Throttle Pushrod Installation - GREAT PLANES Piper J-3 Cub Instruction Manual

the mounting holes. Drill 3/32" [2.4mm] mounting holes
through the marks. Wick two to three drops of Thin CA into
the holes to harden the underlying balsa, then re-drill the
holes. Attach the horns using 2-56 x 5/8" Machine Screws
and Nylon Nut Plates. Do not over-tighten the screws,
crushing the underlying balsa.
❏ ❏ 7. Center the rudder and rudder servo and mark the
pushrod where it crosses the servo arm. Remove the
pushrod from the aircraft. Cut the pushrod wire 3/4" [19mm]
behind the mark.
Use the following sequence to solder the clevis to the
pushrod wire:
A. Lightly sand the pushrod wire and clean it with alcohol.
B. Insert the pushrod into the non-threaded clevis. The
wire should protrude 1/16" inside the forks of the clevis.
C. Apply a small amount of soldering flux to the joint.
D. Apply heat evenly to the pushrod wire and the
clevis and then touch the solder to the joint and
allow it to flow.
E. Allow the pushrod and clevis to cool before
continuing.
❏ ❏ 8. Remove the threaded clevis and nut from the
pushrod. Slide a clevis retainer from the threaded end onto
the clevis just soldered. Slide the pushrod, threaded end
first, into the pushrod tube from the servo compartment.
Attach the clevis to the outer hole of the servo arm. Thread
the nut and clevis back onto the pushrod wire and attach the
clevis to the rudder control horn.
❏ 9. Repeat steps 5 through 8 to assemble and install the
elevator pushrod.
❏ 10. A pushrod brace must be installed to prevent the
pushrods from flexing near the servos. We used 1/4" balsa
to make the brace shown. This brace can be made using
mixing sticks or any other woods you may have lying
around. The brace must be positioned so it won't cause the
pushrods to bind against the tubes when installed. Glue the
pushrod tubes to the brace using medium CA.

Throttle Pushrod Installation

❏ 1. Install a Brass Screw-Lock Pushrod Connector with
the 4-40 x 1/8" Cap Screw on the throttle servo horn. Snap
the Nylon Retainer onto the pushrod connector post
beneath the servo horn.
❏ 2. Assemble the 17-1/2" [444mm] Throttle Pushrod Wire
by installing a nylon clevis and silicone retainer onto the
threaded end. Slide the throttle pushrod into its outer tube
(from the firewall).
❏ 3. Bend the Throttle Pushrod as necessary to reach the
throttle arm without binding. When satisfied with the fit, insert
the pushrod through the Screw-Lock Pushrod Connector on
the servo. Connect the clevis to the throttle on the engine,
snap the clevis closed, then slide the retainer in place.
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