Welcome to PhantomPilots.com

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

After crash, phantom flies lopsided and drifts on its own

Discussion in 'Phantom 2 Vision + Discussion' started by jwegener, Oct 17, 2014.

  1. jwegener

    Joined:
    Sep 21, 2014
    Messages:
    79
    Likes Received:
    3
    So I've got almost everything fixed from my crash a month ago ( viewtopic.php?t=26655&p=248293 ) but still having one weird problem. The phantom seems to drift pretty quickly to the side when it flies and I noticed that it just kind of looked a bit lopsided while flying. I was flying it pretty low to the ground and it didn't have satellite lock. When it has satellite lock it seems to stay put (but I worry about flying low to land and takeoff and having it switch in and out of GPS lock and bolt to the side randomly)

    Just to confirm my suspicion i tried it again in a place with no wind -- my living room! I flew indoors (0 GPS satellites, so ATTI mode) and as soon as it took off it started drifting towards the wall of my apartment at a pretty nice clip and I had to grab it before it crashed! It's always drifting the same direction (to the right if you were looking through the eyes of the drone's camera)

    I've tried compass calibration, basic IMU calibration and advanced IMU calibration including this morning before flying it inside. Nothing seemed to help.

    Any suggestions for how to fix this?! Thanks!
     
  2. jwegener

    Joined:
    Sep 21, 2014
    Messages:
    79
    Likes Received:
    3
    Re: After crash, phantom flies lopsided and drifts on its ow

    Also has anyone else tried flying indoor without satellites? Have you found it to stay in one spot well?
     
  3. pb7424

    Joined:
    Aug 7, 2014
    Messages:
    149
    Likes Received:
    4
    Location:
    Two Rivers, Wisconsin
    Re: After crash, phantom flies lopsided and drifts on its ow

    Are you using a bubble level to make sure the surface used for the advanced IMU calibration is really level?
     
  4. jwegener

    Joined:
    Sep 21, 2014
    Messages:
    79
    Likes Received:
    3
    Re: After crash, phantom flies lopsided and drifts on its ow

    No, I'm just putting it on my floor
     
  5. pb7424

    Joined:
    Aug 7, 2014
    Messages:
    149
    Likes Received:
    4
    Location:
    Two Rivers, Wisconsin
    Re: After crash, phantom flies lopsided and drifts on its ow

    So how level is your floor???? ;)
     
  6. jwegener

    Joined:
    Sep 21, 2014
    Messages:
    79
    Likes Received:
    3
    Re: After crash, phantom flies lopsided and drifts on its ow

    Haha I don't think that's the issue but I appreciate the suggestion. It feels more dramatic of a problem that a slight tilt to the floor.
     
  7. Madwak

    Joined:
    Apr 2, 2014
    Messages:
    291
    Likes Received:
    1
    Re: After crash, phantom flies lopsided and drifts on its ow

    Do the advanced calibration on your floor again but face the phantom in the opposite direction whilst calibrating and then see if it starts to tilt in the opposite direction when flying cos it sure does sound like the calibration is wrong?
     
  8. jwegener

    Joined:
    Sep 21, 2014
    Messages:
    79
    Likes Received:
    3
    Re: After crash, phantom flies lopsided and drifts on its ow

    Great idea.
     
  9. N017RW

    Joined:
    May 2, 2014
    Messages:
    6,256
    Likes Received:
    1,615
    Location:
    Palm Beach Co.- FL
    Re: After crash, phantom flies lopsided and drifts on its ow

    Take a look at the IMU data on the Tools page of the P2 Assistant and see what the values are.

    You may see one parameter 'out of whack' ???

    That could help determine if the IMU was damaged from your crash.
     
  10. jwegener

    Joined:
    Sep 21, 2014
    Messages:
    79
    Likes Received:
    3
    Re: After crash, phantom flies lopsided and drifts on its ow

    Ok, tried this tonight. Adv Calibrated it once, tested the direction of drift (to the right as the camera is looking). Then flipped it 180 degrees so it pointed the exact opposite way and adv calibrated it again. Flipped it back so I was flying with the same orientation

    Unfortunately it still drifted in the same direction.

    I also tried taking a magnet and messing up the compass as per a DJI video, then recalibrating it. Didn't help.

    What could possibly be causing this?! I have only one theory: If one leg is shorter than the other, is it possible it's being calibrated to a non-level state, and then when it takes off its trying to maintain that non level state which puts the propellers at a slight side angel causing the lift to not be straight up in the air but instead a little off to the side? And then since there's no GPS it just drifts? And even with GPS it ends up fighting itself (the propellers pull it to the side but the GPS pulls it back so it just ends up looking lopsided?)

    Would that theory make sense? Any other suggestions to fix it? Thanks!
     
  11. UAVProducts

    Joined:
    Oct 18, 2014
    Messages:
    4
    Likes Received:
    0
    Re: After crash, phantom flies lopsided and drifts on its ow

    Really sounds as if the IMU is not calibrating correctly.
    Other things to maybe look at is if any of the arms are tweaked from the crash (one motor not level).
    One motor starting to go bad (bearing).
    Switch props around.
    Re cal the TX.

    That is all I can think of, hope that helps.
     
  12. N017RW

    Joined:
    May 2, 2014
    Messages:
    6,256
    Likes Received:
    1,615
    Location:
    Palm Beach Co.- FL
    Re: After crash, phantom flies lopsided and drifts on its ow

    How did the IMU data look?
     
  13. Madwak

    Joined:
    Apr 2, 2014
    Messages:
    291
    Likes Received:
    1
    Re: After crash, phantom flies lopsided and drifts on its ow

    Have you looked under the skids to make sure those 4 stick on protectors are all still fitted?
     
  14. jwegener

    Joined:
    Sep 21, 2014
    Messages:
    79
    Likes Received:
    3
    Re: After crash, phantom flies lopsided and drifts on its ow

    Yeah they're all ok. Would lopsided legs/protectors cause that?
     
  15. flyNfrank

    Joined:
    Feb 1, 2014
    Messages:
    4,231
    Likes Received:
    915
    Location:
    Indy, USA
    Re: After crash, phantom flies lopsided and drifts on its ow

    My 1st P2V I owned was the only one of the 3 I had crashed which happened to be involved with a tree. When I found it after the crash it had knocked the camera gimbal off as well as the battery was separated from the quad. When I finished putting everything back together including the battery, I then had a very had time removing the battery. And when I went to install a charged battery, it did not want to close properly.

    So to cure this issue I loosened all the screws as if I was removing the top cover. With the battery in the quad I began tightening the screws up again but going in a sequence. Since this took place I have always had the battery in place prior to putting things back together. And in doing this you might try loosening each motor and the re-tightening as if you were resetting each one. It more then likely wont be the cure, but at least you can cross this off your list on possibilities.
     
  16. jwegener

    Joined:
    Sep 21, 2014
    Messages:
    79
    Likes Received:
    3
    Re: After crash, phantom flies lopsided and drifts on its ow

    Thanks nexus. Any pictures or further explanation of where this is inside the drone? Thanks
     
  17. jwegener

    Joined:
    Sep 21, 2014
    Messages:
    79
    Likes Received:
    3
    Re: After crash, phantom flies lopsided and drifts on its ow

    Interesting, tell me more about the GPS disk being off center. I actually went to unscrew it (to make sure it's not damaged, got halfway done unscrewing it and realized I had entirely stripped the screws. So the screws holding my GPS are a bit lose, but I can't tighten them. Why would this affect whether the aircraft is level?
     
  18. iowahill

    Joined:
    Sep 6, 2015
    Messages:
    197
    Likes Received:
    22
    Location:
    Roseville, CA
    Maybe prop issues? Damaged, bent, or out of balance?
    Try swapping sides of each and see if drift follows.
     
  19. Mako79

    Joined:
    May 16, 2014
    Messages:
    3,418
    Likes Received:
    568
    Location:
    Sydney Australia
    Inside the NAZA is the IMU. Open up the phantom and look at the NAZA and make sure its perfectly level. The NAZA is held by double sided tape and could be wonky.
    And you need to tell us what the IMU values are. There is a possibility that one of the gyro sensors are stuck and requires a physical smack.
    Let us know..
     
  20. RoyVa

    Joined:
    Apr 10, 2015
    Messages:
    2,246
    Likes Received:
    449
    Location:
    Virginia
    Put it back on the floor and put a carpenters level on it. Check it from front to back and side to side. Put anything under the feet to get it perfectally level. Pennies credit cards or even cardboard. Once it's level do the Full IMU calibration. Once it's successful the go outside and do a compass calibration. When completed start her up and be sure before you take off you have 6 or more satellites and you have satellite lock. Take her up about 10 -20 ft and hover. Do a 360 and maintain hover. See if she is solid within 3 ft or if she drifts still. You may want to do a RC stick calibration to be sure they are also aligned. once all that is done and test. If she is stil slipping to the side you have a motor not running at proper RPM or an ESC that has gotten weak. Then the fun begings doing the diagnostics. Easiest way to find that issue is to order for less than $20 a laser RPM meter from EBay and then test it motor at ideal and full rpm to see which one is the culprit. I always recommend change a motor when you change the ESC or change the ESC if you change a motor. Just good cheap insurance. At idle and full RPM they should all be within 75 to 100 rpm or less from each other. Closer the better.
    Good luck! That'll fix er.