Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

How long should I fly with stress cracks?

Discussion in 'Pro/Adv Discussion' started by Porc, Aug 31, 2016.

  1. Porc

    Joined:
    Oct 18, 2015
    Messages:
    106
    Likes Received:
    28
    My P3A has been growing a stress crack for the past year, basically since day one. It is just under a year old. It was small so I wasn't sure if I should wait or not to do something about it, since I may just get another shell that grows stress cracks right away. And, I was hoping that a shell replaced in the future may be stronger if I wait until such stronger shells exist. Today, there's a second stress crack and it's bigger, causing the led cover near it to rattle when I touch it.

    How long is it safe to keep using it? Problem is, I don't want to send it in for repair just before colorful leaf season... I was hoping to use it to video our home and land while it is all colorful. What's the failure mode for a stress crack anyway? Will it appear fine and then just break apart in flight and be wrecked? Or, is it more gentle failure than that?

    And, are the newer shells any better? Would DJI send me (or sell me) a shell and I have to put it in, or do I send the whole thing back? Note that I have occasional minor video flicker too, so sending in the whole thing may be better.
     
  2. iflyhelis

    Joined:
    Aug 15, 2016
    Messages:
    51
    Likes Received:
    5
    Location:
    Boston,MA
    You are out of warranty, but you might try to contact DJI & see if they can help you with your problem.

    If they won't help, I would say that you should try to repair the cracks using "JB Weld" it is a 24 hour cure epoxy that is strong as "Steel" I always used it on my helicopters clutch linings to keep them in place, the heat doesn't effect it! Regular epoxy would give out in one flight.

    So, make the mix of this two part epoxy then spread open the cracks a tad, then apply your mix with a toothpick inside of the cracks. Let cure for 24 hours, & you will be good to go!

    Kurt
     
    Porc likes this.
  3. Porc

    Joined:
    Oct 18, 2015
    Messages:
    106
    Likes Received:
    28
    One of the two cracks has no spread at all... I think it would just coat the outside of it. The other, I'm not sure... depends on how easy it is to get epoxy down a very narrow crack. I think a hair could get down it, but that's about it.
     
  4. phantomi

    Joined:
    Jul 17, 2014
    Messages:
    502
    Likes Received:
    62
    Can you post pics of the cracks?
     
  5. phantomi

    Joined:
    Jul 17, 2014
    Messages:
    502
    Likes Received:
    62
    Although it is easier to repair cracks outside, does doing it from inside presumably should get better results aesthetically and structurally?
     
  6. phantomi

    Joined:
    Jul 17, 2014
    Messages:
    502
    Likes Received:
    62
    My 4 months P3A has its first two hair cracks so I'm concerned.
     
  7. With The Birds

    Joined:
    Jan 4, 2016
    Messages:
    2,578
    Likes Received:
    734
    Location:
    Australia
    I would go for a replacement shell. A few good youtube vids to get you through the process . Worst case failure mode is loss of a motor in flight.
     
  8. Porc

    Joined:
    Oct 18, 2015
    Messages:
    106
    Likes Received:
    28
    And, I'm guessing loss of a motor would mean it would be totally unable to fly and would fall like a rock? I'd be surprised if the software was smart enough to try to compensate and power up the other motors at just the right power levels to try to keep it level. (Maybe some of those with 6 or 8 rotors would have a better shot at surviving a motor failure in flight?)
     
  9. Porc

    Joined:
    Oct 18, 2015
    Messages:
    106
    Likes Received:
    28
    Sure... this is my first time posting a pic here, let's see if it works without using IMGUR...

    20160831_211345.jpg

    20160831_211359.jpg
     
  10. With The Birds

    Joined:
    Jan 4, 2016
    Messages:
    2,578
    Likes Received:
    734
    Location:
    Australia
    Detached motor wont be pretty.

    Looking at your images im not suggesting you throw caution to the wind however i would still fly it pending repair (checking for any further deterioration after each flight). Once you see one apart ot will be obvious, if the cracks manage to extend around the perimeter of, or otherwise involve the motor mounting bosses (which form part of the lower shell) its all over.

    I have seen two part epoxy suggested for repair. From what i have read of others experiences here bondic (uv cure) seems to provide a good repair. Not all epoxies will give good adhesion strenth with the shell plastic.
     
  11. HWCM

    Joined:
    May 2, 2016
    Messages:
    657
    Likes Received:
    138
    If it is less than a year old, is it not still under warranty?
     
  12. Porc

    Joined:
    Oct 18, 2015
    Messages:
    106
    Likes Received:
    28
    I had thought so, but I admit I didn't go check. I have a few more weeks before its 1 year anniversary. I bought it October 18, 2015.
     
  13. HWCM

    Joined:
    May 2, 2016
    Messages:
    657
    Likes Received:
    138
    Dji will fix it under warranty and pay shipping both ways. Mine is in for crack repairs now. Hopefully it will be back next week. They quoted me a two day turn around. I live on the East coast, so shipping takes about seven days either way.
     
    rene van der meer likes this.
  14. rene van der meer

    Joined:
    Oct 16, 2015
    Messages:
    377
    Likes Received:
    70
    Mine will be one years old next week. I have sent it in for repairs. I have cracks only in the top shell.
     
  15. Porc

    Joined:
    Oct 18, 2015
    Messages:
    106
    Likes Received:
    28
    Thanks, this is good to know. I'll probably wait a few weeks so I can get in a couple more flights I was hoping to get in during leaf peeping season.
     
  16. phantomi

    Joined:
    Jul 17, 2014
    Messages:
    502
    Likes Received:
    62
    Thanks. Yours are worse than mine, but mine is just beginning and on its way. I'm sure has to be sending to dji in a couple of months. :-(
     
  17. Sonic Fusion

    Joined:
    Aug 30, 2016
    Messages:
    50
    Likes Received:
    17
    Dounin Front likes this.
  18. iflyhelis

    Joined:
    Aug 15, 2016
    Messages:
    51
    Likes Received:
    5
    Location:
    Boston,MA
    I just looked at your join date October, you may still have time to get DJI to warranty it! Go For It!

    Kurt
     
  19. rk2069

    Joined:
    Dec 21, 2014
    Messages:
    22
    Likes Received:
    1
    I and my friend was live in Hong Kong, nearly to DJI China head office, they have express repair service to change shell within 2-3 hours, so my friend go to there and wait their repair, but after took back to home, he found they cheat him, they didn‘t change the shell, just use epoxy to repair the crack line, brushing and bleaching clean like a new shell, so....even though my bird have crack, I also don‘t want send it back to repair, I prefer buy a shell to change by myself