Excess Aileron sensitivity around neutral

[Troy A. Newman]

Paul,

as mentioned above expo is Negative to soften the middle on Futaba and Positive on JR...

Since you said it is speed sensitive....What servos?  It could be a case of not enough servo...When you at full power the ailerons are not as effective so they could be blowing back. Also look at the aileron linkage. If you have a slightly marginal servo but a poor mechanical advantage on the linkage it will act the same way. You would then be playing with expo to get the full power roll rate (which is experiencing blow back) setup and the result is when the surface is not under as much load your expo is not high enough.

To know for sure about servo need the following answers.

What servo? Torque? Digital? 

When was the pot last serviced  (number of flights)?


What is your ATV (travel adjust set at for each aileron servo? (100%? 70%? 138%) give me both ends of each servo.
What deflection do you have when on "high rate at 100%" Need Right aileron up and down, left aileron up and down. If your High rate is less than 100% what is it?

What is your dual rate value you are actually flying on (70%)
What deflection are you flying with as your dual rate or low rate? Again right aileron up and down, and left aileron up and down.

What is your expo value (45%, -45% ect....) Also what radio are you using?

Once we get these numbers we can determine where to go. This may lead us down another path where we Might need some more numbers like:

Distance from hinge line to the aileron horn clevis pivot point?
Distance from Servo wheel connection point to the center of the servo wheel?
Differential setting in the radio?


Get back with me and we can help you out...There are lots of things that can have an effect...but Making sure the linkage is good is the first step. Once we confirm it has a good linkage whether that means we change it up a bit or it is already as good as it can be we'll look into other things. Sometimes a non-straight hinge line meaning aerodynamically curved can make the ailerons speed sensitive. CG can sometimes make this happen too. Maybe something is flexing in the model when it is under high power conditions....like a wing adjuster/anti rotation pin. Maybe there is some loose covering or a damaged shape to the airfoil like the covering iron got hot and melted the foam below the balsa skin....

So many things to look at that we need to start somewhere. Since the ailerons are the effected culprit lets start with their linkage and radio setup.

Troy Newman

  ----- Original Message ----- 
  From: paul 
  To: discussion at nsrca.org 
  Sent: Sunday, December 04, 2005 4:26 PM
  Subject: Excess Aileron sensitivity around neutral


      I have a Meridian with a frustrating characteristic, the ailerons are excessively sensitive around neutral.
  I'm the second owner of this plane but the first owner said he had the same problem.  Aileron authority at full throttle is not excessive - in fact it slightly on the mild side.    
  Any ideas ?
  Thanks,
  Paul
  NSRCA 3606
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