how do flaperons work?

Question

I recently bought a used Cub and the person who built it used one servo for each aileron (instead of a single servo for both like the instructions said). He wired them both together so that they run off the same channel on the receiver. He said he did this to make the plane more aerobatic (he also built it using the clipped wing configuration).

I would like to reconfigure the plane so that I can use flaperons. He told me that the plane doesn't float as much using the clipped wing, and right now at my place in the learning curve I can use all the float I can get.

My question is how exactly do I wire the plane up so that I can get the existing ailerons and servos to act as flaperons to give me some more lift on takeoff and landing?

I figure I have to resolder the current single connector that both servos are hooked to and seperate them back in to two connectors. Do I now get a computer radio with more than 4 channels and hook each servo to a different channel (which I'll call "true" aileron channel and "flap" channel)? I'm guessing I would then program in the "flap" channel with a 100% mix from the "true" aileron channel (the way the servos are mounted they both turn in the same direction and 1 aileron goes up and the other goes down).

My next guess is that I then mix negative 100% of the "flap" channel to the "true" aileron channel to get the servos to run in opposite directions and lower the flaps.

Is even close to the way it's supposed to work?

Also, for you Cub fans out there, is it ok to use the clipped with without the wing supports? The only reviews I have seen so far all say to make sure to use the supports, but they were all talking about the full wing version and I'm curious now.

Also, I think I may go ahead and build a full sized wing for it to use as I get use to flying the plane and then used the clipped wing once I get a little more comfortable with it. Any thoughts on this?

Thanks for your help. Steve

Morris Lee · Accepted Answer

Steve, you're correct in your assumption that you will need a computer radio with flaperon mixing, and that you have to plug each servo into a different channel. Consult your radio manual on how to program the mixing. However, Cubs are floaters as-is, and I don't see any real advantage to adding flaperons. The Cub is notorious for adverse yaw, where the down aileron creates so much drag that the plane won't turn without help from the rudder, and adding flaperons will probably aggravate the problem. Also, flaperons will increase the tendency to tip stall, something you definitely don't want on landing approaches. As far as whether or not to remove the struts, it depends on how your particular brand of Cub went together. Some do fine without the struts, while in others they're an absolute necessity.

If you're going to get a computer radio, I suggest you use its mixing capabilities to get differential ailerons (more up travel than down) and/or an aileron/rudder mix. Better yet, learn to use both sticks to make coordinated turns.

Morris

Steve Banks · Answer

FYI, you do not "need" a computer radio. A $12 electronic v-tail/elevon mixer will work too, i.e.:

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You will want a seperate channel for flaps however. Plug the mixer into your aileron and flap channels on the radio and plug the wing servos into the mixer.

I've heard of people w/4 channel radios coupling the flaps to the throttle channel, not sure how useful that setup is.

hth

strathboy · Answer

As earlier posters said, using the wing struts does indeed depend on the J3 model you are flying which you failed to mention. I have flown a Sig J3 (full wing 40 size) w/o the struts  with disastrous results. No need to elaborate. However, my Goldberg Anniversary Cub (also full wing) flies regularly w/o struts since the wing is a much stronger construction.  That being said, I like the scale appearance of the struts. I am currently building a 1/4 scale Sig J3 (full wing) and will definitely use the struts on that baby. Can't add anything more than previous posters on the use of flaperons. I agree that they aren't necessary on a J3 and can get you in a lot of trouble. I fly a JR computer radio and use flaperons on planes with a higher  wing loading but not the J3's.  However, I haven't flown a clipped wing version but you should still be able to land at a manageable ground speed without fear of a stall.  Save the flaperons for something hotter and continue with your Y harness connecting...

Six_O'Clock_High · Answer

Steve, he will need a 5 channel radio to use that tool.  I think he said he has a 4 now.

Bill Fulmer · Answer

Steve,NEVER use flaperons with scale type ailerons as a Cub would have.  If theplane has strip ailerons, such as the Goldberg Cub, you may be OK, butflaperons with barndoor style ailerons is an invitation to disaster.Flaps are INBOARD on a wing to induce rthe stall at the root first...  Youdon't want to induce a stall at the wingtip!The general configuration for flaperons is to activate the flaperon mix andhave one aileron on Ch. 1 and the other on Ch. 6.   You'll probably have toplay with servo direction and percentages to dial it in...Bill

me · Answer

When I think of flapperons the first words that come to mind are exotic, esoteric or maybe acrobatic. When I think of a Piper Cub I think stable and trainer like flying characteristics. This doesn't sound like a good combination to me. YMMV. Sign, me

Six_O'Clock_High · Answer

Bill,Of course you are absolutly correct, but telling him that just means he will think of it rather than remember it.  One time I did flaps on the inboard and flaperons on the outboard.  What a dog that was!

S Casko · Answer

While we are discussing radios, since the plane came without radio equipment, anyone got any recommendations? I've been toying with the idea of the Hitec Optic 6 and getting the synthesizer module now (or maybe when I get my next plane) so that I will have some flexibility. Most of the guys I fly with are Futaba fans though. Some of them have recommended sticking with a Tx for each plane so that they are all complete (especially should I decide to sell one of them).

Any recommendation on a good receiver for this plane also?

Thanks for your help...

Steve

Steve · Answer

If your local group is mostly using Futaba, there is a big advantage to using a compatible radio if you ever want to use a buddy cord. (Note that this does NOT imply you must by Futaba as several others including Hitec are compatible.)

The 6 channel Futaba computer radio (the model number escapes me right now 6SX or something like that) appears to be a good deal. The price is quite low, barely over what they are charging for a non-computer 4 channel system. I don't have personal experience with this model, but every Futaba I have ever owned has been a quality piece of equipment.

I also think you can't go wrong with an Eclipse 7 with the Spectra module if you have multiple planes.

My opinion is that you are better off buying one good radio that you are very familiar with and using it for all your planes rather than buying a separate transmitter for each plane. Unless you have a lot of money, the latter plan usually means you are buying several copies of a lower end radio, and you will be missing out on many of the nice features of a mid-range radio.

Boat · Answer

Maybe a misunderstanding? Just get a receiver for each plane, and use thesame transmitter. This only works, of course, if they're all on the samefrequency.One that works with your transmitter.

how do flaperons work?

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