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Question on use of GYRO

Old 08-15-2022, 08:27 AM
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Navy_Flyer
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Default Question on use of GYRO

Old guy here, been flying RC since 1976... yeah, I know...

Just bought an HG3XA 3-axis gyro in hopes it would help me fly a very unfriendly scale biplane - LOTS of adverse yaw and directional instability on takeoff. I've already dialed in differential ailerons which helps, and I've programmed a little rudder mix with ailerons, but the enjoyment factor flying this plane is,, um.... nil. It's always a knee-knocker and white knuckle. Now, not to degrade my abilities, I've flown them all large and small gas and nitro, scale, sport and fun. But this plane is a bear to fly. Straight and level is OK, but make a turn and the heart race and knee shaking begin. It's always a fight. Been successful so far getting it up and down in one piece a half-dozen times.
I read about these gyros to assist with wind, stability (to a point), etc. and I want to put it in the biplane to see if I can mitigate the bad flight characteristics somewhat, or just make it a wall-hanger. Question for the gyro crowd - in HEADING HOLD mode, when making inputs, say to turn, and release the sticks, will the plane then maintain that last heading/attitude once you release the sticks, or return to the heading/attitude it was at when you first engaged heading hold? The destructions do not say. In Normal mode, I get the control buffering to smooth out the flight overall. But wondering about heading hold mode.

Last edited by Navy_Flyer; 08-15-2022 at 08:32 AM.
Old 08-15-2022, 08:52 AM
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BarracudaHockey
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Heading hold works best if you're hovering and doing torque rolls, you dont want to use it generally just flying around. It doesn't work like you think and its hard to describe in words.

Normal or rate mode smooths out wind gusts
Old 08-15-2022, 06:05 PM
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Default Use of gyro

I agree with BarracudaHockey. But I'd like to take the answer a little further. Heading hold is a mode that's particularly useful in helicopters. Or in airplanes that are trying to act like helicopters. But HH can give significant problems when you try to control a more conventional airplane.

I haven't seen your airplane, so can only analyze it from your description of its behavior. If you could include a couple of photos of the model, that will help. I'm suspecting that you have some combination of small vertical tail or short fuselage length. And maybe some significant amount of wing dihedral or sweep causing excessive rolling reaction to yaw inputs. The design may benefit from more tailoring of the control travels and interconnects. Still, a rate gyro may be the only thing that gives significant help with the takeoff control
Old 08-16-2022, 07:16 AM
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I'm flying a Bucker Jungmeister. Biggest issue is with adverse yaw during turns. I changed the aileron throws from 100% both directions to 100% up and 40% down and that's helped and I've been using rudder to coordinate, but it's either too much or not enough, so I programmed in a mix. Still, not behaving well. I've moved the CG forward a bit and that has helped a little in stability, but it is still a handful. I'll try 'normal' mode once I get comfortable with its operation to see if it smooths out.
Old 08-19-2022, 09:00 PM
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I think you're on the right track. Differential ailerons help a little, but generally not enough. Keep working on your aileron to rudder mix. Manually coordinating rudder inputs with aileron can be pretty dicey and inconistent. I'm a lot more comfortable with a transmitter mix for those two channels.

You may have to experiment with your mix amount by in repeated flights, flying overhead in a straight line and then do a sudden bank as if to turn. Note which way the nose goes each time you begin the bank. If you do sudden banks to the right, does the nose go into the turn or out of the turn ? If the nose goes OUT of the turn, then you need to keep increasing the mix. Your goal will be to find the amount of mix where a sudden bank doesn't cause the nose to yaw left or right. Might take several flights, each time adjusting the mix a little more or less. When you get close to the correct mix it will become difficult to tell which way it's trying to go But by then you will probably be satisfied with the way the airplane flies.

Most airplane takes more mix for banking right than left. So your worst case will be for right banks.

Once you get the mix dialed in, the gyro may not even be necessary. But I think you will still like the way the gyro smooths out your flying.
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Old 08-28-2022, 10:24 PM
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I flew a 40Ē span Jungmeister (from the Whitehead plan) for years.
At first it was rather a handful especially on takeoff but not only.
I then put a cheap GWS rate gyro on the rudder with no aileron rudder mixing and the model became one of my favourites. Would easily track straight as an arrow down the length of the runway and was great in flight too. Gyro sensitivity was adjusted to mid range.
Old 08-29-2022, 12:24 AM
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Hi!
I'm an oldtimer to, been flying R/C since 1975 (then 21 ). Have you checked for Wash-out in the wings? Mixing rudder and aileron is not advisable on any airplane.
Have you pictures of the plane??
Old 08-29-2022, 06:08 AM
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Originally Posted by jaka54 View Post
Hi!
I'm an oldtimer to, been flying R/C since 1975 (then 21 ). Have you checked for Wash-out in the wings? Mixing rudder and aileron is not advisable on any airplane.
Have you pictures of the plane??
I have no issues with the wing incidences or washout. Coupling aileron and rudder is done on full scale aircraft / and on many rc - not sure why you say itís not advised. Works just fine.
Old 08-29-2022, 06:11 AM
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Someone should have told the builders of the Ercoup you shouldn't do it on any airplane

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Navy_Flyer (08-29-2022)
Old 08-29-2022, 06:53 AM
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No problem coupling the controls, you can always decouple with the flick of a switch.

Iím sure you are aware the Jungmeister is a highly aerobatic design. Donít expect it to be similar to a lazy Tiger Moth. However with gentle control inputs it can be very friendly.

Have you tried exponential throws?
I believe I had about 40% expo on the ailerons and elevator, gave it a gentle response around neutral for general flying without sacrificing the aerobatic capabilities but still it flew like an aerobatic thoroughbred and not like a gentle trainer.
The tall landing gear and high CG always had to be respected too.
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Old 08-29-2022, 06:59 AM
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Originally Posted by EF View Post
No problem coupling the controls, you can always decouple with the flick of a switch.

Iím sure you are aware the Jungmeister is a highly aerobatic design. Donít expect it to be similar to a lazy Tiger Moth. However with gentle control inputs it can be very friendly.

Have you tried exponential throws?
I believe I had about 40% expo on the ailerons and elevator, gave it a gentle response around neutral for general flying without sacrificing the aerobatic capabilities but still it flew like an aerobatic thoroughbred and not like a gentle trainer.
The tall landing gear and high CG always had to be respected too.
Yes. I have Expo dialed in at 40% and that has helped a little.
Old 09-04-2022, 12:44 AM
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Hi!
Soo it is difficult to handle in the air?!
How big is it and how heavy is it? Does it snap-roll when you turn with full aileron and elevator? If it does it could be too heavy or the wings (one or both) have wash-in.
I have never flown an R/C plane that is not stable in the air ,be it pylon racers (have competed in Q-500, Sport 40 and F3D for many years),Sport airplanes and scale.
Please show a picture of the plane.
Some of my 30-40 planes that all flies the same, slow and stable... fast and stable! All very easy to start and land.




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Old 09-16-2022, 03:04 PM
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Tested my gyro on my Goldberg Eagle 2. Although it’s a stable plane and easy to fly, I noticed the gyro really smoothed out the flight considerably. No issues. Next I’ll install it in the Jungmeister and give I a go!
Old 09-22-2022, 07:11 AM
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Good idea, putting the gyro in your Eagle first. Gives you some experience with the gyro.

Before moving the gyro over into the Jungmeister, you might want to try one more thing in the Eagle to gain more experience. Try varying the gains in each channel to get a better idea what's happening to the behavior when each axis is altered.

Reason ? Your Jungmeister won't react quite the same to the gyro. Especially on aileron and rudder. So you'll no doubt have to play with the gains in the Jungmeister to optimize the effect of the gyro. The Jungmeister will probably appreciate fairly high gain in the yaw axis, and maybe in the roll axis as well. Pitch probably won't be a big deal providing the CG isn't too far aft.

Does the gyro have provision for turning it on and off in flight ? If so, you may learn a lot by turning if on and off while flying just to evaluate the contributions of the gyro as you experiment with gains.

Dick
Old 09-22-2022, 01:27 PM
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Originally Posted by otrcman;[url=tel:12744785
12744785[/url]]Good idea, putting the gyro in your Eagle first. Gives you some experience with the gyro.

Before moving the gyro over into the Jungmeister, you might want to try one more thing in the Eagle to gain more experience. Try varying the gains in each channel to get a better idea what's happening to the behavior when each axis is altered.

Reason ? Your Jungmeister won't react quite the same to the gyro. Especially on aileron and rudder. So you'll no doubt have to play with the gains in the Jungmeister to optimize the effect of the gyro. The Jungmeister will probably appreciate fairly high gain in the yaw axis, and maybe in the roll axis as well. Pitch probably won't be a big deal providing the CG isn't too far aft.

Does the gyro have provision for turning it on and off in flight ? If so, you may learn a lot by turning if on and off while flying just to evaluate the contributions of the gyro as you experiment with gains.

Dick
thanks Dick. Good idea. Iíll play with the gains before moving the gyro. I can turn it on and off in flight.

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