Dynon Avionics EFIS-D100 Installation Guide - Manual (Page 53)

Autopilot Installation and Configuration
STEP 3 - ROLL SERVO INITIAL SETUP
We recommend that you perform the following on the
ground at zero airspeed.
Step 3a – Set Roll Servo Torque: The ROLL
SERVO > TORQUE parameter specifies how much
torque the servos will exert before slipping. Servo slip
is indicated by a yellow background on the slipping
axis in the AP status indicator. Torque must be set
high enough to prevent any slip due to air loads, but
low enough that the pilot can comfortably override
the AP should the need arise. If the servo slips continuously, the AP cannot fly the aircraft.
Torque is specified in % of maximum the servo is capable of exerting. Minimum: 10%,
maximum 100%, default: 100%.
On the EFIS, perform the following:
 If not already in the SETUP > AP menu, enter the menu and select ROLL SERVO and press
SEL►
 (TORQUE value is highlighted)
 Press DEC - and INC + to adjust TORQUE to preferred initial setting for the aircraft.
It may take some experimentation to find the right value for your aircraft, but if you are
comfortable overriding the servo with the default value of 100%, it is safe to leave that setting at
the default value. To test servo override, exit the SETUP > AP menu and return to the main EFIS
menu. Center the aircraft controls. Enter the EFIS > AP menu and press HDG
OFF . Note that the
mode toggles to HDG ON , the HDG bug synchronizes to the current heading, and the roll servo
engages. Ensure that the controls do not deviate far from center.
If you have an AP74 installed and configured, you can accomplish this same procedure
by doing the following: Push the HDG button to ensure that it is lit; push the ALT button
until it is not lit. Push the AP button to engage the AP in Heading Hold mode.
Now, take the controls and override the servo by moving to either roll left or roll right
(remember, you are only overriding the roll servo, so you should feel no resistance in the pitch
axis). Ensure that you are comfortable with the amount of force it takes to override the servo. If
you are not, decrease the roll servo TORQUE value by 10% and repeat the test.
Step 3b – Set Roll Servo Sensitivity: The ROLL SERVO > SENSITIVITY parameter specifies
the how fast or slow the AP responds to deviations between commanded direction and actual
heading or track. If Sensitivity is set too low, the aircraft will “wallow” during changes in
heading. If Sensitivity is set too high, the aircraft will be “twitchy,” with frequent, fast,
aggressive adjustments. Sensitivity is specified in digits. Minimum: 1 (low sensitivity),
maximum: 25 (high sensitivity), default: 10.
This parameter can be tuned in flight; leaving it at the default of 10 is sufficient for initial setup.
If the autopilot is not as “decisive” as you’d like, increase this value; if it is too aggressive,
decrease it.
On the EFIS, perform the following (continuing from TORQUE):
EFIS-D100 Installation Guide 6-17