Aileron measures different up and down

[Dator2]

My rochobby mxs 3d,elevator and rudder measure the same up as down. Ailerons measures different. Turn left is 30mm up and 22mm down. Turn right is opposite. Linkage is in the same hole both sides. Any ideas as to why and how to fix this problem? Ty

[Tom603]

It is called Aileron Differential, and it is to reduce adverse yaw when turning.....

[Konrad]

On a 3D plane with a symmetrical airfoil the need for differential (Ackermann effect) should not need to be that extreme ( usually less than 12%). Do you have any programed in your radio?

[fhhuber]

Also it can be used to make rolls more axial. Many planes tend to roll around a line that is "above" (when the plane is upright) the canopy. Reduce the added lift from the aileron that moves down and you can sometimes bring the roll "down" to a line through the fuselage.

[Konrad]

Also it can be used to make rolls more axial. Many planes tend to roll around a line that is "above" (when the plane is upright) the canopy. Reduce the added lift from the aileron that moves down and you can sometimes bring the roll "down" to a line through the fuselage.

That is one of the tests I use in setting up the ailerons.
Give this chart a good looking over before and while you are trimming out your new MXS. There is a lot of information in it.

http://www.wtp.net/DBEST/trimchrt.html

[PappaBear]

Hello Dator,

If I understand your question correctly. The left aileron travels up 30mm and the right aileron travels down 22mm. When you turn right, the right aileron only travels up 22mm and the left aileron travels down 30mm. Is this correct?

If this is the situation you have. Then you have a problem inso far as the aileron horns and or the servo horns are in the wrong position. Make sure the aileron servo is centered correctly and make sure the aileron horns are in the same position on both ailerons. If you have the situation above it is not good and it is not right.

If both left and right ailerons are traveling up 30mm and they are both traveling down 22mm. This will be fine and the model will fly well.

Aileron differential is to prevent adverse yaw as mentioned above. With an adverse yaw situation the down going aileron produce more drag than the up going aileron produces lift.

Martin.

[Konrad]

As a tech for MotionRC is the ROC MXS spec'd for that much aileron differential 30/22?

I haven't flow one so I have no frame of reference.
And she is a mid wing design.
http://www.motionrc.com/rochobby-mxs...-wingspan-pnp/

[PappaBear]

Konrad,

I haven't flown one either, so like you I don't have anything to go on. However reading the instruction manual for the Roc-Hobby MSX. It states equal up and down aileron travel.

In the case of the situation above above, it is better to have more up going aileron than down. While I agree this figure may be a little excessive. It is better than having it the opposite way round.

Martin

[Konrad]

So something is a miss with the OP's set up.

Dator2 (Ty) can you post a few photos of your set up?