❏
2. With the wings 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
(GPMR2400), 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. weight, or
GPMQ4646 for the 2 oz. weight). If spinner weight is not
practical or is not enough, use
Great Planes “stick-on” lead
weights
(GPMQ4485). A good place to add stick-on nose
weight is to the firewall (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
firewall 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, fuel and
exhaust residue may soften the adhesive 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.
❏
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.
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 25 and place it on or inside your model.
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.
NOTE:
Checking the condition of your receiver battery pack
is
highly recommended
. All battery packs, whether it's a
trusty pack you've just taken out of another model, or a new
battery pack you just purchased, should be cycled, noting
the discharge capacity. Oftentimes, a weak battery pack can
be identified (and a valuable model saved!) by comparing its
actual capacity to its rated capacity. Refer to the instructions
and recommendations that come with your cycler. If you
don't own a battery cycler, perhaps you can have a friend
cycle your pack and note the capacity for you.
Carefully balance your propeller and spare propellers before
you fly. An unbalanced prop can be the single most significant
cause of vibration that can damage your model. Not only will
engine mounting screws and bolts loosen, possibly with
disastrous effect, but vibration may also damage your radio
receiver and battery. Vibration can also cause your fuel to
foam, which will, in turn, cause your engine to run hot or quit.
We use a
Top Flite Precision Magnetic Prop Balancer
™
(TOPQ5700) in the workshop and keep a
Great Planes
Fingertip Prop Balancer
(GPMQ5000) in our flight box.
Balance the Propellers
Charge the Batteries
Identify Your Model
PREFLIGHT
Balance the Model Laterally
2-3/4" [70mm]
22
