Thanks for all the replies......sorry I'm being such a bonehead but some things just don't make sense. Again, this is 2 servos with a Y going into the receiver. The ARF plans call for 1" up and 3/8" down

I have the radio manuel and it says to adjust the EPA by moving the aileron stick to the right, adjust it, and then move it to the left and adjust it. Well, when I move the stick and adjust it, both ailerons move in opposing directions...so how can I adjust them independently?

Also, the crummy manuel suggests....just suggests.... that you can adjust both up and down independently....this doesn't seem to be the case..am I right?

Looks like I need to get some longer control rods.....when I move the servo arm and then try to reset the surface to 0, I'm running out of thread. If I put longer rods on, move the servo arms to get my 3/8" down, won't that greatly reduce my up throw? And if I then move the up EPA, won't that just change my down throw?

I think the answer may lie in what Bruce said.....maybe its not the measurement thats important but the ratio between the 2

If anybody sees where I'm thinking wrong, chime in..I appreciate it all....