The HH gyro, how does it DO it?
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From: Ville-La-Grand, FRANCE
I have mounted the the HH gyro on my CPP and I'm so far quite happy with the result.
Now I just wonder how it does it.
If I give rudder input, the chopper will yaw and (more or less) stay in the new direction. If the wind drives the chopper to yaw, I have the impression that the gyro puts the chopper back in the direction where it was pointed before.
What sort of reference does the gyro use?
I mean, it must compare at least two entities to realize that there's something to compensate...
Could someone knowledgable in this matter explain how a gyro (and especailly a HH gyro) works in terms that I might understand? Including the difference between the ordinary gyro and the HH gyro.
While I'm at it, maybe also a simple explanation of the gyro gain setting?
I realize I'm asking for much, but I do believe that other people may ask theselves the same questions. ;-)
Many TIA
Biker-74
Now I just wonder how it does it.
If I give rudder input, the chopper will yaw and (more or less) stay in the new direction. If the wind drives the chopper to yaw, I have the impression that the gyro puts the chopper back in the direction where it was pointed before.
What sort of reference does the gyro use?
I mean, it must compare at least two entities to realize that there's something to compensate...
Could someone knowledgable in this matter explain how a gyro (and especailly a HH gyro) works in terms that I might understand? Including the difference between the ordinary gyro and the HH gyro.
While I'm at it, maybe also a simple explanation of the gyro gain setting?
I realize I'm asking for much, but I do believe that other people may ask theselves the same questions. ;-)
Many TIA
Biker-74
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From: Toronto,
ON, CANADA
These piezo gyros have a tiny little tuning-fork-like thingie in them that vibrates in a vertical plane. As the heli yaws, the vibration of the fork wants to stay in the same plane and produces a sideways force that is proportional to the rate of yaw. The tiny computer in the gyro senses this sideways force and decides how to push the rudder servo based on how you have the gyro set (mode, gain, etc.)
The gain control is like a volume or sensitivity control for this system.
Newer more fancy gyros like the JR ring gyro also use a silicon micromachine, but in a ring configuration, and the vibration of the ring is like a wineglass "singing" when you drag a wet finger around the edge. The nodes of the vibration stay oriented in one direction, as the heli yaws around the electronics sense the "precession of the nodes" and the computer does the same thing with the info as the other gyros.
The difference in modes has to do with what you want the gyro to do. If you are interested in having it hold a heading until you command a yaw, it behaves a little differently than a rate mode gyro, which is designed to give even yaw rates but will allow the heli to streamline into the relative wind.
The gain control is like a volume or sensitivity control for this system.
Newer more fancy gyros like the JR ring gyro also use a silicon micromachine, but in a ring configuration, and the vibration of the ring is like a wineglass "singing" when you drag a wet finger around the edge. The nodes of the vibration stay oriented in one direction, as the heli yaws around the electronics sense the "precession of the nodes" and the computer does the same thing with the info as the other gyros.
The difference in modes has to do with what you want the gyro to do. If you are interested in having it hold a heading until you command a yaw, it behaves a little differently than a rate mode gyro, which is designed to give even yaw rates but will allow the heli to streamline into the relative wind.
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