GRAUPNER mx-16 ifs, Programming Manual

Page: 82 / 132

82 Program description: helicopter mixers – model helicopter
ing effect may be an over-reaction which manifests itself
as tail oscillation. In order to obtain optimum stabilisation
from a gyro in all fl ight situations, you should make use
of the facility to adjust gyro gain from the transmitter via
the INC / DEC buttons (CTRL 5).
inp8 (Input 8)
normal
0%
SEL
0%
inp8
ch1
ch1 thro
tail
gyro
The adjustment facilities in this line of the menu are only
relevant if your model helicopter is fi tted with a speed
governor (regulator) which maintains a constant system
rotational speed, and you wish to control it using the
“classic” method. The settings should then be entered
in accordance with the instructions supplied with the
governor you intend to use.
However, it is more convenient – and also safer – to
adopt the method described previously on this page,
using the “Ch 1
¼
throttle” mixer.
gyro (adjusting gyro gain)
Most modern gyro systems feature proportional, infi nite-
ly variable adjustment of gyro gain as well as a means
of selecting either of two different methods of working
from the transmitter.
If the gyro you wish to use features at least one of these
options, then it offers you the possibility of pre-setting
both “normal” gyro effect and – if available – “heading
lock mode”, and also of fl ying normal, slow circuits with
maximum gyro stabilisation, but reducing the gyro effect
for high-speed circuits and aerobatics. This is generally
similar to the transmitter control centre adjustment or
offset adjustment provided by other radio control sys-
tems.
We recommend that you set up switchable fl ight phases
for this, and set different gain settings for each phase in
the “gyro” line; values between -125% and +125% are
possible.
normal
0%
SEL
ch1
ch1
ptch
thro
tail
gyro
Based on the offset values determined for each fl ight
phase, gyro gain can be varied proportionally by means
of a transmitter control assigned in the “gyro” line in the
»
contr set. « menu (see page 62). This could be trans-
mitter control 5 (CTRL 5), which would provide infi nitely
variable gyro gain control:
At the centre position of this transmitter control •
the gyro effect always corresponds to the settings
selected here.
If you press the INC / DEC button in the direction of
•
full travel (away from centre), the gyro gain increases
accordingly …
… and diminishes again if you press it in the direction
•
of the opposite end-point.
Important note:
It is absolutely essential to read and observe the
set-up instructions supplied with your gyro before
entering any settings at this point, as a mistake here
could render your helicopter completely uncontrol-
lable.
Adjusting the gyro sensor
If you wish to set up a gyro to achieve maximum pos-
sible stabilisation of the helicopter around the vertical
axis, please note the following points:
The mechanical control system should be as free- •
moving and accurate (slop-free) as possible.
There should be no “spring” or “give” in the tail rotor
•
linkage.
You must use a powerful and – above all – fast servo
•
for the tail rotor.
When the gyro sensor detects a deviation in yaw, the
faster it adjusts the thrust of the tail rotor, the further the
gyro gain adjuster can be advanced without the tail of
the model starting to oscillate, and the better the ma-
chine’s stability around the vertical axis. If the corrective
system is not fast enough, there is a danger that the
model’s tail will start to oscillate even at low gyro gain
settings, and you then have to reduce gyro gain further
using the INC / DEC buttons to adjust the pre-set “Gyro”
value to eliminate the oscillation.
If the model is fl ying forward at high speed, or hovering
in a powerful headwind, the net result of the stabilising
effect of the vertical fi n combined with the gyro’s stabilis-