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New member and drifting advice

Discussion in 'Phantom 2 Vision + Discussion' started by slidebite, Oct 7, 2014.

  1. slidebite

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    Hi folks, new member here. I bought a Vision 2 + and really enjoy it so far, having a blast.

    I have a question which I hope those more technically competent with these than me can answer.

    I picked up a crashed Vision 2+ for a cheap price. The person flew it into a post and it fell 20' or so onto cement below and it supposedly only had an hour of flight time on it (kind of sad). Bent the gimbal arm on the camera and trashed the props but otherwise supposed to be in good shape. Camera itself actually still worked albeit bent.

    I bought it mostly for parts if nothing else. Battery, charger, props, radio, etc. I got it home and took the halves apart, made sure everything was snug, put on the props and figured I'd take it for a flight.

    While it did fly, it drifted pretty significantly, wouldn't hover like miner at all. I needed to constantly correct it and was a real chore bringing it down without it skidding/crashing.

    I recalibrated the magnetometer and made no difference.

    Ideas on what to do? Is there a way to check the health of the components inside it?

    If it helps, it did ask for me to recalibrate it again after I landed, so I don't think it's a stretch that it's magnetometer related.

    Thanks for the help!
     
  2. flyNfrank

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    I would say to check the motor alignment on each motor.

    Would you happen to remember the stats after you completed the calibration? It would be nice to know they were in spec, and that you knew what you were doing. Btw, don't take that wrong.

    Also would you want to sell it without the extras?
     
  3. Mako79

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    Use the Phantom Assistance on the PC/Mac and do an Advanced IMU calibration on a bubble-spirited levelled surface.
    The gyro and accelerometer sounds like its out of whack.

    If the phantom swirls, then you have compass issue.
     
  4. slidebite

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    Thanks guys, will check into it.

    No offense taken flynfrank, I am a complete new Phantom owner, still learning everything. I might ask for more advice if I can't figure it out!

    As for selling it, I'll let you know after I do some more work with it and see if I can fly it straight!

    Assuming I can, I *MIGHT* keep my eye open for either a straight gimbal arm (don't care about the camera as it still seems to work fine) or worst case buy a Camera/Gimbal set as it looks like that's the way DJI sells them from what I can tell (no arm separately).
     
  5. slidebite

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    So thanks for the advice folks.

    I did the advanced IMU calibration and it hasn't solved it. It might be a BIT better, but it still drifts. I also calibrated the controller.

    How do you check the motor alignment exactly?

    I took some screenshots of the software to show how it is right now. I am open to ideas.

    I also tried the camera. It works like a top other than the bent gimbal arm, everything is at about a 15% slant :/

    Seems to respond to the controller just fine and GPS is picking up good satellites.

    [​IMG]
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    [​IMG]
    [​IMG]
    [​IMG]

    As mentioned, I am new at this and any advice would be appreciated. If pointers can be given to troubleshooting guides and the like that would be great too.

    Thanks a lot!
     
  6. flyNfrank

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    The IMU numbers are spot on.

    But.... Your Gain Numbers are way off and need attention!

    Change to these numbers are try a flight. Btw, the numbers below are default. They are also the best combo I have flown with as well.

    Basic Gain: Pitch-125% Roll-125%-Yaw 120% Vertical-140%

    Altitude Gain: Pitch-260% Roll-260%
     
  7. pb7424

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    The gains he has shown are the same as my default gains. Not sure where your gain values came from but they are not default values.
     
  8. Mori55

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    Why can't you bend the gimbal back ? It's soft aluminum. Your gains are fine.
     
  9. ToThePoint

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    What does the GPS see ?
    Do you have a sat lock ?
    If not the GPS module cold be broken and did you check the GPS ceramic antenna ?
     
  10. slidebite

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    GPS lock and everything seems fine, no issues there.

    Regarding gains, those are the same as my "good" v2+ so I'll probably leave them but I'm not against experimenting.

    I'm not against trying to bend the gimbal (nothing to lose really) but I think I'd need to disassemble it to get at the arm itself. I assume they can be taken apart?

    Regarding the earlier post about motor alignment, how does one check/go about that?
     
  11. flyNfrank

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    My post stated my gain numbers were default. It's obvious your quad came off the production before my quad did. You should not allow your ignorance to overwrite your fingers on the keyboard. It's not good thing to disrespect your fellow pilots.

    At any rate slidebite, I don't expect the gain spec's to be what would cure your situation. But in trying to help you I did want to see you updated prior to moving ahead.
     
  12. pb7424

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    FlyNfrank - Meant no offense. Sorry if it came over that way. Please note that his gain values and my default values are identical to the default values shown in the latest version of the Phantom manual (Figure 112 on Page 46).
     
  13. slidebite

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    I do appreciate the help! :)

    Regarding the gains, my V2+ is about a week old and from a fresh batch the distributor had just received, so it's probably pretty darn current but who knows.. not that it makes a bunch of difference really. I think I'll still try your specs on my "good" one to see how I like it, I appreciate you posting them.

    Pointers on the alignment that you mentioned? I'd like to check that.
     
  14. Stile2112

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    And you might need a better understanding of intent then assuming someone is being disrespectful.
     
  15. slidebite

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    Been away for a while so had a chance to tinker again. Gains as expected didn't make any difference. Keep in mind my "testing" regimen is to start it up, take off let it hover. The drifting starts immediately so I bring it down. I don't want to give it too much height and/or distance because I'm unsure what it's going to do. I get it up about 10' and it drifts about 30' before I can get used to counteracting its drift and bring it down somewhat safely.

    I have read some threads about people passing magnets over their sensors to reset/calibrate them. Any value in that?
     
  16. Dirty Bird

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    I am assuming the frame is sound and you have checked that all of the connectors are firmly in place?

    I would guess this is either an issue with the compass or the flight controller. The compass is relatively inexpensive. Since you have another unit and it is easy to remove, you could just temporarily swap and see if is makes a difference. If it corrects the problem, order a replacement. The flight controller is a bit more expensive...around $200 if I recall correctly. A lot cheaper than a new Vision+ if it is the problem. If you decide to replace the FC make sure to order the Vision-specific model. It is cheaper than the standalone NAZA V2 units as it doesn't include unnecessary components and has the Vision-specific firmware.
     
  17. slidebite

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    Thanks for the reply.

    You bet, I took the cover off the crashed one and made sure everything looked snug. It took a bad hit in the crash because one of the small screws near the motor was so ground down from the concrete I had to grind a slot in the screwhead with a dremel to use a screwdriver on it! A small screw got broken off a PCB as well which I removed. The board it came from looks fine though, the IC don't seem to have any breaks or anything.

    BUT, the motor turns great and "looks" straight so I am assuming it's OK.

    I am hesitant taking parts off my good one to use on the parts unit but I guess that's probably the only realistic way to do it.

    Is there a manual that can be downloaded that identifies the components in the quad?

    Thanks again for the help folks! :)
     
  18. Dirty Bird

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    Shouldn't be a big deal swapping the compass but a new compass is only $19. The Vision+ NAZA is $229. These prices are from Helipal and do not include shipping. I've ordered from them several times and with the EMS shipping it gets here to the States in less than a week. I just linked to where I knew they had the components so you may be able to find them elsewhere.

    Vision/Vision+ NAZA-M V2 (this model is specific to the Vision/Vision+)
    http://www.helipal.com/phantom2-09-...ision-naza-v2-flight-controller-main-con.html

    Phantom 2 Compass Module
    http://www.helipal.com/phantom2-vision-12-dji-phantom-vision-compass.html