Set the control throws, Balance the model (c.g.) – Great Planes Shoestring GP/EP ARF - GPMA1328 User Manual

Page 25

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25

Set the Control Throws

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. If your radio does not have
dual rates, we recommend setting the throws at the low rate
setting. NOTE: The throws are measured at the widest part
of the elevators, rudder and ailerons.

These are the recommended control surface throws:

ELEVATOR

HIGH RATE

LOW RATE

1/2"

[13mm]

14°

Up

1/2"

[13mm]

14°

Down

3/8"

[10mm]

10°

Up

3/8"

[10mm]

10°

Down

RUDDER

7/8"

[22mm]

14°

Right

7/8"

[22mm]

14°

Left

5/8"

[16mm]

10°

Right

5/8"

[16mm]

10°

Left

AILERONS

5/8"

[16mm]

17°

Up

5/8"

[16mm]

17°

Down

5/16"

[8mm]

Up

5/16"

[8mm]

Down

Exponential: 40% exponential is recommended on aileron high rates. If your
radio system does not have an exponential function, we suggest using low rate
ailerons for your first few flights.

IMPORTANT: The Shoestring .46 ARF has been
extensively fl own and tested to arrive at the throws at
which it fl ies best. Flying your model at these throws
will provide you with the greatest chance for successful
fi rst fl ights. If, after you have become accustomed to the
way the Shoestring fl ies, you would like to change the
throws to suit your taste, that is fi ne. However, too much
control throw could make the model diffi cult to control, so
remember, “more is not always better.”

Balance the Model (C.G.)

More than any other factor, the C.G. (balance point)
can have the greatest effect on how a model fl ies, and
may determine whether or not your fi rst fl ight will be
successful. If you value this model and wish to enjoy it for
many fl ights, DO NOT OVERLOOK THIS IMPORTANT
PROCEDURE.
A model that is not properly balanced will
be unstable and possibly unfl yable.

At this stage the model should be in ready-to-fl y condition
with all of the systems in place including the engine or
brushless motor, landing gear, and the radio system (and
battery pack if applicable).

1. Use a felt-tip pen or 1/8" [3mm]-wide tape to accurately

mark the C.G. on the bottom of the wing on both sides of the
fuselage. The C.G. is located 3-5/8" [92mm] back from the
leading edge of the wing.

This is where your model should balance for the fi rst
fl ights. Later, you may wish to experiment by shifting
the C.G. up to 3/8" [10mm] forward or 3/8" [10mm] back
to change the fl ying 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 diffi cult to slow for landing. Moving the C.G.
aft makes the model more maneuverable, but could also
cause it to become too diffi cult to control. In any case,
start at the recommended balance point and do not at
any time balance the model outside the specifi ed range.

2. With the wing attached to the fuselage, all parts of

the model installed (ready to fl y) and an empty fuel tank,
place the model on a Great Planes CG Machine, or lift it
upside-down at the balance point you marked.

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

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