Automatic trim
12
This is recommended, but is not absolutely essential. Auto-trim works independently
of the auto-pilot, and makes life considerably easier for beginner and
pro-pilot alike. To use it, your transmitter needs a momentary (self-centring) button or
a toggle switch, assigned to an auxiliary channel. Many transmitters feature a Trainer
switch which can be re-programmed for this purpose. The AUX channel has to be
configured as the trim function using a PC. When the model is flying, a brief button-
press is sufficient to generate the trims automatically for
aileron, elevator and rudder (tail rotor). The settings are stored in the unit, but can be
revised at any time. The automatic trim function requires around eight
seconds of steady hovering in order to record the correct trim values; they can
then be called up immediately by pressing the trim button. Automatic trim can also
improve the performance of the integral tail rotor gyro if the neutral pitch angle of the
tail rotor blades is not adjusted properly. Independently of this, the tail gyro has once
to be adjusted manually, see page 30! To activate auto-trim, the AUX channel has to
be configured as the trim input using the PC adaptor. The trim is then triggered by
switching the AUX signal to +100% (> approx. 60%) (note that in Futaba transmitters
„-100%“ means „+ 100%“ and vice versa).
The LED flickers red to indicate while auto-trim is being sent. The AUX-channel, if
assigned to auto trim, will still switch off the heading-hold-mode by a negative signal
-100% (< -60%), but Gyro gain (sensitivity) has to be set by PC only. Thus a gyro-mo-
de-switch can be combined into the same channel (e.g. by flight state programming).
If you wish heading-hold, then the AUX channel must not send a negative signal; the
trim switch should only switch between zero and +100% (Futaba = -100%). Note that
the trim channel must not be assigned to any other transmitter control actions which
you may have programmed, as you might then trigger auto-trim accidentally. The trim
switch should only be operated with the model in flight (unlike the SET-button).
For erasing the internal auto-trim values: call up the set-up mode (page 23), and then
switch on again.
Fail-safe
If you are using an FM / PPM system without own failsafe function, the auto-pilot im-
mediately responds to a radio link failure by carrying out the following actions: aileron,
elevator, tail rotor to neutral, collective pitch to the last received position, stabilisation
to position mode, set to 65%. Receivers with integral failsafe function should explicitly
be programmed to the mentioned positions. For optimum security we recommend the
use of PCM systems.
Summary of Contents for HeliCommand 3A 3D RIGID
Page 1: ...INSTRUCTIONS M SERIES ...
Page 2: ...2 www helicommand com ...
Page 16: ...Installation 16 ...
Page 42: ...42 Notes ...