Top Flite TOPA0210 - Manual (Page 26)

INSTALL THE SERVOS AND
PUSHRODS
Make the pushrods
❏ 1. Locate the die-cut 1/8" [3.2mm] ply pushrod
brackets. Drill a 3/16" [4.8mm] hole through each
punch mark.
❏ 2. Glue the pushrod brackets to the fuselage sides
at the locations shown on the plan.
❏ 3. Install the plastic outer pushrod tube in the front
half of the fuselage for the steering pushrod as shown
on the plan. You may need to remove the fuel tank to
get the tube in place.
❏ 4. Locate three 2-56 x 36" [914mm] threaded rods.
These will be used for the nose gear steering, the
rudder and the elevator.
Install the servos in the fuselage
NOTE: Before marking any of the pushrods, connect
the servos to the receiver and electronically center
each servo.
❏ 1. Glue the die-cut 1/8" [3.2mm] ply throttle
servo mount in place in the fuselage as indicated
on the plan.
❏ 2. Glue two 1/4" x 1/4" [6.4 x 6.4mm] basswood
servo rails in place as shown on the plan. The rear
rail is glued to the notches in the fuselage doubler.
The forward rail is glued to former F-3A.
❏ 3. Mount the servos to the rails and the plywood
mount as shown on the plan.
❏ 4. Slide a silicone retainer onto the rear end of a
nylon clevis. Thread the clevis 14 turns onto a 36"
wire pushrod (threaded on one end). Slide the
pushrod into the elevator pushrod tube until the
clevis pin is even with the holes in the elevator
control horn. Connect the clevis to the control horn.
❏ 5. Assemble a second wire pushrod for the rudder
pushrod tube.
❏ 6. With the elevator and rudder pushrods connected
to the control horns and the elevator and rudder
centered, mark the pushrod wires where they align
with the servo arms. Remove the pushrods, then trim
them about 1" forward of the marks.
❏ 7. Cut ten 1/8" [3.2mm] long pieces from the 12"
[305mm] plastic inner pushrod. Slide five bushings
onto each pushrod, spreading them out about 2-1/2"
apart, from the servo and the end of the pushrod. If the
bushings are tight and difficult to slide on, cut them to
a shorter length. Check the fit of both pushrods. When
you are satisfied with the fit, apply a small drop of thin
CA to each bushing to keep them in place on the
pushrod. Do not reinstall the pushrods into the tubes
until the CA has completely cured.
❏ 8. Enlarge one outside hole in the elevator and
rudder servo arms with a 5/64" bit. Make a 90 degree
bend in each of the pushrods at the point that you
marked. Cut off the excess wire, leaving about 3/8"
after the bend. Remove the clevises, then insert the
pushrods all the way into the tubes from the servo
end. Reattach the clevises and silicone retainers.
Poke the upturned wires through the servo horns
and secure them in position with nylon FasLinks
™ .
❏ 9. Locate the .074" x 1" [1.8 x 25.4mm] threaded
wire. Screw it into one end of the remaining inner
plastic pushrod. Slide a silicone retainer onto the end
of a nylon clevis. Screw the nylon clevis onto the
threaded wire.
❏ 10. Slide the inner plastic pushrod into the throttle
pushrod tube. Insert it from the firewall back into the
fuselage. Attach the clevis to the throttle arm and fully
close the throttle. Position the throttle servo so that it
would be in the position that will fully close the throttle.
❏ 11. Cut the inner plastic pushrod tube 2" from the
throttle servo. Remove the throttle pushrod from the
plastic pushrod tube.
❏ 12. Screw the .074" x 4" [1.8 x 102mm] wire
(threaded one end) onto the end of the plastic inner
pushrod tube. Reinsert the pushrod into the throttle
pushrod tube.
❏ 13. With the throttle pushrod connected to the
throttle arm and the servo positioned to close the
throttle, mark the pushrod wire where it aligns with
the servo arm. Remove the pushrods, then trim them
about 1" past the mark.
❏ 14. Enlarge one outside hole in the throttle servo
arm with a 5/64" bit. Make a 90 degree bend in the
pushrod at the point that you marked. Cut off the
excess wire, leaving about 3/8" after the bend.
Remove the clevis, then insert the pushrods all the
way into the tubes from the servo end. Reattach the
clevis and silicone retainer. Insert the upturned wire
through the servo horn and secure it in position with
nylon FasLinks.
❏ 15. Repeat step 14 for the steering pushrod.
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