DX6i Battery twitch

[Mutley]

Ok, let me explain.

After a few weekends flights and simulator sessions if i go out for a flight then i notic the tail twitching. It gives a twitch randomly causing a flutter. The reason why i think this it DX6i battery related is because if i change them then its fine again.

Now before i know you come back with the battery response let me just say that currently the battery status is reading 5.9/6.0. Now i think this is more than enough given people are reporting warnings at 4.3

Any suggestions ?, no reason to think its a faulty unit and always kept and looked after in a silver case when not in use.

Receiver is a ar6000 non satellite, all running in a trex450 sport and happens regardless of the 3s pack voltage. Odd, i've tried recabling and management as well.

Thanks for any eye opening - not even sure this would be the correct thread.

Ian

[glen_j]

could be corrosion of the battery terminals or a loose connection possibly?

[Mutley]

could be corrosion of the battery terminals or a loose connection possibly?

Thanks for the quick answer, I have checked the terminals but the unit is spotless. Also i've had somebody over my shoulder checking voltage and its constant at 5.9/6.0 from this weekend.

I'm thinking its signal, and i'm new to 2.4 setups so i am on a learning curve, i have also re-binded but i am currently looking at another receiver to rule out.

It is definately showing as more an interferance glitch than anything. Only happens on tail and throttle though - not cyclic.

Confused

[glen_j]

does it do it with a fresh lipo on the heli too? it could be a number of thing causing a twitch, how often does it do it? and can you repeat the results ie put the old batteries back in and it starts twitching again?

[Mutley]

i've got 4 packs, the 2 older packs have had under 15 cycles, (purchased January) the 2 newer packs have under 5 cycles purchase 3 weeks ago.

Happens on both packs, i've been chasing this a few weeks now and i know very quickly if i have a problem

I either get a clean flying session with all 4 packs or it happens in the first couple of mins

[glen_j]

so when you say you change the packs you mean on the heli itself not on the dx6? if thats the case it may be the lipos you have are on their way out and the voltage is dropping under load, the tail twitch could actually be the low voltage cutoff on the esc designed to prevent you from overdischarging the lipos

[Mutley]

so when you say you change the packs you mean on the heli itself not on the dx6? if thats the case it may be the lipos you have are on their way out and the voltage is dropping under load, the tail twitch could actually be the low voltage cutoff on the esc designed to prevent you from overdischarging the lipos

Really ?

For the pack changes yes i mean on the heli itself, odd though, from my last flight out (Sunday 6th) i used 3 packs, 2 new, 1 old. All perfect and came home.

Charged when i got in and they took an hour to charge at 2.0amp. All cells reading virtually the same voltage as well.

They really do have a kick in them though when first launch, theyve definately not lost there zip yet and gone sluggish.

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As you can see i have done quite a bit of troubleshooting before posting hense i'm struggling

Thanks for your assistance

[Rob O]

How long into the Flight is this happening , and what if any setting do you have on your timer ? Rob.

[scallybert]

Receiver is a ar6000 non satellite, [...]

Actually an AR6000 ? Not a 6100 ?

Spektrum RXs don't like static, which can be caused by tail-belts, etc.

You want QC firmware (V1.6 or above on 6100, 6200, etc).

The behaviour of the RX LED(s) may give a clue.

Tail twitch could also be caused by your gyro, ESC, powertrain, etc, etc (as people are saying.)

[glen_j]

check/re solder the deans connector and bullets on the esc/ motor a duff connection would give an intermittent kick. what esc do you have on the heli? does it have a governer mode if so make sure it's turned off

[scallybert]

what esc do you have on the heli? does it have a governer mode if so make sure it's turned off

Ooh - that's out of order..!

A bad, or badly configured governor can cause tail misbehaviour - but good ones are great.

[glen_j]

Ooh - that's out of order..!

A bad, or badly configured governor can cause tail misbehaviour - but good ones are great.

lol only to rule it out

[Mutley]

cheers guys,

So quick hover last night, thought i'd change the tx batteries last night anyway to rule out, also pulled the rx out of its hole from under the gyro and cable tied it again but looser and further out of the chassis.

Still does it. No govenor (never liked them) i'd rather throttle curve it.

70% throttle curve (reduced from 90 i normally run in normal)
Gyro gain 60%

Now, all fresh batteries and new pack, first 30 seconds 2 glitches.

I upped the headspeed to 80%, i had one glitch but turned the heli 90 degrees (yes entertaining - not)

Upped gyro to 70%, slight hunting but manageable - no glitches at all dropped to 67.5%.

I left it at that as it was just a test.





Conclusion.

I can only come to 3 conclusions at this stage

1. There is rotational "noise" requiring rebuild. But exceptable.
2. Gyro under set and over compensating
3. A BIG oversight. About a month ago i had a crash which did a gear on the ds420 tail servo, in my wisdom i had metal gears left from a ds410 and put these in thinking that i would bullet proof the ds420 by making it mg - would this really cause the issue ?


I'm spending more time troubleshooting at the moment than i am flying, its very frustrating as its definatly 1 step forward 2 steps back.

Cheers for all the help though, much appreciated

[Mutley]

Just to clarify as i got the wrong received model marked.

Its actually this one. :-
Spektrum AR6110E DSM2 Microlite 6Ch Receiver End Pin SPMAR6110E


Now, i'm not liking the fact that it has reduced range so can i get recommendations on a respectable "proper" outdoor receiver - cost permitting.

Cheers
Ian

[glen_j]

i think you've hit the problem, the ds420 isn't a very good tail servo even on a 250 let alone a 450. i'd try another servo. i bet the problem goes away