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RC Gyro help?


SIMON CRAGG
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To try and iron out the bumps when doing some onboard photography, I thought a gyro might help.

 

As I know zero about the subject, can somebody point me in the right direction.

 

It really needs to be:

 

Straightforward to set up and use.

Reliable.

Not silly money.

OK for a basic 4ch trainer.

 

Thanks in advance!

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I recently bought the Eagle A3 Lite from Motion RC. I've had many heli gyros over the decades, but this was the first I installed on a fixed wing. I found it very simple to install and worked first time. It makes a huge difference to my EDF jet, which now flys on rails. It comes with leads to connect between the gyro and your receiver. Then you simply connect your servos to the gyro. 

 

 

https://www.motionrc.eu/products/eagle-a3-lite-3-axis-airplane-gyro-hea3lte

 

Can be bought for less from Banggood and the like. Don't know if they are cheap copies though.

 

 

Edited by Futura57
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9 hours ago, Futura57 said:

I recently bought the Eagle A3 Lite from Motion RC. I've had many heli gyros over the decades, but this was the first I installed on a fixed wing. I found it very simple to install and worked first time. It makes a huge difference to my EDF jet, which now flys on rails. It comes with leads to connect between the gyro and your receiver. Then you simply connect your servos to the gyro. 

 

 

https://www.motionrc.eu/products/eagle-a3-lite-3-axis-airplane-gyro-hea3lte

 

Can be bought for less from Banggood and the like. Don't know if they are cheap copies though.

 

 

Did you have any issues when it came to using a "Y" lead on  the ailerons?

 

I can see a potential problem in not being able to change the individual senses of the wing surfaces.

 

Or is it a case of trial and error. The motion rc video shows the gear going into an Avanti which I have, but the video was not that clear.

 

Did you use a 2/3/ position switch (I got a bit lost when the video started talking about adjusting the trim to go from a 3 position to a 2 position !), or a dial to control the gain?

 

Thanks for your help.

 

 

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10 hours ago, Futura57 said:

Ive used several of these and/or all but identical models, there is a few different models, but all work much the same.

Y lead on ailerons weren't a problem. Spend 5 mins sorting the mechanical trims and travel limits. If things like electronic differential or flaperons are needed, then you're starting to get at the level where this might not be the product needed, but your flying abilities likely won't need a gyro anyway.

I did once, and only once play with inflight adjustable gain. For me, once i found the sweet spot, there was no need to adjust it further: thus no need for inflight adjustable gain If it wasn't obvious, having inflight adjustable gain takes up a receiver channel, but is entirely optional so it doesn't need to take a channel if one is not available.

They also have multiple modes, usually selected by a multi position switch. These modes can be changed between between in flight but there is only two that are NEEDED, which in simple terms, are "stabilisation on" and "off". The names are pretty self explanatory: if you're going to put a gyro in, then you may as well use it, hence the stabilisation on, and if it all goes pear shaped, the be able to turn the thing off! Any other modes (e.g. lock, hover) are optional extras that you don't NEED.  (I treat them as  marketing gimmicks, while they might offer some use to some situations, they are not needed for a beginner with a high wing trainer). Again, being able to change modes uses another Rx channel. 

The most important thing to understand is what (almost) and gyro doesn't do. It isn't an autopilot. It will not recover you from a stall (and can make a stall situation worse). It will not prevent crashes. A properly set up gyro makes a small plane fly like a big one, makes things smoother, and makes flying in windier conditions easier. 

 

10 hours ago, Futura57 said:

Can be bought for less from Banggood and the like. Don't know if they are cheap copies though.

Not directed at Futura57 specifically.

All mine have been from Aliexpress, no problem. I don't think Motion have their own Eagle gyro factory. So get whatever from whatever floats your boat.

Edited by Dale Bradly
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Regarding the A3 Lite gyro, I didn't use a Y lead for ailerons, but I expect it wouldn't be a problem provided your two servos need to rotate in the same sense. If not, then a little inline servo reverser widget will be needed for one. Anything beyond that, such as aileron differential, end point adjustment  etc then look for a less basic gyro.

 

In point of fact I use the gyro in delta wing configuration for elevon control. In this mode the A3 Lite converts the separate aileron and elevator signals (inputs to the gyro) into the two elevon servo signals. I can't remember which two outputs, because the gyro is tucked away inside my model. Elevator trims, subtrims, etc act on both elevon signals according,  but differential is not possible. You'll have to arrange a suitable mechanical setup for that.

 

I use all three gyro modes: Off, Normal and Hold on my tx flight mode three position switch. My flight modes also bring in different levels of vectored thrust control on my EDF jet. Mostly I fly on Normal gyro mode with the VT pitch and yaw mixed in with elevon pitch and rudder, respectively.  Because this mixing takes place at the tx end of business, the gyro only operates the elevons and rudder, not the VT, sadly. I occasionally switch into gyro Hold mode ( flight mode 3) for some slow high alpha passes.

 

During initial gyro setup in a model, the Hold mode is handy to check the sense of direction of each flight control because you can slowly move the model in each axis and see how the gyro reacts. Doing this in Normal mode you have to move the model more aggressively and look carefully for the gyro's momentary corrective input.  I hope that makes sense.

 

I had to dial down the aileron gain very slightly by adjusting the little potentiometer on the gyro unit. Other than that it just works. I have no need to faff about adjusting gains between flights or in flight.

 

As has been said, the gyro makes the model feel larger, with more inertia,  and way smoother in flight.

 

I think I will buy my next A3 Lite from AliExpress 😉

 

 

 

Edited by Futura57
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Members of my club still use separate servos on separate rx output. It's how they told me to do it.

 

They simply use the giro on one aileron output. As it would still adjust roll.

 

Seems to work OK. True on some aircraft types you may get adverse yaw when the giro commanded movement. But again it would correct that with rudder.

 

It's how I'll be doing it in one of my less valuable planes. I have one but not got around to setting it up as yet.

 

Mostly because I learnt post single channel but pre servo reverse, expo, dual rate and computer.

 

Hence for general flying I don't see the need.

 

But to help smooth out some aeros while learning stick moment is what I've considered one!

 

Background to that is...

 

I fly mode 2 aileron elevator on my right stick.

 

I flew slope for years mode 1. But being left handed I switched because it helped when launching having elevator on the right stick... but I have a fused thumb knuckle on my right hand from an injury age 18... So I always get some aileron elevator couple!

 

 

 

 

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6 minutes ago, Nigel Sharp said:

They simply use the giro on one aileron output. As it would still adjust roll.

 

It does, but it can in certain circumstances cause an issue.

 

If the pilot has put in some aileron deflection to bank the model, for a turn for example, and a gust of wind deflects the model at that time causing the angle of bank to increase further, the gyro can cause the aileron on which it is operating to move in the same direction as the non-gyro controlled aileron on the other wing. If that happens to the aileron on the wing on the inside of the turn, both ailerons could then be in the downwards direction, possibly causing a stall.

 

It's a specific scenario I know but I've seen the effect of it on a friend's Piper Cub. It's worth bearing in mind at least.

 

Brian.

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I've never used one before so have no experience of gyros but I've just ordered a Hobbyeagle A3 Lite to play round with.  The plan is that switching from 'off' to to 'heading hold' mode will keep a soarer into wind whilst briefly 'hands off', like the old F1E magnet-steering idea. I think the challenge will be drift over time - hoping it will hold its direction for maybe 30 seconds?...   intrigued to find out, if nothing else its something new to play with  :)

I did do a homebrew unit based on a magnetometer (a solid-state compass) but didnt realise that they are equally affected by changes in pitch as well as direction, so although it worked as per the datasheet, in practise it was a fail 😏

Cheers

Phil

Edited by Phil Green
typo
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Are you suggesting that the Earth isnt flat Andy?    😁

I wonder if anyone has played with the Adafruit BNO-055 or 085 absolute-orientation module?  
A bit expensive around £35 but does all the 3D spacial arithmetic through an on-board Cortex M0 processor 😊

(which is nice...)

 

 

 

Edited by Phil Green
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On 14/11/2024 at 22:34, Phil Green said:

Ron, if you've time could you summarise the Chinglish description here please:

https://www.hobbyrc.co.uk/radiolink-byme-flight-stabiliser

I've never used one but maybe I could use a switchable heading-hold to keep my gliders into wind when climbing gates etc 🙂

Ta

Phil

Sorry Phil, I missed your question! The ‘vertical hold’ function is the one that keeps the model straight and level but is not a heading hold mode as the model can still be manoeuvred but excessive movements are prevented. For true heading hold you really need a flight controller and gps.

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Funnily enough I've just fitted my very first Gyro in any model except helis. An ARTF Yak, electric and  about 40" span of unknown provenance from my late friends collection. An Eagle Tree A3 with the three flight modes and three trim pots. Twelve quid from Aliexpress. The Yak is a nice little model but does get knocked about a fair bit from the turbulence on breezy days from some high ground to one side of our field. I'm very behind the times - plenty of my club mates use gyros from simple little models like mine to quick EDFs and big turbine models - better late to the party than never.

Straightforward to install although I did have to convert to a Y lead on ailerons - gain set to about 25% - switchable, so I'll take off with no gyro and see what happens and switch it in and tweak the gain to suit. Individual gain settings for A E & R would be handy - maybe available on more high end gyros?

Not a great deal of reaction from elevator or rudder when I was testing the install to check for correct operating sense  - much more noticeable corrective movement on ailerons. I guess too much is worse than not enough to begin with. My mate originally fitted out the model with cheapy 9g analogue servos which have been ok up to now, but I'm guessing that better and faster units (digital) would be of benefit. Any comments most welcome.

 

 

 

Nice to be doing something a bit different.

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Thanks Ron, meanwhile I've ordered a Hobbyeagle 3 Lite to try,  it will be easier than the Byme as its PWM in-and-out. Experiments with GPS proved ineffective in a sloper where the model often has a ground speed of zero - GPS vectors of course relying on movement. The HMC5883L magnetometer board does work well but the pitch problem is huge - for conventional compass use it has to be rotated about a perfectly level plane.  If its pointing due South and reading 180 degrees, inclining the PCB whilst maintaining the South heading gives an error of +- 30 degrees or so.  As Andy says, this is expected but I'd not thought it through!  in the magnet glider class F1E its probably not a problem as they're very stable and sit perfectly level until D/T time.  As a straight replacement for the traditional F1E hardware, it does emulate the magnet rudder concept very well. But for interest I might give the BNO-055 absolute-orientation module a try. 

 

C8: you're late to the party? the partygoers will have left by the time I catch up :)

As you say its nice to try something different. In the past I've always thought it was cheating but my excuse is its for one specific job 😁

 

Anywho, sorry for the off-topic diversion - back to camera gimbals?

Cheers

Phil

 

 

Edited by Phil Green
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44 minutes ago, Cuban8 said:

.................. My mate originally fitted out the model with cheapy 9g analogue servos which have been ok up to now, but I'm guessing that better and faster units (digital) would be of benefit. Any comments most welcome..........................

Keep an eye on them.

After several years regular use I burnt out a couple of Hitec 5065 servos a few months after changing to a gyro receiver. They can be doing a lot more work if gyro controlled in turbulent conditions.

The replacement Savox digitals survived OK for a few more years.

 

Dick

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11 minutes ago, Dickw said:

Keep an eye on them.

After several years regular use I burnt out a couple of Hitec 5065 servos a few months after changing to a gyro receiver. They can be doing a lot more work if gyro controlled in turbulent conditions.

The replacement Savox digitals survived OK for a few more years.

 

Dick

Thanks for that Dick - confirming what I had at the back of my mind. I'll test fly the model as is tomorrow if the weather holds, but I think it'll be wise to upgrade soon after.

Re my comment on seperate gains for AER - the Hobby Eagle A3 Pro (red case) has exactly that and a number of other useful features for under twenty quid. Think I'll get one to play with.

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21 hours ago, Ron Gray said:

Use the GPS for direction but airspeed sensor for model speed

Thats ok when the model has some groundspeed Ron but soarers can spend quite a lot of time stationary, then GPS cant resolve a direction 🙂

Hmmm.  I'm talking myself into buying the BNO055 absolute orientation sensor 🙂

 

 

Edited by Phil Green
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Test flew the Yak yesterday with the gyro and I must say that the benefits are well worth the trouble (not that much trouble actually) of fitting and setting. A reasonably breezy day that with the unit switched in had all the lumps and bumps of turbulence on approach smoothed away. 25% gain was pretty close, just a tweak up another few % seemed a good compromise.

A very valuable aid to flying - if you've not bothered to fit one, do give it a try.

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