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Note: It is highly recommended that a computer radio with
exponential be used if this airplane is to be flown using the
3D control surface throws. Use the exponential function to
lessen the control movement around center without changing
the control surface endpoints. -50% is a good exponential
starting value to use for these 3D rates. Feel free to adjust
the 3D throw exponential value to suit your flying style.
IMPORTANT: The Sukhoi SU-31 EP 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 Sukhoi SU-31 EP ARF 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."
Balance the Model (C.g.)
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.
At this stage the model should be in ready-to-fly condition
with all of the systems in place including the motor, landing
gear, battery pack, and the radio system.
o
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 recommended C.G. is located 2-5/8" [67mm]
back from the LE of the wing at the fuselage.
This is where your model should balance for the first
flights. Later, you may wish to experiment by shifting the
C.G. up to 5/32" [4mm] forward or 7/32" [5.6mm] 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.
o
2. With all parts of the model installed (ready to fly) and
the battery pack installed, place the model upside-down on
a Great Planes C.G. Machine, or lift it at the balance point
you marked .
o
3. If the tail drops, the model is "tail heavy" and the battery
pack and/or receiver must be shifted to balance. If the nose
drops, the model is "nose heavy" and the battery pack and/
or receiver must be shifted aft to balance. If possible, move
the battery pack and receiver to minimize or eliminate any
additional ballast required.
o
4. IMPORTANT: If you found it necessary to move the
battery pack or receiver for the Sukhoi SU-31 EP ARF to
balance, recheck the C.G. after this has been done.
Balance the Model Laterally
o
1. With the wing level, have an assistant help you lift the
model by the engine propeller shaft and the bottom of the
fuselage under the TE of the fin. Do this several times.
o
2. If one wing always drops when you lift the model, it means
that side is heavy. Balance the airplane by adding weight to the
other wing tip. An airplane that has been laterally balanced
will track better in loops and other maneuvers.
Identify Your Model
No matter if you fly at an AMA sanctioned R/C club site or
if you fly somewhere on your own, you should always have
your name, address, telephone number and AMA number
on or inside your model. It is required at all AMA R/C club
flying sites and AMA sanctioned flying events. Fill out the
identification tag on page 23 and place it on or inside your
model.
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PREFLIgHT
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