As far as using elevons to control pitch and roll, I considered that, but what I wanted was a motorized version of the paper airplane, with RC assist. If it works at all, I expect it to fly 25 to 30 mph (moderately slow) with a wide turning raduis. If I spiral it up maybe 200 ft, angle the nose down and leave the elevator neutral, the inherent lift will cause it to level out again before too much speed builds up, and it will probably porpoise a bit before resuming its "natural" straight & level speed. So the small pitch force from the ruddervators should be adequate.

I love RC airplanes because the same engine and flight pack combo installed into different types of airplanes can give you many planes with COMPLETELY different flight characteristics! This is a softy, lofty kind of gig. As long as it isn't too heavy....OK I just checked it's wing loading, it's approx 5.4 oz/sq ft. Light!

But DANG! I have been too busy to get out to the field and give it a heave! Maybe this weekend...

Thanks again, keep the ideas brewing!
Will