wazzbat

G'Day

Being quite new to this hobby and not having visited a local club yet, I am still at the very early stages of learning what's what. I have seen in a few posts that people talk about using seperate servos on the Ailerons to make Flapperons instead but I have know idea what that means or the advantages of it? I have searched the forum but can't find it explained anywhere so if someone would be so kind to do so, it would be much appreciated.

Cheers

MinnFlyer

My Feedback: (4)

Flapperons are when both ailerons are made to deflect downward together acting as both flaps and ailerons.

There is really NO benefit (except that you don't have to cut separate flaps) but they are a really BAD idea for several reasons.

Do yourself a favor and forget you ever heard the word and use separate flaps and ailerons

Dr1Driver

The advantage of flaperons is it simplifies building and linkage installation. The disadvantage is it degrades the function of both the flaps and ailerons. Separate flaps require two more servos and associated wiring.

They were, and are, used on competition fun fly planes. When the plane is straight and level, they are deployed as flaps which really tightens up a loop. When making a quick dash back to the runway at the end of the maneuver, they are raised as spoilers, literally sucking the plane back to earth and saving a few precious seconds on the clock.

Flaps are commonly used on scale planes to increase lift for takeoff and landing. They allow the plane to fly slower before stalling. They are also used extensively on control line planes.

jetmech05

Flaps...are devices at the in board trailing edge of wings that drop down.....they increase the curvature of the wing therefore incresing lift....so an airplane can fly slower yet produce the same amount of lift....a side effect of deploying flaps is extra drag, so if you are on board an airplane and the flaps come down you will most likely hear the engines spool up to compensate for the increase in drag.....
Now ailerons are also at the trailing edge of the wings but outboard....ailerons work opposite of each other, (usually) some airplanes don't have ailerons,......anyway when the left aileron is up the right aileron is down, and vice a versa....ailerons control the roll axis of the airplane....
Now Flaperons are when you combine the 2....a strip aileron that goes completely along the trailing edge of the wing....you drop both ailerons to act as flaps.....but either increase or decrease the travel of one aileron, to control the roll axis of the aircraft.....

wazzbat

OK.  That helps a bit.  So if a plane is built with a Flapperon setup instead of an Aileron setup, how do you drop both to act as a flap or only one to control the roll axis?  It's kind of hard to explain isn't it?  But say for a mode one setup with flapperons, if you move the right stick to the right, won't that only move the right aileron and the left stick only move the right aileron?  So how do you move both at the same time to act as a flap?  Or can you only set the plane up to do one or the other?

Dr1Driver

Let's see if I remember this...we hooked one servo to the aileron channel and one to the flap channel and mixed the two, then slaved the whole mess to the elevator so the flaperons would operate whenever the elevator was commanded. Of something like that. Futaba 7UAF radios.

wazzbat

OK.  So elevator control moves both flaps and aileron control moves one flap?  That makes sense.  But you need a programmable controller to do this I'm guessing.  Do the mid price range radios have those functions?

carrellh

I am sure there are exceptions, but, most "ccomputer" transmitters with at least 6 channels have flaperon mixing.

In a mode one system, throttle and aileron are controlled with the right stick. Flaperons are activated with a switch or knob and turning it on moves both ailerons down (or up) a certain percentage of the total available travel. Moving the aileron stick still moves the ailerons normally but the amount they can move is limited because part of the travel has already been used.


In "normal" operation, moving the elevator stick does NOT cause flap or aileron to move. DR1's example is a specific mix that probably is activated by a switch and used to make really tight loops.

Dr1Driver

What he said..."Normal" flaperons are operated by a rotating knob on the transmitter (the flap control) and are independent of other controls. Our case was special use. One aileron servo is plugged into the aileron channel and the other is plugged into the flap channel, then you mix the two. Getting the directions and percentages of movement can be a little bit of a bear to get set up right.

opjose

No, you misunderstood the poster.

Normally flaperons are an attempt to add a flap like function to a plane that has NO working flaps.

Instead the ailerons are moved down in unison a BIT, while still continuing to work as ailerons, in an attempt to give the plane more lift.

This was often then coupled to an elevator via yet ANOTHER mixing function on a computer controlled radio, to make the plane perform very tight loops. But this was never the primary reason for flaperon mixing.

However flaperons can act to get you in trouble. They will cause a wing to stall more quickly, so it is best to avoid flaperons for your purposes ( landings and short field takeoffs ).

Yes you need a programmable radio.

Most non-entry level computer controlled transmitters have flaperon and other advanced mixing functions. Functions that make "mid priced" TX's worth while.

Now-a-days you can find computer controlled radios down to $170.00 or so in price. Well within the Entry level or beginner's price ranges, but often overlooked.

The "mid priced" TX's in the $300-600.00 range have quite advanced mixing and features.

The "high priced" units all but make coffee for you.

mike109

G'day

Computer radios can do all sorts of things. Flaperons is one of the ones best avoided for beginners. Yes, you can do it , but for most of us it is best avoided as it tends to create a plane that becomes less stable and wants to rock and roll all over the place.

On most models the flaps are near the fuselage and the ailerons at the outer end of the wing. With flaperons, the whole length of the moving surface becomes aileron and flap and big flaps are generally not good for stability.

A friend has a model of a Pilatus PC-9 which is an advanced trainer used by the Royal Australian Air Forcel. He did not build the model. The real aeroplane has flaps but the model has been built without them though they are an option on the plan. He tried using flaperons to slow this slippery model down but it just turned a nice flying model into an evil handling monster. He has abandoned that idea and is now about to embark on building a completely new model from the same Airborne plans and this time he is going to incorporate flaps and retracts.

Now Elevons is a good one which you can use on flying wing type planes like the Me-163. In this case, the two movable surfaces on the back of the wing do double duty as elevators (moving up and down together) and ailerons (moving opposite each other). This also needs two aileron servos.

RCKen

My Feedback: (9)

Ok, now that everybody has said "what" flaperons are, and "how" they are setup, I'm going to go back to what Minnflyer said above in the second post. Forget you heard about them.

This isn't to say that flaperons can't be used at all, because as DR1 Driver said, there are legitimate uses for them. But for beginners it's not a good idea for them. And here's why. They make the plane more prone to crashing. Why? Well, as Jetmech05 said flaps do produce lift when they are deployed but they also produce drag. Normal flaps are usually located in the inward portion of the wing close to the fuselage of the plane. When the flaps deploy the entire plane slows as  the drag increases, but it does so evenly because the flaps deploy evenly on both sides. Now when you move the flaps out to the wing tips and combine them with ailerons you setup a condition that could be very bad. With the flaps deployed and you move the ailerons you can cause the wingtip to slow to the point that it stalls, but ONLY the wingtip stalls, which causes what is called tip stall. When that wingtip stops flying and stalls it's going to drop. At altitude this isn't an issue because you usually have room to recover. But at just a few feet over the runway you won't have room to recover from the tip stall and will drive the plane into the ground wingtip first. NOT a good situation for a beginner.  

This is why there normally aren't recommended for beginners.

Ken

noveldoc

My Feedback: (2)

Flap and flaperons are not for a beginner. If your plane needs them, you should not be flying it.

Tom

Gray Beard

My Feedback: (-1)

Listen to what Ken said. I have used them on planes for years but only on FUN FLY COMPITION PLANES AND FOR COMPITION ONLY. Well usually. I have always slaved them with something else too, usually the elevator one way or another. At the moment I only have one plane set up with them and they are slaved to my elevator so as i add more elevator the flaps/ailerons drop. This set up is on a fun fly plane too, an old HOTS. I only use them to fool around in high winds. I have almost lost this plane on more then one occasion when I forget to turn them off and do a landing. The plane gets close to the ground and drops too much speed and tip stalls, right now, no warning. On a calm day they can bite me quick if I have been fooling with them and forget to turn the switch off. They have there place in flying but they do nothing good for most pilots except create problems. I don't even teach how to set them up to students. If a student decides he just wants to fool with them it's all on there heads, not mine.

CGRetired

My Feedback: (1)

My addition to this is what I've said numerous times before. Flaperons reduce the effectiveness of the ailerons. When deployed, the ailerons move down in unison, as said above. Then, what remains of aileron action is limited by, subtracted from, the aileron movement at a critical time, which is during slow movement during an approach and landing.

As GrayBeard, Ken, Minnflyer and others said, they are fine at altitude, but use them when you need aileron control, is just not a good idea.

CGr.

MinnFlyer

My Feedback: (4)

Gray Beard

My Feedback: (-1)

I see you got the munchies!!! BTDT

wazzbat

Alrighty then.  I think I get the idea of it.  I wasn't planning on putting them on my planes (unless everyone agreed it was a good idea of course).  I was just curious as to what and how?  So thank you all for your descriptions.  Much appreciated.

Cheers

pmerritt

My Feedback: (118)

Flapperons, or otherwise commonly known as "Flappinontoomuch" is the horizontalopening between the wife's nose and chin.
(and it's a wonder whyI've been married three times)

MinnFlyer

My Feedback: (4)

I hope you mean the horizontal opening - otherwise you have a whole new problem [X(]

pmerritt

My Feedback: (118)

Thanks for the correction. No wonder I can't fly for crap. LOL

BarracudaHockey

My Feedback: (11)

The biggest problem with them, when you're on approach and move the ailerons, you dump the extra lift created on one side.

IF you're going to do it, make sure its on a plane with full span ailerons, doing it on anything with wing tip ailerons is a BAD thing, you're creating wash in, which is the last thing you want during a landing approach.

They can be cool to play with but definately not while you're learning to fly.

pushinoldrc

My Feedback: (46)

Iwant a radio that makes coffee!

BarracudaHockey

My Feedback: (11)

Get an 11x then

Charlie P.

Now spoilerons, they're OK.

I have flaperons set-up on one model, but that one has tapered ailerons that don't extend to the wingtips. You'll note that in more advanced models with butterfly or CROW mix the outer ailerons lift (aka "spoilerons"). That gives added wash-out and prevents a low-speed stall. If you're slowed on approach and trigger flaperons you run a big risk of stalling one wing panel should you mistakenly try to correct a low altitude roll problem with ailerons instead of rudder.

Since 90% of flyers (not just beginners) would use ailerons in that situation, you can see why it's not generally a good idea. Flaperons down on slow approach near the ground, left wing drops, you give right aileron stick which lowers the flaperon on the left side even more and stalls the left wing completely. Model rolls left (opposite to stick input!), strikes a wingtip and cartwheels into pieces and you yell "I got hit!" instead of "I was dumb!"