Nutin2it,

I assume that you are talking about how to line them up with nothing to reference. I taped a ruler on each flat wingtip so that one edge of the ruler was lined up with the leading and trailing edge centers (in other words down the center of the wing tip) and so it stuck out past the aileron on each side. Then it was easy to adjust them both to neutral relative to the wing and also to insure that they matched each other. You could use a piece of balsa stock or whatever you had as long as it was straight.

Greg