Welcome to InspirePilots.com

Join the leading DJI Inspire community for free!

I lost control after Battery Change

Discussion in 'Inspire 1 Discussion' started by John Casey, Jul 4, 2015.

  1. John Casey

    Joined:
    Mar 20, 2015
    Messages:
    80
    Likes Received:
    13
    Location:
    Queensland, Australia
    I had a fairly scary incident today...

    I was out on a property and did a compass calibration, took off and flew for the duration of the battery with no problems, then landed at 25% to change batteries. I shut down the aircraft, but not the controller or iPad, changed the battery then switched the aircraft back on, then started the motors and took off again and that's when the trouble started.
    The aircraft was almost uncontrollable. I say "almost uncontrollable" because the sticks did actually make the aircraft move around - it made it respond, but very erattic and it flew almost at full speed most of the time. I had it going back and forth in a criss-cross pattern for a while as I tried to work out a pattern whilst making sure it didn't get too far away from me. I realized I could keep it in a basic pattern with this back and forth motion. Incidentally, ATTI mode made no real difference. I decided to lower the altitude from where I had kept it (about 100ft) and managed to bring it down to about 20 ft and brought it basically over the dirt road where I brought it down and landed it on the road safely, and shut the motors down, but left the aircraft switched on.

    I then checked the sensors and calibration readouts and the compass was down at about 1300, and not around 1500 where it normally is. the Accelerometer and Gyro readouts were about normal (between -1 and +1) . I then decided to do a compass calibration as the aircraft was still switched on, and the battery at 50%. After this calibration, the compass readout was back at around 1500. I decided I needed to know if this was the problem and it would be much more conclusive if I took off again whilst it was still the same continuous session, so I started the motors again, set the home point and took off and it flew beautifully again. I flew around with full control for the remainder of the battery and brought it back in and landed with no problems.

    So I guess the confusion in my mind is the experts who have very definitively stated that you do not have to calibrate the compass every time you fly, and some say it can be harmful to do so. I'm now thinking that I will do a compass calibration even after a battery change and even if it is in the same position as the last battery.

    Do any of you have opinions on this - had similar experiences etc?
     
  2. Aviator

    Joined:
    Jul 1, 2015
    Messages:
    389
    Likes Received:
    161
    Location:
    Dorset, UK
    Yes I have!
    I had an almost identical situation, the difference was that I did shut down the RC.
    The AC was almost uncontrollable from the moment it took off.
    Switching to ATTI mode did not help much..
    I managed a hard landing that pulled the camera from its rubber mounts and pulled a pin from one of the ribbon cables feeding the camera,
    Like you I will now ALWAYS do a compass calibration before a flight.
     
    John Casey likes this.
  3. jbrader21

    Joined:
    Jul 4, 2015
    Messages:
    1
    Likes Received:
    0
    I recently crashed into a tree after take off. As soon as the drone took off it drifted sharply to the right and i couldnt control it. It got stuck in a tree and the props continued to rotate causing smoke. I finally got the coptor out of the tree and the camera was ripped off the gimbal. Has this ever happened to anyone and what would something like this cost to repair?
     
  4. John Casey

    Joined:
    Mar 20, 2015
    Messages:
    80
    Likes Received:
    13
    Location:
    Queensland, Australia
    I managed to land with no damage, in fact it was a reasonably soft landing in the end-all things considered. But I really wasn't expecting problems when I was in exactly the same place, just came down to do a battery change and go back up, but the battery change obviously caused the compass to become uncalibrated - unless it could be something else??? So for me, it's the "Inspire dance" every time before take-off with no exceptions from now on.
     
  5. skylabimaging

    Joined:
    Mar 17, 2015
    Messages:
    561
    Likes Received:
    247
    Location:
    Seattle, Washington
    Alternatively you can just check your sensor readouts before you even arm the motors (as you should anyway) from there you can determine that you need to calibrate the compass or not and you would've known had you checked first

    What's really concerning here, is you still tried to fly it after noticing the difference in flight characteristics, this isn't very safe practice.
     
    james tulloch likes this.
  6. Carlo

    Joined:
    Jan 16, 2015
    Messages:
    93
    Likes Received:
    51
    Location:
    California

    I have read that some member have reported that their MAPs are locked and when they review there orientation of there bird it not even in the right direction. I always make sure to unlock my map and use my phone as a hot spot to cache the maps I zoom in and move the map around so it caches a large area, then I check to make sure the my bird shows proper orientation before I launch and then I put all IOS devices in airplane mode before launch. Just to be clear I am not saying this was the reason why it happened, but I have not had this happen to me yet!
     
    skylabimaging likes this.
  7. skylabimaging

    Joined:
    Mar 17, 2015
    Messages:
    561
    Likes Received:
    247
    Location:
    Seattle, Washington
    You just need to do pre-flight checks, I know DJI made it easy for noobers but you gotta do some leg work
     
  8. Aviator

    Joined:
    Jul 1, 2015
    Messages:
    389
    Likes Received:
    161
    Location:
    Dorset, UK
    It depends on the damage..
    Its easy enough to put the camera back on the gimbal but before you do that you need to check the two ribbon cables for damage, these can be bought on ebay, about £6.00 for the pair.
    Once your camera is mounted, power up the bird and see what works and what does not..
    Take it from there.
     
  9. John Casey

    Joined:
    Mar 20, 2015
    Messages:
    80
    Likes Received:
    13
    Location:
    Queensland, Australia
    Skylabimaging, no you didn't read the order of events (or I didn't make them clear). I flew the second battery immediately after the first in exactly the same place without doing a second compass calibration and sensors check because I have been told on this forum that there is no need to do a compass calibration unless you change location, and even then only if the app tells you to do so. So I didn't check before using the second battery in exactly the same location. I certainly did before I went up the first time and it checked OK after that. Where you may be getting confused is the fact that I took it up again after I managed to land after the erratic flight, but I certainly did do a compass calibration, and checked the readouts and they then appeared normal, so I thought it would be good to check it's flight characteristics then as it was one continuous flight session without the need to switch off in between. In other words, it flew erratically, I managed to land, I checked the readouts and the compass was down from 1500 to 1300. I did a compass calibration without switching the aircraft off (motors off of course) and the readout was then normal again (1500) It was after that that I decided to try another flight - after the readouts were back to normal, and yes so too was the flight characteristics ie. that was normal.

    So, no I did not fly after a bad flight without checking that it was likely to be safe to do so. And as a footnote, even though it was perfectly legal, I did this on a private cattle station where there was nobody and nothing for 30 kilometers. There was absolutely no danger to anyone or anything other than the aircraft itself, and perhaps myself and my car.
     
  10. John Casey

    Joined:
    Mar 20, 2015
    Messages:
    80
    Likes Received:
    13
    Location:
    Queensland, Australia
    Read what ACTUALLY happened. I do the legwork!
     
    DJI_Ryan_408 likes this.
  11. John Casey

    Joined:
    Mar 20, 2015
    Messages:
    80
    Likes Received:
    13
    Location:
    Queensland, Australia
    Yeah but you guys also need to read what I said ACTUALLY happened. I do everything the manual tells me to do and more. The simple fact is the manual states that it is necessary to do a calibration ONLY when the App tells you to do so. I do a calibration in each new location, and check the readouts. But I don't normally do a re-calibration after a battery change in the same place and that is when this problem happened ie between batteries the calibration changed. I do follow the instructions but what I am saying is that I believe that they don't go far enough, and that you need to check them before EVRY takeoff, even in the same place and after a battery change.

    But I'm getting annoyed by people telling me I'm lazy or not appreciative of the fact that it is a serious investment ($3K - try $5.5K over here!). No-one takes flying these things safely more than me. I just wish there were consistent, absolute must do procedures that will ensure safe flying because the manual is obviously not correct with this one.
     
    Richard in ky likes this.
  12. JohnHan

    Joined:
    Jun 4, 2015
    Messages:
    65
    Likes Received:
    23
    Wait, ATTI mode is supposed to negate a bad compass cal I thought.
     
  13. skylabimaging

    Joined:
    Mar 17, 2015
    Messages:
    561
    Likes Received:
    247
    Location:
    Seattle, Washington
    I did read it...but since than you've heavily edited your op so it's pointless now
     
  14. turbodronepilot

    Joined:
    Nov 5, 2014
    Messages:
    1,550
    Likes Received:
    1,264
    Location:
    Prather California
    It does..
    if your i1 flys crazy in gps mode and you switch to atti and it doesn't help much you may need to calibrate your imu ..
    If you calibrate your imu and still have crazy flight behavior you might have a bad flight controller. ..
     
    sirnikolas, flyersgirl and John Casey like this.
  15. JimPA

    Joined:
    Apr 5, 2015
    Messages:
    117
    Likes Received:
    70
    Another thing that comes to mind, is if ATTI mode had no effect....are you sure you have your app set to allow you to have multiple flight modes? I had this switch to off and when I would try to switch to ATTI mode it had no effect.

    From what I understand, dropping into ATTI mode should remove the influence a bad compass calibration would have. Also, remember it's not always a BAD compass calibration. Most of the time it is some metal in the area of the craft that if causing it a problem. Also, remember if you had the craft in an area that was causing a very high reading, simply moving it to a new area with a lower reading and launching quickly is not the best idea. I believe it may take 1-2 minutes in the new area to have the AC adjust. I don't know 100% for sure, but I do know once when I launched w/o reading the MOD values and had to fight for control, it took the AC about two minutes to become stable.
     
  16. John Casey

    Joined:
    Mar 20, 2015
    Messages:
    80
    Likes Received:
    13
    Location:
    Queensland, Australia
    What have I edited? I haven't edited anything, all I've done is reply to remarks that I think are a little on the arrogant side.
     
  17. John Casey

    Joined:
    Mar 20, 2015
    Messages:
    80
    Likes Received:
    13
    Location:
    Queensland, Australia
    Well that's probably why switching to ATTI mode did nothing - I wasn't aware that you had to switch the option on to allow ATTI mode. I just flicked the switch on the controller to the middle setting and it made no difference, but when I saw your reply above, I checked the app, and discovered the option to allow multiple flight modes, which was off. The trouble is, after switching it to on, after I came back to it I noticed it had turned itself back off again. However, I did this quickly and the aircraft itself was not on so maybe it has to actually be all powered up, but it does keep switching back to off.
     
  18. John Casey

    Joined:
    Mar 20, 2015
    Messages:
    80
    Likes Received:
    13
    Location:
    Queensland, Australia
    Is there any good online instructions for calibrating the IMU? Are there any traps with doing it?
     
  19. turbodronepilot

    Joined:
    Nov 5, 2014
    Messages:
    1,550
    Likes Received:
    1,264
    Location:
    Prather California
    I'm sure there's some videos on you tube, but to do a IMU calibration isn't very difficult. .
    make sure and take off the props and do it when the I1 is cold and on a level surface, like your garage floor..
    Hit mode on the pilot app and then hit advanced settings then hit sensors then hit imu advanced and then follow the prompts. .
     
    sirnikolas and flyersgirl like this.
  20. mdomeny

    Joined:
    Feb 23, 2015
    Messages:
    429
    Likes Received:
    50
    would that tree parking not be a fault of the inspire 1 and not pilot error??? would sending it in be repaireable on warranty or is that a no warranty issue...