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GYROS and GOVERNORS: Using electronics to take some of the complexity out of setups and fl ight.
What is a gyro? A gyroscope is an electronic unit that senses motion and corrects for it. For example, if the wind blows
your helicopter’s tail to the left, a gyro will sense that motion (and confi rm that no input was given) and will correct for it.
How does it help in helicopter setup? A good gyro will totally eliminate the need for revo. mixing. The gyro will sense and
correct the unwanted motion for you, so you don’t have to spend time to get a complex curve operating properly.
Gyro sensor kinds: There are many different kinds of gyros. Early gyros were mechanical, with a spinning drum similar to
a child’s gyroscope toy. The next generation utilized a special type of crystal, called piezoelectric, which sensed the motion
and provided an electrical pulse. The fi nest gyros at the time of this writing are SMM technology. These silicone micro
machines, or computer chips, sense the motion. SMM is far more accurate and less susceptible to inaccuracies caused by
temperature changes, etc.
Types of gyro responses:
• Normal: sense motion and dampen it (if the gyro rotates off course for 2 seconds, it corrects for 2 seconds).
• Heading-hold/AVCS: calculate the angle of rotation (by tracking the time/rate of change) and then provide correction
until the same rotation is achieved.
• Stick priority: a feature on most high-end gyros. The more input given on the channel the gyro controls, the less sensitive
the gain is automatically. This way, if you give a large input for a stall turn, for example, the gyro turns itself off and
does not fi ght the stall turn. As you ease off the rudder, the gain increases again, minimizing tail wag and keeping the
model straight. (If your gyro does not include stick priority, you can manually create it. Please see www.futaba-rc.com\
faq\.)
Choosing the right gyro for your skills, your helicopter, and your budget:
• Mechanical: some are still available. They are very challenging to set up and not as reliable as piezo or SMM.
• Non-Heading-Hold Piezo: these are now inexpensive gyros that are reliable and easy to set up. Some have dual rates and
remote gain control to adjust sensitivity in fl ight. Lack heading-hold capabilities for precision fl ying.
• Heading-Hold Piezo: Until recently, the cream of the crop. Expensive, and more complex to set up. Adds GPS-like
heading recognition. Exhibits minor diffi culties with temperature drift (position setting varying with unit’s temperature).
• Heading-Hold SMM: 21st Century gyro technology. Computer chip technology. Expensive, easier set up, higher
durability. Signifi cant decrease in temperature sensitivity. Many include frame rate settings to allow faster response when
using specialized digital servos. Examples:
• GY401: Simpler set up. Ideal for learning aerobatics through 3D.
• GY502: Better centering than 401 for more advanced aerobatics. Ideal through Class III competition.
• GY611: Exceptional center. Extremely fast response time. Requires specialized servo.
GYRO
: simplifi es adjusting/selecting the gyro sensitivity, and can provide more than 2 gyro gain settings. (The higher the
gain, the more correction the gyro provides and the “softer” or less responsive the helicopter feels.) This function makes
the best possible use of the infl ight adjustable gain of most gyros.
Adjustability:
• Plug the gyro’s sensitivity adjustment to channel 5 of the receiver. (not assignable)
•
STD
and AVCS/Heading-hold (
GY
) setup types available to simplify adjustments for AVCS/Heading-hold gyros.
• Full switch assignability or may select
Cond.
option.
•
Cond.
option provides separate gyro settings, one for each condition, automatically selected with the condition. Allows
changes in gain to meet the specifi c needs of each fl ight condition.
• Each gyro setting may be set from 0 to +100 (
NOR
100% to
AVC
100%) gain, equating to ATV settings of -100% to +100%.
• Dual mode gyros (heading-hold/AVCS and normal) are easily triggered to each mode by changing the gyro setting’s sign.
Negative settings trigger normal mode; positive settings are AVCS mode.
• Larger percentages indicate more gain, or gyro responsiveness.
• Tail wagging or shaking indicates excessive gain settings. Turn down gyro setting until wag stops.
