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The JR 120°/140° three servo CCPM relies on the radio’s
special CCPM swashplate mixing, rather than a conventional
mechanical mixer that is utilized to achieve the same results.
The radio’s 120° or 140° 3-servo CCPM function automatically
mixes the three servos to provide the correct mixing inputs for
aileron (roll), elevator (pitch), and collective. The following is an
example of how each control input affects the servo’s movement.
1. COLLECTIVE
When a collective pitch input is given, all three servos move
together in the same direction, at equal amounts, to raise
and lower the swashplate while keeping the swashplate
level. During this function, all three servos travel at the same
value (100%) so that the swashplate can remain level during
the increase and decrease in pitch. As mentioned, this
mixing of the three servos is achieved through the radio’s
CCPM program.
2. ELEVATOR (PITCH)
When an elevator input is given, all three servos must move
to tilt the swashplate fore and aft, but their directions vary.
The servos move together in the same direction, while the
rear swashplate servo moves in the opposite direction. For
example, when a down elevator (forward cyclic) command is
given, the front swashplate servos will move the swashplate
down, while the rear swashplate servo moves so that the
swashplate will tilt forward. During this function with 120°
CCPM, the rear swashplate servo travels at 100%, while the
front swashplate servos travel at 50% (1/2 the travel value).
This difference in travel is necessary due to the fact that the
position of the 120 CCPM rear control ball is two times the
distance of the two front control ball positions as measured
from the center of the swashplate. With 140° CCPM selected,
all three servos travel at 100%, eliminating elevator trim
changes during quick collective inputs.
3. AILERON (ROLL)
When an aileron (roll) input is given, the front swashplate
servos travel in opposite directions, while the rear
swashplate servo remains motionless, such as, when a right
aileron command is given.
understAndIng ccPm control systems
Summary of Contents for Vibe 90SG
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