Great Planes Super Chipmunk ARF - GPMA1303 - Manual (Page 23)

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Use a Great Planes AccuThrow (or a ruler) to accurately
measure and set the control throw of each control surface
as indicated in the chart that follows. Note: The throws are
measured at the widest part of the elevators, rudder
and ailerons.
At this stage the model should be in ready-to-fly condition
with all of the systems in place including the engine, landing
gear, covering and paint, and the radio system.
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1. Use a felt-tip pen or 1/8" [3mm]-wide tape to accurately
mark the C.G. on the top of the wing on both sides of the
fuselage. The C.G. is located 4-3/4" [120mm] back from the
leading edge of the wing measured at the fuselage.
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2. With the wing attached to the fuselage, all parts of the
model installed (ready to fly) and an empty fuel tank, place
the model upside-down on a Great Planes CG Machine, or
lift it upside-down at the balance point you marked .
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3. If the tail drops, the model is “tail heavy” and the
battery pack and/or receiver must be shifted forward or
weight must be added to the nose to balance. If the nose
drops, the model is “nose heavy” and the battery pack
and/or receiver must be shifted aft or weight must be added
to the tail to balance. If possible, relocate the battery pack
and receiver to minimize or eliminate any additional ballast
required. Our prototype required 20 oz [567g] of lead on the
nose. Additional nose weight may be easily added by using
a “spinner weight” (GPMQ4645 for the 1 oz. [28g] weight, or
GPMQ4646 for the 2 oz. [57g] weight). For additional weight
This is where your model should balance for the first
flights. Later, you may wish to experiment by shifting the
C.G. up to 1/2" [13mm] forward or 1/2" [13mm] back to
change the flying characteristics. Moving the C.G. 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 C.G. aft
makes the model more maneuverable, but could also
cause it to become too difficult to control. In any case,
start at the recommended balance point and do not at
any time balance the model outside the specified range.
More than any other factor, the C.G. (balance point) can
have the greatest effect on how a model flies, and may
determine whether or not your first flight will be
successful. If you value this model and wish to enjoy it for
many flights, DO NOT OVERLOOK THIS IMPORTANT
PROCEDURE. A model that is not properly balanced will
be unstable and possibly unflyable.
Balance the Model (C.G.)
IMPORTANT: The Super Chipmunk 1.20 ARF has been
extensively flown and tested to arrive at the throws at
which it flies best. Flying your model at these throws will
provide you with the greatest chance for successful first
flights. If, after you have become accustomed to the way
the Super Chipmunk flies, you would like to change the
throws to suit your taste, that is fine. However, too much
control throw could make the model difficult to control, so
remember, “more is not always better.”
These are the recommended control surface throws:
High Rate Low Rate
ELEVATOR: 1" [25mm] up 5/8" [57mm] up
1-1/4" [32mm] down 1" [25mm] down
RUDDER: 4" [102mm] right 2-1/4" [57mm] right
4" [102mm] left 2-1/4" [57mm] left
AILERONS: 1" [25mm] up 3/4" [19mm] up
1" [25mm] down 3/4" [19mm] down
FLAPS: 1-7/8" [48mm] down
Set the Control Throws
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