Great Planes Super Sportster EP RxR - GPMA6006 - Manual (Page 9)

9
Balance the Model (C.G.)
More than any other factor, the C.G. (balance point) can
have the greatest effect on how a model fl ies, and may
determine whether or not your fi rst fl ight will be successful.
If you value this model and wish to enjoy it for many fl ights,
DO NOT OVERLOOK THIS IMPORTANT PROCEDURE.
A model that is not properly balanced will be unstable and
possibly unfl yable.
At this stage the model should be in ready-to-fl y condition
with all of the systems in place including the brushless motor,
landing gear, the radio system and battery pack.
❏
1. Use a felt-tip pen or 1/8" [3mm]-wide tape (do not apply
tape over the trim scheme!) to accurately mark the C.G. on
the top of the wing on both sides of the fuselage. The C.G. is
located 2-5/8" [67mm] back from the leading edge of the wing.
This is where your model should balance for the fi rst fl ights.
Later, you may wish to experiment by shifting the C.G. up
to 3/4" [19mm] forward or 3/8" [9.5mm] back to change the
fl ying 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 diffi cult
to slow for landing. Moving the C.G. aft makes the model
more maneuverable, but could also cause it to become too
diffi cult to control. In any case,
start at the recommended
balance point and do not at any time balance the model
outside the specifi ed range.
❏
2. With the wing attached to the fuselage, all parts of the
model installed (ready to fl y) and battery installed, 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 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 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, use Great
Planes (GPMQ4485) “stick-on” lead. A good place to add
stick-on nose weight is to the fi rewall (don’t attach weight
to the cowl—it is not intended to support weight). Begin by
placing incrementally increasing amounts of weight on the
bottom of the fuse over the fi rewall until the model balances.
Once you have determined the amount of weight required, it
can be permanently attached. If required, tail weight may be
added by cutting open the bottom of the fuse and gluing it
permanently inside.
Note: Do not rely upon the adhesive on the back of the lead
weight to permanently hold it in place. Over time, the adhesive
may fail and cause the weight to fall off. Use #2 sheet metal
screws, RTV silicone or epoxy to permanently hold the 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 motor propeller shaft and the bottom of the fuse
under the TE of the fi n. 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 fl y at an AMA sanctioned R/C club site or if
you fl y 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 fl ying sites
and AMA sanctioned fl ying events. Fill out the identifi cation
tag on page 12 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 battery the night before you go fl ying,
and at other times as recommended by the radio 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 fl ying with batteries
that are only partially charged.