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My H3-3D has turned into a JERK!

Discussion in 'Zenmuse H3-3D/H4-3D GoPro Gimbal' started by DesertFlyer53, Sep 4, 2014.

  1. DesertFlyer53

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    So... I've had my H3-3D for about two months now and have around 15 flights on it with no issues at all. Today I went flying... at altitude and at a relatively fast forward speed, the gimbal will occasionally jerk left to the point where I can see the landing gear (and I have the aftermarket wide and tall gear) for about 3 seconds, then straighten out. It did this about 5 times during a 15 minute flight. Now, when I'm down low and slow, it doesn't do it! When I first noticed it, I starting troubleshooting in the air to see which flight conditions induced it. Sure enough... only when I'm going full bore forward. Seems more pronounced when I'm in atti mode going fast forward. Not so much in GPS mode with the slower speed. This has me stumped! Besides doing an IMU advanced cal, anyone have any ideas what could be causing this??
     
  2. OI Photography

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    I get the same whenever I'm snap-yawing or flying forward at high speed. My guess is that those maneuvers (and the related aerodynamic forces on the gimbal) cause it to get pushed outside the acceptable range of motion and it does that little jerk to reset.

    It only happens to me in those situations and has been easy to avoid now that I know how, but I do see numerous reports from those who get the "jerk to the left" motion who say they aren't flying any way that would be expected to induce it.

    You can try doing a full IMU calibration on the Phantom, it's possible that could help but I haven't seen a solid confirmation either way. Worth a shot if it's starting to do that a lot.
     
  3. Lockdo

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    I called dji and getting mine replaced seems they will warranty mine. I'm picking my new one up from the local dealer tomorrow. Tried calibrating and it doesn't improve it from my experience. Dji was suggesting that the gimbal could be defective. So I'm just happy they said that fingers crossed. Mind you I have had no crashes or hard landings.
     
  4. iversens

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    I'm having the same problem with my newly installed H3-3D. I initially thought it was yaw motor clearance so I added some washers, but still get the same JERK.

    I'm going to try to recal and then call my dealer.

    Let us know if you have better luck with your new gimbal.
     
  5. iversens

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    Check out this other thread - viewtopic.php?f=26&t=24456

    This sounds a lot like my problem since my camera also tilts to one side without power. I'm going to try balancing it to see if I can get it working.

    Bummer we have to make mods to "production" hardware.
     
  6. EMCSQUAR

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    Try changing out white insulators to 40% black (non ribbed in center) insulators. Cured my 3Ds twitch - here's vid of crosswind making wobble -> https://www.youtube.com/watch?v=tbD9uL5 ... VSNdmm127A
     
  7. UrAwFuL

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    I probably experienced the same thing as you.

    [youtube]https://www.youtube.com/watch?v=vinEQfsVqUM[/youtube]

    I had a GoPro hood on at the beach (about 10mph winds) and I believe I was at around 80% forward throttle when it happened.

    I'm going to do another test flight tomorrow (without hood) to see if it happens again, replace the wiring if it does happen, and if that doesn't work then I guess I'll contact my dealer. :lol:
     
  8. Damon

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    Use Phantom Assistant click on Advanced and then Gimbal tab. Lower the Horizontal Limit down 5 degrees. It solved the problem for me. Before that mine would do the same thing, especially when flying full speed. I suspect when fighting the wind speeds face on straight up is just to much, forcing the gimbal to "reboot".
     
  9. DesertFlyer53

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    Wow! Didn't expect this many responses with the same issue. Thanks for all the replies and suggestions. I will do all the above and see what happens. I bought the gimbal from B&H so shouldn't be a big deal to return it if all else fails. Do you all think it's a hardware issue or maybe software. I'm wondering, does DJI know about this issue?
     
  10. UrAwFuL

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    I have a similar theory to OI Photography. I think I was flying against wind at a high speed would end up pushing against the gimbal (especially with a gust) causing the reset. Winds tend to get pushy. :lol:

    But then again, I think I've seen videos of people flying distances at full forward speed without problems though. :lol:
     
  11. Lockdo

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    It could be the software giving it an incorrect compensation for wind. If they tweaked the software to have a higher tolerance to the wind we could be good.
     
  12. Damon

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    It might be a designed failsafe to keep from damaging gimbal motors.
     
  13. beeline

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    My quad has started doing the same thing. Until now, I was convinced it was caused by the gimbal rubbing against the battery, as discussed in the thread below. I can see marks on the battery where the contact occurs.

    http://www.phantompilots.com/viewtopic.php?f=26&t=15747
     
  14. DesertFlyer53

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    Mine is not rubbing the battery. I'm going to balance my gimbal, do the advance IMU calibration, then see what happens. If those two things fail to correct this, I may send it back to B&H for a replacement.
     
  15. DesertFlyer53

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    I have a theory. See if this makes sense. I would like to know how many of you with this problem are using a neutral density filter on your GoPro. I am. Looking at my P2, the filter is mounted on the GoPro lens, which is left of the center point on the yaw axis of the gimbal. Is it possible that at high speeds, the large surface area of that ND filter is catching the head wind and putting pressure on the yaw motor to the point of it resetting? I could see that if power is removed from the gimbals yaw motor, the GoPro would swing to the left especially with a ND filter attached. Next time I'm out flying, I will remove the filter and counter weights and see if I can still induce this jerk at high speeds.
     
  16. iversens

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    I'm not using any lens filter and still had the problem. After running the advanced calibration again my H3-3D is dead. The LED is still lit when powered, but it no longer moves and is not listed as a device under the Phantom 2 Assistant.

    Tried exchanging with Helicopter World (Century Heli) and got terrible customer service. They refused to exchange or return and told me to contact DJI. Don't make the mistake that I did. Better to go with a proven dealer like B&H.
     
  17. Away Point

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    I've messed around with is issue a lot, and wind pressure from the front is most definitely a contributing factor when the problem occurs ... I call it yaw narcolepsy, as the yaw server motor shuts down, or "sleeps".

    If you check out how a strong air flow from the front effects each axis, you'll see the yaw axis is unique, in that wind pressure is not centered on the rotation point of the gimbal, but rather, much more loaded on the left side. In other words, a strong wind does not induce a pitch or roll of the camera, but it does become a force to yaw the camera left. A force which the gimbal must constantly counteract. I surmise that if the gimbal is out of balance, combating those two forces similataiously (roll and yaw) overloads the gimbal.

    I won't say the penny balancing has cured mine, but it has yet to happen in about 25 flights, some of which were in strong winds.
     
  18. DesertFlyer53

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    I would tend to agree with all of the above. Thanks for your input!
     
  19. gregorym777

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    It would seem that this "yaw snap" issue is pretty common and there are few if little answers that actually rectify the issue.

    I think it might be a physical hardware issue and it would be great if anyone reading this can do this experiment and let us know here what your results.

    With NO power on the gimbal, push your camera to one side and see if it automatically centers itself like its subtly spring loaded. Then check to see if it centers from both directions. My H3-3D will only center from one side. It would make sense that it should center from both sides and not just one.

    Let us know here what you find…

    https://www.youtube.com/watch?v=PeoL92A ... PG40DwCcAg
     
  20. QYV

    QYV

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    the yaw snap is when the motor resets, goes limp and then comes back on. For me, it was caused by the gimbal not being perfectly balanced, so during flight the motor has to work harder and harder and under certain conditions it goes over a threshold and then does that snap/reset.

    This is how you can tell if your gimbal isn't balanced... with the power OFF you should be able to place the gimbal/gopro in a normal forward-facing position and it won't move too much. Here is an example of an UNbalanced gimbal: https://www.youtube.com/watch?v=JalsB-N5QP0

    so to fix the above issue I applied counterweight in the form of small strips of gaffer tape to the right side until it basically stayed balanced when I released it. Since then I haven't had any noise from the motors and no yaw-snap resets during flight.
    https://www.youtube.com/watch?v=I5J_CCL62UE