CSM ICG400 Manual

Like other CSM gyros, your ICG400 gyro incorporates advanced features not found in other makes of gyro. Please read this manual
fully before installing and flying.
With their pioneering Heading Lock, Yaw Rate Demand and Flight Mode concepts CSM revolutionised the tail rotor gyro with their
ICG360.
This new ICG400 builds on those ideas and extends gyro technology still further with its Heading Lock System+.

ICG400 key features:-

•
Heading Lock (as pioneered by CSM)
•
Gyro Flight Modes (as pioneered by CSM)
•
NEW Auto-setup system allows rudder trim, gyro reversing, and servo travel limits to be set FROM YOUR TRANSMITTER.
•
Preset 'Look Ahead' gain.
•
Preset 'Exponential gain'.
•
Preset 'Glitch Limiter'.
•
Yaw Rate Demand with preset linear + exponential Demand Curve.
•
NEW Fuzzy logic Drift Compensation.
•
NEW High Resolution pulse measurement and generation systems.
•
Two stage power supply regulation - ensures gyro is fully functional down to 2.5 volt supply (even if your radio isn't!)

Radio System requirements

The wiring of this gyro is compatible with JR, Futaba, Hi-Tec, Graupner, Robbe and the new style only (Blue Plug) Sanwa/Airtronics radio
systems. If you are considering using this unit with other makes of radio please check the feasibility with the service centre in your country,
look at our website (http://www.rcmodels.org/csm) or e-mail the CSM service centre (tech@csm-ltd.co.uk) The gyro requires an auxiliary
channel with travel adjustments to control the gyro mode/gain. It cannot be used with basic RC systems that lack such a channel. We
recommend that you use an RC system that also provides travel adjustment on the rudder channel. Most current production computer RC
transmitters have these facilities.

Servo choice

Servo speed

Optimum performance from the ICG400 is obtained when it is used in conjunction with a high speed servo (0.12 seconds/60 degrees or better).
Batteries, power consumption, and wiring
Although the power consumption of the gyro unit itself is very modest, as with all high performance Solid State gyro systems the speed of the
gyro response will work the tail rotor servo harder than slower mechanical gyro systems. Especially where a high performance servo is being
used the battery drain from the tail rotor servo can be high. We recommend that you use a good quality battery state monitor and check it
carefully before each flight.
Your receiver battery is a vital part of your tail rotor system. Remember that a battery in a low state of charge or an old battery that has
developed a high internal resistance will adversely affect servo performance, especially its acceleration, and may even cause the tail to wag on
an otherwise well set up helicopter. You may wish to consider maintaining the charge in your receiver battery between flights by the use of a
quality Delta Peak type field charger. In installing the gyro also bear in mind that voltage drops down long servo extension leads will also
detract from servo performance. Where the installation requires extensions to be used (either between the receiver and gyro or between the gyro
and the servo) avoid using ones that are unnecessarily long.
The ICG400 philosophy
To get the best from this gyro system it is useful to understand how the ICG400 differs from conventional gyros.
Conventional gyro systems
In a conventional gyro the pilot applies a rudder command which is transmitted through the gyro to the servo. As the helicopter responds to the
command the gyro detects the movement and opposes the pilot's command and reduces the servo deflection. The yaw rate achieved in such a
system depends on the 'gain' of the gyro. The more gain the gyro has the lower the yaw rate that can be achieved. It is common with such
systems to have to reduce the gyro gain to achieve the required yaw rate for some manoeuvres (this being accomplished with the gyro gain
switch).
The ICG400 system
The ICG400 employs a 'Yaw Rate Demand' philosophy making it a true yaw rate gyro. In this system the rudder command from the pilot is
interpreted as a request to the gyro to establish the desired yaw rate. The gyro drives the tail rotor servo as needed to obtain this yaw rate. This
means that the ICG400 makes full yaw rate available even at high gain settings. With this system you can use the rudder travel adjustments
('Travel Volume', 'ATV') and rudder rates facilities to set up the desired full-stick yaw rate and the gyro gain switch now becomes a 'Flight
Mode Switch' for the gyro. There is no need for so called Pilot Authority Mixing - indeed you should not use pilot authority mixing with this
gyro
It is important to realise that with this system the limits to the servo travel are set by the gyro and not by the transmitter's travel adjustment of
the rudder channel. The servo travel limits imposed by the gyro are set during the auto-setup sequence as described later in this manual.
Behaviour on the ground
For those used to conventional gyro systems the behaviour of the ICG400 on the ground may seem unusual.
Unlike conventional systems, it is quite normal for the ICG400 in Standard mode (mode 0) to provide full tail rotor servo movement for rudder
commands that are as little as 30% of the full stick movement. This is a consequence of the Yaw rate demand feature, and is why the ICG400
gives such a crisp response.
With the helicopter on the ground and the ICG400 set in Heading Lock mode (mode 1) you will find that even very small movements of the
rudder stick or trim will set the servo moving slowly and may, over the course of a few seconds, reach full travel. Your transmitter rudder trim
will affect the direction and speed of this movement. This apparently strange behaviour is caused by the stationary helicopter not responding to