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Old Oct 07, 2008, 05:29 PM
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Thousand Oaks, CA
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GY611 servo goes full travel with half stick input

My GY611 servo moves full travel with only half transmitter stick input. There is no adjustment I can make on the gyro or transmitter to correct this. I have searched the forum and internet for that matter and can't find anything on this. It is not an adjustable travel volume issue. No matter what the ATV setting, full travel is reached with half stick input. I should also note that this even occurs with the servo horn removed and no physical restriction. With power removed I can move the servo through a larger range by hand but that seems to be normal with all servos. Am I the only one seeing this behavior? Is this normal? Is there a way to correct this? Thanks for the help.
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Old Oct 07, 2008, 06:33 PM
A man with too many toys
United States
Joined Feb 2001
17,356 Posts
Sounds like you have the gyro mode/gain wire plugged into the incorrect channel. What radio do you have?
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Old Oct 07, 2008, 09:11 PM
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Thousand Oaks, CA
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I am using the Spektrum DX7. The Gain wire is plugged into Aux2 spot on an AR7000 receiver.
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Old Oct 08, 2008, 09:07 AM
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Virginia Beach
Joined Sep 2002
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Yes, it is normal for Heading Hold gyros.
With modern piezo HH gyros, the rudder stick does not control the servo directly. The stick input to the gyro represents a 'rotate xx degrees in xx seconds' request and the gyro will adjust the servo to meet the yaw demand. The amount of stick travel has nothing to do with the amount of servo travel. In GY401 and similar basic gyros, the yaw rate is set in the gyro and the heli yaw will vary with wind resistance encountered by the tail. The 611 and other high performance gyros will keep a steady yaw rate no matter what external influence (wind/ forward flight etc) is on the tail.
Speed of rotation is adjusted by inc/dec the rudder channel ATV. Servo travel is adjusted in the gyro. Gyro gain is adjusted by the AUX input to the gyro.


Fritz
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Last edited by fritzthecat; Oct 08, 2008 at 09:14 AM.
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Old Oct 08, 2008, 03:52 PM
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Thousand Oaks, CA
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There's one thing I'm not clear about in your explanation. With everything set properly will I see an increase in the pirouette rate with the stick deflected beyond the halfway point when I am actually flying the helicopter?
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Old Oct 08, 2008, 04:47 PM
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Does it do it in rate mode?
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Old Oct 08, 2008, 05:29 PM
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It stays that way in both Normal and AVCS modes.
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Old Oct 08, 2008, 08:04 PM
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Quote:
Originally Posted by Ralgh
There's one thing I'm not clear about in your explanation. With everything set properly will I see an increase in the pirouette rate with the stick deflected beyond the halfway point when I am actually flying the helicopter?

Yes. For example if the gyro is set for a max 360 deg rotation per second (adjusted by the rudder channel ATV). Full stick deflection will give you 360deg/sec. No matter the wind or fwd/back/sideways flight. Moving the stick to the 1/2 deflection point will give a 180deg/sec piro rate. 90deg/sec at 1/4 deflection.
The max deflection of the tail pitch slider is set in the gyro (limits). You can up the rudder ch ATV until the piro rate doesn't increase anymore at which point the tail pitch slider is maxed out. Note that at that point you are at a very high piro speed and you better make sure your battery is held down real good.

Fritz
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Old Oct 10, 2008, 11:53 PM
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USA, UT, Salt Lake City
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Fritz is right - the best way to think about it is that "the gyro owns the limits"

However, you can use the (dual) rate setting in the radio to control the yaw rate
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