What Gyros are People Currently Using?
 

I have been flying for a long time but I am just now interested in buying my first gyro. I need something to tame the takeoff of a semi-scale Beech Staggerwing. It is very short coupled with proportions similar to a Pitts Special with a wider track. It has a steerable tail wheel. It swings wildly on takeoff. I'm pretty much stuck with using a paved runway as the wheels are small enough that it has difficulty taxiing through the grass at the local field. I have done the basics such as adding right thrust and checking the toe-in on the main gear. A rudder gyro seems to be my best bet. I'm pondering a Hitec HG3XA but thought I would see what people here are using. Any suggestions?

I run these in a few of my planes. http://www.hobbypartz.com/60p-dy-1017.html
In two years they are holding up fine.
One is in an overpowered 60 size P51 with limited rudder throw. This one had a tendency to get squirrely just as the tail lifted. Another is in a 40 Stik. It helps reduce the plane from drifting during outside square loops, humpty-bumps etc. I experimented with both Rate Mode and Heading Hold. (ACVS). I quit cycling between them on the same flight. Going from Heading Hold to rate mode sometimes caused the rudder not to center properly. After a while, I quit using Heading Hold completely. The Rate Mode setting took out enough uncommanded yaw much quicker than I could react. Otherwise you would never know it was there.

I've been using a Hitec HG3XA in a small Tiger Moth for about a year. It has proven reliable and easy to set up. Gain capability is more than adequate. Like WARHWK, I use Rate Mode. No Heading Hold for me -- it's no doubt useful for helicopters and quadcopters, but makes airplane flying very unnatural.

Many people disagree, but I'm of the opinion that a gyro makes a model fly more realistically. As a full scale pilot, I find that the response rates and gust response behavior of a small model are utterly unrealistic. A gyro slows the body angular rates so that I feel more in contact with the model. And the model looks more realistic in flight, to boot.I've used a number of other brands of gyros, but the Hitec is my current favorite. It's fairly inexpensive, simple to set up, doesn't pick up airframe vibrations, and the instructions make sense.

Dick

Thanks for the info. Any comment on how much gain to use?

Gyro gain is dependent on a lot of factors, start low and work your way up to what will provide good correction without any oscillations at speed.

I've found the best way is to put it on a knob, experiment in flight so you get it where you want and then take that value and transfer it to a switch.

Every plane will be different. I start at 40% and increase the gain until the tail starts to wiggle at speed. I'm currently at 80% on my Stik

I've always wanted to try BarracudaHockey's gain adjusting technique. But my limitation has been that remote gain gyros usually have just one master gain adjust for all three channels. So when turning up the gain in flight, one axis goes into oscillation before the other two. That becomes the limiting gain for the entire installation.

Flying tailwheel type models, I tend to use pretty high gain on the rudder. The reason is that takeoff and landing (where the yaw control problem manifests itself) involves very low airspeeds. So you need large rudder input to maintain control -- high gain. But aileron oscillation often occurs before sufficient rudder gain is reached. That's one of the reasons why I keep using the Hitec gyro; it doesn't have remote gain, but at least I'm able to adjust each axis to a different level.

BH, I've read many of your posts and know that you are far more involved with gyros than I am. Are there any reasonably priced gyros out there that offer remote gain adjustment on the three axes ?

To answer the question of Post #4, I usually start low on all three axes and work my way up one axis at a time. That takes quite a few flights, but each flight can be pretty short. I set up a single two-position switch for RATE and OFF. That keeps me from accidentally getting into Heading Hold. Each flight consists of a preflight gain adjustment, a takeoff and short evaluation of the "feel" of the model at the new gain, and then a climb to altitude and a dive to see if the system breaks into oscillation. Once I reach a satisfactory gain level for one axis I move on to the next. And, by the way, you don't have to keep increasing gain until you break into oscillation. If the system is producing the flying qualities that you want, you can stop right there.

In the case of your Staggerwing model, Matt, yaw control on takeoff is your biggest complaint. So I would experiment with the yaw axis first. You already know the model is flyable once in the air. So you might start around 30% on all three axes and then work your way up from there. You may find that the low gains in roll and pitch are fine right where you started. Even so, explore the speed range for any oscillation in spite of the low gains.

Dick

Thanks for the input. My main experience with gyros comes from watching a new pilot try to fly an ARF from an oil field lease road in North Texas. He had a gyro on the rudder ( I think it came with the plane) and it was waging the tail like a happy puppy due to the gain being misadjusted..

What I do in that situation is lower the gain in the channel that wags first in the software (such as the Aura, Igyro, or Cortex) then repeat the process till all three are maxed out. It takes a couple flights but you can knock it out pretty quick.

Then I throw a mix in so that when the gear is down or the the flaps extended I bump the gain because less speed means you can run more gain for takeoff and landing

I've ordered the Hitec product. I'll come back and comment on how it works.

I've been experimenting with a Spectrum AS3X receiver in a 1m foamy. Very impressed with its capabilities, turbulence dampening and auto mix. Also, an absolutely superb graphic interface/programing from you iPhone. The best, most intuitive and visually descriptive graphic interface I've yet seen from any producer. After many years with Futaba and JR competition sets, I bit the bullet and bought a mid range Spectrum tranny for testing and foamy flying right outside my house. So far the set has functioned perfectly. Seeing that it's American, Im very surprised that it doesn't have a stronger following. Luditism I expect. As mentioned previously, I thought it was wise to check out the new technology on offer, thus the AS3X receiver/with built in 3 axis gyro, automix and turbulence control. I'm absolutely blown away with it's capabilities and options. Of which I've now programed 3 different versions that I have on the 3 position switch and can flick between them as I see fit or just turn it all off and go manual. The new technology options are great IMO. Worth thinking about.

My Hitec HG3XA arrived today from Tower Hobbies. The instructions look pretty straightforward although the font is a little small for middle aged eyes.

On a stick? Yikes.

Download the instructions so you can enlarge them for easier reading. I bought the Hitec too I just haven't finished the airplane yet. I thought it might help my DR-1 a bit.

Yeah, They are pretty handy. Amazing what you can find manuals for online, I've not flown a BUSA Dr-1 but I had a Proctor-VK triplane some years ago. Take offs were easy since the .60 yanked it into the air before it could get squirrely but landings were always a handful.

My D-1 is the VK Models Fokker from the early 70s. I received as a gift as an unfinished kit. I'm making slow progress on it but should get it done this year.

I don't get it, perhaps i am just old school. We should not need gyro's to fly fixed wing aircraft. If the plane is built straight and true and you know how to fly then fly the plane, not with some electronic gadget.

Yep, thats old school :)

Of course I heard the same about dual rates, expo, and 2.4

I built my first model airplane from scratch in 1959, and I've been flying RC for about 35 years. I'd really like to try a gyro. It makes total sense to me, because we can't sit in the pilot's seat in our models; a gyro can. Yes, you can get a VK Dr.I off the ground quick with a .60, but if you want to do a scale-like takeoff, I think you need a gyro. I plan to give it a try this season.

Jim

i've given you a heads-up, you scalies with your delicate models have to look into this AS3X technology. It's a game changer. You can take an extremely light weight foamy that's being battered by a light wind, turn on the technology and it's like the model has just scaled itself up and 3kgs has been added. It's remarkable.

I'm wondering if the AS3X system is any different from other brands of 3-axis rate dampers ? The AS3X was certainly early on the market for 3-axis gyros, and fully integrated into models that sorely needed a rate damper. But does anybody know whether the Spektrum system does anything different than, say, the Hitec or any other rate only gyro ?

Barracuda Hockey, you probably have played with more different brands than most of us. What have you observed ?

Dick

I haven't got my gyro installed yet but I will weigh in on my reasoning. There is a satisfaction in mastering the handling of a model aircraft. My Busa N-17 doesn't have a gyro for instance and I have enjoyed some of the 1/12 scale combat models in the past. Both types of models have presented their challenges and are satisfying to fly. Some aircraft were challenging in their full scale form and reducing them to in size seems to magnify these challenges. For some models it comes to a question of is it going to be a wall hanger, is it going to beat itself to pieces before it ever gets off the ground or are you going to enjoy flying it? Granted their are master pilots who can fly a plane with scale power loading and aft CG and nail every takeoff and landing but I'm not one of them. I have a considerable investment of money and even more time in the Staggerwing. The same is true for those who build planes like the VK Dr 1. The gyro is a very cheap investment as compared to the rest of the plane and I want to be able to fly it.

Related to the VK Fokker: The kit as produced by Proctor is a joy to behold. The plans are pretty enough to hang on the wall and materials are top notch. it is in many ways an odd little airplane. At 48 inches wingspan a .60 seems a bit much but there is a lot of wing and a lot of drag. The plans showed a Supertiger .60 if memory serves. I used a relatively heavy Irvine engine and it worked well for me. The prop shaft stuck out a little too far but the airplane balanced perfectly with no additional weight. Unless I wanted to indulge in a vertical climb I seldom used more than half throttle. Even with the full scale aircraft the tail is up and the airplane is off the ground in short order. Once off the ground the Triplane is relatively easy to fly. If you are into triplanes there are lots of good articles on their aerodynamics and mass distribution and how that affects their handling. If balanced conservatively the slow speed handling is good right up until the moment when the wheels touch the ground and physics takes over. In my opinion (for what it's worth) this is where a gyro will totally pay off. I quite enjoyed my Fokker until I tried to swap in a four stroke .60. The power was sufficient and I thought I had the CG right but nope.

Thanks DIck, yes I've flown most of the gyros on the market and I've written several articles on the subject.

As to the use of gyros in general I will say this. This is a HOBBY, it's for ENJOYMENT. Do whatever you care to so that you enjoy your hobby. If you live where its windy and often pack up your plane and go home because the wind kicks up at 8am and have to mow the grass (which most of us don't find enjoyable) then a gyro is simply a tool for you to gain more enjoyment from your hobby. Can/will a gyro make you a better pilot? YES!! Why? Because if you are enjoying yourself you will FLY MORE, the way to become a better pilot is to fly more, see my point?

Conversely, if you gain enjoyment from mastering a particularly recalcitrant airframe, by all means do so, thats awesome! But don't look down your nose to someone that takes a different route to enjoy their hobby.


Now, about the different gyros. They all have some great features, not all of them have every great feature I'd like to see but they all work pretty well for what they do.

I've found AS3X to be a wonderful route to get planes like the UMX series that would be nearly impossible to fly without it. I was, frankly I'll admit, skeptical about its use in larger airframes, particularly gassers. The first plane that swung my opinion is the Carbon Z T-28 which flys wonderfully and keeps flying that way even in the wind. I was still skeptical about the vibes from a gasser but I just reviewed the new UltraStick and they sent an AS3X receiver for it. It flew great with it disabled but it was really stable with the AS3X enabled and point roll stops were even crisper and it just flew like a much bigger plane. It's also very natural if you have the gain set right, it doesn't feel at all like you're fighting the gyro which some do.

I'm using a .46 on my DR1.

A good .46 ought to be plenty of power. It's been quite a few years but I think the VK Dr1 is a sub 5 lb airplane. I would bet that your .46 is quite a bit lighter than the Irvine and JTec muffler that I used so I would suggest that you keep a close eye on the CG.