aeajr

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OK wizards, I have an idea and I want to see if anyone has tried this on a parkflyer.

The average parkflyer is three channel, typically T/R/E. Fun and stable, but not very aerobatic. Most of us would move to a 4 channel aileron plane to get to the next aerobatic level. I was wondering about a different path.

Suppose you take your elevator, split it and put it on two servos. Now turn on elevon mixing on your radio, or put in an elevon mixing device in the plane. Now you have an elevator/aileron mixed surface, similar to a flying wing.

If you only have three channels on your radio, you will have to give up the rudder, but if you have 4, you can keep the rudder as well.

1) Would the typical parkflyer have enough strength in the tail area to handle the stress of making the elevator an elevon? We are introducing twisting forces here beyond what the rudder induces.

2) Would we have enough authority to get significant roll this way? I imagine if you can keep the rudder working and you coordinate the rudder with the aileron input the plane should roll fairly well, though perhaps not totally axially.

How much would the dihedral wing of a typical parkflyer fight this roll?

I keep reading about people who want to add ailerons to three channel park flyers and thought this might be an interesting alternative to modifying a wing. Perhaps easier, and with the popular inclusing of elevon mixing, even on standard radios, this might be fun to try.

Has anyone ever done this?

BuzzBomber

My Feedback: (4)

Several modern jet fighters use "tailerons" like you describe, and I do remember reading a thread either here on the e-zone about installing them on a parkflyer. Unfortunately, I can't remember a dang thing about the discussion, whether they worked as expected, etc. It has definitely been done, and perhaps a search will yield some more info. Sorry I couldn't be of more help.

[edit]

As for the title of the thread--I have made a GWS cub VERY manueverable on rudder/elevator by shortening and strengthening the wing, increasing the dihedral, and just about doubling the r/e control throws. If I time the inputs right, it can do a fairly axial roll that would make you swear it has ailerons.

Jason Beach

My Feedback: (4)

Interesting idea.
I've seen a couple of WalMart gliders converted to RC with this kind of control. The one's I've seen were jets, and the wings were very narrow at the tips. I think this is part of the reason that they worked so well. I'd imagine that doing this on a parkflyer with a constant cord wing would result in sluggish behavior.
However, if it works well, it'd provide another alternative to putting ailerons on or buying a new plane.
Let us know if you do this modification, and how it works out.

Jason

aeajr

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I did the search several times. If you have the time, please run the search and post the link here. I would love to read the thread.

BuzzBomber

My Feedback: (4)

aejr:

I can't seem to find the specific thread I was looking for. IIRC, it was sometime last winter. I did find several reference to tailerons in the jet forums, and a few on the e-zone, but the general consensus isn't really too encouraging as far as applying the concept to slow/parkflyers, which, now that I think about it in simple physics and aerodynamics, seems about right. Still, it's an intriguing concept.

john 8750

It will slowly turn the plane but not enough for a roll.
Give it a try and let us know.
But dont try it over 1500 feet away!
Just kiddin.

aeajr

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1500' ?

You must have read one of my posts about the range of receivers in parkflyers and sailplanes.

I will give it a try when I have time. Probably not until January or so. Right now I have a Great Planes Spirit sailplane that got a really bib boo boo trying to launch off of a winch. Nasty winch!

The Spirit comes first as sailplanes are my true love.

Then either this project or a foam board slow flying 3D plane that is currently waiting for electronics.

Actually the foam plane will actually have this arrangement. Elevon and rudder, but the surfaces are huge. I know that will roll. I hope to make it corkscrew going straight up, at a nice slow climb.

john 8750

Man! You are very much into planes. Sounds like fun, and some work.
I am the one who said 200' was a good distance out for a park flyer. It is only my openion.
I enjoy reading about your and others work. So keep it up.
The plane to the left weighs 4.34 ounces, 27" WS. It's a model from the 60's. Flys like a baby.
Stay in touch now.

aeajr

My Feedback: (2)

My wife says I have an obsessive/compulsive disorder.

I don't think it would stand up to clinical evaluation, but when I get interested in something I can get pretty intense. In this case I have wanted to get involved in RC flying since I was a child, but it never happened because it was too expensive and there was always something else.

With the current state of electrics and particularly RTFs, the cost has become so low I finally put my foot in the water. Once I got that toe wet, I dove in all the way. It is close to a year now and I have not surfaced for air yet.

Joined a Glider/parkflyer club - totally hooked on gliders

Your post got me to thinkning - what is the state of my current projects - let's prove my wife correct

Flying at this time:

AEROBIRD - Just can't seem to kill it! - 100+ flights and going strong - Really want an Challenger for air to air combat and Pro mode performance

ELECTRAJET - delta wing elevon plane - 30 flights - a learning platform for elevon flight

SAGETTA 600 - RES 2 meter Glider - first flights 2 weeks ago - Sweet flyer - could become contest plane in RES class

Actively on the building table

GREAT PLANES SPIRIT - RES 2 meter Glider - My first glider - 65 flights before the big crash trying to move from hi-start to winch launching - Wings rebuilt and outer section sheeting added to enhance lift - fuselage almost finished with rebuild - Then cover - Rearranging all interior components from original positions to reduce ballast weight required and accommodate removable electric power pod for alternate launch method by electric motor. Built the power pod a couple of months ago.

Pending Projects in various states

DART - 2 meter fiberglass flat wing high speed glider - Given to me by club member - awaiting electronics installation - have not flown yet

AIRTRONICS LEGEND - 3 Meter Full House Glider - Purchased recently from club member - awaiting receiver installation and conversion of servos from Airtronics to Hitec standard plugs, then balance - Will not fly till late spring as I need more practice on Sprit and Segetta to prepare for this one - Big step up for me - could become contest ship in unlimited class

FOAMBOARD - 3D electric plane - awaiting electronics - hope to make this one a full 3D slow fun flyer using low cost GWS motor - should be able to fly in front of house

YARD BEE - electric slow flyer - picked this one up built but in need of minor repairs, then I will -install electronics - Create split elevator to evaluate tailoron on a park flyer.

SPIRIT- (same glider as above) - build second interchangeable tail section - install split elevator tailorons and add servo - test platform to evaluate the impact of split elevator tailerons on thermal turning -

Tailerons Investigation - have several threads going on this taileron idea in parkflyers and glider sections on 4 boards - looking for advice from the wizards. Spirit and Yard Bee will be the test platforms.

john 8750

That's a great collection of planes.
I am a builder from the early sixties. I like the old timer free flights.


Flying;

Rascal by top flight.
GWS cub.
Ranger 30 by carl goldberg.
Slow stick.

Building;

B24 Bomber, 36 inch 13 ounces.

Planning;

14 inch delta wing, 4 ounces I hope.


I like park flying. Its no wonder that you like good radio range flying the gliders.
My wife gave up on me a long time agao.
Keep in touch!

aeajr

My Feedback: (2)

I think my wife is about to give up.

My college age daughters think it is cute. Daddy and his planes.

Gklugie

My Feedback: (1)

I flew some 1/2 A models years ago, and can tell you to go ailerons, elevator, and throttle. The .049 planes we had back then did not have throttle... so we flew two channel ( full throttle) until we ran out of fuel ( about 12 minutes). Plenty of pep for cool aerobatics.

aeajr

My Feedback: (2)

I guess the minimum that is acceptible changes over time according to cost and availability.

Your 1/2A planes sound like fun!

Certainly 3 channel was expensive back then, but three channel is cheap now.

I don't like the idea of not having throttle control. On/off is ok for e-gliders as the objective it to climb and then cut the motor, but for anything else, I would require and recommend full throttle contol. It gives you so much more flexibilty.

Gklugie

My Feedback: (1)

We all had 4 channel radios. The problem was, Cox Black Widow .049 engines were not throttleable, thus we flew 2 channel.

aeajr

My Feedback: (2)

Of course ...... aaaaa.... I knew that!

BMatthews

You're barking up the wrong tree with the taileron idea. On most conventional designs the elevators are MUCH to close to the center line to have the leverage required to be effective. It'll work but it'll be a SLOOOWWWW response.

If you don't want to change to ailerons then the proper way to enhance the 3 channels models is....

[ul][*] Add more throw and make the control surfaces larger. At low speeds you need LOTS of control authourity to get snappy responses.[*] INCREASE the amount of dihedral. This will greatly increase the yaw-roll couple of the model. The rudder dose NOT turn the model. The rudder yaws the model and the slip angle of the new airflow acting on the dihedral rolls the model so it can then fly around turn.[*] Move the balance point back but watch for it getting so critical that the model wants to try and tuck under in a dive.[*] Give up and use ailerons...
[/ul]

Note that one of the hot mods to the Lite Stiks is to bow the wings up with a tip to tip thread. The increase in dihedral from the bend is what makes the rudder response better.

The jets using the tailerons works because of the usually short wingspan and the widely spaced elevators thanks to the dual engines spaces well apart. Look at the top view and you'll see that in such designs the elevators are out almost to where the ailerons would be.

aeajr

My Feedback: (2)

Bruce, you make some REALLY good observations about why tailerons would be effective on a jet, but not so on other typical planes.

Well, it has been an interesting intellectual excercise, but it is starting to make sense that this may not be worth a major effort, but if an opportunity presents itself to do wit with not too much effort, I may try it.

Thanks!

BMatthews

It's all a case of how long the lever is. Jets have the elevators out a long way from the center line so they have good leverage. Normal models have themin close so they have a small leverage. More leverage equals more effect. Low leverage equals little effect.

BMatthews

A [link=http://www.rcgroups.com/forums/showthread.php?s=&threadid=178477]Practical Example[/link] of this idea in non-action.

aeajr

My Feedback: (2)

Outstanding link. It is good to know this has been tried and the kind of results that occured.

I have learned a lot, and isn't that the point of saying, "what if".

Thanks for you help!

aeajr

My Feedback: (2)

I remembered this thread where we discussed the merrits of tailerons, using the elevator like ailerons.

Well, this guy took the V tail on an Aerobird extreme adn increased teh working surface area. Now a plane that can't roll, can.

Thought you might like to see it.

They guy modified the tail and created what he calls the "pro-tail". Now the plane does full rolls. You can see the video here:
http://www.hobbyzone.com/albums/albu...st_a_taste.wmv

There is a full description of how to do it posted here
http://www.hobbyzone.com/modules.php...x&page=tailmod

Essentially he turned the Rudder/elevator into effective tailerons.