Table of Contents
Advertisement
At this stage the model should be in ready-to-fly condition
with all of the systems in place including the engine, landing
gear, covering and paint, and the radio system.
1. If using a Great Planes C.G. Machine set the rulers
to 3-1/4" [82mm]. If not using a C.G. Machine, use a felt-tip
pen or 1/8"-wide [3mm] tape to accurately mark an
approximately 7" [200mm] line on the top of the wing 3-1/4"
[82mm] back from the leading edge.
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 1/4" [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 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. Bolt the wing to the fuselage. With, all parts of the
model installed (ready-to-fly) and an empty fuel tank, place
the model upside-down on the Great Planes CG Machine,
or lift it upside-down with one finger from each hand on the
line you marked on the balance point.
3. If the tail drops, the model is "tail heavy" and weight
must be added to the nose to balance. If the nose drops, the
model is "nose heavy" and weight must be added to the tail
to balance. If possible, start out by relocating the battery
pack and/or receiver to minimize or eliminate any additional
ballast required. If additional weight is still required, nose
weight may be easily added by using a "spinner weight"
(GPMQ4645 for the 1 oz. weight, or GPMQ4646 for the 2
oz. weight). If spinner weight is not practical or is not
enough, use Great Planes (GPMQ4485) "stick-on" lead. A
good place to add stick-on nose weight is to the firewall or
to the inside of one of the fuselage sides in front of the
firewall. To find out how much weight is required, begin by
placing incrementally increasing amounts of weight on the
bottom of the fuselage over nose or tail until the model
balances. Once you have determined the amount and
location of weight required, it can be permanently attached.
Tail weight may be added by cutting the covering from the
side of the fuselage and gluing it inside. Cover the hole with
another piece of covering.
Note: Do not rely upon the adhesive on the back of the lead
weight to permanently hold it in place. Over time, fuel and
exhaust residue may soften the adhesive and cause the
weight to fall off. Use #2 wood screws, RTV silicone or
epoxy to permanently hold nose weight in place.
4. IMPORTANT: If you found it necessary to add any
weight, recheck the C.G. after the weight has been installed.
Balance the Model Laterally
1. With the wing level, have an assistant help you lift the
model by the engine propeller shaft and the bottom of the
fuse under the TE of the fin. Do this several times.
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.
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 41 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 receiver batteries the
night before you go flying, and at other times as
recommended by the radio manufacturer.
37
Advertisement
Table of Contents
