©2008 Skookum Robotics, Ltd
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10 After Setup: Final Check!
Any time you change the gyro’s setup, always do these checks:
1)
Put the gyro into setup mode, with the servos connected and the swashplate
mechanically set up.
2)
Try full right aileron. Check that the swashplate tilts to the right.
3)
Try full up elevator (nose up). Check that the swashplate tilts back.
4)
Command full up collective pitch. Check that the swashplate moves to give
maximum blade pitch.
5)
Try zero collective pitch, with throttle hold active. Check that the
swashplate moves to give zero blade pitch.
6)
Put the gyro into Flight mode, leave it undisturbed and wait for the LED to
turn green.
7)
Pick up the helicopter, wait a few seconds, and then tilt it nose down and to
the right. The swashplate should tilt back and left.
Note:
In flight mode, the swash will tilt forward slightly at full positive collective
pitch, and backward slightly at full negative pitch, to compensate for tail-drag
during fast climbs and descents.
11 Flight with the SK360 Gyro
In flight mode, the swashplate will not respond to the controls directly. Its action
will be similar to a heading-hold tail gyro. Also, after it has been static for a few
seconds, it will level the swash during spool up to ensure a stable take off.
When you land your heli, always wait at least 5 seconds after the rotor spools down
before spooling up again, so the gyro knows the helicopter is spooling up. Don't
move the cyclic stick until the heli is light on its skids to prevent confusing the gyro
when it can’t fly. If the
Auto trim at Initialization
feature is on, avoid using the
transmitter trims for elevator or aileron. If you do use trims, you’ll have to zero
them before every flight.
ALWAYS do these pre-flight checks:
1) The Indicator LED should be solid green (not flashing).
2) Positive collective should increase blade pitch.
3) Right aileron stick should tilt the swash for a right roll.
4)
Nose-up elevator stick should tilt the swash for nose-up.
©2008 Skookum Robotics, Ltd
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12 Basic Tuning
If you have set up your helicopter’s mechanics properly, and the cyclic throws are
correct, then tuning should be easy.
Note:
always let the gyro be still for a few
seconds after adjusting the gain dials, so the gyro knows to read the new settings. If
your heli is nitro-powered, you’ll need to stop the motor.
Definitions:
Bell gain
adjusts how much aileron and elevator control will directly tilt
the swashplate.
Hiller gain
adjusts the stability and holding ability of the gyro.
Follow these steps:
1)
As a starting point, adjust the dials on the gyro to about
30% for the Bell
elevator gain, and 50% for Hiller gain.
2)
Lift the helicopter off into a hover, and try some small elevator and aileron
motions.
If it oscillates or does anything violent as you spool up, email
tech support for help.
3)
If the helicopter doesn’t hold well in pitch or roll, or “slides” to the side,
turn the Hiller gain up a small amount. If the helicopter oscillates while
hovering, turn the Hiller gain dial down slightly. Repeat until you get the
best gain.
4)
Try some forward flight. If the helicopter oscillates in roll at high speed,
turn the Hiller gain down a small amount. If it doesn’t hold well in pitch,
turn the Hiller gain up.
5)
While in a hover, pitch the helicopter sharply nose down, centre the cyclic
stick, then do the same nose-up. If the helicopter is slow to start, turn the
Bell gain dial up a small amount. If the helicopter snaps back a bit and
oscillates after it stops, turn the Bell gain dial down a small amount. Repeat
until you get the best balance. For sport flyers, the Bell gain needs to be
only roughly correct.
For most users, no further tuning should be required. But if the maximum aileron
and elevator motion of the heli is not fast enough for you, or for other advanced
tuning, see Sections 15 and 16.
Good starting points for the gains can be found in the “Default”, “Scale”, or
“Basic_3D” setup files, all of which are included with the USB interface software.
