20
Use a small box or something similar to prop
up the fuselage until the wings and horizontal
stabilizers are level.
1
Take the reading of the surface you are
measuring at the widest part of the control
surface at the trailing edge.
2
Move the control surface and move your
ruler forward. Read the measurement to get
the throw.
3
Move
the ruler
forward
❏
2. Hold a ruler vertically on your workbench against the
widest part (front to back) of the trailing edge of the elevator.
Note the measurement on the ruler.
❏
3. Move the elevator up with your transmitter and move the
ruler forward so it will remain contacting the trailing edge. The
distance the elevator moves up from center is the “up” elevator
throw. Measure the down elevator throw the same way.
❏
4. If necessary, adjust the location of the pushrod on the
servo arm or on the elevator horn, or program the ATVs in
your transmitter to increase or decrease the throw according
to the measurements in the control throws chart.
❏
5. Measure and set the
low rate
elevator throws and the
high and low rate throws for the rest of the control surfaces
the same way.
These are the recommended control surface throws:
ELEV
A
TOR
LOW RATE
HIGH RATE
Up and
Down
Up and
Down
Up and
Down
Up and
Down
Right
& Left
Right
& Left
RUDDER
AILERONS
3/4"
[19 mm]
18°
5/16"
[8 mm]
11°
1- 3/16"
[30 mm]
18°
7/8"
[23 mm]
19°
17/32"
[13 mm]
18°
1-3/4"
[44 mm]
29°
If your radio does not have dual rates, we recommend setting
the throws at the low rate settings until you become familiar
with the airplane. You might later consider putting them at the
high rate settings.
NOTE
: The throws are measured at the
widest part
of the
elevators, rudder and ailerons.
Balance the Model (C.G.)
More than any other factor, the C.G. (center of gravity/
balance point) can have the greatest effect on how a model
fl ies and could determine whether or not your fi rst fl ight will
be successful. If you value your model and wish to enjoy it
for many fl ights,
DO NOT OVERLOOK THIS IMPORTANT
PROCEDURE.
A model that is not properly balanced may
be unstable and possibly unfl yable.
At this stage the model should be in ready-to-fl y condition
with
all
of the components in place including the complete
radio system, engine, muffl er, propeller, spinner and pilot. If
you’ve built the electric version, install the motor battery. If
you’ve built the glow version the fuel tank should be empty.
❏
1. If using a Great Planes C.G. Machine
™
, set the rulers to
2.75" [70mm]. If not using a C.G. Machine, use a fi ne-point
felt tip pen to mark lines on the top of wing on both sides of
the fuselage 2.75" [70mm] back from the leading edge. Apply
narrow (1/16" [2mm]) strips of tape over the lines so you will
be able to feel them when lifting the model with your fi ngers.
This is where your model should balance for the fi rst fl ights.
Later, you may experiment by shifting the C.G. 7/16" [11mm]
forward or back to change the fl ying characteristics. Moving
the C.G. forward will improve the smoothness and stability,
but the model will then be less aerobatic (which may be fi ne
for less-experienced pilots). Moving the C.G. aft makes the
model more maneuverable and aerobatic for experienced
pilots. In any case,
start at the recommended balance
point
and do not at any time balance the model outside
the specifi ed range.
