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New Guy - Needs Help

Discussion in 'Phantom 2 Vision Help' started by johnnyd, Apr 7, 2014.

  1. johnnyd

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    Hi everyone, brand new guy here. Bought a P2V. First flight, great even in wind. Solid hover, some pics etc... Second flight, not so good. Clipped a tree about 50 ft. up and fell straight down. Not much damage, except to the car I hit. Replaced props, put the camera back on and battery back in. That's all it seemed to need. Small crack on shell, hardly noticable, by one of the air vents. No other visible damage or warping... Anyway, with new props, advanced calibration, firmware upgrade etc. I go out to try again. This time I just pull up in a hover to see how she flies. That's when I noticed the big circle...

    My IMU cal. was successful, my compass mod. ended up around 1460... The on the ground compass cal. was flawless with no error indications. But now in GPS mode, I get the dreaded toilet bowl. I called DJI and got no help. Before the crash, hovered like a rock, now drifts in a counter clockwise circle all the while showing green GPS indicators. I had 9 sats connected. It calms down in ATTI, but being new I am very careful not to stray out too far like that. IOC seems to work too telling me the sat is probably guiding... When I try to fly out in GPS it nows tracks in a left diagonal from me instead of straight... But it does seem to lock in the sats so I was focusing on the compass being the culprit.

    There is no visible damage to the compass. I even took off the shell to look at the inside and nothing pops out. I tried the magnet technique I saw on YT and did more recalibrations and it didnt help. So I figured I'd suck up $19 bucks and try a new compass in case it smacked the tree or something. Still waiting for that but wanted to know if any of you guys have seen or heard of this?
     
  2. RogerClark

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    AFIK the toilet bowl effect can be caused by miss aligned motors

    Check if you have twisted the whole frame or possibly cracked the motor mount, so that one of more of the motors no longer faces exactly upwards.

    BTW. I doubt this is an issue with the GPS its self, but when in GPS mode the way the Phantom operates is markedly different.
    i.e in GPS mode the Naza (FMU) is constantly making adjustments to the motor speeds to attempt to maintain an exact position, but in ATT mode its less vigorous and hence the toilet bowl effect is probably less pronounced
     
  3. OI Photography

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    The TBE is often a result of the NAZA having to deal with conflicting GPS/compass info.

    I would suggest removing the GPS board in the lid and inspecting it (including the square ceramic GPS antenna on the top side).
     
  4. johnnyd

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    Thanks guys for the quick response. I will look over the motors very closely when I get home. In SD CA now for work. However I would think if it were a motor issue, the aircraft wouldn't hover well in ATTI either?? Nor would it fly very well. Just my thought, may be wrong. To replace the compass I have to remove the lid. When I did that before, I didnt think to look at the GPS module, so I will inspect it closely. Thanks for the suggestions, I will certainly provide an update when I can get back to my machine....