Trio Avionics EZ Altitude Control - Manual (Page 17)

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The servo Torque Control nut (the adjustment nut inside the servo on the output shaft)
sets the override force - the force you will feel at the stick when the servo clutch begins to
slip.
Engage the servo by pressing the LCD switch. You should hear the solenoid operate
inside the servo housing and the servo crank arm should become firmly held in place by
the gear train. Then push the control stick hard enough to override the servo. Using an
11/16 “ or 17mm open end wrench set the override force to a value that seems strong
enough to give a fairly good pitch authority, but not so strong as to be difficult to override
with the control stick. Work toward setting the servo slip clutch to the minimum torque
necessary to give enough elevator authority to handle a reasonable amount of turbulence
or trim error. Do not tighten the nut to the point where the clutch cannot slip. If you
do, and exert sufficient force on the control stick, it may cause gear teeth in the
servo to strip – this is a safety feature to allow control movement in such a
situation.
6.6 Adjustment of Servo Rotation Direction, Trim Rotation Direction
(optional) and Factor Default Setting restore.
After installation wiring is complete the system servo direction check must be
accomplished.
IMPORTANT – Prior to performing step 6.6.1 the system must be powered up and
placed in the READY mode for a full 5 minute period to allow the gyro and
accelerometers to bias to their zero position. During this time the aircraft must remain
perfectly still. After the 5 minute period has elapsed secure power to the EZ altitude
control system and perform step 6.6.1
6.6.1 Servo Direction Setting - The servo direction must be set so that the
system knows which way to drive the controls for an increase or decrease in
altitude. This is a one time ground setting and should never be attempted in
flight.
Do the following to enter the servo direction setting mode:
Turn on power to the system.
While the SYSTEM TEST message is being displayed, simultaneously press and
release both the LCD switch and the ENCODER switch – The LCD switch will
now display the amber SERVO DIR NORM or SERVO DIR REV message.
a.
Rotate the ENCODER knob clockwise while observing the elevator
travel direction. The elevators should move in a direction that would
cause an increase in altitude.
b. If the elevators drive in the opposite direction momentarily press the
ENCODER switch. The LCD message will now read SERVO DIR REV.
NOTE: At this point the servo will engage and drive the servo to its mechanical zero
position.
NOTE: This is a CRITICAL setting and MUST be verified before flight. If the
command to the servo motor is not correct the aircraft will be forced into a divergent
climb or dive when the system is engaged.