Hi good folks.

I need some help from the gyro gurus. I have a jet that I think can really get some help from gyro stabiliztion through the roll and pitch axis, especially on landing.

And it uses tailerons.

I have read two possible solutions:

1. The now outdated, out of production futaba 352 dual axis (I've found a couple on fleabay though) that can control roll and pitch AND has a mixer for elevons/delta

2. Getting two single axis gyros (one for each taileron servo) and placing them at 45 degrees to both axis'(once mounted, the gyros look kind of like a wedge or snowplow formation) and then fine tuning the gains to make the appropriate deflections on the tailerons.

Any one else have any input on this? I'd really appreciate it.

Raf

Ok, since I still haven't found much talk about gyros in tailerons (Wojtek used that futaba 352 in a BVM f-16 and was pretty happy) I'll post a link with two gyros at 45 degrees that some dude made up.

http://www.mycoolrc.com/gyro/elevongyroinstall.html

I bought two of JR 370A gyros and I'll see how that works! I guess I'll be the first one to do this in a jet and post it online for others to learn from.

Raf,

You can not get a better (or more expensive) gyro than the Fuzzy Pro SMM Jet. A search on the Fuzzy Pro will reveal the same. There are less expensive alternatives, but this really is the best out there.

Check my site for more info, or shoot me a call.

Chad

Ouch! $340!

Have you tried those gyros for tailerons/delta/elevons.

If I was going to put one gyro on a single axis with two servos controlling that surface, I'd do that gyro.

Since I'm trying to do a taileron set up here, I'm going with those JR gyros. I've been VERY happy with a $100 JR 410T gyro (no longer made) on my nose steering for years. They have been abused, fuel spilled on them, dirt landings, yada yada yada and they've kept on ticking!!!

I have been really happy with JR gyros.

The futaba GYA-352 is still producing.We use it on many jet model ,like F-16.F-22,Mirage-2000,etc,because we always set them to elevon mode.It work very well.I thick the your Futaba dealer can order this Gyro from Futaba(because it was produced at Futaba factory in Taiwan).

Raf,

There is another possibility. You can use two single axis gyros (oriented for pitch and roll) and rather than mixing elevons at the transmitter, use an external mixer (downstream of the gyros) to mix the elevons. Electrodynamics sells a mixer for $16.95 [link=http://www.electrodynam.com/rc/EDR-116/index.shtml]http://www.electrodynam.com/rc/EDR-116/index.shtml[/link]

I used this setup on my original Gripen and it was fine.

Jim

I use the ACT Fuzzy Pro on the elevons of my Typhoon. It is aligned for ailerons only. I would not use a gyro on the elevator function and definitely not use the same gyro for both pitch and roll. You should not need a gyro on pitch. If you tilt the gyro's axis to give you some roll and some pitch information, the gyro will read roll and pitch as the same thing and give the same output - always move the elevons as ailerons or always move them as elevators! It will not magically know when to apply aileron or when to apply elevator, it is designed to apply just one, so either it will make the plane roll when it pitches, or pitch when it rolls! So, technically it will not work and you should not need a pitch gyro anyway therefore I suggest you stick to using the gyro on ailerons only or ailerons and rudder.
H

I can see your point. That said, MANY people are doing just what I am planning with two gyros aligned at 45 degrees.

I must admit that I am intrigued by the futaba dual axis gyro solution, it seems quite elegant. I may have to try it as well.

Its not about "needing" it or not. I want it and MANY people do it. Now gyros are ok to use in the JWM and JR and ACT fuzzy (among others) are making airplane specific gyros. If the pros who spend 100's of thousand of dollars, euros and pounds, why wouldn't I take advantage of it?

Remember horse driven carriages? They were the best thing until cars showed up. Gyros maybe the next push. I think my jet can reap some benefits.

Here is a vid of a guy who put this two gyro set up to control both roll and pitch in his tailerons. Granted, it was a foamie and he was using cheap stuff. I am not using cheap stuff at all.

http://www.youtube.com/watch?v=L7mm5e7Am_c

Hey Raf.
I am using a Futaba Gy352 on the outer surfaces of my Mirage 2000 ( I have 4 surfaces mixed as elevon) and it has transformed the model. I have to admit though I have yet to fly a delta or taileron model that needed them on pitch. It has always been roll control where they felt a bit fidgety and unstable. A good quality gyro really helps take care of this, and make the model so much more enjoyable to fly.
A saying I quite like is " A gyro equipped model will hit the ground through cack flying just as easily as one without.. It's just that the one with a gyro will do it smoother and in a more locked in manner"
Let me know if you need a 352. I don't know if you have anyone heading out to FJ next week, but I could pass it to them to bring to you if you want?
Regards Al

Ali, thanks for that input. I'm not sure that the airplane "needs" it all on any surface. Shoot, maybe I just need to fly more and in worse conditions, but like you say if it makes me look better doing it then why not?!

I tried four exact little foamies this past weekend, two with 3 axis gyros and two without. I must admit I was truly IMPRESSED with the gyros. The gyro equipped foamies didn't bounce around in the sky and they tended to lock in much better on the final approach to landing. I was sold immediately. My workload was decreased, say 20-30 percent. I could really concentrate on doing maneuvers more instead of correcting for all the bouncing around that foamies do.

Granted I'm yet to think that my BARF or Ultra need them as they feel so rock solid to me, but my little f-14 sweeping wing jet was really fighting me all over the sky! It was fun, but I was working!! I enjoyed being really challenged by my airplane.

Hmm, I can't say that I have anyone I know going to FJ off the top of my head. Bbbbuuuutt, if you wanna drop it off in the mail while you're here, I wouldn't mind! I'll pm you my address and I'll happily paypal or however you wanna be paid for it, if that's cool with you. I'm curious to see it in action.

Even the great Ali uses gyros!!! A backwards, little country jet flyer, like myself can probably benefit also!!! LOL

Hey Raf,


Yep, I have openly been using Gyros in my jets for the past 6 years, and have taken flack for it. Not that it worries me, as there are some jets that I would not even consider setting up and flying without them. It has made me chuckle watching some of those that have taken pot shots, or made digs about me using them struggle to fly certain models, or even flying them and seeing that they present like cack in the air..... Especially now they are running gyros themselves.
What you have write pretty much sums up my experiences with Gyros. Contrary to popular misconceptions.. I don't have gyros fitted to all of my models. In fact right now I only have it on my little F-4 on roll. In the past I can think of the following models that I have fitted them to ( and reasons why )

Airworld F-100 on roll to stop a tiny bit of roll bounce it had

Airworld Mig 21 on roll to make it look better than a 2 bit piece of poo on roll that it was without it

Epic Victory on roll and rudder as in anything other than flat calm the model looked as if it had parkisnsons.

Mirage 2000 On roll as no matter what I did, i could not get that locked in solid sit that the full size has when doing its demo flights

Airworld Cougar on Roll, again just to smooth out some roll bounce/ fidget it had.

Thats about all I can remember. I have never felt any need to put them on a Bandit, or especially an Ultra Bandit. There are two planes that are solid as it gets. Having said that I did fly an Ultra Bandit last year in California that was shocking in roll ( Slow rolled itself from horizon to horizon ) but I have a feeling that may have been something to do with the poor workmanship

Having had the pleasure of flying B1's F-14 at BITW [X(], I have recently advised another F-14 owner that I wouldn't even consider flying another without a gyro on roll.... Oh and control surfaces that stay attached!

I will take a 352 to FJ with me. Ideally I was looking for payment and delivery at the event to keep things simple. You know me well enough to know that I am simple


Regards Al

Yes with two gyros aligned at right angles to each other, for example one aligned 45 degrees inwards and the other 45 degrees outwards. But you can't do it with one gyro which rules out using one dual input/output gyro like the ACT Fuzzy Pro. You could use two Fuzzy Pros and just use one input/output of each but that gets a very expensive way of doing it.

There is still a potential disadvantage to using a gyro aligned at 45 degrees to the two axes you want to involve. There is only one gain setting so it will respond with the same amount of control travel to pitch and roll. Depending on the model, this may be very unequal. For example, on my Typhoon elevons, the elevator travel is large and the aileron travel is small. Therefore the roll gain is very low. If I aligned the gyro at 45 degrees then the gain would have to be a bit higher but the end result is the same, a small amount of control deflection. It would respond the same way to pitch disturbance, a very small deflection of elevator which would have no useful effect since the elevators need a lot of travel. Turning the gain up to an amount useful to elevators would be several times too high for the ailerons and a severe rolling wobble sets in as soon as the gain exceeds a critical point. So the only option is to set the gain for roll, which would be too low to be of any use in pitch, thus negating all the bother of setting it up that way. It will depend on the travels for your particular model.

By far the best option would be two gyros but one on each separate axis so you can set different roll and pitch gains. That would require them to be fitted in series in order to drive elevons, don't know if that would cause any problems.

H

Ali, thanks for the input about gyros. I just bought one off fleabay.

You do know how to take your nudging just a bit too far sometimes.

No Worries Raf, Good luck with your gyro set up. You have got yourself a great gyro in the 352.
Too far???? I am only just getting started Anyway, I seem to remember you giving as good as you got [&:] Your just upset because my Whoo Whoo Dust buster beat you [:@]
Regards Al

In this instance you could increase the mounting angle, say to 110 degrees, which would increase the visability of the roll rate at the gyro while decreasing the pitch. It would take some expermenting, but could be done.

For what its worth - the gyros in an Inertial Measurement Unit (IMU) are at 45 degrees to the major axis'. Of course there are 3 gyros and a computer to come up with the final answer. An IMU is the device in a missile, airplane, or sub that tells it how it is moving.

Steven

And of course it's the 3 gyros and the computer that makes the difference! Mounting any gyro off its perfect axis means it will respond to rotations in the other axes too, so it is not well suited to our purposes. By using 3 gyros and a computer, the computer can compare the readings from all 3 to realise that the vehicle is actually just rotating in one axis, or the relevant amounts in each axis. Whilst it may seem a complicated way of doing what we get from 3 gyros on perfect axes, it does provide redundancy, comparison between different gyros to improve accuracy and so on.
H

Just so I'm clear on this, to use a gyro for the "aileron" only function of elvons (i.e. one mixed control suface on each side of a delta wing configuration), you install the gyro between the rx and servos and orient the gyro in the roll axis. You would obviously need a gyro with two channel inputs/outputs, one for each side. Then just make sure the servos react in the correct direction and you are good to go? Presumably the "elevator" function is unaffected?

Craig

That's exactly how it is with the ACT Fuzzy Pro on the roll axis for the mixed elevons of my Typhoon.
H.

I have used this 352 gyro and at least for awhile it was a very hot item in europe to use on 2 axis in heading hold (switched on and off in flight). I think it was normally used in roll and yaw for locked in knife edge. I used one for awhile in a Bobcat as an expeiment, it worked fine, very robust unti with flexible prgramming. raf I have a couple NIB if you need one, good price!

Markus Zipperrer tried to explain to me how he used it inheading hold mode on roll and that somehow the roll control turned into some sort of roll rate command, I could never really understand how he did it.

Hi all

I am doing a 16 foot Concorde from Peter Michael in Germany. It is elevons and each side has three surfaces. I am set up with the JR gyros set one for each side and they operate in the roll direction. The Concorde flies fine without the help until you try to land it. The problem with delta wings is that they need to be a little tail heavy to be at all stable in the landing configuration. The nose is up and the wing is at a high angle of attack so the wing tips like to take turns stalling and the plane walks along while the pilot fights it.

The gyros are set standing up and perpendicular to the center line of the plane. They are side by side and set in the same plane. This gives roll stabilization in the elevon mode. I am using the gains on different knobs on the transmitter so that they can be adjusted as we need to.

I think the gain question is the hard one when you use the JR equipment.

More details are on my site at www.dream-rc-airplanes.com in the workshop section.

Thanks Harry!

Hi Craig,

You are correct with your summary. i have used gyros for years on several models......they work really well. One thing to watch out for.....I don't use mine in low wind conditions on landing because: a0 you don't need it then anyway, and b) it can mask the signs of impending stall (wing wobble).....I found that out the hard way when my airworld panther that was a bit tail heavy snapped on finals. All fixed now but a lesson learned the hard way.

Raf,

If you want 2 axis stabilisation, the 352 (dual axis, single channel) is the way to go. If you want only single axis stabilisation, go the 351 (single axis, twin channel, so good for tailerons, flaperons etc) or the act fuzzy pro (the latter is just more expensive).

My F15 is having the 352 fitted soon on roll and yaw axes.

Good luck with yours.

Craig.

Hello Craig,

Good advise. I intend to give a gyro a try on my BV Rafale ailerons. If flies great but never perfectly stable in roll and I was never quite sure how to hook one up in an elvon configuration. I actually have both the elevator and ailerons on each wing acting together as single elvons and I think I'll connect the gyro to just the ailerons.

You are correct about the wing rock close to a stall. I also notice with my Rafale that the nose keeps coming up and the ailerons also start to loose effectivness if I get too slow. I'll be sure to put the gyro on a switch so I can turn it off and on.

Thanks,

Craig

I bought the 352 as well. It seems like it will be the easiest most functional way to make my tailerons work on a gyro.

I am kind of enamored with the idea of tinkering with 45 degree mounted gyros. Simple, compact, no wierd intra-gyro mixing of the elevons. It is a throw back to when I'd mess with my propeller airplanes wondering what I could get away with.

That said, maybe that kind of experimenting can be done later. The 352 is a dedicated gyro just for elevons/delta/taileron airplanes.

I'll get both types of gyros in my hand and I'll decide!!!

Hi Raf

I have the 352 in my GJC F-4D Skyray on the elevons and it made very easy to fly. It’s pretty gusty in Hawaii were we fly so without Gyros some planes things get really bounced around. I also moved the cg back a bit to land slower, so I was experiencing PIO's in pitch on landing the 352 cured that!

I originally had the elevon mixing in the radio, then had to undo it when I put in the GYA-352: Aileron in one plug and Elevator in the other and the gyro does the mixing (sry being thorough). Pretty neat unit