Crash video: X8 with KDE 4014 into the water!

Discussion in 'Cinestar 8' started by Bryan Harvey, Jun 21, 2014.

  1. Sam Fleishman

    Sam Fleishman Member

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    Hey Andy,
    Is there any reason to use bullet connectors larger than 3.5 on ESCs or motor wires? I'm talking about heavy lift applications. U7 size motors and 70+ amp escs. I ask because everyone uses ec5 connectors and those have 3.5 bullets. The new KDE motors and ESCs have 4mm and up bullets but is that necessary. The power hungry board only has 3.5mm bullets.
    I would love to hear everyones thoughts.
     
  2. Steve Maller

    Steve Maller UAV Grief Counselor

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    I'm using 4mm Castle bullet connectors throughout, and not only is it a slightly more robust connection, but the mechanics of the Castle bullets are more sound than many of the other bullets. Holger Buss did a deep diagnostic on a crash that somebody had and found that solder flux had contaminated a bullet connector and rendered it marginally effective, and it had failed under load. This seems less likely with the Castle design. I experienced some motor restart issues at one time, and I discovered that I had mistakenly used one of the old-style bullets on a few of my motors. Once I replaced them, I haven't seen those motor issues since.

    http://www.castlecreations.com/products/ccbullet.html
     
    Michael McVay likes this.
  3. Michael McVay

    Michael McVay Active Member

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    Thanks for the tip Steve...this is something I should probably switch to.
     
  4. Sam Fleishman

    Sam Fleishman Member

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    Hey Steve,
    I'm running dji, what type of power distribution board are you running? Should I make a 12 gauge pdb wire harness for my pdb? With 10 wires for dual ec5s?
     
  5. Sam Fleishman

    Sam Fleishman Member

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    10 gauge I meant
     
  6. Steve Maller

    Steve Maller UAV Grief Counselor

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    I'm not a big fan of custom wire harnesses unless you're a super good technician. I use the MK PDB with built-in ESCs (BLs in their terminology). Some folks use the Power Hungry Systems power distro boards. Beware the cheap imitations of that board.
     
  7. Sam Fleishman

    Sam Fleishman Member

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    The problem with the power hungry board is it only comes in 3.5mm bullets. Kde told me not to use 3.5mm
     
  8. Sam Fleishman

    Sam Fleishman Member

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    Is there a solution out there?
     
  9. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Sam I have built a few power distro's before using a bunch of deans connectors glued together. Then put deans connectors on the ESC power wires and just plug them in. Works really well and haven't had any issues.

    Josh
     
  10. Josh Lambeth

    Josh Lambeth Well-Known Member

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  11. Jason Lee

    Jason Lee New Member

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    I have been interested in getting these KDE motors. The specks look great and so does the mechanic build.

    There have been several documented crashes concerning these motors and the A2. I am very skeptical as if the problem is the motors. All copters were flying an A2.

    Recently, a client of mine crashed his flat octocopter after 7 months of hard use. The reason is unclear but it it started yawing uncontrollably before it crashed. It too was flying an A2 (firmware tbd) but with TM3515.

    Any thoughts?
     
  12. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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  13. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

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    Josh sorry to disagree a little here there has been another case just like Brian where the shaft broke in mid air and this one was not flying an A2

    "Quote"
    Well guys, I don't know what to say but I had exactly the same problem as Bryan.

    Today, while fyling, one of the motor's shaft broke and I could hardly land. While the case of the motor flew away, it also damaged the prop on another motor. Basically, I lost almost two motors. The motors are KDE 4014XF 380KV.

    MK FC handled it pretty well, I could land it without incident. Before this flight, I changed two of these KDE 4014XF motors due to other problems, which I will talk about in another topic.

    First time in my RC life, a shaft broke. I always use perfectly balanced props, always take good care of these girls.

    Here are some pictures.

    [​IMG] [​IMG]

    My understanding on the entire Brian crash in to the water thread is that the impact to the water is not the reason why the shaft broke
    I am also flying on one of my copters a A2 and so far ok but with all happening Im so scare of a suden surprise, you analyzed your incident very well and all the sense point to the A2 failure, but in Brians case it doesn't point that the failure was A2 related never the less I could be wrong
     
  14. Jason Lee

    Jason Lee New Member

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    Jose,

    I know KDE updated their shaft material. When did you buy these motors and what is your AUW?

    Thanks
     
  15. Tristan Twisselman

    Tristan Twisselman Active Member

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    They didn't update their materials until these shafts broke. Also the photos above aren't of Jose's copter but someone else on the forums, he was just quoting them. One thing is for sure, at least one KDE motor seemed to have for sure broke the shaft mid flight, one possibly broke during flight and was flying A2, and one A2 just crashed using KDE motors but it seems to be an A2 issue.
     
  16. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

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  17. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

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    Hi Tristan I would love to know like many others the real, real reason why the A2 are having trouble I own one and Im so afraid of a suden surprise base on other bad experiences, specially when DJI is now where to be found but to be objective or maybe to make diagnostic even more difficult the other day flying my A2 copter I lost 1 motor in mid flight I clearly saw the prop stop I was able to land easily with out any fight no yaw or anything drastic and I was in GPS it was a bad bluet connection fix it and flew again
     
  18. Tristan Twisselman

    Tristan Twisselman Active Member

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    You and I both. I have had some issues with my WKM at times a year or so ago and DJI never really admit to doing anything wrong or a fault in their product. More so now than ever I think DJI is just about making money and is more concerned about pumping out product and selling it then taking care of their customers.
     
  19. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

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    let me give you an funny example of how disconnected DJI are from customers I sent a email to the chines address thinking that I would get closer to some one from software engineering with a simple request on the Iosd II here is the exchange:

    jose Luis Ocejo
    Aug 07 06:52
    Hi I have a Iosd II many times the graphics can not be read on the monitor because they are mostly white specially the ones on the top of the screen against a light sky is it posible that your tech team look in to a firmware update to be able to change the seize and the color of the Graffics
    Thank you


    Zach Zhang (DJI)
    Aug 07 20:46
    Dear Jose ,
    Thank you for contacting DJI Technical Support.
    Would you share me a picture to me, i want to know about it more clearly.
    Thank you for choosing to fly with DJI.
    Best Regards

    Its like !!!!! really
     
  20. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

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    Guys this bullet connector topic of size, type, and the quality of the solder job, could very well be a reason for failures copters loaded 20+ lbs, current picks, generated heat, time,
    do we know what is the limit on 3.5 Bullets
     

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