Flaperons
 

I have never programmed flaperons before. My radio (DX7) offers me the availability to program in elevator with the flaps. Should the elevator be up or down when flaps are employed? Also, the flaps can be in two stages. I arbitrarily picked 20% and 80%. What are your thoughts on these numbers? Thanks for your help.

RE: Flaperons
 

Go easy with this feature. You can crash a plane if you do too much. Generally flaperons are set such that when you give up elevator, both ailerons go down a little bit (start with 20%). There are really two things you can do: 1) you can program "flaps" such that both ailerons go down a little bit when you flip a switch. or (2) you can program "flaperons" such that the ailerons go down when the elevator goes up. Frankly, with most planes these functions are more trouble than they're worth.

RE: Flaperons
 

Depends on the model, airfoil of the main wing and the specific center of gravity of your plane. Most will need some down elevator (5 to 20%) when the flaps are down Others up elevator. Flaps add lift and also drag; which affects different models in different ways. Problem is the flaps may or may not have as sudden an effect as the elevator, and vise versa. That is, even when trimmed to keep a level attitude at a low speed the initial deployment may cause the model to balloon or dip until they "catch up". Some radios allow a elevator mix delay that helps in some cases. The only sure way is to start with small movements and try them on your model. I generally "cheat" and slow the model then give a tad of down elevator a heartbeat before I flip the flap switch (with a down elevator mix). The initial deployment needs more correction than the final landing approach.

I generally set the flap to where I like it after repeated landings (or takeoffs) and then worry about the elevator mix. I also assign a switch so I have the choice of elevator mix or not. As just mentioned - during a Short Take-Off with flaps you might not want the elevator mix fighting you.


20% flaps is a good number, but 80% is a tad much, especially for full-width flaps. 10% & 20% might be a better place to start. My Contender has a 60 degree drop (1-3/4"), but that is only the 12" central apron flap. Without the down elevator that will pitch the nose up 45 degrees with any speed on at all on approach . . . and the Contender glides like a turnip without flaps so there is usually some speed on during approach. The flap makes a world of difference on that model. My SK-50 had full strip flaperons and they made little difference at all. Depends a great deal on control throw and the area of the control surfaces. My Hot Stik has HUGE control surfaces and dual servos in each wing so I can set the outer ailerons to lift while the inner ones drop (aka "CROW"). That's great fun to play with.

Be sure when deploying flaps your airspeed is slow. Deloying flaps at higher speeds will cause the model to pitch violenty and may overstress the flap/servo(s)/hinges. There is a lot of drag on a deployed flap.

Note also, most trainers already have lift out the giggie and raising the flaps ("spoilers") instead may give you a better landing approach.

RE: Flaperons
 

Thanks for the input so far. I probably should have mentioned that the plane I will be experimenting with (flaperons) is an E-Flite Mini Funtana X. Not really a trainer, but a pretty good intermediate low wing plane with a pretty predictable glide slope. I have no problems landing the plane without flaps, but I want to learn how?

RE: Flaperons
 

I recently recovered an LT40 and replaced the 1-1/2" x full length ailerons with 3" x full length flaperons. The 3-position switch is set up as no flaps, about 15 degrees and about 35 degrees. The plane is a dream to fly in the wind and with much of a breeze, it can be flown backwards. It lands at a snail's pace and will take off in about 8 feet. With a longer run and full flaps it will take off and climb out at less than 1/4 throttle (ST .51 engine). I don't have any elevator mixed in and at high speed, it just balloons without really changing attitude when the flaps are deployed. However, all this comes with a catch...

You need to be fast on the throttle and ailerons when flying slow because it will tip stall instantly if you get careless. I had a Stik that the former owner had set up with elevator coupling and a combo flaperon/spoileron setup. I hated the thing because it climbed or dove rather than slowing when either was deployed. The flaps on the LT40 are great fun and always draw a reaction from the other guys at the field when I do a flyby a foot off the ground at less than walking speed. Just remember that they are unforgiving if you go outside the envelope and I already had one minor incident when the plane tip stalled into a death spiral at 35 feet up on takeoff. I almost recovered it before it hit the ground and there was minor damage but it taught a valuable lesson.

Experiment and have fun!

Neal

RE: Flaperons
 

Hi,

I have the funtana X mini , and am using the JR X9303. I have flaperons on it, and they seems to work real well. I have a lot put in, I'll get it and check how much I have. I also put in auto land ( that adjusts the elevator for me, when the throtle is moved to a low level) . I don't think you will need much down elevator at the lower speed for landing, if thats what you are doing. I can floot mine in at slow speed in just a little wind, but I tested it at a high alt. before trying to land. I must have played with it a couple of flights before trying it for a landing.

Ok, I'm back hope that did not take too long for you!!!!:D

The first setting is a 1 inch drop and the second is 1.5 inch drop ( don't have a degree for it), and I have not used the second one (1.5 inch) . I have broght it in , in very little wind and just about landed on a spot landing. I have not seen any indication of a tip stall problem on mine, but I do watch for it and it can happen( remember when you play sometimes you pay).

let us know how you come out.....

RE: Flaperons
 

Just flew the funtana mini x this morning , I forgot just how it flew with the flaps.

I have it set up for auto land on my x9303 2.4 and when I drop the throtel I had to put in a little up ( not much about 1/8 of a inch ) to get it to hold level at all. But I am using it for landing and having the nose drop a little is the way I like it.

I then tryed landing without flaps at all and it lands better without them!!!!! Its till fun to play with flaps.

RE: Flaperons
 

I will second the warning on working up to high values of flaperon mix esp. if the CG is forward.

The flap effect can cause you to run out of elevator authority, just try a real slow speed nose up pass at altitude and see what happens. If the nose over is pronounced then either flick the switch [preferred] or power up.

However with the model you have I suspect 75 degrees elevator with 50 degrees flap is a good guess for 3D flying. Dual rates and lots of expo advised though!

RE: Flaperons
 

get the plane up high, really high, and hit the flap switch and see what happens. See what you need to do to keep the plane flying level, and copy this with your mix. it's the only way to tell what mix you need with flaperons activated.

RE: Flaperons
 

I've had a couple "oopsies" with flaps.

Once while doing touch and goes I goosed the throttle and then zeroed the flaps at about three feet up. Model hit like a basketball and bounced three feet back into the air. Ouch - but no harm done (that I know of). Be careful when REMOVING all that lift.

Also: several long, slow approaches at low idle that looked just beautiful . . . until the stall. RATS! Again - no harm done (that I know of). The model looks to be just hanging there beautifully and you forget Rule #1 ("Speed is Life"). Flaps tend to steepen and slow the approach, so don't try and "stretch" it out beyond stall speed.

I'm fretful that any hard landing may knock a wing rib or two loose (this particular model has the main gear mounted in the wings).

RE: Flaperons
 

Flaperons can be A lot of fun. I started using them A long time ago on my fun fly planes to help give me A bit of an edge in some of the events. I had them set up on A switch like most people do.
I still have an old fun fly plane, A Mid West Hots with A YS 1.10, maybe A bit of over kill on A 60 size plane but it just adds to the fun.
I have my flaperons slaved to my elevator on this plane. I have A Futaba 9-C and as I recall it's A three step process to do this. I have to use my instruction book on every set up I do because I can't recall them all. That has bitten me A few times too, can't always remember what switches do what to each plane.
Anyway, this set up allows me to hit A switch and it turns on my flaperons, as my elevator goes up my flaps go down. You can set it up to go either way too.
For even more Plane Fun another old guy that writes for RC Report named Ed Moorman likes to do his A different way. {sorry about that old crack Ed :)} Some of the things Ed does with A plane sometimes scares me but I usually try them anyway, A few close calls but what the heck. :D Ed likes to set his up as spoilerons and sets them up to his throttle. As you start to slow down the flaps go up into spoiler position and the plane will start dropping to just about anyplace you want it. I have been trying to figure out how to set my plane up so I can do it his way and mine?? Just way more thinking then I can do at one sitting!!;)

RE: Flaperons
 

After reading these replies it occurs to me that a lot depends on what radio you are using to set your flaperons/spoilers/ elevator for your use. Apparently each manufacter has thier own means of doing this. I use JR Spectrum and can set the flaperons to deploy by a switch/ coupled with my throttle. In that way I choose at what throttle position they will come into use as well as just by increasing throttle they now go back to normal, no need to flip switch. This also includes whatever elevator rudder mix I have also chosen to use. Great when you decide to go round again for another approach.

RE: Flaperons
 

This is the Auto Land feature that I was talking about on my JR 9303, that I am using on my Funtana mini X. I have the speed a little over stall when the flaps come on.