Differerential
 

Hi Guys
I have a question on aileron differential.
Which side has the greater movement, the one going up, or the going down?
I should know this but at my age :D


Thanks

Falcon

RE: Differerential
 

A well balanced symmetrical wing 3D bird should have equal throw up and down on the rons.

RE: Differerential
 

most people set it up to have the greater movement on the aileron going up. I don't use differential on "3D" setups, but I have used it on other set ups for pattern flying.

RE: Differerential
 

A little more on the UP motion. According to aerodynamics, the down deflection of the same magnitude causes more drag than the up deflection. The plane should yaw with nose towards the down aileron. Add a little more up aileron than down to equalize the drag and eliminate the yaw. At least that is my understanding, and I am sticking to it, haha, until corrected. :P Jon

RE: Differerential
 

Ok now flip the plane over. Your differential will be working against you. 3D planes have symmetric wings. Unless you are offsetting some weight imbalance top to bottom, differential will give you a corkscrew instead of an axial roll.

RE: Differerential
 

See how it rolls before you mess with it.

RE: Differerential
 

Now, that is the best advice! Definitely don't program any until you see how the plane reacts first.

RE: Differerential
 

Yes, I agree, if it ain't broke, don't fix it. If it rolls straight, it's good.
To explain the original answer to the question: Differential on non symetrical wings refers tomore up aileron movement than down aileron movement.Air flowing over the wing is "less dense" than air going below the wing. The ailerons are less effective in "lowerair pressure" regions, hence more aileron movement. Certain high wing, semi symetrical wingplanes like larger Cubs etc may need some differental to improve normal handling - like a tug plane, perhaps 20%.

RE: Differerential
 

Hi Guys

Good to see some explanation here.
Reason I asked is that the plane does corkscrew a little on the roll and would like to get rid if it.

Many thanks


Falcon

RE: Differerential
 

This corkscrew can also be from a too far forward CG and some elevator to get level flight. Does it climb or dive if you are inverted at mid speeds? If the answer is yes to that question, then fix the CG before messing with reflex or differential. What airframe are we talking about?

RE: Differerential
 

You are on te right track but I think your explanation is off just a bit at least in proper terminology. The main reason you use aileron differential is to try and eliminate the effects of adverse yaw. The low wing that is being lowered produces less left therefore less drag. When you raise a wing to make say, a left turn, the right wing has to be raised by lowering the aileron which creaets lift to do that. Whenever you create lift you create induced drag. That is why the nose will tend to drift in the opposite direction of the turn initially and cause what is called a slipping turn. All that being said though, I never worry about it on my 3D planes. I just max out the throws and have fun! Adverse yaw is more of an issue on sport and pattern planes where nice pretty coordinated turns are required.

RE: Differerential
 

TruBlu02, yes, they taught usthat in pilot flight school back in 1976,and being an old timer, my memory is slipping a bit in the evenings after a couple of Taliskers....but, yes, you are right,there are more factorsinvolved thansimply transverse wing turning dynamics -true airspeed over both wings in a turnaffecting lift and drag on each side (but Falcon is concerned aboutROLLING in a straight line, not banking).

One also needs to checkaileron movement for binding limiting movement to one side, down/side thrust lines,lateral (cg) wing balance,positive/negative horizontal stab angle (bad build quality), skew fin, possibly warped wings, warped ailerons, unequal (unsyncronized)aileron servo movement, sloppy/loose hinges/control rods, improper programming ofTx, esp with electronictrims, zero and movement.Sometimes it could justbe a loose servo.....

Falcon 32 did not say which plane is doing it. Ifthe plane's set up is 100% good, high wing planes (Cubs etc) are more difficult to roll than low wingers, they have a natural tendency to roll out (corkscrew) .

If heis flying mode 1 or mode 2 - some right hand/left hand people find it easier with one or the other when it comes to aerobatics. Switching modes can also effect flying,On mode 2 the the elevator and aileron gimbal springs settings also have an effect. I prefer my mode 2 Tx gimbal spring to be slightly stiffer on the elevator than the aileron and on mode 1 the elevator gimbal spring stiffer than the rudder one,but that is personal preference.

But one need to try the very basics first, then go int the above checklist

Cheers mate. Bundubasher</p>

RE: Differerential
 

Hi Guys

Sorry I am a bit late getting back on this.
Thanks for the advice, but it's a bit academic now as I had to take the plane (Fliton Extra Freestyle) home in a plastic bag on Sunday[:@]



Thanks

Falcon

RE: Differerential
 

Bummer...