Ok here is the dumb question of the day - I have flaperon mixing on
my radio and am setting up flaps - I have got the 2 servo 2 channel
thing figured out and have also set up a 3 position switch - flaps
up/down/neutral which works fine - when I am taking off do I want
the flaps up or down - up would be the same direction as the elevator
which logically would give me more lift but is there a balancing issue
(i.e too much lift ) The manual for my radio is not very helpful only
talking about flap/elevator mixing for aerobatics. I have full strip aerlirons
on a GP big stik 60 which tends to come in hot sometimes so I also
want to be able to slow it down on landing - Again flaps in an up or down
position? Please set me straight prior to my flying it as rebuilding sucks !!

Chris

Chris,

Flaps aways go down on RC airplanes. They start at neutral with the 3 position switch in what I will call position 1 (normally all the way up or towards the front of the radio). In position 2 (middle position) the flaps would be half way down. In position 3 the flaps would be fully down. You will have to experiment with the angles of the flaps in the mid and full down positions. Also, most of the time you do not use the flaps during take off.

By the way, the flaps work in the opposite direction of the elevators. If you look at some of the control line stunt planes, they have flaps on the wings that are linked to the elevators. When up is applied the wing flaps go down and the elevators go up.

George

http://www.rcuniverse.com/forum/Flap...1183411/tm.htm

Chris, check out this thread.

I also had a question regarding throws for flaps. I got some interesting feedback telling me that flaps could have the opposite effect I wanted if they were too far aft of the CG. (Lowering flaps on landing approach would actually bring the nose DOWN.) I haven't tried it yet. I had a mishap at the field and fried my electrics right out of the plane!

My advice is to try it with flaps up, then stage 2, stage 3 probably is way too radical.

Best of luck 2 u.

Yea, don't get too crazy with them. Use very small deflection at first, and remember that flapperons can increase your chances of a tip stall.

The one thing no one has mentioned. From the way you're decribing this, you've programmed the flaps when "up" to be above the trailing edge of the wing. That's not flaperons, that's spoilerons! And will bleed OFF lift causing the plane to sink dramatically.

When we talk about the flaps being "up", we are referring to what you're calling "neutral"! Flaps NEVER go above the trailing edge of the wing.

The three positions you want would be around "neutral", 15% down, then 30% down.
Dennis-

When flaps are dropped, they always increase drag, and most always increase lift.

However, in doing so, the airplane may pitch nose up or nose down. Note that a nose-down pitch does NOT mean a reduction in lift. So be sure to try your flaps up high first and be ready for a pitch change. In general, short coupled planes tend to pitch down with flaps, planes with longer tails will pitch up. But it's not easily predictable as there are several factors at work such as the CG as mentioned above.

Raising the ailerons as "spoilerons" can help you drop in for a landing on a short field by killing lift, and can be useful, but isn't seen much on powered planes. If your plane is a real "floater" that never wants to land, spoilerons can help. Other than that, though, I wouldn't bother with them.

Thanks for the input guys that is kinda what i figured. Here is a follow
up. If the flaps are raised above the leading edge (spoilerons ) and
the aircraft is inverted would that have the same effect as flaps?
I am thinking of low speed inverted passes ( I saw it done at a local club
a while ago - very cool) Is this a good idea or am I heading to the
balsa graveyard. My plane incidently flys very well inverted.

Chris

Yes that would work, and flying low and inverted is ALWAYS inviting danger.

Go 4 it, but practice up high first.

Some call them "Crasherons."

Have a video camera going when you do that inverted pass with spoilerons deployed!!

Regards and have fun.

Crasherons LOL I love it - Warning Mike I am going to steal
that line !! Upon reflection programming my radio with a "Crash Now"
button doesn't seem like the smartest idea I have ever had. I think I am
going to take DBCherrys advice set them for 2 down positions and
not worry too much about inverted low speed passes (maybe I will
tell my buddy about it - he'll try anything ) and I will make sure
to have my camcorder at the ready for the balsa explosion!! [X(]
Any opinions about coupling elevators and flaps I understand it
is possible to do some wicked loops with this setup - input on
coupling percentages ?

Chris

Just a guess but it sounds like maybe you're not chopping the throttle soon enough on approach, or maybe the idle is too high. Flaperons can be fun to play around with but you really shouldn't need them on a Big Stick.

     

        Thanks for asking the question, I have never used flaps before, but planning on it with a new Cherokee and RV9. When using my G5.5
 this afternoon I found it easier to land without flaps but really had to slow down way on out before the runway. With flaps fully on It wanted
tip stall without a little power added then didn't want to come down. I think I'll try the up high practice with 15 or 20 degree of flap for a baseline.
Thanks to this forum you guys may have saved me from shame !!! By the way the only Dumb question is the one that  wasn't asked.

It sounds like some of the posters on this subject may not have actually tried mixing flap and aileron functions, or if they have, not experimented with it too much. Spoilerons will help kill lift if the airplane is slowed down enough. But if you increase the power and gain speed, the airplane will climb and can easily overpower the elevator. Same thing will happen as flaps, though the airplane goes down instead of up.

So when Minnflyer says:
It would be good to follow the small deflection at first advise.

Not a video and low quality, but here is my Sig Somethin Extra low, slow and inverted. I modified the wing to have flaps and in the picture I use a crow mix coupled to elevators (up elevator gives down flap and up aileron and vice versa). The SSE coud be flown at a snails pace. Very fun!



Here you can see what the wing looks like: [link=http://www.rcuniverse.com/forum/fb.asp?m=10040553]post 19[/link]

IMHO full span ailerons should not be used as flaperons for landing. Tip stalling problems may occur if to much flaperon is applied and also aileron response can be sluggish or even reversed. If you are determined to try it, start out with very small deflections.

Not always, it does depend on the plane. factors like the CG location in relation to the flaperons and the tail moment have an effect. Planes with really short tail moments can almost act like flying wings, where raising spoilerons raises the nose and causes a climb as you say. While planes with a longer tail sometimes to go nose-down with the spoilerons up and nose-up with flaperons down. My combat planes are short-coupled with very short fuses, and I can and do trim the pitch by adjusting where the ailerons are at center. I "reflex" or raise both ailerons or lower them a bit to change the way the plane flys.

On the other hand, I have a Mossie that goes hard nose-up if the flaps are down and I'm going very fast. At very slow speeds, there's no noticeable pitch change at all. But adding power with flaps down gets an immediate nose-up. I had an old funfly plane years ago, I think it was called a tadpole, and it pitched up with flaperons down, which was desireable to help make really tight loops, control-line-flap style.

Ithink you might have a little too much downwards aileron throw when you have flap deployed. Depending on your set you can link the flap selection to a dual rate selection so that when your flaps are in the fully down position, the downwards aileron throw is reduced dramatically. By this, I mean you can assign to the dual rate selection the same switch that puts down the flaps.
The other thing to practice, at high level, is to feed in rudder input when you want to turn at low speed. Most models will respond very well to this, more effective in producing a turn than aileron alone.

When deploying flaps, your airspeed should be slow. They get unpredictable when used at high speed. I have a Stick that will loop all by itself if full flaps are deployed in cruise.

Also, it's hard on the equipment. Saw a wing fail in flight from flap use in high-speed flight.

I think flaperons and spoilers are great to use on a Stick of any type. I've used them on Big Stick 40, Ultra Stick 40 & 60, Wild Stik 40 & 120, Joss Stick, Little Stick.

I set the flaperons to move opposite to the elevator for tighter maneuvers. These are great for downward outside loops and outside square loops. It gives you enough control authority so you aren't afraid of hitting the ground.

For landings, I use about 15 degrees spoilers (flaps upwards) mixed to throttle so the spoilers start to deploy at half throttle and are fully up 15 degrees at idle. This keeps the Stick from floating and makes for good spot landings. As you add power, the spoilers also drop down slightly, increasing your float. When you throttle up for a go around, they drop to the normal aileron position.