Flaps or flaperons?
 

I have a really old goldberg cub with standard ailerons. Ive experienced that is a bit hard to land, often the plane passes the airstrip in speeds thats to fast for landing.

Im may gonna make one servo on each side of the wing, then its possible to use the flaperon function on the radio. Thats the easiest solution. Will it work, will the ailerons haveenough"power"to steer the plane enough when I use the flaperonfunction?

Another solution is to cutaproximatly 1/3 of the ailerons and use these as flaps and have just one servo for the flaps, and one servo for the ailerons, both in the center of the wing. The reduced length of the ailerons could also reduce the "power" of them to steer the plane.

Any experience or opinions?

RE: Flaps or flaperons?
 

Flaperons tend to stall a wing if one is not careful. I've seen two cubs at the field dorp like a rock on final because the pilots were using flaperons and the use of ailerons at slow speed. Go with the flaps, you will be much happier.

Don

RE: Flaps or flaperons?
 

If you can follow the scale design you will usually see better results.
Standard ailerons on a cub are big. Turning them into flapperons will develop an even greater Yaw moment as you maintain roll control; i.e. to get enough roll you need more input because the ailerons are pitched down. This creates even more yaw from the surfaces. This narrows the flight control envelope which is why many say flapperons cause tip stalls.
What may work is a very shallow amount of flap it can help with less Yaw but you just can't fly beyond its limits.

RE: Flaps or flaperons?
 

ful span flaperons are practical - just go slow in setting up the deflections
TheyARE used on full scale craft- for use in the bush country where short take off /landing is important
I have watched video of these craft taking off and landing in a little as a single length- in a light headwind
the flapperon deflection is easily seen- and the planes are very controllable adverse yaw - which has been beaten to death in this thread - is old as the hills and the fixes commonly used -including differential movement are effective
Theory is fine (Iguess ) till practical application provides a more accurate answer.

RE: Flaps or flaperons?
 

I've one of the Goldberg Cubs and tried flapperons. They only very slightly provide additional drag but reduce aileron authority by around 50% so unless you are good with the rudder, I'd add some aileron to rudder mix. I tried them and abandoned the effort and changed prop.

Go up one size in length and down one pitch and note the difference, it could be dramatic because it will provide much more braking action at idle speed and do far more to slow the model than flapperons. If you are running a 12x6 on a four stroker for example, go 13x5.

RE: Flaps or flaperons?
 

Definitely make sure you are using a low pitch large diameter prop and a good low idle. The other thing to do is get up high and practice trimming the plane for a nice slow stable glide. This will allow you to set the trim and use throttle to adjust your descent. A good slow stable descent is the key to a good landing for a Cub.

RE: Flaps or flaperons?
 

The plane had an OS 61 SF earllier, but soon Im gonna mount an OS 91 FX, and yes of course, Im gonna use a prop withextra lentgh and low pitch, as already planned

Actual props may be APC 13x6, 14x4w and 15X4w

May it will be possible to hover the cub withthese engine/prop combinations :). The cub isnt a 3D plane, but it may work anyway.

I guess im gonna try flaperons first, flying high, use the flaperons and look how the plane behaves

Aileron rudder mix could be a good idea

Of course, I dont need to mount 2 servos off center, on each side, Imsimplygonnamount one more servo in center, using the original control rods in the back of the wing

RE: Flaps or flaperons?
 

I'm a little confused. Why is it that you want to put a bigger engine on a plane that you already have trouble slowing down? As you stated, a cub is not intended to be a 3D plane and while the engine may be able to make it hover, the structure probably won't be able to handle it, for long at least. You don't give a lot of info about your approaches so it's really hard to recommend a solution to your landing problem, but I will guarantee that a bigger engine is not the solution.

RE: Flaps or flaperons?
 

I flew a Goldberg Cub that belonged to a fellow flying buddy for it's first flights. His had the same OS .60 on it as you mentioned The model is already overpowered with the .60 so I don't see how putting a .90 on it will make it any easier to land.

Flaperons on standard ailerons is a REALLY bad idea. Deflecting them down also adds the wrong sort of aerodynamic twist to the wing so the risk of tip stalling becomes VERY high. And if it tip stalls low to the ground you will end up crashing for sure. The proper way to deflect the ailerons to aid in landing is to deflect them UP. Then they are known as Spoilerons. Deflecting them up produces washout in the wing and makes the tips less prone to stalling so the landing approach will be safer.

But either way this is a lightly built model with lots of wing area. Even with the spoilerons angled up 60 degrees the drag added will be fairly minimal. In my buddy's model's case the engine power even at idle was enough to make it all but impossible to land. THe proper method of raising the nose to get the glide speed slower and raise the wing's angle of attack where it's more draggy just resulted in the model "gliding uphill" even at idle. I found that the only way to get the darn thing to land was to line it up and then actually shut the engine down and land dead stick.

For taking off I never did reach full throttle before it lifted off. I advance the throttle slowly so I can deal with any veering off by adding rudder. And even with moving the throttle towards full over a couple of seconds the model was always airborn by the time I was at about 1/3 throttle. After seeing how it flew he took it home and put a .40 into it. I never saw the plane again but he showed up one evening with another model and in talking with him he said the .40 was still easy to take off and climbed at a high angle at good speed but now the model actually could land fairly easy at idle.

It was the sort of model that if the pilot found himself in a thermal I don't doubt that he could shut down the engine and soar with it.

So I sit here aghast at the idea of this same airplane with a .90 on the nose. You really do have the wrong airplane for this. Or perhaps it's the airplane has the wrong owner.... :D Either way, with a .90 on the nose even with spoilerons you won't get it to land with the engine running. There will still be enough power at idle to actually climb at a shallow angle And I doubt that spoilerons will ruin the wing's lift enough to make a big difference on this count.

RE: Flaps or flaperons?
 

IMO a big engine will be much heavier, thats gonna raise the wing loading and make her fly faster - it'll be even harder to land in a small area. Big inboard flaps, with lots of drop (40 degrees or more)  used at very low throttle should slow her up and provide a steeper, but slow decent.  You can enhance the effect by fitting leading edge slats which will allow a few more degrees AoA before the stall sets in. With that combo she should drop slow and steep - practically like a parachute.

RE: Flaps or flaperons?
 

A note of different opinion-
Full span aileron /flap/flapperon does assist in making slower horizontal speed landings
BUT a more epowerful engine /motor is an asset as it takes more thrust to fly slowly than to fly at cruise .
Why?
vectored thrust is required to replace the wing lift lost at slow speed
The extremely high drag to lift configuration ,literally has to be drug along by thrust
You may find this is some book - I dunno
However - if you actually try it you will see how it all goes together

RE: Flaps or flaperons?
 

I agree with everyone here. I use flapperons on my seaplane so I can get it out of the water faster, I don't use them for landing. My throw measurement on the flapperon down is 1/4." On a semi scale plane like your mentioning is not a good idea. Some fast sport planes, flapperons are fine, and others forget about it! Your plane was designed to fly scale like, any extra quick drag your plane could make your plane eat dirt before you know it.



Pete

RE: Flaps or flaperons?
 

rmh,
I agree that more torque is required to fly slowly, but in this case, it sounds as if he already has more torque than he needs, so adding more won't solve the problem. I also get the impression that 1976kjell isn't mounting the bigger engine for the purpose of solving the problem. He states that he thinks he'll be able to hover with it. If it works, perhaps he'll solve the problem by performing 'harrier' landings ;)

RE: Flaps or flaperons?
 

I havent written that the The OS 91 FX  will get it easier to land, but  in reality its a bored 61 engine, and its lighter. Using a low pitch prop will reduce the speed. The power when these engines are on idle, isnt very much.

I want some more power out of the plane, not only boring scale-flying.

Remember, the clipped wing cub was an acrobaticplane

Its not much work to try flaperons, just an extra servo, and trying it high in sky wont eventually damage the plane

RE: Flaps or flaperons?
 

If it is the Goldberg Anniversary Cub, it will do all the aerobatics routines with a Saito .50 so I'm not getting the hot .60 two stroke... no wonder it won't slow down.

As others have pointed out well, going larger engine on an air frame brings liabilities with whatever pluses one thinks they are getting. The poor landing speed seen is one of those liabilities. In my opinion you should be thinking less motor rather than more... and thinking of another airframe for boring holes in the sky.

An often seen mistake with this sort of air frame (and many trainers) is when they are overpowered, they get trimmed for level flight at that power and the low power trim is ignored. Usually their problem is that they have serious climb with all the power so the elevator gets trimmed down. When landing and power is off, all that down trim has them diving for the ground and they come in very hot.

Those who have been around this hobby long enough to learn from old free flighters, know that the first rule of trim is to trim a plane for low power, then one adjust the airframe to bring it into trim for high power. One way to do that is with a throttle to elevator mix so that when going high power, the elevator trims down, but when coming off the power, the plane's desired landing glide path is what it should be.

Even after all that is said in this thread, some planes are floaters and unless the Cub was truly build clipped wing, it is certainly in the floater category and if there is no headwind, then slipping to induce drag was the way full scale pilots dealt with killing speed when landing and it also works for models.

RE: Flaps or flaperons?
 

I wish this forum supported videos
I have lots of video demonstrating very slow forward speed flight.
If anyone has a Vapor model (17 gram electric) , the proof of how this business of high angle of attack and greatly increased thrust all works together - -extremely well
My old Kadet Seniorita also would demonstrate how the increased thrust and high AOA work together to provide reduced forward speed flight
fear about tip stall etc., is actually nothing more than trying to fly at an increased angle of attack -without the necessary thrust to offset the increased drag.
I recently built yet another flat foam electric model with ailerons comprising 30% of the wing area.
Using my new DX8 radio -I setup a few flap/elevator combinations
It was very ineresting how lift off and landing speeds could be controlled with balanced amounts of thrust. The take off roll went to almost zero tho forward speed was very low.
Much of the conjecture can be quickly laid to rest with a small electric model setup to duplicate the the parameters in question

beats the st out of text book formula.

RE: Flaps or flaperons?
 

Again learn to slow it down on final. If at idle you still climb then it is and engine/prop/idle problem and until that is addressed it will not get better. I believe with any engine you should be able to slow it down, you just need to work out the bugs and learn to trim for T.O, cruise, and landing.

RE: Flaps or flaperons?
 

set up the proper sink rate -
if you learn this technique - which involves practicing power level and AOA- you will learn to land at lower over the ground speeds
trying to aim and idle it - don't work

RE: Flaps or flaperons?
 

Just picked up propellers with large diameter and low pitch.

In addition to try flaperons, It could be an idea to give the cub a bit more weigth in the tail, to increase AOA (angel of attack I guess).

This is also actual to make more possibilities to hover the plane.</p>

RE: Flaps or flaperons?
 

forget the tail heavy stuf - -balance the wing at 30% from le -

RE: Flaps or flaperons?
 

30% from leading edge may include some more weight in the tail compared to the balance which the plane have now</p>

RE: Flaps or flaperons?
 

Donate the old Cub to a new club member to help him get started and them mount that 91FX in a plane that will fly the way you want, not "boring scale-flying". Why do people insist on hacking up a perfectly good basic airplane to try make it do things it was never designed to do. Start with the right airframe for the performance you want and you'll get the style of flying you are looking for without compromise.

As to your flaperon question, I DO use them on my E-Flite 450 size Taylorcraft on floats. It has a good combination of thrust and light weight and the slight droop of the flaperons give the clipped wing some added stability/lift for takeoff and landing. As soon as it's off the water at a safe altitude, I retract the flaperons and it is fully aerobatic...even with floats.


Jaybird

RE: Flaps or flaperons?
 

I have 3 Goldberg cubs 2 on floats with saito 125 with a 15/6 prop and 1on wheels with saito 100 with a 15/4 prop all three land at a slow walk and yes mine will hover

RE: Flaps or flaperons?
 

some of these points were made but you seem to be changing the setup to suite a landing profile, which will effect the rest of the flight profile, without it appears at some of the comments to change your approach and landing method. Many have done so so its not an issue with needing to change much with the plane.

Consider. Prop with lower pitch.... good idea and the 60 let alone a bored 60 will turn a low pitch prop to have better thrust control, but thrust is thrust. Unless you can't get the idle down enough you should be able to throttle back to have the same effect of using a lower pitched prop.

If this is all still an issue then the comments about approach should be considered because even the clipped winged cub still have a very low wing load. This like most trainers need to be flown to the ground meaning they have extra lift. A controlled powered approach even with such still means you go to a reduced power setting, use your pitch control to set just below level flight, and feather altitude with the last of your throttle control. If the lift is still too great it may just need more negative pitch input but as you arrive over the field you should be able to throttle to idle and flair just as you are about to touch down.

I fly EDFs mainly and this gets very important to land under power and under a controlled "Stable Approach" so that you're not replacing landing gear more than you need to. Check the FAA and Stable Approach. Its actually how FS pilots are taught to land also.

RE: Flaps or flaperons?
 

How about just SLOWING THE PLANE DOWN?

Doesn't it occur that others with the same plane/engine combo don't have any problems?  That Cub will land just above a walk if set up right.

Ed