I am interconnecting my ailerons -it is good enough for full scale - done right - it LESSENS loads on the control devices
attach the ailerons at 2/5 points from ends
This stuff ain't that hard.
Build light - and use thick trailing edges - good enough for full scale .

Interconnecting ailerons does not lessen the loads. Aileron loads do not cancel out - they add. Draw the force diagrams.
Full size (puddle jumpers) interconnect ailerons for the simple reason that they have to connect somewhere - there's only one control stick. Models do not have this restriction - you can have two servos, one for each aileron. This also applies to big airplanes with hydraulic controls.
Good enough for full size is a dangerous engineering principle. Models and full size have significant differences in their physics in addition to design compromises needed to accomodate the fact that there is real live person on-board.
Thick trailing edges - see earlier comments - suit yourself. Seems to me the TE thickness on full size is a structural limitation. The minimum is twice the skin thickness plus a stiffener. Most PJ's I've seen it's about 1/4" - well that's pretty sharp on a 30ft wing. Thickest I've seen lately is the flap TE on a Lancair, which looked a bit odd because the flap TE was thick and the aileron TE was very sharp. I've asked but no-one yet has provided a plausible explanation for this asymmetry.

Interconnecting the ailerons is an good idea for flutter prevention.
It is hard to two wings that are exactly the same frequency.
When you have no mass balance and model ailerons you carry all the load on one gear tooth in each wing.
Darryl

On models -- where the servos are individual per aileron-- the servo has to hold aileron in position -against airloads .
Properly interconnected - a positive/negative G can NOT move the aileron --as one has to go up whilst the other goes down.
The full scale aerobats all use this arrangements --plus counterweights and spades .
So--- the pilot only has to provide desired inputs to ailerons and these are extremely light -being a two finger type force. (referring to EXTRA 300L).
early RC models tried torque rod hookups for ailerons - these were/are very bad. I am extremely familiar with the poor linkages used on some setups.
The first TOC model I built had these (against my advice not to) and one side promptly broke -
The model then got two servos (one each side ) as a fast patch up . (Contest was in a week)
The problem then was the poor center holding power of the 1970's servos. But it made it .
Using proper rod and bellcrank setup-the potential "windup" in individual aileron servos can be eliminated as the interconnection will for all practical purposes, prevent one aileron moving without moving the other a like amount in the opposite direction . The servo will tneed only enough force to start a roll. (similar to full scale practice.)
So -this is why I said the load is lessened on the control device.
Which it is .
Oh yes - the thick trailing edge -
really no big deal on the model except that the very thick edge does add rigidity and - as practiced on some aerobatic airfoils -- the very thick,blunt edge acts to create a very low pressure - which (theoretically) helps attach air on the ailerons .
I have no experience with building working on big aircraft -such as you apparantly are familiar with.
Just small stuff.

Darryl - interconnecting the ailerons can lead to a very serious form of flutter. If the wing is not stiff enough in torsion the ailerons act as servo tabs and cause the wing to twist. A down-going aileron causes the attached wing to twist to a more negative angle of attack and so the wing bends downwards. Because the other aileron is connected and operates in the opposite direction, the other wing bends upwards. The entire wing thus takes on an S shape. This resonant mode has a low frequency compared to other modes and will therefore occur at the lowest airspeed. It is very destructive and usually results in one or both of the wings breaking off somewhere near mid span, often at the corner of the aileron cutouts. It is a consequence of the mechanical interconnection of the ailerons. It should be noted that the presence of a servo attached to the interconnection should prevent motion from one aileron being transmitted to the other. In reality, this is not the case. In a resonant event it is most likely that the servo holding power is over-ridden by the forces involved and the servo thus acts only as a dampener. Furthermore, any free play in the linkage system will allow a small amount of movement to be transmitted from one aileron to the other at all times and so contribute to the problem.

Interconnected ailerons do not cause control forces to be neutralized. Each control force, whether the control is deflected up or down, results in a torque restoring the control surface to its neutral position. Thus the up-going aileron and the down going aileron both create restoring torques in the same direction at the servo. The servo must drive both ailerons against their respective restoring torques. There is no "free lunch" in nature.

Interconnected ailerons do cancel out the effects of G loading, as you say, but let's put some real numbers to the problem and see if it is worth the trouble.
A large aileron I have here is 60cm x 8cm and weighs 43g. Since it's cross section is triangular, its CG is at the 1/3 chord point, which is 8/3cm from the leading edge.

The torque on the aileron due to G loading is therefore 0.043x8/3 = 0.115kg.cm/G. If this airplane were pulling 10G (a lot), the aileron torque due to this would therefore be 1.115kg.cm. A suitable servo to drive this (huge) aileron is rated at 15kg.cm, so the effects of G load induced torque at 10G is less than 7% of the servo's capability.

Using one well know servo torque calculation formula, this aileron deflected 45deg at 100kph requires a servo torque of 13kg.cm, so the selected servo is only marginally capable of service and in practice a larger servo would be more prudent, in which case the G load induced torque would be an even smaller proportion of its capability.

Considering the very considerable advantages of independent servos driving ailerons, I would live with the 7%.

I would also like to know how a low pressure region BEHIND the wing manages to keep air attached to the ailerons (AHEAD of this low pressure region). I certainly never saw such a thing in any of the wind tunnels I worked with when I was young.

I appreciate and do understand your ideas.
From a purely practical standpoint - the setup I described -(the 300L) works very well.
We have tested our arrangement on extremely light (100 gram) models
the ailerons being up to 40% of the total wing area -and on flat wings to boot!
The single driven pair works as well, rolls as rapidly, has no flutter problems - these designs are quite flimsy and very high (for them) speed will induce flutter but low speeds -work perfectly.
These are made from 3--6 mm thick Depron , a firm expnded foam .
We do a lot of initial idea testing with these -cheap and easy to work with -electric powered .
Our larger gasoline models -for this setup will be in the 20 pound region.
Flutter on these occurs readily with poorly setup individual servos -plenty of experience there.
.
A hydraulic setup would be nice -I have patents (now expired ) on unique control systems -but from a practical standpoint -not good for models .

The low pressure stabilization idea was not mine -but does appear to work
we have done fixes on rudders which hunt due to oversized aero counterbalances .
by making the trailing edge thicker (from top to bottom along entire t e) the "hunting" is stopped .

1) I'm not sure what you mean by G can NOT move ailerons, unless you mean the G forces acting directly on the ailerons. That would be true. But the primary cause of flutter is airspeed. Not really related to G forces except that pulling out of a dive at high airspeed involves simultaneous high G. The primary cause, airspeed, is going to move interconnected control surfaces. Interconnected or not.

2) The only thing wrong with torque rods is usually bad design. Remember, if you get down and look under many automobiles, you'll find a torque rod somewhere in the suspension system. It all depends on how they're designed and what they're used for. I think on most small models they're a cheap and fast solution. On larger models they're more expensive and harder to design and implement than clevis and horns, so you only see the cheap, quick failing ones.

3) Which brings me back to one of my favorite harps: You can't make sweeping generalizations about ......well about many things connected with aircraft design. Just like you can't say that the rudder turns the plane. You can only correctly say that the rudder controls the yaw axis of the plane.

In that same way, you can't say that interconnecting ailerons will eliminate flutter. You can only correctly say, that, among other remedies, if the ailerons are interconnected in such a way that the interconnection reduces frequency resonance, that interconnection, eliminates flutter.

And according to the articles referenced above, even NASA finds that the only way to detect and eliminate flutter is, in addition to testing models, to test the actual planes by inducing vibration and observing if that vibration is dampened or amplified at HUNDREDS of different airspeeds and configurations of the aircraft.

Resonance can occur at ANY FREQUENCY. There are multiple cures. But the cures only work when they change the resonant frequency characteristics of the two parts of the system that are analogous to the spring and shock absorber of a car's suspension.

Of course, speaking of favorite expressions, above the door of the church where I go is engraved, "If it ain't broke, don't fix it." Also spoken by that prophet was, "If the adjustment you just made cured the problem, its fixed. Who cares why?"

PS.- I thought the only good TE was one you had to be careful not to cut your fingers on?

I never should have said "G" forces -
I was referring to high +/- airloads on the wing from aerobatics.
Stabilizing the ailerons during these loadings is important.
The least bit of deflection on one side, changes the next heading.
Unless the entire airframe is tested -the idea of what is a good control setup and what is a bad setup - is futile.
I do understand linkages and torsion setups -
good linkages do not twist or deflect.

Torsion bars on cars / trailing links/ etc., are another story -and a lifelong hobby of stuffing different engines in cars.
Anyway the new plane will have a rock solid rod and crank interconnection -at two point on each aileron-then crossing to the other aileron
The servo will simply position the linkage-again just like a good full scale aerobat.
I gather from a number of comments in this forum, that these craft are not familiar to many.

TDGF, I liked your comments and all fell into the wealth of info I have observed in testing and instrumenting all types of flying craft, big and little. Could not find any fault with any of them. Good work.

TGDF is right. If it aint broke don't fix it.

Really, this is what this thread is all about. All the discussion about the influence of various design features on flutter and other dynamic problems really has but one outcome - don't tempt mother nature. Use this knowledge to construct sensibly designed control systems of the highest quality that you can. If after doing this you get no dynamic problems, then leave it alone. Experience shows that in the case of model airplanes, this is generally enough.

Adding mass balancers is starting at the wrong end of the solution. Yes, it will work, but you make a lot of compromises to fit them, and you really should try all the other solutions first. If at some point in trying the other solutions the airplane becomes "not broken", then this is where you stop.

The comment above about experience in the case of model airplanes relates to engineering principles accumulated over many years and found applicable to models. This needs to be considered in context. Dick, you caught me broadside in your last post when you discussed a 100g depron model. Much of the engineering we are used to in modelling does not apply to 100g models. It also does not apply to 50kg models. To analyse these models we certainly need to refer to the underlying physics and throw in some of our model engineering knowledge, but we also need to put some numbers to the results - factors which are insignificant to a 2m F3A model may be extremely important to a 100g depron model. An FAI pylon racer will usually suffer tailplane stall at the turn if the pilot is too vigorous with back stick, even using a simple balsa/foam wing. Similarly mishandling a giant scale 50kg pylon racer will have an entirely different, and much more spectacular outcome.

Separate servos on ailerons for F3A and F3B models is these days essentially a design principle. What is completely appropriate for pattern models and gliders clearly is not necessarily so for a 100g foamie. On my jet I have split ailerons with separate servos for each - 4 digital servos in total all with titanium pushrods and ball race linkages - and there are sound engineering reasons for doing this, some of which have nothing to do with aerodynamics.

It's good to discuss and understand theory. It is essential to the construction of safe airplanes and the safe flying of them. Ask the airforce why you need an aerospace degree to fly a fast jet!! But at the end of the day the theory must be mixed with experience to make it useful - neither on it's own is any use.

I am not a novice at the theory or the construction of models -of all sizes -I have a number of designs which have won or placed in world /national and other competition such as the TOC.
I also designed a number of patented, successful industrial machines .
So yes I do understand the theory - but -no I never leave "well enough " alone .
Just not my nature
If I did take that approach - I never would have designed anything .
We all have different approaches to doing things.
I do understand and appreciate your comments .
Shared info is shared wealth.

Way too technical for me, most of this I'm afraid! I do however take issue with Jfitters comment that mass balancing was starting at the wrong end of the solution scale. Practically, it has worked and practically, it was probably the easiest mod to make, except for the stiffer linkages/horns that went with it. That said, "if it aint broke don't fix it" seems to apply

Here's why we try all the other solutions first.

You can't put mass balances inside a model wing - the control surface deflections are too great to keep the balance weights completely within the wing. Mass balances at the end of the ailerons don't work because light weight ailerons cannot be made stiff enough in torsion. Leading edge mass balances are impractical in models - in full size they use depleted uranium and Frieze ailerons both of which help a lot. That only leaves external mass balances - weights on arms extending forward of the aileron hinge line and normally mounted on the bottom so they are not such an eyesore.

Disadvantages;
1. Increases live weight and moment of inertia of control system.
2. Ugly.
3. Added complexity.
4. When the wheels fold (belly landing) the mass balances are torn off and the servo gears are stripped. Even a wing drop on landing can result in this if the grass is long.
5. Difficult to fit wing bags.
6. Target for handling and transport damage.
7. Additional point of failure - if the weight falls of in flight you have a problem.

Light, stiff, friction and slop free - that's what it takes.

You can add mass balances nicely -thru small jogged tip extensions -and they look good and work well
Use em all the time
a fishing bob on a small rod at the aileron root also works fine . tho not scale looking
I will stick in some picslater of the new aileron coupling linkages --

I'm afraid I'm not with you on this one. Have a look at my Funtana pictured below. The ailerons on this beast are extremely large stiff cross-braced structures and have had no problems handling the 50g plus weight fitted in the balancers. Done right they dont look bad either and I have no problems with my wing bags either [8D]

Spoiler, you've got to show both the dark close up shop pix and the well lit pix on the plane. I couldn't figure out what the heck that was when you first posted the dark, tip shot taken in the workshop by itself. Only because so much of communication and understanding is already knowing what you're looking at before you even see it. Not because it was a bad picture. Just not enough info at first.

Those balancers really LOOK neat cause of the sort of reverse scoop style. Anyone have any idea if that really works or if its just a large added drag. Also, is a mass balance just the kind with added weight? Are the rudder balancers that consist of just the airfoil that wraps around over the top of the tail considered mass balancers or just aerodynamic balance?

Yep, the full plane shot is a tad indistinct. One comment on the "scoop" design I had was that it would cause the aileron or hinges to break near the outboard end of the wings because of the drag caused by the scoop. Practically, the scoop is faired in at the front and only cataches the air when the ailerons are deflected. After about 6 or so flights, no problems were evident and no flutter occurred despite some high speed passes. Sadly, the plane is in need of a new right wing after a mid air collision and subsequent crash into a tree while trying an emergency landing!!

Noooo, It was the full plane shot that explained it for me. Looking at the dark shot on the bench, I was totally clueless. See that's the thing about already knowing what's about to be said in most conversations. I was in the dark even with all the details because the design was so strange and original (to me). When I saw the full plane, even though the picture IS indistinct, I knew instantly what the deal was because I already had all the details. MMMMmmmm, I wasn't thinking so much that damage might result, but, yes, flutter if the linkages weren't sloppless, and a whole lot of drag. I saw the fairings ahead of the scoop, but I just wondered if that was opening up a huge hole for upper/lower surface pressure differential and vortexes all over the place. I wondered, if the linkages weren't perfectly sloppless, if the scoop might be jerked open a bit more as soon as it caught the air. But its all balanced. It just looks like such an original/rad idea. Yes, yes!! A law against all trees in needed immediately!! So let it be written.......

Thanks for the comments TGDF. The balancers do look rad and seemed to work too. If I manage to replace the wing, the old balancer will be re-used for sure.