Balance The Model (C.g.); Preflight; Identify Your Model; Charge The Batteries - GREAT PLANES J-3 Cub Instruction Manual

IMPORTANT: The FlatOuts J-3 Cub 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 FlatOuts J-3 Cub 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 battery, receiver
and ESC.
❏
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 2-1/2" [64mm] 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 1/4" [6mm] forward or 3/8" [9.5mm] 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.
❏
2. With all parts of the model installed (ready to fly), place
the model upside-down on a Great Planes CG Machine, or
lift it at the balance point you marked.
❏
3. If the tail drops, the model is "tail heavy" and the battery
pack must be shifted forward to balance. If the nose drops, the
model is "nose heavy" and the battery pack must be shifted
back to balance. This model is very weight sensitive. Do not
add any weight to achieve the suggested balance point.
Instead, shift the battery pack forward or aft to alter the C.G.

PREFLIGHT

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 14
and place it on or inside your model.

Charge the Batteries

Follow the battery charging instructions that came with your
radio control system to charge the batteries. You should
always charge your transmitter and motor batteries the night
before you go flying, and at other times as recommended by
the manufacturer.
CAUTION: Unless the instructions that came with your
radio system state differently, the initial charge on new
transmitter batteries should be done for 15 hours using
the slow-charger that came with the radio system. This
will "condition" the batteries so that the next charge may
be done using the fast-charger of your choice. If the initial
charge is done with a fast-charger the batteries may not
reach their full capacity and you may be flying with
batteries that are only partially charged.

Range Check

Ground check the operational range of your radio before the
first flight of the day. With the transmitter antenna collapsed
and the receiver and transmitter on, you should be able to
walk at least 100 feet away from the model and still have
control. Have an assistant stand by your model and, while
you work the controls, tell you what the control surfaces are
doing. Repeat this test with the motor running at various
speeds with an assistant holding the model, using hand
signals to show you what is happening. If the control
surfaces do not respond correctly, do not fly! Find and
correct the problem first. Look for loose servo connections or
broken wires, corroded wires on old servo connectors, poor
solder joints in your battery pack or a defective cell, or a
damaged receiver crystal from a previous crash.
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