I set mine up to use servos further out on the wing, but if you want to use servos side by side in the centre section of the wing, I think you'll have to enlarge the cut out somewhat.. as to how much, I think it's going to depend on which servos you use... although most standard servos are pretty close in size. Best suggestion I can make is get hold of whatever servo you're going to use and use it as a guide as to how big to cut the hole. Hope this helps.