I'm setting up a 35% plane working for the first time with the Hitec programmer and I've seen DOD videos demo the usage of the programmer quite a few times.

I still have one thing that I'm not sure about. In one video he was talking about setting up the servo and linkages mechanically to acheive exact same movement distand of the servo arms to both directions and the movement of the control surface both up and down the same distance. Achieving it by ajusting the linkages length and as far as I understand this is done mechanically (moving it by hand). and only then setting up electronically with the programmer, but I didn't understand how come when we set up the end points we are not getting the exact same values (for up and down). for example -130L and +130 right and if those values are different from each other how come liniarity is not harmed (one direction faster than the other) ? I would think that it wouldn't damage anything as long as the center is exactly between the two end points but in case of two different values for left and right the center is already set therefore the travel of the servo arm is no longer the same distance to both directions and that what confuse me.

Another question I had is about the dead band, do you use this function when you gang rudder servos ? do you use this function on a multiple servos control surfaces as ailerons?

Thanks for your help