Great Planes Giant Extra 330L Kit - GPMA0250 - Manual (Page 46)

❏ 2. With the wing attached to the fuselage, all parts of the
model installed (ready to fly) and an empty fuel tank, hold
the model upside-down with the stabilizer level. NOTE: If
you are using the CG Machine
™ as described in the Expert
Tip below, we strongly recommend having the model
upside-down. If you are checking the CG by hand, the CG
can be checked right-side-up, although upside down is
always preferable for better accuracy on a low wing model
such as this.
❏ 3. Lift the model at the balance point. If the tail drops
when you lift, the model is “tail heavy” and you must add
weight* to the nose to balance the model. If the nose drops,
it is “nose heavy” and you must add weight* to the tail to
balance the model. NOTE: Nose weight may be easily
installed by using a “spinner weight” or gluing lead weights
to the firewall. Tail weight may be added by using Great
Planes (GPMQ4485) “stick-on” lead weights or by adding
the optional second rudder servo.
* If possible, first attempt to balance the model by changing
the position of the receiver battery and receiver. If you are
unable to obtain good balance by doing so, then it will be
necessary to add weight to the nose or tail to achieve the
proper balance point.
❏ 1. Slide the wing tube, with its already installed first panel
and 6-32 x 3/4" bolt, through the fuselage, plugging in the
servo leads as you do so. Slide on the second wing panel and
plug in the servo leads. Thread in the second panel bolt.
❏ 2. Attach the stab to the fuselage as you did the wing.
Proper maintenance of your Giant Extra is important to its
longevity. Be sure to check these and all components regularly.
❏ 1. The phenolic tube sockets will gradually wear and feel
loose when you’re assembling your model to fly. When they
do, apply a small amount of thin CA to a paper towel and
wipe it inside the sockets in the fuse (be SURE there is no
accelerator on your hands or in the air!). Allow to cure
completely before completing assembly.
❏ 2. Tighten the landing gear bolts.
❏ 3. If you have the tube secured into one panel and always
unscrew the other, check the secured side’s bolt to be sure
it's not vibrating loose.
❏ 4. Confirm that the anti-rotation dowels are tight in the
fuse and do not wiggle, rotate or slide, including checking
the canopy dowels.
❏ 5. It is not necessary to remove the canopy to assemble
the aircraft; however, do so occasionally to check the
structure of the model for any damage.
❏ 6. Check that the cowl screws, engine mounting bolts and
exhaust bolts are tight.
❏ 7. Regularly inspect all ignition wires of your gasoline
engine for chaffing.
Maintenance of the Giant Extra
NOTE ON INSTALLING YOUR WING: When you fit the
Extra’s wing to the tube, you will find it is a snug fit that
requires some force. When putting your aircraft together
to fly, it is helpful to have someone put light pressure
against the first wing tip or to butt the tip against a car tire,
then push the wing onto the tube from the other side. To
remove the wing from the aircraft, stand with the fuselage
resting against the back of your legs and pull the wing
away from the fuselage. Always handle the wing by the
leading and trailing edges and be careful not to put your
hand through either the wings’ or fuselage’s sheeting.
Assembly of the Giant Extra
ASSEMBLY & MAINTENANCE
To use the standard CG Machine on a model this large,
you’ll need to screw pieces of leftover 1/8" x 4" x 4"
plywood to the top of the balance pads. Attach foam to
the top of the plywood. Use two pieces of 3/16" x18"
piano wire to replace the base rods so the stand is wide
enough to fit the Extra’s fuse.
Using a Great Planes CG Machine
to balance the Giant Extra
46