10
HEAD GYRO OPTIMISATION
The attitude stabilisation („head gyro“) for the rigid linkage maintains any pilot-operated attitude and prevents disturbances, like e.g. ballooning. On ground,
the function is visible at the swashplate: when giving control commands and let go off the stick, the swash moves slowly back to level, maybe even stays in the
inclined position for a short while.
AN EFFICIENT WAY TO OPTIMISE THE RIGID SETTINGS:
• We suggent to use a pot or slider at the radio to easily fi nd the optimum gain. Use the ‚Head-gyro‘ channel or, in case no signal is supplied from the transmitter,
it‘s default gain slider in the [Rigid] menu to set the gain as high as possible, approx 10% below the onset of oscillations. For safety reasons, begin with small
values. Too high gain may provoke oscillations, for example like a ‚shivering‘ in roll axis or a pitching in elevator axis.
• Then set the ‚agility‘ slider in the PC software as desired. Only with 3Xbase, use the transmitter‘s travel settings.
• Usually at this point the performance is close to the optimum or perfect. If improvement is necessary,
you can test sudden halt (‚locking-in”) after vigorous and abruptly ended stick defl ections:
In case of a tendency of rocking / luffi ng in elevator axis, increase the elevator fi lter value (see the tool-tip). This job is easily done by using RealTime-Tuning,
after having pre-set the elevator fi lter to a medium value.
In case of abrupt and jerky reaction to small and sudden stick inputs:
Reduce ‚Initial response‘, or increase ‚Rigid gain’ or ’P-portion’.
In case the turning continues a short while even after ending the stick defl ection:
for avoiding a too soft (sluggish) reaction: Increase ‚‘Initial response‘; possibly also increase the ‚Rigid gain’ and/or the travels in the [Mixer] menu.
for avoiding exaggerated and harsh reactions: reduce ‚Agility‘ in the [Rigid] menu, and carefully increase the travels in the [Mixer] tab.
If aileron and elevator impulses cause mixed movements, this might be because of an incorrect setting of „virtual swashplate
rotation“. Test it with reduced rigid gain: If the tail moves downwards in the event of rolling to the right, then increase swashplate rotation in the positive direction.
• Test response to long stick elevations:
In the case of a strong fi rst reaction and then decelerated continued reaction: reduce ‚Initial response and, if applicable, increase the „Agility“.
• Test high-speed fl ight
Against slow ballooning or undercutting: reduce or resp. increase the „withdraw rate“.
Against temporary nose-up („dolphin“) during harsh coll.pitch rises: increase ‚Rigid gain‘ as far as possible.
Also try with increased P-portion and ensure mixer is set to maximum travels.
Against lasting ballooning after hard coll.pitch-up: see mouse over text for „altitude holding range“.
• In case of tilting or tumbling motion during pirouettes:
Align the sensor parallel to the rotor shaft.
Trim the swashplate exactly straight while there is a connection to the [Trim] menu (necessary to have all servos at neutral).
