Welcome to PhantomPilots.com

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

Phantom 3 Pro Gimbal Yaw Issue After Crash

Discussion in 'Pro/Adv Discussion' started by ChrisGTS, Sep 24, 2016.

  1. ChrisGTS

    Joined:
    Sep 24, 2016
    Messages:
    2
    Likes Received:
    0
    So I have never had any issues with my Phantom 3 Pro before, but the other day I was at the top of a hike and bringing my P3P back to me after getting a few shots. I was on a fairly tall rock and the P3P was below me as I was pulling it back home. When it got very close to me, I let go of the controls to bring it to a stop, but it kept charging and ended up hitting the rock and (luckily) landed on top of the rock instead of falling to the ground.

    After a few checks and inspections, everything seems to be running fine... except when I turn on the drone for a flight, the gimbal goes through its range of motion test and then slowly slides facing a few degrees left (left when facing the camera lens). The camera then stays in this position, which when in flight will reveal the left landing gear more often than desired. Even after calibrating the IMU in a wide open area, several attempts at gimbal calibrations and compass calibrations, the camera points left about 10 degrees. I have also tried tightening the yaw are set screw and realigning the yaw motor shaft. I have watched several videos online, but nothing seems to work. I can't find anyone else getting the same issue too. Any ideas on how to reset or adjust it? Or am I going to have to replace the whole yaw motor?

    I haven't found anything that DJI has given me to recalibrate the yaw setting of the gimbal or adjust it.
     
  2. yo5bdm

    Joined:
    Aug 11, 2016
    Messages:
    21
    Likes Received:
    1
    Location:
    Baia Mare, Romania
    Exactly my problem also. I replaced the yaw arm completely and still same problem. I posted a question a few weeks ago with no luck.

    Sent from my Redmi Note 3 using PhantomPilots mobile app
     
  3. jiminyfixit

    Joined:
    Jun 2, 2014
    Messages:
    106
    Likes Received:
    3
    After repairing dozens of the P3P 4K cameras, I have experienced this issue many times, from a severe angle to the right or left, to a slight angle. The slight angle is most often due to a slightly bent yaw arm. There is no way I know of to adjust the yaw motor shaft, but the yaw arm can be bent back to a "0" position. BE VERY CAREFUL however. If you are comfortable with removing the camera from the body and comfortable with removing the plate and cover and undoing the small set screw in the arm, you will most likely be comfortable with the rest of the "fix". So, flip up the two ribbon cable locks, (very carefully). If you are not familiar with this procedure, there are a few YouTube videos that show how to do this. Pull out the 2 ribbon cable ends from the circuit board, remove the set screw completely and place the roll motor , camera and all, into a small machinists vice, (with smooth jaws), with the yaw arm sticking up. Make sure no other parts of the camera are in the way. Take a medium sized crescent wrench and place it on the yaw arm, near the tip, (where the set screw goes), and bend the yaw arm TOWARDS the angle of offset, (from "0"), VERY carefully. If you are mechanically inclined and enjoy working on stuff like this, you will be sensitive enough to know when and how much you moved the yaw arm. Put it all back together and take a look at your handy work. If you are not comfortable with any of this, I can make the repair for you. This is a $15 fix, plus postage; usually about $25 total with a one-day turnaround at my end.

    Hope this helps.
    Jim
     
  4. yo5bdm

    Joined:
    Aug 11, 2016
    Messages:
    21
    Likes Received:
    1
    Location:
    Baia Mare, Romania
    @jiminyfixit

    I completely replaced the yaw arm with a brand new one and still get a slight angle. it's either bending or replacing the whole gimbal?
     
  5. ChrisGTS

    Joined:
    Sep 24, 2016
    Messages:
    2
    Likes Received:
    0
    Thanks for the detailed response. I am going to take it apart tomorrow night and will update with results.
     
  6. jiminyfixit

    Joined:
    Jun 2, 2014
    Messages:
    106
    Likes Received:
    3
    I would go ahead and bend it as I detailed in previous post. The P3P.& A cameras do not have a yaw potentiometer sensor like the P2V+ cameras do. They have a magnetic washer on the yaw motor shaft that functions like a Hall sensor. There is a small sensor mounted in close proximity to the magnetic washer that establishes location, electronically. I have seen too many of these washers broken from crashes, rendering the yaw function "inop" The sensor apparently suffers some sort of "misalignment" electronically, even if the washer is unbroken, resulting in a useless main circuit board. I'm sure the factory has a way of "resetting" the sensor.....electronically. All in all, I find the P3 cameras have more robust circuit boards than the P2V+'s.
     
  7. yo5bdm

    Joined:
    Aug 11, 2016
    Messages:
    21
    Likes Received:
    1
    Location:
    Baia Mare, Romania
    Thank you :) will try it. Also i am noticing hard shaking of the camera when hovering, that wasn't there before. Props are calibrated with dubro. What could be the problem?

    Sent from my Redmi Note 3 using PhantomPilots mobile app
     
  8. jiminyfixit

    Joined:
    Jun 2, 2014
    Messages:
    106
    Likes Received:
    3
    Does the camera shake without flying? Is there a vibration when the props are spinning before take off?
    With the props OFF, can you detect a vibration coming from one of the motors?
     
  9. yo5bdm

    Joined:
    Aug 11, 2016
    Messages:
    21
    Likes Received:
    1
    Location:
    Baia Mare, Romania
  10. yo5bdm

    Joined:
    Aug 11, 2016
    Messages:
    21
    Likes Received:
    1
    Location:
    Baia Mare, Romania
    From the next 2 images you can clearly see the problem of the yaw arm.

    [​IMG]
    [​IMG]

    Sent from my Redmi Note 3 using PhantomPilots mobile app
     
  11. jiminyfixit

    Joined:
    Jun 2, 2014
    Messages:
    106
    Likes Received:
    3
    From your great photos, it looks like your camera is suffering from the same malady as others that I have tested. I can see the flat section on the yaw shaft is not 90 degrees to the main camera body, indicating a problem with the main circuit board/sensor. It doesn't appear that the yaw arm is bent sideways because the camera module seems square with the rest of the gimbal, so I wouldn't attempt to bend it. I have fiddled, (spent way too many hours), swapping out yaw motors with offending circuit boards and getting the same results. I have a number of circuit boards that have produced this problem and I've considered them "inop". Not sure if you are under warranty. I would ask a DJI technician if this is repairable, but I'm sure they would suggest buying a new camera. I apologize for not being more helpful.

    Regarding props. Have you tried putting the original props back on? DJI props are very good and all the ones I have checked for balance are **** near perfect. At what RPM does the vibration become noticeable? Low speed, high speed?

    Not sure of the severity of the crash you had that damaged the yaw arm. If I had your P3 on my bench, I would check the motor mounts for loose screws, cracks, arm being slightly bent, and an RPM test without the props, but I'm sure you've already done all this.:}
     
  12. yo5bdm

    Joined:
    Aug 11, 2016
    Messages:
    21
    Likes Received:
    1
    Location:
    Baia Mare, Romania
    At idle rpm (on the ground) it's not happening. But after i take off, it is visible. I only work with original props and also checked them with dubro. So i think it's not a prop problem...

    Sent from my Redmi Note 3 using PhantomPilots mobile app
     
  13. jiminyfixit

    Joined:
    Jun 2, 2014
    Messages:
    106
    Likes Received:
    3
    At this point I have to go back to the original issue....Crashing into the rocks. The accelerometer, the 1" square cube in the middle of the main mother board of the quad, is very sensitive. I have had to replace the complete mother board due to a separated accelerometer from a crash where the quad landed hard, upside down. The GPS module is twice as thick as the P2V+ and is so close to the accelerometer that it punches it through the board. I have yet to determine if a slightly compromised accelerometer can effect the yaw angle though. The only way to determine that would be to replace your existing camera with a known good one.

    So. the vibration could be from a bent motor shaft. Try to isolate which motor might be the culprit. I have replaced several motors that have bent shafts. Hard crashes bend shafts.
     
  14. yo5bdm

    Joined:
    Aug 11, 2016
    Messages:
    21
    Likes Received:
    1
    Location:
    Baia Mare, Romania
  15. Memmer

    Joined:
    Oct 30, 2016
    Messages:
    3
    Likes Received:
    0
     
  16. Memmer

    Joined:
    Oct 30, 2016
    Messages:
    3
    Likes Received:
    0
     
  17. Memmer

    Joined:
    Oct 30, 2016
    Messages:
    3
    Likes Received:
    0
    jiminyfixit can I talk to you about a gimbal yaw motor/arm repair on my PH3 Pro?
    Thanks!
     
  18. Ted4797

    Joined:
    Nov 23, 2015
    Messages:
    978
    Likes Received:
    157
    Location:
    Florida
    I don't have time right now but there is a way to modify the main board so that it points straight ahead. I have posted on here how to do it.

    Sent from my SM-G935V using PhantomPilots mobile app
     
  19. yo5bdm

    Joined:
    Aug 11, 2016
    Messages:
    21
    Likes Received:
    1
    Location:
    Baia Mare, Romania
    I can't find the thread or post, can you send us a link, please? :)
     
  20. Ted4797

    Joined:
    Nov 23, 2015
    Messages:
    978
    Likes Received:
    157
    Location:
    Florida
    Yaw motor swings to Left or right
    In the photo you will see the yaw motor ribbon cable sticking up. Tape it down so you don't get heat on it.
    I would start out by just locking the yaw arm on the shaft to the left or right of the flat. If this works you can lock it down there and use it or try moving the magnet. The magnet is VERY fragile and will break if you use too much force. I have broken several trying to figure out how to free it up. Also if you do this make a scratch mark on the top of the magnet in the center of the flat so you will know where it was when you started. After it is off the shaft you will need to clean the shaft so it goes on easy and you do not need to force it. forcing it WILL break it.
    I hope this helps you. I have done several of these. It does take a lot of time getting it right and you have to take the camera apart several times and adjust. The factory has a meter to set it correctly.
     
    yo5bdm likes this.