Get Your Model Ready To Fly; Balance Your Model; Balance The Model Laterally; Final Hookups & Checks - GREAT PLANES Extra 300S Instruction Manual

your receiver. Wrap the receiver in foam rubber and mount
it in the location determined earlier. Glue a piece of 1/8"
balsa or plywood to securely hold your receiver in position.
Be certain that nothing interferes with the pushrods or
servo horns.
2. Wrap your battery pack and mount it in the
predetermined location the same as the receiver. Be certain
the battery pack is secure so it will not become dislodged
during aerobatic maneuvers.
3. Mount the on/off switch and charging jack in a
strategic location that will not interfere with other radio
components but is easy to reach from outside the model.
4. Make a strain relief from a cutoff servo arm and fit it to
your antenna. Route the antenna out the bottom (or side) of
the model and attach it to a T-pin or the tail gear wire with a
small rubber band. Do not push the T-pin through the
antenna wire.

GET YOUR MODEL READY TO FLY

Balance Your Model

Note: This section is IMPORTANT and must NOT be
omitted! A model that is not properly balanced will be
unstable and possibly unflyable.
C.G. Machine
This is the balance point at which your model should be
balanced for your first flights. Later, you may experiment
by shifting the balance up to 1/4" forward or backward
to change the flying characteristics. If you move the
balance point forward it may improve the smoothness
and tracking, but your Extra 300 ARF may then require
more speed for takeoff and become more difficult to slow
for landing. If you move the balance aft it may make your
Extra 300 ARF more agile with a lighter feel and allow you
to slow the model more for landing. In any case, please
start at the location we recommend and do not at any
time balance your model outside the recommended
C.G. range.
All components should be in the model and it should be
ready-to-fly with an empty fuel tank. Lift your model at the
balance point or place it on your Great Planes C.G.
Machine. Your balance point should be pretty close since
we've already pre-balanced it. If necessary, add nose
weight or tail weight to balance the model where indicated.
Note: Nose weight may be easily installed by using a
spinner weight or gluing lead weights to the firewall. Tail
weight may be added by using Great Planes (GPMQ4485)
"stick-on" lead weights. Later if the balance is O.K., you can
open the fuse bottom and glue the weights in permanently.
Do not confuse this procedure with checking the C.G. which
you already performed.
1. With the wing level and attached to the model (and
the engine and muffler installed), lift the model by the
propeller shaft and the fin. This may require an assistant.
Do this several times.
2. The wing that consistently drops indicates the heavy
side. Balance the model by adding weight to the other
wing tip.
An airplane that is laterally balanced will track better during
aerobatic maneuvers.
1. Take the servo horns off your servos, turn on your
transmitter and center all the trims. Reinstall all the servo
horns and secure them with the screws.
4" [101.6mm]
at fuse
2. Double-check all the servos and make sure the servo
horns are secure. Install a silicone retainer on all clevises.
19

Balance the Model Laterally

Final Hookups & Checks
SILICONE RETAINER
NYLON CLEVIS