Pat, If you look at the photos you will see the reason I asked. Attached are photos of my WH 28% Edge 540 wing panel. When the pivot point is lined up with the hinge line and the aileron is deflected in the down direction the horn arm will hit the bottom of the wing. This actually prevents full down travel. If I shorten the arm about 3/8" it should clear.

The other problem I just noticed can be seen in the other photos. If I connect the push rod at 1.25" on the servo arm the push rod is no longer perpendicular to the hinge line. I believe this condition will cause binding as the aileron travels up and down. The right wing panel is not as bad but it has the same problem. As you can see in the photos the only time the push rod is perpendicular to the hinge line is if the rod is less than 1/2" out from the center of the servo, and 1/2" on the servo arm will not provide enough throw for 3D. I hope Tom will chime in on this and let me know how I can fix this.