RE: Airplane rudder gyro

RE: Airplane rudder gyro
View related threads: (in this forum | in all forums)

Logged in as Guest

Users viewing this topic: none

Printable Version

All Forums >> Radios, Batteries, Clubhouse and more >> RC Radios, Transmitters, Receivers, Servos, gyros >> RE: Airplane rudder gyro

Page: << < prev 1 2 3 4 5 6 7 [8]

Login

Message

<< Older Topic Newer Topic >>

RE: Airplane rudder gyro - 8/18/2008 3:22:36 AM

lucky9910

Posts: 111
Joined: 5/30/2005
From: Castaic, CA, USA
Status: online

Why when i switch between off and Normal/Avcs, the rudder is not centered? Normal and Avcs is the same, but off is slightly off. They should be the same, right?

Thanks
Lucky

(in reply to Big_Bird)

Post #: 176

RE: Airplane rudder gyro - 8/18/2008 3:33:03 AM

lucky9910

Posts: 111
Joined: 5/30/2005
From: Castaic, CA, USA
Status: online

By the way im using a 401 gyro.

(in reply to Big_Bird)

Post #: 177

RE: Airplane rudder gyro - 8/18/2008 3:44:24 AM

Big_Bird

Posts: 3334
Joined: 12/18/2001
From: Arlington, TX, USA
Status: offline

Lucky, I think we need a lot more details. Radio? 3 position switch? Control channel limits? Limit on 401? Delay on 401? etc.

_____________________________

Ken
WACO Brotherhood #70

(in reply to lucky9910)

Post #: 178

RE: Airplane rudder gyro - 8/18/2008 4:04:15 AM

lucky9910

Posts: 111
Joined: 5/30/2005
From: Castaic, CA, USA
Status: online

sorry, jr 9303 using 3 position switch. no delay, not sure on limit.. need to check

(in reply to Big_Bird)

Post #: 179

RE: Airplane rudder gyro - 11/5/2008 8:22:42 PM

nesikachad

Posts: 38
Joined: 5/10/2007
From: sturgis, SD, USA
Status: offline

Okay, first off:

You guys are killing me. I've been in Baghdad for the last six months. I'm now in Pattaya, Thailand and I'm supposed to be deflowering local girls and instead I've been glued to this damn screen for two hours devouring every word from the confines of this hotel room. I should be in an alcohol induced catatonic state right now. This is by far the best thread I've ever read in a forum.

My sanity and credit card thanks all of you cause I have some squirrelly airplanes in my hangar back home and I think this may be the fix I've been looking for. It gets quite breezy in S. Dakota and the place I often maiden planes can be a bit of handful due to the curbs and crown of the road.

Now for questions:

I have a couple heli's (CF Trexx 600 electric) and my gyros are the Logi Tech 6100's. I realize this isn't what you folks are using but in principle they all pretty much do the same thing right?

It's been said not to touch the rudder trims on the radio with the gyro activated. Why? My heli's don't go into cardiac arrest when I do this, why would the rudder? I just can't get my head around that.

Would I want to increase the gain instead?

Where I'm going with this is on very high powered planes (USRA Giant Scale Racers for instance) if the plane starts to yaw would I crank up the gain or use trims? These planes are quite a handful on takeoff due to the torque, P factor, and lack of control surface on the vertical stab.

Next, if using a digital servo (hi techs in my case) should I still program the servo's center and end points?

There's three planes I plan on using this for. My little 50" Sundowner with a Jett60, my 80" sundowner with a Moki210 and a 115" composite Kelly F-1 USRA legal pylon racer set up with a Zenoah 80cc running gas. The last one makes my butt crunch walnuts as its a $7,000 one of a kind airplane.

The Kelly has yet to fly under my guidance as I have not picked it up yet. (Bought it from a guy in Utah and have to go get it once I get home next week) but from what I've read all the USRA legal planes tend to go where they want to on take off. I can't help but think this is a great aid during landings as well. Especially in cross winds.

I just bought a JR12X and plan to use the JR1221 receiver to take advantage of the peripheral receivers due to the composite construction of the plane. The gyro shouldn't care about this right? (I plan to stuff the Futaba Gyro in it but may fiddle with the Logitech too since I have it already.)

Last, I can't thank you all again for this thread. I've asked this question a dozen times and it always resulted in the same answer, "learn to fly kid." (hate that!)

Thanks again.

C

< Message edited by nesikachad -- 11/5/2008 8:24:03 PM >

(in reply to lucky9910)

Post #: 180

RE: Airplane rudder gyro - 11/5/2008 9:21:21 PM

Big_Bird

Posts: 3334
Joined: 12/18/2001
From: Arlington, TX, USA
Status: offline

Hi C (isn't that a fruit drink)

Glad you made it out of Iraq OK and I'm sure you will be glad to get home. Thanks for your service to the country.

I can only speak from my experience with a Futaba GY-401 gyro in a 1/3 scale Bucker Jungmeister. It has 2 modes plus off. The first is AVCS or heading hold mode. I use it for takeoff when the wind is not down the runway. I initialize in heading hold and throttle up without touching the rudder. If the wind is a strong cross wind then I usually have to apply some aileron into the wind to keep the plane level. Once the plane has some altitude, say 10' or better I switch to the other mode which is Normal or rate mode. All of the rest of the flight is done in the rate mode.

As far as not touching the rudder trim I think that only applies to the AVCS mode. I make it a practice to never touch trim or rudder during takeoff. It is amazing how straight the takeoff can be with a 10 mph cross wind. If the wind is straight down the runway then I just leave the gyro in the rate mode. I can think of no reason why you shouldn't use the rudder trim in the rate mode. In the rate mode if the tail should get a gust of cross wind the gyro gives it a proportional bump in the opposite direction but does not return the plane to it's original path. Rate simply smooths the flying out.

Hope this helped.

_____________________________

Ken
WACO Brotherhood #70

(in reply to nesikachad)

Post #: 181

RE: Airplane rudder gyro - 11/6/2008 12:09:09 AM

BarracudaHockey

Posts: 10993
Joined: 7/13/2003
From: Orange Park, FL, USA
Status: offline

Simple. The gyro memorizes neutral rudder (0 yaw) at boot up. If you move the rudder the gyro takes that as a command to turn. The gyro doesn't know the difference between moving the stick a little or moving the trim a few clicks, either way it sets up a turn, usually a slow one that people think is gyro drift.

Move the trim and reboot the gyro and it memorizes that as 0 yaw and goes about its business, but there should be no reason to do that.

_____________________________

Andy - Helicopter Forum Moderator
AMA 77227 http://www.jaxrc.com

(in reply to Big_Bird)

Post #: 182

RE: Airplane rudder gyro - 11/6/2008 2:39:04 AM

Flyfast1

Posts: 395
Joined: 9/25/2005
From: Livermore, CA, USA
Status: offline

What Andy and Ken said is correct. I will only add that if you move the rudder in AVCS mode it effectively changes the zero or neutral point. So, after initialization, moving the rudder stick a little to the right and then allowing it to immediately return to neutral will not neutralize the rudder, like it normally does on an airplane. Instead, the rudder will now be deflected a little to the right and the gyro will now hold this heading. The problem with doing this during takeoff is that it will induce a yaw into the airplane and it will be difficult to see from the ground what is going on. Holding rudder will cause the rudder to move to its limit. Then releasing the stick will not cause the rudder to return to neutral. It will stay at the limit. The bottom line is to not touch the rudder while in AVCS mode after initialization. I strongly recommend experimenting with this on the ground until you are completely comfortable with the behavior. It is different than what we are used to.

Gyros are excellent (and fun) tools for airplanes, but there is a learning curve.

Good luck!

-Ed B.

(in reply to BarracudaHockey)

Post #: 183

RE: Airplane rudder gyro - 11/20/2008 5:38:48 PM

Big_Bird

Posts: 3334
Joined: 12/18/2001
From: Arlington, TX, USA
Status: offline

The Futaba GY401 is now on sale at Tower Hobbies for $129.99

http://www.towerhobbies.com/products/futaba/gyros_e.html

_____________________________

Ken
WACO Brotherhood #70

(in reply to Flyfast1)

Post #: 184

RE: Airplane rudder gyro - 11/22/2008 10:21:37 PM

Eplane65

Posts: 116
Joined: 5/26/2003
From: Zephyrhills, FL, USA
Status: offline

Maybe someone already has asked this, but is the GY401 compatible with JR/Spektrum radios?

(in reply to Big_Bird)

Post #: 185

RE: Airplane rudder gyro - 11/22/2008 10:37:25 PM

BarracudaHockey

Posts: 10993
Joined: 7/13/2003
From: Orange Park, FL, USA
Status: offline

quote:

ORIGINAL: Eplane65

Maybe someone already has asked this, but is the GY401 compatible with JR/Spektrum radios?

Yes. It just takes a signal and acts on it, it has no idea what type of radio sent it.

_____________________________

Andy - Helicopter Forum Moderator
AMA 77227 http://www.jaxrc.com

(in reply to Eplane65)

Post #: 186

RE: Airplane rudder gyro - 11/22/2008 10:39:57 PM

BarracudaHockey

Posts: 10993
Joined: 7/13/2003
From: Orange Park, FL, USA
Status: offline

126 with free shipping at http://www.ronlund.com (put it in the basket, the listing on the radio page is MAP pricing)

_____________________________

Andy - Helicopter Forum Moderator
AMA 77227 http://www.jaxrc.com

(in reply to BarracudaHockey)

Post #: 187

RE: Airplane rudder gyro - 11/22/2008 10:54:51 PM

Big_Bird

Posts: 3334
Joined: 12/18/2001
From: Arlington, TX, USA
Status: offline

Andy, that's even a better buy. My GY401 sure has been reliable.

_____________________________

Ken
WACO Brotherhood #70

(in reply to BarracudaHockey)

Post #: 188

RE: Airplane rudder gyro - 11/23/2008 1:51:59 AM

flaviosi

&nb