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Transmitter / receiver issues, help needed pls

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DAIRE CONNOLLY19/06/2019 22:59:43
11 forum posts

Hello all. I'm new so please be gentle!

After getting myself a small RTF plane for Christmas I asked my wife to get me a kit plane as I like tinkering in the garage etc (who doesn't). Anyway, after getting my new toy built I had to buy an rx tx combo. I decided to go with the fly sky fs-i6 mainly due to the price but also reviews suggested it was cheap and cheerful. Being new to this I took my time setting everything up and testing each servo as I connected it up.

Problems started when I got the alerons connected on the wings. I noticed that if I moved the two sticks simultaneously sometimes the servos would blip and go a bit crazy, but recover quickly. Then I noticed if I moved both sticks and let them go all the servos would go nuts, the tx would beep alot an the servos would keep trying to rotate. At this stage if I powered off the tx the motor would light to 100% power - not good.

So thing that I'm here for is to ask if there is something I am completely not grasping or if I just have a bogus tx or rx?

Any help is much appreciated.

Phil Green19/06/2019 23:13:26
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1531 forum posts
309 photos

Hi Daire, first of all when setting up, always remove the prop

The jittery problem is almost certainly a battery or BEC that isnt up to the current demands of your setup.
The supply is sagging under the demand of all your servos centring simultaneously, and the transmitter beeps are most likely the telemetry reporting this very problem.

You dont say if your model is IC or electric powered - for IC you need a good quality 4-cell battery (eneloops and Vapextec 'Instants' are very good) and for electric your BEC (usually part of the speed controller) should be adequately specced - say 3 amps.

With a solid power supply I'm sure the jitters will be gone.

Regarding the motor powering up (ah I see now its electric!) make sure your failsafe is set to low throttle and that your throttle channel reversing is set up appropriately (forward stick = fast, stick back = slow)
This is where fingers have been lost, always remove the prop when experimenting.

I very much doubt you've bought a lemon, the FS i6 is a great set, I was surprised when RCM&E omitted it from their 'best budget sets' article as I would place it top of the budget class.

Cheers
Phil

 

 

Edited By Phil Green on 19/06/2019 23:22:08

Ernie19/06/2019 23:25:09
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2513 forum posts
20 photos

Hi Daire, A wee bit more information would help. Normally there is one servo in each wing to control the ailerons. The two leads can be joined by Y connector, and connected to the servo output on the reciever. OR one lead goes to the servo output, and the other goes to a spare output, and the whole caboodle is sorted on the menus in the transmitter.

What certainly doesnt sound right is two sticks. ailrons are always controlled by one stick

what setup do you have

whate plane is it

are the batteries well charged

ernie

DAIRE CONNOLLY20/06/2019 03:55:44
11 forum posts

Hi folks, thanks for the replies so far.

The plane is electric powered, not 100% sure of what exact motor but can check tomorrow. There are 4 servos, two in the wings, one for rudder/front wheel and one for elevators. Alerons are connected via a y connector though I did try separate channels mixed and had the same problem. And yeah, controlled by one stick. Battery is fully charged as I thought this could be problem.

The esc is 20a and the battery 20c, 3 cell, 3000mah - should the batt be higher? The esc also feeds the rx through channel 3. The plane is a foam and ply construction from Amazon, think its called dancing wings, again cheap and cheerful for my first go. The esc and motor came with the kit.

So do I need a larger 'c' battery or is the esc possibly at fault here?

Edited By DAIRE CONNOLLY on 20/06/2019 04:16:04

Trevor Crook20/06/2019 07:29:29
874 forum posts
65 photos

The battery you have should be fine. My money would be on the ESC. I had an identical problem occur only last weekend, with an ESC that had previously been fine. I tried two others that I had in my "come in handy" box and they both powered the rx with no problem.

Strangely, monitoring the regulated voltage from the faulty ESC didn't reveal any abnormal drop when the servos were moved. Something more subtle must have been going on that would only be visible on an oscilloscope. Anyway, it's binned now!

Best to buy another ESC. Make sure it'll give at least 20A with a minimum 3A BEC.

Denis Watkins20/06/2019 07:30:48
3929 forum posts
61 photos

Just to add, while the lads prepare to answer Daire,

Take the prop off, it will harm you indoors

Your failsafe is upside down, throttling up with no signal

So rebind with the throttle down

If the motor still springs into life on switching the Tx off

Then reverse the throttle

Your battery pack does appear adequate size at this point

Dont go spending yet

Edited By Denis Watkins on 20/06/2019 07:31:32

DAIRE CONNOLLY20/06/2019 08:27:07
11 forum posts

Again thanks for the responses.

I am a little embarrassed to admit it but I did learn the hard way regarding removing the prop when on the bench. The first time this went haywire, I had the prop on (god knows why) and it took a bite out of my arm... 7 stitches later the prop was off.

Trevor - I presume I can go for anything over 20a for the esc? No harm in going higher?

Denis - I will 100% get this failsafe reversed as I can now make it fail regularly so I'll do that today while I wait for a new esc.

Simon Chaddock20/06/2019 08:49:30
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5483 forum posts
2878 photos

Daire

You appear to have an issue when the servos are moving so the best course of action is to check things logically one by one.

First disconnect ALL the servos from the receiver leaving just the ESC connected in its correct channel as this provides the power to work the receiver..

With the prop (already!) removed now only the motor should turn when the throttle stick is moved from off to full speed.

If all is OK then connect one servo, say the elevator, to its correct channel and check it moves correctly with the appropriate stick movement.

Does the servo make a buzzing noise when it is at full travel? If it does disconnect the linkage from the servo arm so there is no load on the servo. Does it still make a buzzing noise?

If it does then there is something wrong with the servo. If it doesn't then the linkage is putting en excess load on the servo and leave it disconnected. You have identified one problem but there may be more.

Add another servo to the receiver and check it works as it should and so on until you have all the servos working correctly.

If to achieve this you have servo linkages disconnected then you need to investigate what is causing the stiffness. A common cause is unduly stiff control surface hinges.

By this sort of logical approach you should discover which servo(s) is/are causing the problem and hopefully why.

You did say you like to tinker!

Do let us know how you get on.

Frank Skilbeck20/06/2019 08:53:41
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4515 forum posts
101 photos

One other thing to check is that you haven't got a faulty servo which is overloading the ESC BEC (which powers the receiver and servos), we had this on one model and only found it after the problem persisted with a 2nd ESC.

You can test this by unplugging each servo at a time.

Romeo Whisky20/06/2019 09:05:02
713 forum posts
193 photos

One possibility that occurs to me is that you've got the transmitter very close to the reciever or getting signal "bounce" inside the garage.

Try it outside and stand with the transmitter a few feet away and see if that's better.

Don't forget to remove the prop first or restrain the model firmly.

DAIRE CONNOLLY20/06/2019 09:08:57
11 forum posts

Ok guys I'll check each one, one by one at lunchtime today. I only have seen this issue when all 4 servos are plugged at once but I haven't yet checked each on individually. Let me try that.

Romeo Whisky20/06/2019 09:14:29
713 forum posts
193 photos

By the way, I know the manual for the FlySky is vague about a lot of things - especially the fact the Expo should be negative. There is a good programming tutorial for this transmitter

HERE

Max Z20/06/2019 09:29:40
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527 forum posts
238 photos
Posted by DAIRE CONNOLLY on 20/06/2019 08:27:07:

Denis - I will 100% get this failsafe reversed as I can now make it fail regularly so I'll do that today while I wait for a new esc.

Correct, reverse the failsafe, NOT the throttle. The Tx should show the throttle channel as "Normal", not "Rev", practically all ESC's should then initialize properly. Sometimes it will be necessary to trim the throttle channel all the way down as well. By the way, "throttle closed" is pulling the stick towards you, as you probably know by now, but it is a known beginner's error.

Max Z20/06/2019 09:38:24
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527 forum posts
238 photos
Posted by Denis Watkins on 20/06/2019 07:30:48: So rebind with the throttle down

Denis, I am sure you meant to say initialize (the esc) with the throttle down. Binding is the process of connecting the Tx and Rx, and has nothing to do with the throttle position. This to clarify it to Daire.

Denis Watkins20/06/2019 09:46:57
3929 forum posts
61 photos
Posted by Max Z on 20/06/2019 09:38:24:
Posted by Denis Watkins on 20/06/2019 07:30:48: So rebind with the throttle down

Denis, I am sure you meant to say initialize (the esc) with the throttle down. Binding is the process of connecting the Tx and Rx, and has nothing to do with the throttle position. This to clarify it to Daire.

Thanks Max,

We do try to explain so much in a few words

It is simpler to do than it is to explain

DAIRE CONNOLLY20/06/2019 11:51:49
11 forum posts

Right, update. Seems it's not one servo causing the madness but combinations. If I have 2 servos, any 2, everything is fine. If I have 3 attached I get random glitters in movement and if I have all 4 I get the madness. At that I think I'm ruling out a servo problem for now. What I did notice this time was the rx went back into flashing led mode (like it had just been started). I checked the esc, its an epower 20a - looking online it has a Bec of 2a only - could this therefore be the culprit?

I got to the failsafe settings in the tx, all channels set to off. No matter what I told it to do with channel 3 the throttle still spun right up - more messing needed there I think.

FlyinBrian20/06/2019 11:59:47
527 forum posts

It does indeed sound like a power problem, the ESC's BEC (Battery Elimination Circuit) can not handle all servos at once. Either get a new ESC with a BEC of min 3 Amps or use a NiMH 4 /5 cell battery pack to power the RX/servos. If you use a battery you will need to remove the red wire on the ESC lead that plugs into the Rx.

Good luck

Max Z20/06/2019 12:44:59
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527 forum posts
238 photos

2A seems ample to drive 4 servos, especially when these are not seeing any flight loads. Unless the servos are digital types which are famous for drawing a high current just to get moving. It sounds more like high friction control linkages to me, have you heeded Simon's advice and uncouple the servo linkage while testing?

Or indeed your esc is a rotten apple and needs to be binned and replaced.

Edited By Max Z on 20/06/2019 12:46:32

DAIRE CONNOLLY20/06/2019 12:49:21
11 forum posts

Sorry - I thought I edited the last post - all linkages are disconnected. I did this back at the start to save the control surfaces from being over stressed. so yeah - no load and still it goes mad.

Just ordered a 30a (with a 3a BEC more importantly) to arrive tomorrow. I'll get this on tomorrow evening / Saturday morning and see if its any better.

DAIRE CONNOLLY20/06/2019 16:08:22
11 forum posts

Hey, so I'm pretty convinced it's the esc now. Remember I mentioned the RTF plane I got 6 months ago, well when it bit the bullet (road, car, bang) I stripped it of all it's electrics so I still had the battery sitting here. It's only 3.7 volts but when I plug it is as a batt all servos work fine without issue. Just played with it for about 5 minutes there without a problem. Tx goes nuts because of the low voltage but it does work.

Anyway, new esc tomorrow hopefully will get to the bottom of this one.

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