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After Crash Advice

Discussion in 'Pro/Adv Discussion' started by Shacky, Jul 31, 2016.

  1. Shacky

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    I crashed my P3 Advanced into a tree the other day and since it just doesn't seem quite the same. First, it was a mild (stupid) crash, in fact, I'd say it was more of getting stuck in a tree than a crash. I was able to use an extension ladder and a pole and got it down gently. No damage was evident, just a little green stain on the blades from the leaves that cleaned up easily.

    Before this happened, the bird would return to home and land within a couple feet of the home point. Right away, I could tell that now it would return 10-15 feet away. I did an IMU calibration and then a gimbel calibration. Recalibrated the compass and tried again. I noticed that the IMU warmup seemed to take a bit longer than normal and I wondered if it was my imagination.

    Now, for the first time ever, it's drifting a bit while it hovers and the return to home was the worse ever. Landed about 20 feet away and almost landed on something. When I calibrated the IMU I used a piece of Styrofoam and leveled it up in the middle of my yard.

    Any advice?
     
  2. ROD PAINTER

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    I would level it up inside on a surface that you know is perfectly level. Check front to back and left to right for accurate level! You can eliminate the warm up process by doing a cold imu calibration. I stick my P3P in the fridge for 30 minutes and as soon as I take it out I stick in the battery, have the go app screen ready to do a imu calibration. if go app says warming up dont wait. Do the imu calibration right away! Make sure you do compass calibration away from any metal.
     
  3. Numone

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    I concur. I hand a drift issue and did the perfect level and cold I IMU calibration. All sorted and love the zero startup time..
     
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  4. Shacky

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    You put your entire drone in the fridge?
     
  5. flyNfrank

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    Calibrate the IMU inside. The colder you can get the aircraft the shorter the IMU warmup. Some put the aircraft in the refrigerator or freezer prior to calibrating. Don't pull the aircraft out until you have the R/C and App setup and ready for the calibration. That way the aircraft wont warm up on you through the starting the calibrate IMU process.

    You need the aircraft 100% level as possible. Some prefer to remove the 4 props and place a sheet of glass on top of the motor bolts. You don't have to use glass. but you need to be positive to not use any metallic material. Nor do you want to be around any when calibrating, such as screws or nails in the floor. I use either the travel case or the box the aircraft came in to set the aircraft on.

    After the IMU calibration in complete you can calibrate the R/C and Gimbal. Then before you fly is a good time to calibrate the compass. Make sure you know how to properly calibrate the compass, and do not launch without receiving enough Satellites for the aircraft to save the Home Point location.
     
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  6. Shacky

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    Ok, bird is chilling' in the freezer now. Regarding compass calibration, I've seen 2 ways. One way is to hold it about chest high and pivot your entire body 360, the other is to hold the phantom in your hands and rotate it using only your hands. Is one way better than the other?
     
  7. ROD PAINTER

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    I use a all plastic level and use top of motor to level mine, front to back, side to side!
     
  8. ROD PAINTER

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  9. ROD PAINTER

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    I prefer doing the body rotation. I think it is more accurate
     
  10. Numone

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    Yes, without the battery and in the fridge for 15 mins as it runs at 4c. What lead to me doing this was when I missed some really important footage of my sons wedding, whilst the AC sat in the car park outside the church for 2 bloody minutes warming-up; that was probably the longest I'd ever had to wait for it to warm too. Anyway, I prepped the AC on the surface to do the calibration in advance of cooling it down and once the timer went off, I quickly removed the AC, put the battery in and ran the calibration. The AC is now ready to fly after 5 seconds - perfect.
     
  11. Numone

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    I hold the AC at arms length and turn 360, then turn the AC pointing down and repeat the 360.
     
  12. Shacky

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    I did the cold recalibration and things are definitely better. It still seemed to drift a little, but I think it got better after a little bit. May have still been cold from the freezer and it affected it. Thanks for the help, this is a great forum!
     
  13. Numone

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    Nice one. Pleased it's helped.
     
  14. Numone

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    And probably a good idea to let it hover for 10 seconds or so before starting your flight. I now move it gently away from the home point too, just for the first 50 yards or so, as it's easier to deal with compass / GPS issues that may pop up when it's not too far from you. The only time the AC went into ATTI mode following a GPS / compass problem (both warnings came up) was when I'd taken off and away from me very fast, and it was already some distance away from me. I was very nervous getting it back. I recalibrated the compass in a different spot and, touch wood, all has been ok since.
     
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  15. ElGuapo

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    Also double check and make sure the Vision Positioning is still turned on in the RC. In another forum I read that removing the DJI Go App from your device and reinstalling it helps a lot.
     
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