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Crashed with P3P & is not smooth after fixing. See video

Discussion in 'Pro/Adv Discussion' started by Angel, Feb 15, 2016.

  1. Angel

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    Hi guys,

    I crash my P3P a while ago and fix it (the Gimbal Roll Ring Arm cracked). I replace it with another one and now it's not working well. Something is not fine....

    I have re-calibrate the IMU and the gimbal but still something wrong going on.
    In this video you can see the first minute how is "not working well" from the hand before taking off and "on the air" from the second minute.



    Any suggestions?
     
  2. DiluxEdition

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    the gimbal is likely rubbing the bottom of the Lightbridge aluminum housing. You need to loosen the grub screw and then tighten it while pulling the gimbal down so it doesn't rub.
     
  3. octaver

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    use only 2 lock plastic pins on the Gimbal
     
  4. Angel

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    Here is some video of the gimbal.....:


    Is it rubbing to the Lightbridge aluminium housing??. I can't see that happening Dilux....
    What do you mean with 2 lock plastic pins octaver?? don't understand what are those??
     
  5. With The Birds

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    You may have meant yaw arm rubbing on lower gimbal plate. The lightbridge board is inside the bottom of the phantom with the vps board.
     
  6. With The Birds

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    The securing pins that go through the rubber mounts (intended to stop canera dropping off in a crash). Ordinarily only two are fitted at opposing corners in production. I doubt this is causing your problem.
     
  7. Angel

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    The security pins I have are two...
    I can't feel any rubbing in the whole gimbal. The footage seems to jump more when I climbs up or go down (like in 01:49)
     
  8. Angel

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    Ok, I had a closer look this morning and Dilux was right!. The yaw arm was rubbing a bit on the lower gimbal plate. I did what Dilux said and now works better!!!. Although when I went to test it there is still a tiny bit of vibration (that wasn't there before the crash) and now it shows specially when hovering.... is a minimum vibration thats is difficult to appreciate when uploading into youtube as the image is not sharp enough....:


    Any ideas on how to sort this out?.

    Thanks!
     
  9. DiluxEdition

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    You may have to try harder. It takes quite a bit of force to get that yaw arm to stop rubbing, and it may come back later on... You also need to do a gimbal calibration on a flat and level surface after its not rubbing anymore. Worst case you may also need to do an IMU Calibration... And don't forget to do compass calibrations once in a while.
     
  10. DiluxEdition

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    Actually I just compared my gimbals on 2 P3Ps. The one that had the rubbing problem (also from a crash) has a bigger gap between the yaw arm and the bearing/bushing that it sits on. We may need to figure out how to press it back in better. The gap is around .5mm to 1mm. On my non-crashed P3P the space is about .1mm to .4mm and there is more than enough space from the aluminum plate so it definitely wont rub... I will see what I come up with getting that bearing/bushing back in properly and let you know...
     
  11. DiluxEdition

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    The yaw motor also is .5mm to 1mm higher on the crashed P3P, so that needs to come back down... Dunno if there is another grub screw somewhere (cant see it), will likely need to remove the gimbal and either push the yaw motor down or find another grub screw...
     
  12. DiluxEdition

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    Removed my gimbal. Don't see any other grub screws. Cant really push the motor down. But I did tighten the 2 screws for that plate that the yaw arm rubbed against and also loosened the grub screw and moved the yaw arm up and down the shaft a few times while pulling the back of the arm down, now there is a bigger space and it definitely wont rub.
     
  13. Ranger003

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    It appears that the gimbal motors are working very hard to stabilize the camera. Are the motors hot to touch on the gimbal? If so realign the rear gimbal motor post there are several posts on this. See my post on this as it may help.
    Also the suggestion of the arm rubbing on the light bridge is great!! Ensure that every this is free moving on the gimbal when the aircraft is off.
     
  14. Angel

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    Thanks for this info guys, is great!!!.

    Great tips Dilux, obviously you know what you are talking.

    I just took a picture of the distance of the jaw arm and the lower gimbal plate and post it here (see the red arrow). I think right now is not rubbing at all, the distance between the bottom of the aluminum housing and the yaw arm is probably 2-3mm. I think to get it further is tricky.


    I will try tomorrow calibrating now the IMU and the gimbal as I didn’t do it after you told me the trick…


    Good thought about the gimbal motors Ranger, it looks to me that it could be something like that. I will check out the temperature tomorrow to see. How could I know if they are actually too hot and where exactly should I touch them? (maybe putting the finger on the plate where the yellow arrow points in the picture?).


    Ranger, I did look into your posts trying to find how to “realign the rear gimbal motor” and look on the forum but couldn’t find how to do it….


    Any chances you could have a quick look to it for me please???.


    Another thing that I was thinking it could be the problem is that the gain could be too high??. How could I adjust that??
     

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  15. Ranger003

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    This video provides a little more definition of adjusting the rear gimbal motor post. Just remove the back cover of the motor and check for proper alignment and adjust accordingly. Recalibrate the gimbal in the DJI GO APP after adjustment. If you have not changed the gains hopefully this should work. Post results good info for everyone.
     
    dronesnaps likes this.
  16. Angel

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    Ok guys, thanks for your help. I just test everything you suggested and did look well into it. But the small "micro" vibrations still there.

    I have checked the rear gimbal motor as Ranger suggested and looks as if It was ok already (see pictures attached).
    I got the yaw arm to stop rubbing which got rid of the "bigger" vibration, and have done a gimbal calibration on a flat and level surface after its not rubbing anymore. I even did an IMU Calibration... And the do compass calibration!.

    As you can see in the video that I am uploading there is something that is still not right. I look into the gain setup that appears on the DJI GO App but all those gain settings seem to be for the drone rather than for the gimbal itself (I haven't touch them since the crash though, btw it was not a major crash but I did have to open the camera to replace the Gimbal Roll Ring Arm that had a crack...).

    If you look at this points in the video:
    0.05: Strange Movement from the camera without me doing anything a well after I switch on everything.
    0.13: Another strange movement with the camera that I didn't do.
    The small vibration is much more noticeable in the HD footage as it comes out of the memory card and less noticeable in the youtube footage (as the resolution is lower) but here are some of the bits that are more obvious to see in the video if you pay attention:
    0:19 , 0:53, 1:30, 1:56 and the most obvious one in 2:12 when looking at the cathedral.....
    The vibration is very low but makes the picture not look sharp at 100%....
    Any suggestions on how to take it from here?
     

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  17. Ranger003

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    Something is definitely binding and prevents smooth gimbal performance. Check the ribbon cables wrapped around the camera arm.
     
  18. phantom1972

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    If that's your house just buy another!
     
  19. Angel

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    Hi Ranger. I just checked the ribbon cables wrapped around the camera arm and they seem to be fine. Check the pictures I am attaching here....
     

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