User Manual

SUB TRIM
Sub Trims are intended for relatively minor adjustments to servo linkages and not for major trim
adjustments to the aircraft. Using excessive Sub Trim percentages can cause a loss in servo
resolution where the servo reaches its travel limit and stops moving before the control stick is
fully deflected. For more information on Sub Trims and linkage setups please refer to the Sub
Trim Usage and Mechanical Advantage article contained in the Glossary.
Use Sub Trims to fine-tune the alignment of servo arms. Install servo arms on the servos so that
the arms are at 90˚ or perpendicular to the servo case/linkage. Rotate, swap and reinstall the
arms or try different arms if necessary to get them as close to 90˚ as possible. It is not unusual
for the arms to be off-center just a little bit. Now use the Sub Trim function to fine-tune the
servo arms that are not quite at 90˚ to the linkage/servo case.
Highlight and select Sub Trim in the Function List to obtain the Sub Trim Display.
Function
Name
Sub Trim Values
[Sub Trim]
THRO 0 GEAR 0
AILE 8 FLAP 0
ELEV -4 AUX2 0
RUDD 0 AUX3 0
AUX4 0
ENT
LIST
CLR
Channels
Sub Trim Values – (Sub Trim)
These values indicate the amount of Sub Trim and direction (plus or minus) for each of
the 9 channels. The amount of Sub Trim can be adjusted by highlighting and selecting
the channel and dialing-in a new value with the rotary selector until the servo arm is at
90˚ to the servo case or linkage.
Channels – (Sub Trim)
The abbreviations for all 9 channels are included on the display and they are named
according to any special assignments that have been made. For example, if Flaperons are
activated the 6th channel which is normally named FLAP is renamed to LAIL to
represent Left Aileron. No more guessing at what channels are being used for dual
controls or other special assignments.
CLR Button – (Sub Trim)
Pressing the CLR button while a channel is selected will reset the Sub Trim to 0.
LIST Button – (Sub Trim)
Press the LIST button to return to the FUNCTION List, or rotate the rotary selector until
LST appears next to LIST and select it to return to the SYSTEM Menu.
ENT Button – (Sub Trim)
Pressing the ENT button returns to the Main Display.
JR XP9303 Detailed Function Descriptions 42