Rudder
Set the high rate to maximum throw (about
240mm) both sides, and at low rate reduced
to about 150mm. The Extra needs quite a lot
of rudder for nice stall turns, so you should at
least add 25% exponential for smooth track-
ing corrections. At the same time you should
remember that the Extra rudder is VERY sen-
sitive, and the plane starts shaking at high
speed if the rudder linkage is not really rock
solid. So check your linkages and closed-loop
cables again and make sure that there is NO
slop at all ! On the other hand these charac-
teristics are also the reason for best rudder
sensitivity at the slowest 3D-speeds.
Ailerons
Aileron throw for high rate is 90mm
(measured at root) both up and down.
Use at least 30% exponential at high
rate. For low rate you should
decrease the throw to the TOP to 50
mm, and the BOTTOM to 60mm. Yes,
you’re right - this is a
reversed
differ-
ential due to the hinge line being in
the top skin instead of on the centre
line. You will have to finalise this dif-
ferential figure during flight, as men-
tioned earlier in this instruction book. At high rate, for 3D maneouvres, this doesn’t effect the
rolling too much, so you can maximize the throws to whatever is mechanically possible, even
more up than down if you wish. You may need to lengthen the slots in the servo hatches by 2mm
or so at the front to obtain these high rate throws.
In General
Your Extra has very large control surfaces. This makes it very sensitive and reactive. It is always
possible that these huge control surfaces can flutter at high speeds if the assembly, servo instal-
lation and linkages are not made perfectly, and if a servo gear or output disc/arm strips the flut-
ter will not stop until the plane hits the ground….
So please do yourself a favour, and make sure that you only use the best servos available, and
take the utmost care making your linkages. Check every linkage for slop, and rather reduce the
maximum throw than risking a high speed flutter due to sloppy servo gear or linkages. To pre-
vent this for sure, we recommend reduced control travels (reduced by using short servo arms,
not by using electronic settings). Using 2 servos per control surface as described in this manu-
al will never overload or damage high quality servos, even if the maximum travel of each servo
is slightly off. The aileron control surfaces have enough torsion flexibility so that damage to the
servos should not occur.
The Composite-ARF TOC 3-Metre Version of the Extra 330S is known for very good and crisp
‘snapping’, and we think that the 3.1m ‘SuperXtra’ snaps even better. It’s like an explosion ... and
it still stops immediately that the sticks are released. Be aware of this fact when you try it for the
first time. The trick for nice crisp ‘snaps’ is to stall the plane with a quick hit of ‘up’ elevator, and
then release the elevator to zero, while you give full rudder and aileron together. But of course,
Composite-ARF SuperXtra 330L
(3.1m span)
34
AILERON THROWS
low rate: 60mm down
high rate: 90mm down
high rate: 90mm up
low rate: 50mm up
RUDDER THROWS
high rate: 240mm (max.)
low rate: 70%
low rate: 70%
high rate: 240mm (max.)