Hangar 9 Sukhoi SU-31 Instruction Manual page 17

Step 4. Temporarily plug the servos into the receiver and set
the programming to get the aileron functioning correctly. Center
the control surface with the trailing edge of the wing.
Step 5. Install the clevis on the outboard control horn screw.
Screw on the clevis until the bottom of the clevis is the same
distance from the aileron hinge line as the inboard clevis, not the
bottom surface of aileron.
Step 6. Deflect the ailerons stick to full right. Hold it there (the
easiest way is to have your transmitter set to PCM: hold and
then turn off the transmitter). Hold the clevis on the outboard
servo up to the horn and note how the holes align. Turn the
transmitter on and hold full left aileron and again note how the
holes align. The holes have to line up nearly perfectly. If they
don't line up perfectly, adjust the horn length (distance out from
the aileron) in or out a few turns and recheck. Repeat this
process until it is nearly perfect at full deflection in both stick
directions and at neutral.
Step 7. Attach the swivel clevis to the horn with the supplied screw.
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