av8r4aa,
The aileron connection hardware and resulting setup for the WM Ultimate 40 does not result in equal moving ailerons.

They provide average, everyday control horns that have been chopped short. The idea to chop them short is moving in the right direction, but not by much. They place them "facing each other" and that makes things a little worse, it's a step in the wrong direction.

The best connection for ailerons that're connected top to bottom, like in this model, would be to have the connection points in line with the aileron hinge lines, and with each other. The basic law of rc pushrods is that the pushrod connection makes a right angle with the servo arm or with the surface hinge axis. If you look at the way this ultimate is setup, there isn't anything close to a right angle anywhere. The way the ARF is setup, when you give the model full aileron command with your tx stick, one side's ailerons will move almost equally while the other side's will be pretty screwed. Say you give the model a right aileron command. The right ailerons will move with the upper one moving about 10% less than the lower. Not too bad. But the left upper aileron is only going to move down half what the lower is going to move. Some aircraft have differential aileron setups. This setup actually results in something opposite of what results with conventional differential aileron.

If you draw a line from the aileron hinge axis to the connection point for the top wing and then for the bottom wing that'd be two lines right. And then draw a line connecting the two connection points. Those three lines ought to have two right angles. The setup design gives you one fairly sharp acute angle and one somewhat open obtuse angle.

For a rod connector to drive both ailerons the same distance on this model, the connect point for the top aileron would be just aft the TE and about 3/8" above the TE. And the same location for the lower aileron's connect point.

I was pretty sure that I started a thread about this model and this problem, but I can't find it. Think it had a picture in it. I'll go look for the original of the picture.