Linkage Menu
F X - 4 0
16.14
SWASHPLATE
BASIC SWASHPLATE SETTINGS
This function is used to program the mixer functions required
to actuate the swashplate of a model helicopter. It is not avai-
lable if you select the swashplate type SWH1, as no mixers are
required for the collective pitch function with this configura-
tion.
If you activate a model helicopter with any of the other swash-
plate types, you can access this menu to set and reverse the
stick travels of the roll (aileron), pitch-axis (elevator) and col-
lective pitch functions. The essential mixer functions can also
be programmed at this point.
Mark the ‘Swashplate’ option in the base menu. The screen
now looks like this:
The software of the FX-40 provides a very convenient method
of optimising the swashplate settings.
• Neutral point adjustment
The first step is to optimise the neutral point setting, which
is entered as a percentage value. First adjust the servo out-
put arms mechanically, so that the neutral point is close to
50%. Now mark the ‘Sel.’ (select) field, and its background
will turn red. Adjust the position of the collective pitch stick
until the servo output arms are exactly at 90° to the push-
rods. Now press the ‘Sel.’ field again, and read off the dis-
played percentage value; this figure is also displayed in bar
form.
• Adjusting stick travel
The stick travel settings can be optimised for the roll, pitch-
axis and collective pitch functions: mark the field in the
swashplate frame, and enter the required percentage value
using the arrow buttons which now appear. The adjustment
range is -100% to +100%; the default setting is 50%.
Pressing the “Reset” field restores the default setting.
You should now use the servo reverse function to correct
the direction of servo rotation where necessary, so that all
the servos move in the same direction when you operate
the collective pitch stick. With these settings correct, set
the appropriate direction of rotation for the pitch-axis and
roll functions by changing the + / - prefix where necessary.
It is important to set the control travels to the largest possi-
ble value without the pushrods or servos striking their end-
stops. Check the maximum control travels carefully when
the collective pitch, roll and pitch-axis functions are at their
extremes of travel. Remember that the swashplate may jam
if you set excessive travels, although this varies according
to the method of actuation and the design of the rotor head.
The swashplate menu has two display levels; pressing the field
at top right takes you to the second level: Swashplate (AFR).
The display changes, and the screen for setting up the mixer
rates appears. It looks like this:
• Setting the mixer rates
Example of an HR-3 120° swashplate type with electronic
mixing (ECCPM).
The purpose of adjusting the mixer rates is to obtain even
mixing (as far as possible) of the three swashplate servos
which are responsible for the control functions roll, pitch-
axis and collective pitch.
• Linkage compensation
Any unwanted interactions between the various pushrods
can be corrected in the right frame on the second screen
page.
• Speed compensation
The two roll servos feature shorter control travel at the
swashplate, which can result in an unwanted collective
pitch response when a pitch-axis command is given. At this
point you can set a delay for the roll servos to prevent this
happening.
A detailed description of the swashplate mixer set-up pro-
cedure can be found in Part 2 of the “Model Helicopter
Menu” instructions. See Section 19.5 ‘Swashplate mixers’
on page 90.
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