RE: Manipulating aileron linkages for perfect rolls?
Rather than trying to create differential throws mechanically, it is easier to use 2 servos and adjust it with the radio. The other way is to offset the linkages on the servo(s). Typically you need more up than down to eliminate adverse yaw. A large factor affecting the throw of the upper aileron in the first picture is the distance between the wings themselves, which is something you wont be able to adjust. On the one plane I have with the setup in the first picture, a DP Ultimate 40, I cannot detect what effect the linkage has, if any. The wings seem to by far enough apart that the amount that the linkages is offset makes very little difference. All my other biplanes are setup like the second picture.