Great Planes SU-31 3D ARF - GPMA1412 - Manual (Page 27)

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the servo. Be sure to apply thin CA to the holes to harden the
wood. Center the servo with your radio system (depending
on the location of the receiver, a 6" [152mm] servo extension
may be needed).
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2. Determine the location of the throttle pushrod based
on the position of the throttle arm on the carburetor. Drill a
hole through the fi rewall for the throttle pushrod using a long
3/16" [4.8mm] drill bit. If you do not have a long drill bit, you
may need to temporarily remove the engine in order to drill
the hole. Before drilling, confi rm that your hole will not pass
through the fuel tank! If you are unsure, measure the shape
of the tank and lightly draw the outline of the tank shape onto
the fi rewall using the location of the fuel tank neck hole as a
centering guide.
❏
3. Insert the outer pushrod tube through the hole in the
fi rewall and slide it through the formers in the fuse toward the
servo arm on your throttle servo. Mark and cut the pushrod
tube to the necessary length. Use sandpaper to scuff the tube
where it will be glued to the fi rewall and the throttle pushrod
tube support. Reinstall the tube into the plane and glue the
forward end to the fi rewall. Clip the throttle pushrod tube
support near the aft end of the tube. Use the pushrod tube
support to align the outer pushrod tube level with the throttle
servo arm. Glue the pushrod tube support to the fuse former
as shown and glue the tube to the support.
Use the following four images for steps 4 and 5.
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4. Thread the 2-56 x 1" [25mm] threaded rod approximately
3/8" [9.5mm] into one end of the nylon inner pushrod. Thread
a nylon ball link onto the other end of the threaded rod. Insert
the inner pushrod into the outer pushrod tube and connect
the ball link onto the carburetor throttle arm. Mark where the
inner pushrod will need to be cut to length.
❏
5. Remove the inner pushrod tube and cut it to length at
the mark you made and re-install it. Clip the ball link onto the
carburetor throttle arm. Cut the included .075" x 36" [1.85mm
x 914mm] pushrod to approximately 6" [152mm] long to
make it easy to work with inside the fuse. (Be sure that the
piece you cut off includes the threaded end.) Thread the
6" [152mm] piece of pushrod into the nylon inner pushrod
approximately 1/2" [13mm]. Mark where the 6" [152mm]
pushrod needs to be bent in order to align with the outer hole
of the throttle servo arm. (Be sure that the arm is positioned
so it will open and close the carburetor correctly when the
pushrod is installed.) Bend the 6" [152mm] pushrod at the