ROBBE HeliCommand 3A Manual De Instrucciones página 19

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First fl ight
Before the fi rst fl ight you must carry out a check of the
sensors and controls for all sensor directions
• Neutral setting, directional sense of all stick and servo movements.
• Pilot channel and (if used) auto-trim button: check by LED.
(before checking auto-trim, please set collective pitch to minimum.
This prevents the trim channel from doing a (blind) trim action, yet allows
the LED to show the autotrim trigger.
• All three sensor directions. Any sensor working in the wrong direction would
cause the helicopter to crash. Set the stabilisation to "yellow" mode and briefl y
move the model to and fro by hand, working around all three primary axes: tilt
to the side, tilt forward and rotate. At each movement the appropriate servos
must respond with the opposite action: the swashplate should try to remain
horizontal, the front faces of the tail rotor blades should move in the opposite
direction to the tail swing direction.
• Carry out a range check with the transmitter aerial collapsed.
Test-fl ying
If you are a beginner, we recommend that you ask a modelling friend with expe-
rience of helicopters to check the settings and help you with the fi rst fl ight.
Notes on trimming: see pages 12 + 30
Internal-combustion helicopters: vibration test
Severe vibration or body resonance can cause serious problems with the cor-
rect operation of the sensor; three checks are therefore necessary:
1) Place your hand on the case of the HeliCommand unit and feel whether it is
vibrating.
2) Before take-off, switch to "yellow" mode and observe whether the
swashplate stays level at all rotational speeds.
3) Take off initially in "OFF" mode, then switch the auto-pilot only briefl y on
and off again, as a fi rst try for safety's sake. If applicable, repeat this at
different motor speeds.
If problems occur, please refer to the installation notes on page 16
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Trimming
If the automatic trim is not used, then it is better to set the trims initially with the
auto-pilot switched off.
After this, and always when the transmitter trim positions have been changed
signifi cantly, the transmitter neutral setting should be re-calibrated using the
SET button (see page 22).
In the fi rst few seconds after take-off, the accuracy of the stabilisation system
is reduced, but precision automatically increases after about ten seconds of
fl ying.
For this reason, when the auto-pilot is active, it is good to wait a little while,
rather than setting the trim immediately. In most cases the trim does not need
to be readjusted after this.
If the trim is different with and without stabilisation: the transmitter neutral set-
ting needs to be re-calibrated (page 22).
With automatic trim
Simply press the auto-trim button on the transmitter, regardless of the stabi-
lisation mode you are using. The helicopter only needs to have been in an
approximately steady fl ight state for about eight seconds before you do this.
The trim always refers to the transmitter's neutral setting, as calibrated in the
HeliCommand unit. For this reason it is not possible to adjust the aileron and
elevator trim on the transmitter at the same time (in fact, you can tape over the
trim sliders!). However, if you do move them, the new values must be "learned"
again as the "transmitter neutral setting" (page 22) before you use the auto-trim
button on the transmitter again.
Heck-Trimmung
The transmitter trim slider is only used to adjust for stationary servo position,
while in heading hold mode, and then to be left in that position.; this adjustment
can be done on the ground. If you are not using "auto-trim", we recommend
that you additionally trim the tail rotor mechanically with heading lock switched
off, as this will avoid trim value differences when you switch between heading
lock and normal. If sensor drift occurs due to temperature fl uctuations or after a
long period of operation, this can be eliminated by switching the unit on again.
(Don't use the automatic trim for this; this only corrects the servo centres.)
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At take-off
Prior to take-off the helicopter should be standing as level as possible. If you have
to hold the helicopter inverted or at a steep angle before fl ying, switch the HeliCom-
mand off, then on again before take-off. (When angled in this way, the gravitational
forces are applied perpendicular to the rotor shaft which do not occur in normal
fl ight, and these can have an adverse effect on the operation of the sensors.)
Checking the controls before each fl ight
Steuerbarkeit und Neutralstellung der Taumelscheibe auch mit eingeschaltetem
Autopilot prüfen! Nie starten, bevor sich die Servos bewegen lassen!
Gain setting
Start the test-fl ying schedule with a reduced gain setting! Not all helicopters
will tolerate settings above 70% in both modes, as severe oscillatory move-
ments may occur, depending on the type and installed height of the unit. This
applies in particular when the distance between the sensor and the ground is
very small (< 0.5 m). The optimum (slider) position must therefore be tried out
during test-fl ying.
Set the gain so that optimum stabilisation is achieved in the "green" Pos mode
at an altitude of about 0.5 m.
If oscillation occurs ► reduce. If it drifts uncontrolled ► increase.
With tail rotor gyros it is usual practice to set the gain hard up against the limit
of oscillation, but this is not necessary with the Pilot channel of the HeliCom-
mand. "Softer" settings look better in fl ight, as the model's fl ight path is affected
less directly by the auto-pilot's spontaneous control actions.
If your helicopter is extremely unresponsive or extremely agile, you may fi nd it
necessary to optimise the stabilising effect by making use of the supplemen-
tary settings which are available via the PC adaptor.
During high-speed fl ight the HeliCommand only brakes the model slowly by
itself. This means: if you override the auto-pilot by giving powerful control com-
mands (see page 34), you will have to control the helicopter actively.
Please note that a variable "forward freewheel" option can be set using the
PC adaptor.
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