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 essentially "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 altitude change command, anything a little above 50% will bring your copter up and vice-verse, so we can utilize throttle curve function 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 maneuvers.
*Doing this in manual, will either pull your copter straight up or slam it down since in Manual mode, throttle input is raw feeding, if and only if you have your copter's weight right on the 50% maximum thrust of your motors, you will be able to lock your altitude in Manual mode*
I hope these will help. Anymore questions please don't hesitate to pm me.
