What are the ABC's for Gyros in Jets. (Full Version)

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Kmarks -> What are the ABC's for Gyros in Jets. (12/28/2008 4:03 PM)

Hello All

Just a curious question to the Jet community. Besides using a gyro on steering and rudder, what is the benefits of having a gyro on aileron and elevator??

Please explain the benefits or problems associated with having a gyro on ailerons, and/or elevator.

Are there a few gyros out there that are recommended for jets, and any tips for set up and what to expect??


Thanks

Kevin



Pete737 -> RE: What are the ABC's for Gyros in Jets. (12/28/2008 7:20 PM)

I am interested in this as well, Not to steal the flying but make it look more scale and stable.

Pete



SinCityJets -> RE: What are the ABC's for Gyros in Jets. (12/28/2008 11:54 PM)

Kevin,

Aside from rudder/steering, ailerons is probably the next most popular surface to gyro. Main reason, it flies on rails. When it is adjusted properly, it just goes where you point it, without that normal buffeting that can rock the wings side to side. You can definitely tell a difference. While it is not necessary, it certainly does look more scale.

The Fuzzy Pro SMM is probably THE gyro in terms of best quality dual in/ Dual out gyro. Since it uses an SMM sensor, and not a piezo, it is not prone to "heat drift" issues. That is when the "centering" can be thrown off as the temperature of the area around the gyro increases/decreases. I have them available on my site and they come direct from the factory in Germany.

If you are just looking for a good single in / Single out, I hear futaba makes a decent one, although I do not have any first hand knowledge.

Chad



jescardin -> RE: What are the ABC's for Gyros in Jets. (12/29/2008 1:57 AM)

One question regarding gyro assited aileron control, how do you set the gyro axis, longitudinal?. I suppose so but I may asure you that even better than that is mounting the gyro with its axis 120º from that of the plane (this is 30º over the vertical towards the plane tail).

This set up not only produces a more stable flight but also add autostability on yaw but, mainly and more noticeable, on roll. For your information this is the roll gyro set up used on "simple" -not equipped with acelerometers- proffesional and military UAVs for "out of sight" flight conditions together with a reduced aileron control so as to make it impossible to roll inverted the aircraft.

Only drawnback is the "feeling" of aileron control as this configuration makes the pilot to command turn aileron -more travel than normal- and keep the aileron imput along the entire maneouver or the plane stabilizes as soon as the pilot relaxes the stick and it is easy that few first turns become very, very large in diameter, something you have to look after with our jets and their velocity as it is very easy to "run out" of sky. In the positive side it is that it becomes almost imposible to roll the model upside down.

Of couse, if you want to give this set up a try -most recomended-, please use a relatively slow propeller driven model for test and training and ALWAYS check the gyro stabilization commands before attempting to fly...SECURITY FIRST, SIRS!.

Best Regards and Happy New 2009 Year.

Jesus Cardin



SpiderJets -> RE: What are the ABC's for Gyros in Jets. (12/29/2008 8:57 AM)

Why making things unnecessarily complex ???
If it is REALLY necessary to stabilize two axis, use two gyros.
There is NO benefit of putting one gyro in 120° and let it correct rudder and aileron at the same time.
If one day you are going to try and demonstrate this theory on an RC jet of linking action of rudder and ailerons and making turns with it, please come over, I'd love to see it [8D]
Don't even try to fly without me being there because there will not even be a second flight of yours. [:D][:D][:D]




jescardin -> RE: What are the ABC's for Gyros in Jets. (12/29/2008 10:44 AM)

"SpiderJets" I do not use it in my models because I always like "FLYING" them and if I find a model needs to be stabilized I simply think it a wrong design, give it up and go for another one.

But aside this personal liking I may assure you I have full experience with above mentioned configuration with nearly 200 hundred target UAVs and more than 500 flights during a period of 10 years. Why this set up work?, well I prefer someone so clever like you think further about it as I didi 12 years ago only to find that engineers from TTL in UK already discovered it for their Banshee before me and if you do not belive my words, please, give it a try and then comment about it.....you will be surprised!.

By the way, I may also turn your question over asking why to use two gyros -which is more expense and complexity- when you may get good enough results with just one retaining full control authority?.

So you do not need to wait me fly with this set up nor be afraid a second flight should not be possible simply because it is the way it is being done today and from many years ago in far more sofisticated areas than our hobby.

Best Regards, and please, give a second though on the matter.

Jesus Cardin

P.D.: sorry, reading again your comment I think perhaps I didn´t describe the set up clearly; the inclined gyro "senses" roll and yaw but it is ONLY conected to aileron servos -not to the rudder servo- and so corrects roll and yaw with ailerons and that even having more sensitivity to yaw (90º) than to roll (30º) and I am giving you a good clue to the main reason behind this set up......



mick15 -> RE: What are the ABC's for Gyros in Jets. (12/29/2008 10:54 AM)

Jusus, I'm interested to know how you control more than one plane, is it a single or dual axis gyro. Most model set ups involve two channel ailerons?

m



jescardin -> RE: What are the ABC's for Gyros in Jets. (12/29/2008 11:47 AM)

"mick15", yes it is a single axis gyro and due to mentioned inclination -which dind´t prove critical- it corrects 2 planes of the aircraft. It must be tested to fully believe the strong autostabilization it provides.

The test I got involved 12 years ago studied stability in the aircraft three axis and we concluded:

1.- Pitch axis proved unsuitable for gyro autoestabilization -which was what we seeked for- althought it showed more difficult to deviate the aircraft from it; we made dives to the sea from 300-400 meters high and many times we raised just over waves as it was need a lot of more elevator to pull out with gyro activated than not. For the tests we aligned the gyro axis with the target UAV transversal one.

2.- Roll axis autoestabilization proved not poor but null with gyro axis aligned with UAV longitudinal one. This proved to be the worst of all test carried being very easy to roll the aircraft and, of couse, it never returned to level flight. The test were done with a normal gyro and then we decided trying with a "heading lock" one but we prefered, thanks god!, testing with an RC model first. It was mounted like the normal one but proved impossible to control on any gyro gain: the RC plane was certainly very stable and returned to level flight after turning with rudder but.....we got two quick rolls when we tried to turn by aileron control!. We didn´t go any further with this set up and, of course, even didn't tried on the target UAV although though it should be feasible if, later in time, plane specific "heading lock" gyros became availble (the one used was the first "heading lock" one intended for aerobatic helicopters).

3.- Finally, and also on the RC model, we tested an idea I had with the normal gyro mounted on a support we could incline to any angle starting with the vertical one but controlling ailerons. And that proved to be a total success from the first flight although a little over corrective. We, of couse, could program less gyro gain but tough it to be a complexity to the UAV operators -which had more than enough learning to fly and keeping "alive" the planes- so we tried rearward angles which reduced the vertical axis component and even added a bonus with a certain longitudinal axis which added roll stability. That way we had best of both worlds: roll stability due to rearward angle and roll autoestability due to the vertical one. Since that moment and till the company I used to work for introduced full autopilot as an option it was the configuration for all the target UAV produced, both propeller driven with a Quadra-Aerrow 82 cc engine (65 m/s capable) as well as those turbine powered with Artes and JetCat 12-15 Kg thrust class turbines(100 m/s capable) which acounted arround 200 aircraft and well above 500 live fire and training flights during years.

Hope you find usefull the explanation and understand my not very "refined" english.

Best Regards,

Jesus Cardin



mick15 -> RE: What are the ABC's for Gyros in Jets. (12/29/2008 12:27 PM)

I understand what you are saying about gyro, in spite of your English, which is a lot better than my Spanish. What I don’t understand is how you convert more than one receiver output to more than one control plane with a single axis gyro, which presumably has only one output.

m



jescardin -> RE: What are the ABC's for Gyros in Jets. (12/29/2008 1:31 PM)

"mike15" no, it is not necessary to make any conversion nor modification to the receiver or the gyro,..... it is just so simple!.

You use just a normal gyro -without "heading lock" or AVCS as call it Futaba- with one single axis, two imputs (control channel and gain) and just one output (for the control servo or servos via an "Y" harness).

Then a normal receiver and a normal transmitter without any special mixes but with enough channels for controlling the gyro gain.

Finnally a relatively slow RC model or, if you have long experience flying, even a medium speed low wing acrobat or semiscale model in wich to mount the gyro with its axis passing the aircraft vertical axis and located as nearly to the model CG as possible. Then you must connect it to the AILERON and gain servo outputs at the receiver and the AILERON servos to the gyro output (yes, even when it is mainly detecting yaw desviations).

Then, on the ground, check for gyro compensation and if wrong, reverse it via the appropiate switch on the gyro. Recheck several times till you are satisfied that the gyro compensates with opposite aileron to both yaw (easy to note) and roll (more difficult to detect). Anyway if the gyro compensates yaw with aileron correctly (righ yaw with left aileron) for sure roll corrections will be OK as far as the gyro is inclined to the tail of the model -if it is leaned to the model nose, then the gyro will compensate yaw just opposite to roll due to the "signs" of the deviations which be different; you must to think a bit about it to fully understand and it was the mainstay behind the original idea. Again it is just not the same to lean the gyro towards the nose than towards the tail.

Then take off with gyro djusted to 0" gain and, after taking some height, give it between 75-90% gain; you will inmeaditely note how straight and level the plane will fly and then, that you need a well a lot off of aileron command to make the plane roll even slightly and what will surprise you even more that as soon as you relax the aileron imput -rather than inmediately at the same time- the plane autoestabilizes in roll so making you -at least it was what happened to me- to command/relax several times getting a very large radius turn.

When used to the feeling, you will notice that only thing neccessary is to command a quite large ammount of aileron control and KEEP the stick deflected to keep the roll angle during the turn. If you try this with the gyro disconnected you know well the model would become inverted during the turn but with the set p described not.

Please, belive me that this set up must be tried to be believed as far as you want an autostabilized aircraft while maintaining agility and aerobatics capabilities. It outperforms any other set ups described in this and other forums using specific and quite expensive gyros. If you try this, you will see any other option is well behind this one.

Best Regards,

Jesus Cardin



mick15 -> RE: What are the ABC's for Gyros in Jets. (12/29/2008 1:43 PM)

Ok I understand now I will give it a try, thanks.

m



DAN AVILLA -> RE: What are the ABC's for Gyros in Jets. (12/29/2008 7:56 PM)

I have been using Aileron and rudder gyros on all my jets (BVM F100,P80,Bandit) for the last 8 years. What it does is smooth out the way the plane fly's in bumpy air . I also had a flap servo die on my P80 at Florida jets . I was able to land with one up and one down. What the gyro did is buy me time to gain control. I always use the gear switch as a mix to change the rate. Gear down a higher rate than gear up. The only thing that happens if the rate is to high is it will osolate at high speed. The answer is just slow down the plane and fly out the fuel load. When back on the ground make the new gain adjustment and try it again. If I was to rock my plane at high rate would deflect about 5mm and low about 3mm. That is a good start point. Dan Avilla



Kmarks -> RE: What are the ABC's for Gyros in Jets. (12/29/2008 8:09 PM)

Thanks to all

who have contributed to this thread, I have gone ahead and bought off Ebay a futaba GYA 351 gyro. It is a mid cost gyro at about $135 and I have read that it should be a good introductory gyro. I really Like the new Fuzzy Pro2 sold by Sin City Jets but at the lower price of the futaba I will try that one first.

I plan to put this in my New, Not Maidened yet large FEJ F18F.

Anyone have set up recommendations with the Futaba GYA 351 gyro with a JR 10X and the limiting AR9000 9 channel reciever. I plan to set up on ailerons, but I do not have a small prop job as a test bed, so how can I set up with limited gain, and increase as needed??

Thanks

Kevin Marks



Aero65 -> RE: What are the ABC's for Gyros in Jets. (12/29/2008 8:17 PM)

Hi Jesus

Thank you for the detailed information on the setup. That is a very interesting setup, and the way that you explained it makes it very clear for me thank you, I think im going to try that one for sure, i could use it on my F-104.

aloha

Duke



SinCityJets -> RE: What are the ABC's for Gyros in Jets. (12/29/2008 8:57 PM)

Jesus,

I am having a hard time understanding how you are mounting the gyro sensor. 120 degrees to what?

If anyone else understands and can explain it, feel free to jump in...

Chad



jescardin -> RE: What are the ABC's for Gyros in Jets. (12/30/2008 7:44 AM)

Chad, good morning from Spain.

The set up is quite simple. I will try to explain the instalation in another way: you most probably know helicopter fliers mount the gyro in their helicopter with the "sensing" axis vertical; well here it is the same but a litltle tilted to the aircraft tail. That is why I spoke of 120º, that is the gyro "sensing" axis should end 120º relative to the aircraft longitudinal axis (all in the vertical plane) taking as 0º the aircraft nose.

Anyway the amount of degrees you tilt the gyro to the back is not a critical figure and then remember to wire as explained before, this is the gyro controlling the AILERONS SERVOS and NOT the rudder servo.

Hope this clarifies the idea. If not, please, let me know and I will prepare a sketch.

Best Regards,

Jesus Cardin



davo580 -> RE: What are the ABC's for Gyros in Jets. (12/30/2008 11:55 AM)

why use them i think mind over thumbs is better



seanreit -> RE: What are the ABC's for Gyros in Jets. (12/30/2008 1:57 PM)


quote:

ORIGINAL: davo580

why use them i think mind over thumbs is better

Considering you have never tried it, on what are you basing your opinion? I'm really curious considering your input, which is clearly opposite of what others are saying. Please share how you arrived at this.



Kmarks -> RE: What are the ABC's for Gyros in Jets. (12/30/2008 2:55 PM)

Mr Davo 580,

I started this thread to learn something that I had little information on, so why dont you sit back, keep your "OPINIONS" to yourself, and maybe the rest of us can be enlightened!

Most people I would assume do not use gyros, you being in the majority, we all now know that, but some do. It is the knowledge from these enthusiasts I would like to learn from.

So far this has been excellent information, lets keep it going.


Also Mr. Jescardin, can you take a picture of how your Gyro is positioned and location relative inside jet.

Thanks

Kevin



Craig B. -> RE: What are the ABC's for Gyros in Jets. (12/30/2008 3:27 PM)

Dave,

You really need to come and have a look at a jet flying with one. To be fair, no-one over here until recently has flown with one, have they? Come and have a look at my F16 (tigermeet) next time I fly it and you will understand without me having to say anything. You will need to bring a paper towel to wipe the egg of your face mate [;)]. Now you of all people should know that I don't NEED a gyro to fly my jets. When you see the difference it makes you won't ever need to ask that question again.

It is very simple mate. It does not matter who you are or how quick you think your reflexes are, a gyro can counteract buffeting of a model in a way that no human is capable of. It does NOT fly the aircraft for you, it just smooths things out. I guess you won't notice much difference on a model like your baby boomerang because it is very docile anyway, but on the scale jets it makes a big difference because they are far more twitchy. My scale models will be fitted with them after my recent testing, and I dare say that you will end up doing the same after you test fly your PST panther. The first time a gust picks that baby up and puts you knife edge one foot of the ground and you end up cart wheeling down the runway you will perhaps consider using one yourself. It has nearly happened to Mike and me with our F16's on the same day on one particular occasion, and you know that we are no slouches on the sticks. You have asked both of us to fly your boomer for you and you would not have done that if you thought we were anything other than capable I am sure. A gyro would have prevented that from happening with our F16's because it can react faster than we ever could......it's just simple unchangeable human physiology mate. A near miss or two was enough for me to look into it.

I am happy to show you next time we our out at Whiteman. Give me a ring if you are interested.

Kevin,

I am using a futaba gya 351. I started with 80% gain and also tested 90% gain and had no problems with oscillations on either setting. The higher gain did produce a greater effect but I will now need to up my dual rates because the gyro has slowed the roll rate a bit. My experience with Helis is proving to be useful with these things. I love this hobby!!

Hope that helps.

Craig.





E.N.T. -> RE: What are the ABC's for Gyros in Jets. (12/30/2008 4:05 PM)

THANK YOU for this thread. NOW I understand better how to and when to use the gyros.
This is what is all about. Learning and learning, aking use of.

Thanks

Hector



Ian R -> RE: What are the ABC's for Gyros in Jets. (12/30/2008 5:47 PM)

Hi Craig

What set up are you using on your f16, Tailrons or elevator and ailerons. I assume you have the gyro on roll axis control

I agree a good thread from those that know

thanks Ian



SinCityJets -> RE: What are the ABC's for Gyros in Jets. (12/30/2008 6:29 PM)

Just a quick caution, be careful with the higher gain settings on the Act Fuzzy's. I have not seen people run them very high. I'm sure the gain requirements differ between manufacturers. Again, TEST your gyro on a lesser expensive aircraft first. I think this is sound advice.



Aero65 -> RE: What are the ABC's for Gyros in Jets. (12/30/2008 8:28 PM)

Hi Everyone

Ok here are a couple of drawing that I did to see if I understand this correctly. Jesus could you please comment if this is correct.

Just a simplified fuselage for purposes of this illustration.



Craig B. -> RE: What are the ABC's for Gyros in Jets. (12/31/2008 12:16 PM)

Hi Ian,

I am using elevators and flaperons. The gyro does not interfere with the flaperon function at all. I use around 8mm flap deflection for landing and full upward aileron deflection for full brakes.

It only took me half a flight to be convinced on the virtues of gyros, and yes, I have it installed on the roll axis. The gya 351 has two channel input and output, one for each aileron channel, and is a single axis gyro. The futuba gya 352 is a dual axis gyro with one channel dedicated to each axis.

I am using the 351. Setup was very easy. I hooked it up and checked that it was working in the right sense, and applied what I thought would be the amount of aileron stick deflection necessary to correct a gust induced wing drop. I then looked at the amount of aileron deflection that was produced. I then dialed up the gain, and with the help of a mate, rolled the aircraft quickly to simulate a gust induced wing drop and observed the amount of aileron deflection that the gyro produced. I adjusted the gain until it was similar to the initial stick induced deflection and left it at that. I also setup a lesser gain setting and an off setting on a three position switch so I could get myself out of trouble quickly if the gain was to high or I encountered some other problem with roll rate etc. The only thing I found is that my roll rate was slower, but I will be able to address that by changing the aileron dual rate setting.

Please understand that this is my first experience with gyros, so I don't claim to be an expert, just a convert, but one that is learning quickly. I was able to fly with 95% gain without problems, but it must be understood that each gyro will have its optimal gain settings.

Hope that helps Ian.

Regards,

Craig.





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