©2010 Skookum Robotics, Ltd
9
6
Mounting the Gyro
The gyro unit can be mounted upside down, backwards or rotated 90 degrees, but
it must be level and have its sides aligned as accurately as possible with the
fore-aft axis of the helicopter as shown in Figure 6.1.
By default, the servo-port end of the unit is the front end. It can be installed in
other orientations but
the SK720 label must always face up or down.
Note that
misalignments of even a few degrees (2mm or 1/16” difference between the front
and back edges of the case) may cause problems with tuning the gyro. The gyro
should also be as far as possible from any heat sources, and at least 10cm from
Xtremelink
tm
receivers.
Figure 6.1 – SK720 Mounting Alignment
For vibration resistance, mounting tape with good damping must be used. The
gyro’s case should not directly contact any hard surfaces on the helicopter’s
frame. If a safety strap is used across the top of the gyro, it should be padded
slightly. Cables connected to the gyro should be flexible and should have some
slack near the unit (i.e. do not strap the cables together or to the airframe within 5
cm of the unit. Ideally, use a cable sleeve because this maintains a neat
appearance while allowing the cables to move relative to one another.)
©2010 Skookum Robotics, Ltd
10
We strongly recommend using the Skookum Robotics SK-PW7 power bus
accessory for helicopters with blades larger than 500mm. The power buss will
reduce transmission of vibration into the SK720 by heavy-duty servo cables and
will allow different voltages to be used for the tail and swash servos.
If your helicopter is a nitro-powered helicopter, use the included metal damping
plate to mount the SK720. Apply one vibration damping pad between the SK720
and the metal plate and a second pad between the metal plate and your helicopter.
Check that everything on your heli is secure, and the motor runs smoothly.
Details like a canopy that rattles against hard mount points can cause problems
with self-levelling and flight logs.
If you plan to use the SK720’s self-levelling / bailout feature, it’s better to mount
the unit close to your heli’s center of gravity. Also, the lower the vibration levels
on your heli are, the better self-levelling / bailout will work.
Be sure to clean the SK720’s base and the mounting site on the helicopter with
isopropyl alcohol before mounting the gyro. A loose-fitting padded safety strap
may be used to ensure the gyro is secure in flight.
