Model Tech Yak 54 Assembly Instructions Manual page 30

q Use a couple of pieces of masking tape, taped between the rudder and the stabiliser, to hold the rudder centred.
q Remove the masking tape from the rudder and double-check that both servo horn and the rudder are still centred. If the rudder is
not centred, readjust the clevises until it is.
q Move the rudder right and left several times to ensure that the control linkage does not bind. It should operate smoothly in both
directions.
q Check the tension of the stranded cables. To do this do the following: move the rudder control stick to the left. Let the control stick
go and check to see if the rudder returns to centre. Do this a couple of times in each direction. If the rudder does not come back to
centre, one or both stranded cables are too tight. You can adjust the tension of the stranded cables by adjusting the clevises. Ideally,
the stranded cables should be as tight as possible, while still allowing the rudder to return to centre. The stranded cables should not
have slack in them, yet they should not be so tight that the linkage and/or the servo bind.
q Temporarily thread one M2 hex nut and one 2mm clevis onto each of the two
threaded couplers, then feed the plain end of each of the two lengths of stranded
cable through the slots in the fuselage and into the servo compartment.
q Snap each clevis into the hole in the adjustable control horns, then firmly
tighten the two hex nuts up against the clevises to lock the threaded coupler
into place.
q Enlarge the hole in each side of a servo horn that is 3/4" (9mm) out from
the centre of the servo horn, using a 5/64" (2mm) diameter drill bit.
q Install one Z-Bend coupler into the hole in each side of the servo horn that
you enlarged.
q Centre the rudder servo, then install the servo horn onto the servo, making
sure that it's centred.
q Install the servo horn retaining screw to secure the servo horn to the servo.
q Attach the stranded cable from the right side of the rudder to the Z-Bend
coupler on the right side of the servo horn, then attach the stranded cable
from the left side of the rudder to the Z-Bend coupler on the left side of the
servo horn. Use the same techniques that you used to attach the stranded
cable to the threaded couplers.
IMPORTANT Make sure that both lengths of stranded cable are pulled
tight. There should not be any slack in either of the stranded cables.
q Once you are satisfied with the alignment and setup, cut two 1/8" (3mm)
long pieces of heat-shrink tubing and slide one piece over each clevis. The
heat-shrink tubing will ensure that the clevises do not open up during flight.
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