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Old Mar 16, 2008, 05:33 PM
Trex 450 V2, Spektrum.
airsoft1779's Avatar
USA, SC, Greenville
Joined Aug 2007
333 Posts
Question
Why Are HH Gyro's Always at the front or back of the Frame???

Title saids it all

Is it possible to put one near the main shaft or in the center and just turn the gain up

Is it more accurate farther away from the center?

Thanks
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Old Mar 16, 2008, 06:01 PM
Dodging Birdstrikes
Houston Texas
Joined Oct 2007
169 Posts
Hi airsoft
I am asking the same quesion over in the micro forum for a Firefox 100 that I am putting the finishing touches on, so can't help you but if I get a answer I pass it on to you.
Peace
Mike
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Old Mar 16, 2008, 06:20 PM
The Great Santini
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Madison, NJ 07940
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I believe it just needs to be in the same plane as the tail and mainshaft, therefore, it is fine sitting up front in the nose area, or back of the main shaft. It need to be oriented correctly, so it can be flipped so the top is up or down, but not sideways or anything else. For example, in a trex, you can place it on top of where the boom is secured to the frame or flip it and place it underneath, which is preferred so it does not take a hit from a paddle in a crash; or it can be placed out front, under the batt tray. Most prefer to place it under the boom facing down so its less likely to take a hit.
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Old Mar 16, 2008, 08:10 PM
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Denver, CO
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Works great under the main shaft. I would say it works better under the shaft. Kind of hard to rate that since it is a Futaba that works good almost anywhere. This is my Piccolo. http://www.rcgroups.com/forums/attac...mentid=1215515
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Old Mar 16, 2008, 08:10 PM
21st Century Space Cowboy
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Chipping, Lancs, UK
Joined Oct 2006
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If you really wanted to, you could stick the gyro on the side of the frame..... AS LONG AS the gyro's axis is parallel to the main shaft, you can position it anywhere around the mainshaft. I suppose the main reasons why you see the gyro mounted at the fornt or back of the mainshaft is that it would look kind of silly hanging out of the side of the heli.

Tach.
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Old Mar 16, 2008, 08:12 PM
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Singapore
Joined Jan 2004
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Actually the best (sensitivity) of the tail gyro should be at the same axis on the main shaft (that is below the main shaft).

The problem of putting gyro just below the main shaft are:
1. Difficult to adjust/trim it or set the Nor/Rev switch.
2. Too close to motor or ESC. Most gyro are very sensitive to EMF generated by the motor and ESC.

SH
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Old Mar 16, 2008, 08:17 PM
X-Ikarus
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United Kingdom, North York
Joined Feb 2003
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Quote:
Originally Posted by airsoft1779
Title saids it all

Is it possible to put one near the main shaft or in the center and just turn the gain up

Is it more accurate farther away from the center?

Thanks

It does not matter were you place it , it only senses Rotation.

normally front or back , not many gyro's will fit in the centre
those that do I haven't noticed any difference in performance

Although I'd agree with SH below the main shaft will give the highest
mechanical gain.
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Last edited by Reflex1; Mar 16, 2008 at 08:22 PM.
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Old Mar 17, 2008, 07:27 AM
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United States, OH, Strongsville
Joined Nov 2000
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Another vote for "Placement does not affect gyro"
You can place it anywhere, and it will still detect rotation equally well.
Orientation does matter. The axis of detection for the gyro must match the axis of rotation that you are trying to control.

Now, there ARE some placement considerations other than rotation detection.
1. vibration - you do not want to place the gyro where it will pick up excess frame vibration. The boom block is often used, as is the bottom of the main frame.
2. RF interference - you want to distribute all of your RF emitting/sensitive components as far away from each other as possible.
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Old Mar 17, 2008, 08:23 AM
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Maryland
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As the others have stated, it doesn't matter where it's placed. So with that said, place it where you feel it is best protected and away from electronics like your esc and motor.

Skarn
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Old Mar 17, 2008, 12:59 PM
electric head
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Randburg
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I've seen certain gyro manufacturers (CSM I think) recommend playing the gyro's as close the the pivit point as possible.
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Old Mar 17, 2008, 03:26 PM
Trex 450 V2, Spektrum.
airsoft1779's Avatar
USA, SC, Greenville
Joined Aug 2007
333 Posts
Im trying to move the gyro where my receiver went on my Falcon 3d to try and get rid of the extion of the servo wire, I was having inconsistant tail failures when I was flying and that is the only problem I could think of, but you said to try and keep it away from the motor/ESC and the ESC is right below it, I think ill try to mount it on the boom somehow.

Any other suggestions
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Old Mar 17, 2008, 07:31 PM
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Nova Scotia, Canada
Joined Apr 2006
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You can mount the gyro anywhere on the heli so long as the sense axis is parallel to the mainshaft. The gyro sense's angular motion not linear. All parts of the heli turn about the mainshaft at the same angular velocity. It makes no difference to the gyro is on the tip of the nose or tail. However some people will caution you about putting it too close to the mainshaft bearings to avoid bearing noise affecting the gyro operation.

airsoft1779, Some ESC's will generate more noise than others. I keep my RX and gyro as far away as possible from my ESC.
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Old Mar 22, 2008, 07:55 PM
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Tennessee
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Thanks Stikflyer, good bit of information there. I was curious as to the possible change in sensitivity when moving the gyro closer or further away from the center of pivot. (main shaft) It makes sense that if the gyro senses only angular differences the distance from the pivot point would be irrelevant....I think.
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Old Mar 23, 2008, 09:30 PM
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Genoa, Italy
Joined Sep 2007
13 Posts
I don't know exactly what kind of sensors are used in the HH gyros, but I remember some of them actually suffer an error from acceleration. That is, they take ("linear") acceleration for a (small) angular velocity. But I think this doesn't matter too much because they are used in a closed-loop control, so this effect reduces to a curiosity "for the interested reader". But, this is why (I think) someone suggests to put them as close to the pivot point as possible.
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