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I reckon this is the cause of flyaways

Discussion in 'General Discussion' started by discv, Sep 29, 2013.

  1. discv

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    By flyaways, I mean where pilot error and other external influences can be positively ruled out.

    I have been studying this occurrence since the beginning of the year. Many reported flyaways, when looked at in detail, are in fact nothing of the sort.

    Recent reports that spring to mind- a guy flying in a 20 knot wind lost his, another flying right under HV electricity cables, Gopros with wifi left on, and so on.

    So, looking closely at the genuine flyaways, and then narrowing it down to just more experienced fliers a common factor emerges.

    Namely the stock RX [onboard receiver]. I am struggling to find one case in my narrowed down list of experienced fliers getting a flyaway.

    The transmitter can be excluded as a suspect- knowledgeable pilots will have this switched off.

    The Naza can be excluded. It is not unique to the Phantom, and has a good history.

    That leaves the stock RX as the, almost certain, culprit.

    So, you may say, why has DJI not told us? My view- I think they know. But how in the world could they go public. Imagine the cost in replacing the RX in every craft they have sold- and the consequential loss claims..........

    I am so sure I am right, that I have grounded my Phantom till I can afford a Futaba TX/RX.

    Final question to you guys, anyone had or know of, or even heard of a dead cert flyaway that DID NOT involve a stock RX
     
  2. Ksc

    Ksc

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    quick noob question. TX and RX. What is what? Is the RX this: http://www.intelligentuas.com/DJI-Phant ... e=receiver and the TX this: http://www.ebay.com/itm/DJI-Remote-Cont ... 3385c23718

    or vice versa. I just fried my stock remote (this: http://www.ebay.com/itm/DJI-Remote-Cont ... 3385c23718 ) and was trying to find another. Should I say screw it and buy a futaba? Also, I assume I need a futaba for the flame 450 I just got, can I use the same futaba for both? Obviously will need to fly them independently.
     
  3. discv

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    Yes, you have highlighted the receiver/RX/fitted within the craft, and the transmitter/TX/ the bit you hold.
    These are the two parts I am ditching. They also will end up on Ebay- No returns accepted!
    I will be replacing them with a Futaba 8J transmitter and a futaba receiver. In your case the transmitter and two receivers [ one for each craft]
     
  4. The Editor

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    Yes - I came to the same conclusion some time ago although I think you are being too kind on the TX as well (that's a piece of junk as much as the stock RX :lol: ).

    In answer to your last question - NO. I have not heard of a single so called 'Fly Away' where an good aftermarket TX/RX has been fitted.
    In fact if you trawl through the posts and forums you can usually see one of my post shortly after a reported flyaway simply asking "Stock TX/Rx or after market?" In every case that I've come across I get the answer back "Stock".
     
  5. BruceTS

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    I replaced my stock Tx/Rx simply because I'd lose range too quickly.

    Ksc, yes if you fried your stock system, you'll be better off replacing it, many of us use the Futaba T8J. You can also use the same radio on your F450, just buy another Rx. I use mine on my TBS Discovery as well and have a separate profile saved on the Tx.
     
  6. RedFishChaser

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    Hi, thanks for this thread.

    Other than stock RX/TX, how does one go about installing and tuning (or whatever the terminology) once getting a replacement like the Futaba?

    Does the Futaba T8J come as a package of TX & RX?

    Thanks.
     
  7. discv

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    Yes - I came to the same conclusion some time ago although I think you are being too kind on the TX as well (that's a piece of junk as much as the stock RX :lol: ).

    In answer to your last question - NO. I have not heard of a single so called 'Fly Away' where an good aftermarket TX/RX has been fitted.
    In fact if you trawl through the posts and forums you can usually see one of my post shortly after a reported flyaway simply asking "Stock TX/Rx or after market?" In every case that I've come across I get the answer back "Stock".


    In no way I being kind re the TX. I agree totally it is bin fodder. And the bin {or Ebay] is where it going :twisted:

    However, I am certain it is not the cause of REAL flyaways.
     
  8. discv

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    So far as I understand the T8J is supplied with a suitable receiver for the Phantom, and it is not rocket science to configure.
    But I will be finding out :D
     
  9. The Editor

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    The T8J Transmitter usually comes with a D-Bus RX like the R2008. Fitting it is simplicity itself (even for non tech savvy).

    Unscrew the top shell of your Phantom. Undo two small phillips screws holding the stock rx in place. Pull thru the antenna cable from the leg of the old rx. Unplug old RX (one plug).... plug in new Futaba RX (same one plug). That's the hard bit done :lol:
    Use some double sided tape or similar to secure the Futaba RX in place. Feed one antenna (the Futaba has two) wire back thru the leg and tape like the original, feed the other one at circa 90 degrees across the inside of the Phantom. Screw the lid back on.... Job done !
    Will take a noob no more than 15 minutes tops.

    To set up the Transmitter, your best option is to follow some of the very good set up video's on You tube (they are very informative.

    Go into Naza assit and select D-Bus as Rx type, do a complete stick calibration. make sure all you switch/stick inputs do as they should do by checking the sliders in the assit software..... Then go and fly and have fun with a warm fuzzy feeling that your set up now is VERY unlikely ever to suffer a 'Fly Away' !!! :D
     
  10. martcerv

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    I did lots of flights wish the stock tx/rx along with pushing it way beyond where it should have been. I lost range plenty of times with it but never had a flyaway issue, I have seen posts where the rx has physically failed and also the tx so they are pretty cheap and nasty parts but mine was pretty solid for what it was. Definitely an upgraded radio setup will be a big help especially if your going to get more rc flying toys in the future where you just need to buy an extra rx for each and can setup multiple models on any good radio easily.

    I ended up going with the futaba 8fgs which I have also given a few stress tests, sure id have much more faith in the futaba but for basic flying in most cases the stock isnt terrible or guaranteed to cause flyaway issues. Having only used one stock phantom radio my views are only based on that one unit which never failed me beyond losing range a few times. It doesnt mean that no stock radio setup wont ever fail and cause a flyaway but it also means that not all of them will.
     
  11. GeneL

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    Good information in this thread. I would highly recommend that anyone that is serious about flying their Phantom step up to one of the more sophisticated and versatile radios. Once I got my Futaba 8J, I wondered why I tolerated flying so long without it. I bought it for my new f550, but then decided to get an extra Rx for my Phantom, too, and never regretted it.

    It's very easy to install and set up. If you do get the 8J, Richard Whelan did the definitive video how to install the Rx and configure the Tx to work with functions similar to the stock radio.

    http://youtu.be/jRUDKZGhwuU
     
  12. rilot

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    I doubt that all flyaways are caused by the stock Tx/Rx. If that were the case, flyaways would not be happening with other copters that use the Naza.
    Check out Rrcgroups or djiguys or multirotorforums and there are plenty of people with F550s, F450s and S800s with Naza and Wookong that have had flyaways with every radio under the sun including DX8s, T8Js etc.

    I think it's a problem with the Naza code crashing in such a way that it overwrites the registers that store the home location. Maybe due to vibrations or some other thing.
     
  13. discv

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    When I first posted this thread, I thought that maybe I'd get my legs shot from under me! Clearly not the case.

    So I will add a couple more observations/trends on flyaways.

    Playing with the numbers, and factoring in guesstimats, I concluded that less than 5% of all Phantoms will suffer this.

    Almost all cases that I have been able to research in detail, show that the Phantom had been flying normally. It then behaved as if both sticks had been put fully forward. The craft went up and forward at speed.

    Naza and gyros were still functioning, it would seem in Atti mode. No swerving or spinning.

    The above two trends rule out the possibility of spurious wifi etc. signals. They would not cause this single flight behaviour, we would have reports of craft flipping/spiralling into the ground etc.

    Of the Phantoms that had been found, or had handed back control, most seemed to suffer the problem yet again at some point.

    So what we really need to find, is an RX involved in a genuine flyaway. Then test cycle it on the bench. We could then video a flyaway, but on a bench.

    At that point, I would wager, DJI would respond to emails re the issue
     
  14. discv

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    Your comments are noted and valued. I must confess that my research has been limited to the Phantom. To bring into the equation all craft fitted with a Naza would be a task beyond me.
    I understand your theory that the Naza might be involved, but question why a phantom, in the hands of an experienced flier, would suddenly decide to ignore TX input and seek out an incorrect home location

    As you say, there are many cases logged as a 'flyaway' that have been fitted with other than a Phantom stock RX.

    Forgive me repeating the question in my first post. Can anyone definitively come up with a genuine Phantom flyaway were the stock RX has been replaced with a Fubata
     
  15. rilot

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    F550 with Naza M V1 (Same as the Phantom) and Futaba Tx: http://www.djiguys.com/Forum/viewtopic.php?f=7&t=1175
    Another F550 with Naza and Futaba: http://www.djiguys.com/Forum/viewtopic.php?f=7&t=1219
    F550 with Naza and Spektrum DX8: http://www.djiguys.com/Forum/viewtopic.php?f=7&t=716
    QAV with Naza and 12FG Futaba Tx: http://www.multirotorforums.com/showthr ... ht=flyaway
    S800 with Wookong and Futaba T8J: http://www.multirotorforums.com/showthr ... ht=flyaway

    As you can see, the only common component is the Naza controller. I am utterly convinced that the Naza and Wookong are flawed and no matter what you do, if you fly enough time you will eventually get a flyaway.

    DJI have never commented on any flyaway events.
     
  16. martcerv

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    Overall its very hard to say any definitive cause for a flyaway and 95% of claims id say are simply pikot error or radio interferance. The amount of NAZA units flying will have a few cases of issues that may come up and this may seem a large number to some but when out into perspective with the total amount in use the percentages are very low. Add to this the high number of variables in every single case and the simple fact that there is no definite pattern to these flyaways.

    Now compare this to the issues with the new qx450 which has a clear manufacturing and assembly fault causing a very high percentage of prop failures and crashes. This is a widespread issue effecting nearly all of these units within the first few weeks of launch and all being consistant in the issues they suffer. The most ironic thing is how many people were scared of naza flyaways and went for that rtf quad instead and it has a much greater issue with likely more prop failures already reported in its first weeks of sale then NAZA flyaways or DJI prop fails over the last couple years.

    I have pushed the Phantom to its limits on hundreds of flights, if there was a system wide issue causing flyaways then mine would surely be gone by now. The NAZA is an amazing bit of kit and is pretty solid in my use, sure its not perfect but its far from what many people claim to make it out to be.