Great Planes Giant Extra 330L Kit - GPMA0250 - Manual (Page 45)

❏ 4. Wrap the battery pack in at least 1/4" of foam rubber,
secure to the servo/tank tray (we prefer Velcro straps for this
task for easy removal).
❏ 5. Wrap and mount the receiver as you did the
receiver battery.
❏ 6. Mount the receiver switch in a convenient location that
will not interfere with the servos and pushrods inside
the fuselage.
❏ 7. Route your antenna. Be sure to use a strain relief to
protect the antenna from an accidental hard pull.
❏ 8. Glue the servo/tank tray in place with medium CA.
NOTE: If the radio does not have dual rates, then set the
elevator and rudder control surfaces to low rate throws and
the ailerons at 1-1/4" deflection each way.
HINT: The Extra has been specifically designed for
exceptional performance at the recommended throws. For
truly hands-off knife edge flight the model will require a mix of
roughly 3-4% positive elevator to rudder. If set up as
described, the model has no roll couple on rudder application.
NOTE: The balance and control throws for the Extra
330L have been extensively tested. We are confident
that they represent the settings at which the Extra 330L
flies best.
Please set up your model to the
specifications listed above. If, after you become
comfortable with your Extra 330L, you would like to
adjust the throws to suit your tastes, that’s fine. Too
much throw can force the plane into a stall, so
remember, “more is not better.”
Install the cowl, then mount the spinner backplate, prop,
prop washer, and prop nut. Install the spinner.
NOTE: This section is VERY important and must NOT be
omitted! A model that is not properly balanced will be
unstable and possibly unflyable.
❏ 1. Accurately mark the balance point on the top of the
wing on both sides of the fuselage. Use thin strips of tape or
a felt tip pen to make the marks.
The balance point (CG) is located 6-7/16" back from the
leading edge where the wing meets the fuse as shown in
the sketch and on the wing plan. This CG can also be
checked at the wing tip. The CG is located at 4-7/64" back
from the leading edge of the wing at the wingtip.
Hint: Reference the full size wing plan to help you locate the
proper balance point. This is the balance point at which the
model should balance for your first flights. After initial trim
flights and when you become more acquainted with your
Extra 330L, you may wish to experiment by shifting the
balance up to 5/8" forward or 5/16" back to change the
flying characteristics. Moving the balance forward may
improve the smoothness and stability but the model may then
require more speed for takeoff and make it more difficult to
slow for landing. Moving the balance aft makes the model
more agile with a lighter, snappier “feel” and often improves
knife-edge capabilities. In any case, please start at the
location we recommend and do not at any time balance
your model outside the recommended range.
Balance Your Model
Install the Cowl
We recommend the following control surface throws
High Rate Low Rate
ELEVATOR: 2" up 1/2" up
2" down 1/2" down
RUDDER: 6-1/4" left 3-1/4" left
6-1/4" right 3-1/4" right
AILERONS: 1-7/8" up 3/4" up
1-7/8" down 3/4" down
The throws are measured at the widest part of the
elevators, rudder, and ailerons. Adjust the position of the
pushrods at the control/servo horns to control the
amount of throw. You may also use the ATV’s if the
transmitter has them but the mechanical linkages should
still be set so the ATV’s are near 100% for maximum
servo power and the best servo resolution (smoothest,
most proportional movement).
Please read the Great Planes booklet: “A Look at
Aerobatics” for more information.
Set the Control Throws
One of the advantages of a gasoline engine is the ability
to shut it off by terminating power to the ignition. This is an
added safety feature in the event of an in-flight or ground
emergency such as a throttle servo failure, stuck
carburetor, etc. We STRONGLY recommend you take
advantage of this safety feature by having not only an
external kill switch on the exterior of the aircraft to shut off
the ignition but also an onboard kill switch (such as
GPMG2150) so that your engine’s ignition can be shut off
by simply flipping a switch on your transmitter.
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