Model menu
Swashplate mixer
F X - 4 0
The correct settings can then be set while you are still in the
‘Swashplate AFR’ menu.
NOTE:
While you are carrying out this set-up procedure it is absolu-
tely essential that the ball-end bolts on the inner ring of the
swashplate line up very accurately with the ball-end bolts on
the outer ring of the swashplate. If not, you will get a pitch-axis
effect when you give a roll command, and vice versa. Accurate
adjustment is required to eliminate this potential problem.
Adjust the servo travels in such a way that the swashplate
remains exactly at right-angles to the rotor mast over the full
range of collective pitch travel. Check carefully that there are
no superimposed cyclic pitch deviations when you move the
collective stick.
In the base menu mark the ‘Swashplate’ option, then mark the
‘Swashplate detail’ button field in the top right corner.
In the ‘Mix rate’ frame the first two mixers are ‘Collective pitch
-> roll’ and ‘Collective pitch -> pitch-axis’. The purpose of
these two mixers is to align the swashplate correctly at both
ends of collective pitch travel. When you move the collective
pitch stick, you will see that the marking of the input fields
changes. To alter a value, click on an input field in the marked
line, and use the arrow buttons at the right margin of the
screen to change the value. Move the collective pitch stick to
maximum collective, and look at the swashplate from the front:
adjust the ‘Collective pitch -> roll’ mixer until the swashplate is
exactly horizontal.
Now move the collective pitch stick to minimum collective,
and repeat the adjustment as described above. For this proce-
dure It is advisable to use a collective pitch gauge set to 0°,
and attach it to one flybar paddle. You can use the top edge of
the rotor head as reference line. This arrangement will enable
you to pick up even the slightest unwanted movement in the
swashplate. Now rotate the rotor head through 90° so that you
see the flybar paddle and the collective pitch gauge from the
side of the model. Adjust the ‘Collective pitch -> pitch-axis’
mixer until the swashplate is accurately aligned at minimum
and maximum collective pitch.
The purpose of the remaining three mixers is to prevent
unwanted interactions at the swashplate when the collective
pitch stick is at 50% or centre. The ‘Roll -> collective pitch’
mixer should be set up in such a way that the swashplate
remains horizontal when viewed from the side with full roll to
right or left applied. The next stage is to set up the ‘Pitch-axis
-> roll’ and ‘Pitch-axis -> collective pitch’ mixers; this time the
swashplate must remain horizontal when viewed from the front
when full forward and back cyclic (pitch-axis) commands are
given.
The next step is to set the linkage compensation: this setting
compensates for interactions at the swashplate towards the
extremes of collective pitch travel. In each case there are four
adjustment facilities for high and low collective pitch values.
View the swashplate from the side while you move the collec-
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tive pitch stick to max. collective, and set a value for the ‘Roll
mixer’ to eliminate any change in the pitch-axis travel at full
right or left roll travel. When you are satisfied, rotate the rotor
through 90° and adjust the ‘Pitch-axis mixer’ in the same way.
The final stage is to repeat the whole procedure with collective
pitch set to minimum.
Speed compensation can now be applied. The purpose of this
setting, which is only provided for 120° ECCPM swashplates, is
to compensate for mechanical differences between the roll and
collective pitch servos; when operated together in response to
a pitch-axis command, they operate faster than the single
pitch-axis servo. This problem can usually only be picked up if
you move the pitch-axis stick from one extreme to the other at
high speed. Adjust the speed compensation value so that the
ball-link in the centre of the swashplate does not jump up and
down when the pitch-axis stick is moved quickly.
The screen shot above shows a typical programming example
with a speed compensation value selected.
