for Naza, without GPS, you need two position switch to select between Atti and Normal flight modes, and it can be perfectly done on the Gear Channel with gear switch.
for Naza, with GPS, same as WK-M, you need a three position switch to select between GPS, Atti, and Manual flight modes. Since you generally want to find that switch easily, you may use F Mode, FLAP switch for that channel. To do so, you first make sure you selected your model, and then hold the scroller while turning on Tx power. You should be able to find "Switch Selection" menu. In there, you disable Gear Switch (by default it controls Gear Channel), then you may scroll to either F Mode or FLAP switch, there you should have gear channel controllable.
Once that has done, while plug in your FC to computer, you should be able to flip the switch you assigned and see the change in travel of U Channel (Flight Modes). You might noticed it's not triggering to Manual and GPS but only Atti, that is because the travel range is too great on Gear channel. Limit the travel down to where you can trigger both of them.
On to Fail-safe, you basically need a two way switch to alter your Gear channel travel, to do such, go to your Mix function on DX8, scroll to Mix1, and then here are the settings:
GER > GER
Rate: -50%
-50%
Offset: 0%
Trim: INH
Sw: Mix1
this setting will esentially "shift" your gear channel by 50% when you flip the Mix switch, which then should trigger your FailSafe mode.
Last, again this is optional and needs extra attention when operating. You go to Throttle Curve and activate it, make all your points to 50% thus having a flat throttle curve, but on the very bottom be sure you select a switch to operate this. Reason of doing such is, in Atti/GPS mode, FC is sensing your throttle position as a altitute change command, anything a little above 50% will bring your copter up and vice-versa, so we can utilize throttle curve funtion to "trick" FC as if we are always giving a 50% (Remain Altitude) command. Hence no interaction between rudder and throttle when you do any manuveurs.
I hope these will help. Anymore questions please don't hesitate to pm me.
