I meant to say look at the side view of the W1 rib on theplans........the one that shows the servo in it. I used 3/8 x 1/4 hardwood for the servo rails. Your right though, Sig could of been more clear on the radio installation.. Which would help out a beginner. But thats the only gripe I have with the kit. The rest of it is top notch in my opinion. JT