Dual/triple rates and exponential (D/R,EXP): assigns adjusted rates and exponential.
Dual/Triple Rates: reduce/increase the servo travel by flipping a switch, or
(ACRO/GLIDER) they can be engaged by any stick position. Dual rates affect the control
listed, such as aileron, not just a single (ex: channel 1) servo. For example, adjusting
aileron dual rate will affect both aileron servos when using FLAPERON or AIL-DIF, and both
aileron and elevator servos’ travel when using AILEVATOR or ELEVON or a CCPM helicopter.
Activation:
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Any SWITCH, A-H. If you choose a 3-position switch, then that dual rate instantly becomes a triple rate (see example).
•
Stick position (ACRO/GLIDER). (Ex: On rudder you normally use only the center 3/4 of the stick movement except
for extreme maneuvers such as snaps/spins/stalls. As long as your RUDDER STICK does not exceed 90% of maximum
throw, the rudder responds at your lower rate, allowing small, gentle corrections. When the stick passes 90% (ie. stall
turn), the rudder goes to high rate’s 90%, which is a MUCH higher amount of travel than your low rate at 89%.)
Ex: EPA = 1” Low Rate = 50% High Rate = 100%
At 89% Low Rate = .45”
At 90% High Rate = .9”
Adjustability:
•
Range: 0 - 140% (0 setting would deactivate the control completely.)
Initial value=100%
•
Adjustable for each direction(ACRO/GLIDER). (ie. Up/down,
left/right) (Ex: Most models fly upright without any elevator trim,
but require some down elevator when inverted just to maintain
level flight. By increasing the down travel by the amount required
to hold the model inverted, the model now has equal travel
available from level upright or level inverted.)
Exponential: changes the response curve of the servos relative to the stick position to make flying more pleasant. You
can make the servo movement less or more sensitive around neutral for rudder, aileron, elevator, and throttle (except HELI
type - use THROTTLE CURVE instead).
Why use expo? Many models require a large amount of travel to perform their best tricks. However, without exponential,
they are “touchy” around neutral, making them unpleasant to fly and making small corrections very difficult. Additionally,
by setting different exponentials for each rate, you can make the effectiveness of small corrections similar in each rate, as
in our example below.
The best way to understand exponential is to try it:
•
Having made no changes yet in the D/R,EXP screen, move S
WITCH D to “down” (toward the AILERON STICK
).
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Cursor down to EXP and dial to 100%.
•
Move S
WITCH D up. Hold the AILERON STICK
at ¼ stick and move S
WITCH D down.
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Notice how much less travel there is.
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Go to 3/4 stick and repeat. Notice how the travel is much closer, if not identical.