GY401 setup:
There are five controls on the gyro and one on the transmitter which require setup on the GY401.
Setting DS:
This should be OFF unless you are using a S9253 S9250, S9450, etc digital servo compatible with a fast update rate. Not all digital servos are compatible with the GY401 DS mode!
Setting DIR:
- Turn on the transmitter.
- Disconnect the heli motor.
- Plug in the heli battery.
- Wait for the gyro to initialize.
- Turn the heli right about 20 degrees. If your tail rotor faces left (Corona) then the tail rotor blades should increase in pitch. If your tail rotor faces right (ECO, Logo) then the tail rotor blades should decrease in pitch.
If the tail rotor blade pitch change is wrong, then flip the direction switch on the gyro, and retest.
Setting DELAY:
Set this to about 50 initially.
If your tail servo is fast (<0.11 sec/60 degrees) set this to a lower value.
If your tail servo is slower or you are using a fixed pitch tail driven by a variable speed motor (Piccolo, Hummingbird, etc) then set this to a higher value.
Setting LIMIT:
This controls the amount of tail servo travel.
- Turn on the transmitter.
- Disconnect the heli motor.
- Plug in the heli battery.
- Wait for the gyro to initialize.
- After the gyro has initialized, make sure the tail servo is at the center of its travel range (90 degrees to servo body) and the tail pitch lever is at the center of its travel range as well (90 degrees to tail boom).
- Turn off the AVCS mode temporarily at the transmitter.
- Use the rudder stick and give full left rudder and full right rudder. The tail servo should be moving the tail pitch slider through its full range of motion.
- If the tail pitch slider is not moving far enough, then you will need to increase the LIMIT control.
- If the tail pitch slider is moving too far and hitting the ends of travel and the tail servo is emitting buzzing sounds, then decrease the LIMIT control.
It may be necessary to move the tail servo mount on the tail boom or adjust a ball link or something else to ensure that:
1) The tail servo can move the tail rotor pitch from minimum to maximum without binding (e.g. without the tail servo making a buzzing sound).
2) The tail servo should be centered when the tail rotor pitch is at the middle of its range.
Be sure to reenable AVCS mode after setting the LIMIT control.
Setting SENSITIVITY:
This is done at the transmitter on channel 5 for both Futaba and JR radios. If you have a newer Futaba radio (like a 9C) this is already handled in the GYRO SENS menu. In this menu set the mode to AVC and the sensitivity to about 50%.
If you have a Futaba/Hitec (negative shift) radio, channel 5 settings below 50% are non-heading hold mode sensitivity and settings above 50% are heading-hold mode sensitivity. Initially, set your channel 5 to about 88% travel.
If you have a JR (positive shift) radio, the settings are swapped, e.g. below 50% is heading hold sensitivity and above 50% is non-heading hold sensitivity. Try setting your channel 50 to about 12% travel.