setup the swash servos BEFORE you finish putting the heli together.
on a NEW/DEfault model memory with only HELI mode and 120degree swash option enabled.
plug in the 3 swash servos while theyre mounted in the bare frame (aileron or pitch doesnt matter youre going to reverse it anyway). no head, no maingear, pull the top bearing block. use Reverse servo and swashmix menus to get the 3 servos moving the correct way. (probably have to reverse at most 2 servos if you orientated the servo's the right way and pluged them in the correct order).
after you determine theyre moving the swash the correct way given cyclic and collective input, remove the arms. at default pitch curves, at 50% stick input/output via the "monitor or pitch curve cursor" put the arms on all centered and level.
at that point i usually scribe "6" into the connector of 6th channel servo so that i know the other two obviously go to elevator and aileron. disconnect it all and then finish building the heli.
NEVER touch travel adjustment for any of those 3 channels.
you use SWASHMIX to reduce throws on those control surfaces. default is 60% mix, adjust accordingly if you have binding.