Great Planes Yak-54 1.60 ARF - GPMA1411 - Manual (Page 29)

Due to the size of the control surfaces on the GP Yak 54 1.60
ARF, use of a Great Planes AccuThrow
™ is not possible for
measuring throws. A ruler should be used 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, and the radio system.
❏
1. Use a felt-tip pen or 1/8" [3 mm]-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 5-1/8" [130 mm] back from the
leading edge of the wing at the fuselage.
❏
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.
❏
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. If
additional weight is required, nose weight may be easily
added by using a “spinner weight” (GPMQ4645 for the 1 oz.
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" [13 mm] forward or 1/2" [13 mm] 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 (G.G.)
IMPORTANT: The Yak 54 1.60 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 Yak 54 1.60 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.” In order to achieve the full 3D rates noted in the
chart above, you will need to purchase longer servo arms.
Refer to the
“Optional Supplies & Tools” section on page
4 for part numbers.
These are the recommended control surface throws:
High Rate Low Rate
ELEVATOR: 1-1/4" [32 mm] up 7/8" [22 mm] up
1-1/4" [32 mm] down 7/8" [22 mm] down
RUDDER: 2-1/2" [64 mm] right 1" [25 mm] right
2-1/2" [64 mm] left
1" [25 mm] left
AILERONS: 1" [25 mm] up 7/8" [22 mm] up
1" [25 mm] down 7/8" [22 mm] down
3D RATES
3D ELEVATOR: 2-1/2" [64 mm] up
2-1/2" [64 mm] down
3D RUDDER: 4" [102 mm] right
4" [102 mm] left
3D AILERONS: 2-1/4" [57 mm] up
2-1/4" [57 mm] down
Set the Control Throws
29