Brian, you have to cut the servo holes yourself. It's not hard...an Xacto (Approxo
) knife and a flat blade screw driver will have it done in a minute. I just mark the proper position, cut in with the knife and dig out the foam with the screwdriver. One comment, the designer has the servos sideways relative to conventional design. I put mine in the normal orientation, as rearward and near the middle of the surface as possible to reduce the linkage length. I'm using JR's mid-size digital servo (9411) to reduce the necessary depth.
PatternFlyer, the balsa doublers are pretty fragile alone, but once glued, the cross grain doubler makes the completed assembly extremely stiff. No need to worry...