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Old Sep 23, 2012, 03:05 PM
AKA, Cheap Chiseler
Sculptor's Avatar
United States, FL, North Fort Myers
Joined Mar 2012
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Quote:
Originally Posted by Prof100 View Post
DJ,

I played with rate gyros on pitch and roll of an Aerocat (pusher prop flat jet) with full 100%. The wings flapped like a bird and the pitch was hilarious.

Bill
That's what I would have expected from all I've read here. Do you know any reason that didn't happen?

DJ
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Old Sep 23, 2012, 03:06 PM
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Canton, Michigan USA
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Originally Posted by Sculptor View Post
That's what I would have expected from all I've read here. Do you know any reason that didn't happen?

DJ
This was several years ago when gyros from helicopters were first being used on planes. It was an experiment. You don't learn without experimentation. Back then the effects were NOT common knowledge.
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Old Sep 23, 2012, 03:22 PM
It flies or it dies
Russ The Flyer's Avatar
Deville, Louisiana
Joined Sep 2008
833 Posts
Bill I don't know about that. If I dial my gain back anymore it's gonna quit working all together.

My Peaks ran out of juice while it was flying over the dirt/grassy area. It came down as smooth at glass. Looked like it would be alright until the wheels hooked into a clump and grass and flipped the plane over. No damage to the plane but it ripped my landing gear mount out by the roots. So now I've gotta fix that.

Russ
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Old Sep 23, 2012, 08:52 PM
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Russ The Flyer: My Peaks has 4" dubro no bounce wheels without the fairings. 1-3/4" sullivan tailwheel kit. With "clumps of grass" you dont want small stock wheels and fairings...asking for flips.
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Old Sep 23, 2012, 09:07 PM
Team Wack-a-Mole
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Maryland
Joined Oct 2008
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My rule of thumb is to fly (or have someone else fly) the plane w/o NO GYRO. Any new plane is best maidened on a calm(ish) day.
If you want to add a gyro to it, add the gyro and test it on a calm day. I like the gyros that you can turn the gain off and it acts as if no gyro is installed (guardian,BLight,A3Pro). The heli gyros are cheap if you just need one axis but if you want 2 or 3, your better off just getting an A3 pro at the minimum and go OFF/RATE on it.

My next rule of thumb is to start your first venture at 30% gain. Each 3 axis gyro is different but the heli gyros and the A3/A3Pro/i86ap gyros will tend to want you to keep the Aileron gyro lower than the elevator or Rudder. My experiance is the rudder can take the highest gain but don't forget, there are other factors. Yes, it is possible to have a gain of 100% on the rudder and it won't oscillate, but the real test is a high speed dive. But look out, it could rip the plane apart until you can slow it down. Use ony the amount of gain you need and try not to use more than that. Generally, if a plane needs a rudder gyro, it may be because there is something mechanical or the way you are taking it off that causes it (misaligned tail/nose wheel vs. Rudder).

Short coupled planes like the Cub or many WWII biplanes really benifit from a rudder gyros but it does not mean in my opinion to slap it on and forget that you still need to use your left hand on take off. Have fun and if your learning, when your comforatble, ween yourself off the gyro slowly and then have it there for a windy day or a day you feel you need it.
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Old Sep 23, 2012, 11:13 PM
It flies or it dies
Russ The Flyer's Avatar
Deville, Louisiana
Joined Sep 2008
833 Posts
The truth

Ok. Here's a video of the plane in action yesterday. Use full screen as this isn't a HD camera. But it does shoot good video.


Russ

September 22, 2012-Peaks with gyros (6 min 9 sec)
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Old Sep 23, 2012, 11:26 PM
It flies or it dies
Russ The Flyer's Avatar
Deville, Louisiana
Joined Sep 2008
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Actually the wheels are big enough. It's the wheel pants that grab onto everything.

Russ
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Old Sep 24, 2012, 10:49 AM
Team Wack-a-Mole
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Maryland
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Russ, I can't see what your complaining about in the video.
What's the problem?
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Old Sep 24, 2012, 01:52 PM
Your customer
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Berkley, MI
Joined Dec 2009
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Quote:
Originally Posted by jj604 View Post
Not disagreeing with this as I think it is how most people would understand gyro action but to be really pedantic:

Gyros respond to ANY disturbance - whether from external forces or commanded by you.

So if you send a roll command to the plane by deflecting the aileron stick, the gyro doesn't know this. What it does know is that the plane starts to roll and it will issue a countermanding instruction to the servos.

This is what is called the "fighting the gyro" effect I believe.

Clever software can overcome this but simple rate gyros will always exhibit this phenomenon.
It really depends on how the unit is programmed. On the AS3X systems the control stick will override the gyros when a commanded move is held. I forget if it is gradual - so that the override becomes 100% at full stick deflection, but this is how that system is programmed.

Same with the Guardian, and the FY30A. I have helicopter gyros that will even provide the option to adjust this override.

So, no, not all gyro units will fight you. Only the simplest of units will, and those I speculate just run your plain jane text book PID Algorithms that allow nothing more than gain adjustments, servo reversing, and if your lucky - mode control.
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Old Sep 24, 2012, 03:04 PM
It flies or it dies
Russ The Flyer's Avatar
Deville, Louisiana
Joined Sep 2008
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Quote:
Originally Posted by Melnic View Post
Russ, I can't see what your complaining about in the video.
What's the problem?
You didn't notice that the pl;ane wants to stay in hover? You didn't see the ailerons shaking the plane? Use full screen mode and a higher definition and you'll see it clearly. Plus I wrote a few comments throughout the flight and made some comments in the video.

Russ
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Old Sep 24, 2012, 03:09 PM
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Canton, Michigan USA
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Quote:
Originally Posted by Russ The Flyer View Post
You didn't notice that the pl;ane wants to stay in hover? You didn't see the ailerons shaking the plane? Use full screen mode and a higher definition and you'll see it clearly. Plus I wrote a few comments throughout the flight and made some comments in the video.

Russ
Russ, The plane was a dot in the sky most of the time and I viewed in full screen mode. Bill
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Old Sep 24, 2012, 03:18 PM
Team Wack-a-Mole
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Maryland
Joined Oct 2008
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If the ailerons are shaking, lower the gain.

"wants to stay in a hover", is that what you wanted it to do? or are you saying it pulled up on it's own into a hover?

Pull the elevator gyro off for now.
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Old Sep 24, 2012, 03:21 PM
It flies or it dies
Russ The Flyer's Avatar
Deville, Louisiana
Joined Sep 2008
833 Posts
Quote:
Originally Posted by Melnic View Post
If the ailerons are shaking, lower the gain.

"wants to stay in a hover", is that what you wanted it to do? or are you saying it pulled up on it's own into a hover?

Pull the elevator gyro off for now.
It seems to want to get into hover. I have to keep nosinig it down. I've got the gain for it set to about 10

What I don't understand is why I can't get the ailerons to shut off in HH like you do. Probably something in your video I missed.

Russ
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Old Sep 24, 2012, 03:29 PM
Team Wack-a-Mole
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Maryland
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I don't "Shut it off" in HH mode. It's in HH mode when its in HH mode.
If it's on the ground and I switch into HH mode, it does not drift because my trims are all 0 and my subtrims are all 0 and I"ve mechanically trimmed it.
If it drifts then try rebinding your RX. HH mode does not like subtrims or trims. That's one big reason I keep preaching to use RATE mode at first.

If it keeps pulling up on you in rate mode, then you can use your trims if you are always flying in Rate mode.
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Old Sep 25, 2012, 12:00 AM
It flies or it dies
Russ The Flyer's Avatar
Deville, Louisiana
Joined Sep 2008
833 Posts
Quote:
Originally Posted by Melnic View Post
I don't "Shut it off" in HH mode. It's in HH mode when its in HH mode.
If it's on the ground and I switch into HH mode, it does not drift because my trims are all 0 and my subtrims are all 0 and I"ve mechanically trimmed it.
If it drifts then try rebinding your RX. HH mode does not like subtrims or trims. That's one big reason I keep preaching to use RATE mode at first.

If it keeps pulling up on you in rate mode, then you can use your trims if you are always flying in Rate mode.
We're on the same page Mate. Only I've gotta wait until the new gyro comes in. Maybe I'll use the gyros for a different airplane ... like a wing.

Russ
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