Garmin G3X Installation Manual page 680

Pitch Servo Configuration
The installer needs to make the following pitch servo configuration selections when setting up the GSA 28
based autopilot system. These selections are made in configuration mode using the AP CONFIG page and
the pitch servo setup screen in the autopilot setup menu in normal mode.
Table 32-7 Pitch Servo Autopilot Configuration Settings
Configuration Setting
Max Torque
Pitch Servo Gain
Pitch Servo Direction
(configuration mode only)
Clutch Monitor
(configuration mode only)
Trim Motor Control
(configuration mode only)
190-01115-01 G3X/G3X Touch Install Manual - GDU 45X/46X Config and Post Install Checkout
Rev. AA
The GSA 28 pitch servo has a configurable maximum torque setting. This
determines how much torque the servo will output before the electronic slip
clutch begins to slip.
The Max Torque setting should be set high enough to not slip during in
flight air loading, but the torque setting should be low enough for the pilot to
override the autopilot if required.
The Max Torque setting can be adjusted from 10 to 60 inch-pounds in 5
inch-pound steps.
The GSA 28 pitch servo has a configurable servo gain value. This
determines how aggressively the pitch servo will move the elevator
surfaces.
The Servo Gain should be set high enough to properly fly the desired pitch,
vertical speed, and altitude, but low enough to avoid being overly
aggressive in the elevator movements.
The servo gain setting can be adjusted from 0.05 to 10.00 in steps of 0.05.
The GSA 28 pitch servo has a configurable servo direction.
The Servo Direction should be set to Normal if the servo arm should move
clockwise to cause a nose down elevator movement.
The Servo Direction should be set to Reverse if the servo arm should move
counterclockwise to cause a nose down elevator movement.
After selecting the proper servo direction, the installer should engage the
autopilot system in normal mode and verify proper elevator response by
rotating the pitch reference up and down from the current pitch.
The GSA 28 pitch servo has the ability to monitor itself for a stuck clutch
situation.
If the servo has a large amount of side loading (typically due to a capstan
installation), this can occasionally lead to invalid stuck clutch failures.
The Clutch Monitor should be enabled for all control arm installations.
The Clutch Monitor can be disabled for capstan installations with larger
side loads to prevent invalid stuck clutch failures.
Note that the user can reset clutch monitor faults by pressing the RESET
softkey on the pitch servo configuration page in configuration mode if an
invalid stuck clutch failure occurs.
The GSA 28 pitch servo has the ability to control an auxiliary pitch trim
motor.
The Trim Motor Control should be enabled if the GSA 28 pitch servo was
connected to an auxiliary trim motor.
The Trim Motor Control should be disabled if the GSA 28 pitch servo was
not connected to an auxiliary trim motor.
Description
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