Installing the bavarianDEMON Cortex three-axis gyro is clean and simple. Servo wires run
from the receiver through the gyro, and the
servos plug directly into the Cortex gyro. This
sophisticated unit has many features that can
enhance your model’s flight characteristics.
Ken Olsen equipped his Xtreme A.R.F. Viper with a PowerBox Systems
iGyro 3e to enhance the aircraft’s flight characteristics, especially
on windy and turbulent days. Even a great-flying airplane can be
improved by installing a quality three-axis gyro.
Setting up your first gyro
by Jim Hiller
Three-axis gyros for flight assistance in jet modeling have become popular. They are a wonderful
addition to your airplanes, primarily
because they dampen turbulence when
flying on a windy day, but the advantages
don’t end there. First, let’s discuss the
Gyros will not make you a better pilot,
and they will not fly the airplane for you.
They will, however, improve the flying
characteristics of many aircraft. After you
start flying with a three-axis gyro, you
will understand the many other benefits
of installing one.
I have been using two three-axis
gyros: a bavarianDEMON Cortex and a
PowerBox Systems iGyro 3e. Both are
good, proven, and popular gyros, and
have performed exceptionally well. The
Cortex gyro has been around for a while,
earning a reputation as a high-quality
unit, while the iGyro 3e is a second-generation unit also known for its quality.
The setup procedures for these two
products differ greatly, so study your
instructions carefully before installation
and usage. Note that both units
recommend first flying your model to
establish control travel volumes before
turning on the gyro. Failure to do this
creates some unusual problems.
Keep in mind that normal flying travel
volume is an important parameter for the
gyro’s control equations. This becomes
crucial as travel volumes for normal flight
move away from 100% adjustable travel
volume settings. With a servo arm that is
too long, you will use only 30% to 50%
of your travel volumes.
The installation of the iGyro 3e is
straightforward. Install it horizontally
in the direction indicated, with leads
from the receiver to the gyro forward
and leads to the servos in the rear. This
properly aligns the gyros for each axis
with the preprogrammed unit setup.
Servo leads from the receiver to the gyro
inputs are connected as indicated, and
the servos are connected to the gyro
There is also a USB output slot for
connecting to a computer for advanced
programming features, but remember
that the gyro is set up with parameters
appropriate for a standard aircraft
configuration, so tread lightly here.
The gyro is usually programmed with
an auxiliary channel to control the gyro
gain. Think of this as the sensitivity
of the gyro.
A slider or
rotary knob is
for the first
flights with a
gyro to find the
gain. Set the
at +100% to -100% with the center point
at 0% travel. You will rotate this knob in
flight to determine the appropriate travel
volume for the gain.
For the iGyro 3e, 0% to +100% travel
is range A, normal rate gyro. This is the
typical use of a gyro on an aircraft. Travel
from 0% to 100% is range B, heading
mode, which is seldom used on an
airplane. With experience, you will find
uses for this mode of operation.
You are finally ready to power up
the gyro. Simply turn on the airplane,
wait for the radio to bind, and wait for
the iGyro 3e to initialize. In the setup
procedure, check the direction of effect
for gyro compensation. It’s important
to get this right. If you get the control
compensation reversed, it makes the
airplane almost unflyable.
Push the tail down and the elevator
should move down to stop its
movement. Lift a wing and the aileron
should move up to stop the movement.
For the rudder, push the tail of the
airplane from right to left and it should
move to the left to stop the motion.
100 Model Aviation SEPTEMBER2015 www.ModelAviation.com