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Final hookups and checks, How to mark the balance point – Top Flite TOPA0220 User Manual

Page 47

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2. All components should be in the model and it

should be ready-to-fly but with an empty fuel tank.

3. With the wing attached to the fuselage, the

landing gear extended (if you have retracts) and an
empty fuel tank, lift the model at the balance point or
place it on your C.G. Machine (shown in the sketch).
If the tail drops, the model is tail heavy and you must
relocate your battery pack or other components

forward or add weight to the nose. If the nose drops,
it is nose heavy and you must relocate your battery
pack or other components aft or add weight to the
tail. In order to save weight, relocate your battery
pack and/or other components before you add
additional weight to arrive at the correct C.G. You
may install nose or tail weight by gluing lead weights
inside the fuselage where necessary.

Note: The amount of weight required will depend on
the engine you are using and how heavily or lightly you
built the tail. Our prototype with the O.S. .46 FX
two-stroke required 1-1/2 oz. [42.5g] of lead on the tail.

FINAL HOOKUPS AND CHECKS

1. Install the receiver battery at the location

determined when you balanced your model. Wrap it
in 1/4" [6.4mm] foam and hold it in place with some
basswood sticks, glued to the fuselage sides. Our
battery was mounted aft of the elevator servo on the
fuselage bottom.

2. Take the servo arms off your servos, turn on

your transmitter and receiver and center all the trims.
Set the flaps to the center of their travel. Reinstall all
the servo arms and secure them with the screws.
Turn off the transmitter and receiver.

3. Double-check all the servos and make sure the

servo arms are secured with screws and all the
clevises have a silicone retainer.

4. Make sure the control surfaces move in the

proper direction as illustrated in the following sketch.

5. Adjust your pushrod hookups and set up your

radio to provide the control surface movements as
follows. Use a ruler or a Great Planes Accu Throw

Control Surface Deflection Meter (GPMR2405) to
measure the throws.

4-CHANNEL

TRANSMITTER

TRANSMITTER

4-CHANNEL

TRANSMITTER

4-CHANNEL

TRANSMITTER

4-CHANNEL

How to mark the balance point

The balance point is measured from the leading
edge of the center of the wing.
Mark the balance
point outward a few inches so you can see where
to lift the wing when it’s bolted to the fuse.To do this,
mark the balance point with a felt tip pen or tape on
both sides of the center section. Place a
straightedge across the marks. Mark the balance
point along the straightedge further out on the wing.
Mount the wing to the fuselage.

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