First crash

[davemorts]

There were a few flights without incident before this one.
I flew around my local golf club to a distance to approx 500 Yds.
I also flew approx 900 yds from my front garden to a river junction.
I didn't re calibrate the compass after I fitted the LOC8TOR.

 

[davemorts]

DJI Flight Log Viewer - PhantomHelp.com

This is the flight round the golf course without loosing control.
I do see YAW errors and COMPASS errors but it never flew away during this flight.

 

[BudWalker]

There were a few flights without incident before this one.
I flew around my local golf club to a distance to approx 500 Yds.
I also flew approx 900 yds from my front garden to a river junction.
I didn't re calibrate the compass after I fitted the LOC8TOR.

I don't know the particulars of the LOC8TOR; I'm just spit balling here. If it does cause magnetic distortion then the extent of that distortion is very small. If it's removable then each time it gets attached it's position and orientation could change enough to change how the magnetometers are affected. At this point you'll have to decide if this is a plausible explanation. Did it get removed and then re-attached before and after the incident flight?

One other thing you could do is provide the .DAT of a flight where it wasn't installed and hen the flight immediately after that.

 

[davemorts]

Once I fitted the LOC8tor it was never removed.
I will look up some other flight data.

 

[davemorts]

Golf club dat file

 

[BudWalker]

Golf club dat file

That .DAT appears to be one of those tablet .DATs that got split. There should be another .DAT immediately before this one.

 

[davemorts]

Sorry for the delay I had to give a friend a lift.

DJI Flight Log Viewer - PhantomHelp.com

I think this is a flight before fitting the LOC8TOR.

I will look for that other DAT file now.

 

[davemorts]

I think this is the dat file immediately prior to the one sent earlier.

 

[davemorts]

Gotta go to bed now, the wife is up really early in the morning.
Thanks BudWalker for all your help, I'm learning a little more every day.

Hope to chat again soon.

 

[davemorts]

Here are all dated 1st Dec 2017 from one of my phones. I hope It's among these.

 

[davemorts]

When looking through the flight records I came across this one from from early November. This time it was my spark but with similar YAW and COMPASS errors.
DJI Flight Log Viewer - PhantomHelp.com
I lost control when the spark went into ATTI mode but luckily regained contol again.
This was long before I purchased the LOC8TOR.

 

[davemorts]

This is the video. I meant to fly down to the river but the spark went into ATTI mode and drifted sideways in the wrong direction.

 

[Mossiback]

I sure don't like hearing about a Mavic going into Atti mode while flying outside. I could see it happening around tall buildings or in a canyon but neither was applicable in this case. It was mentioned that a LOC8TOR was attached at the rear of the drone and that's where I understand the GPS receiver is located. Perhaps that is what made it loose GPS. Is it possible that it weakens the received GPS signal enough that when the Mavic is turned and the satellites are in a certain orientation that it will switch into Atti mode? That might explain why it happens one day and not another. I am wondering if others that have had a sudden loss of GPS in unobstructed conditions also have something attached to the Mavic.

 

[davemorts]

I was thinking along those lines myself, when I get the mavic back I will try to put the loc8tor in a different location.
I had watched a video on youtube and placed the loc8tor in the same position as this guy did.

The previous video above (fly away 2) is from my spark long before I bought the LOC8TOR.
I am thinking that maybe I was close to my car when I calibrated the compass on both drones and caused these compass errors.

 

[Mossiback]

...The previous video above (fly away 2) is from my spark long before I bought the LOC8TOR.
I am thinking that maybe I was close to my car when I calibrated the compass on both drones and caused these compass errors.

OK. I missed that it has happened to your Mavic and your Spark. That being the case, I would look for what was common in both flights or their setup. I saw some open space close by in your video. My suggestion would be to go there, calibrate your compass away from anything metal (don't forget the rebar in concrete or your keys in your pocket) and fly there. I would not feel comfortable flying over a neighborhood until some error-free flight time was logged.

 

[davemorts]

Thanks Mossiback, I will bring the spark to the field away from my house, I will remove anything metallic from my person and re-calibrate the compass and IMU then try that flight path again. ( hopefully tomorrow weather permitting).
It would be great if that cured the problem.

 

[davemorts]

Hi BudWalker, sorry I haven't sent you the Dat files you asked for, I have been in bed with a flu this past couple of days.
I can't find any Dat files after 17-12-15. Here are all the Dat files from that phone (new S8) in two zipped folders:

 

[Callum]

The loc8tor will definitely affect compass as has metallic innards and a battery.

Look in DJI go at the compas calibration screen which shows interference. Move the loc8tor to and from the site you had it fixed and see what interference you get.

Any time you add anything like that to the mavic calibrate with it in place, and again if you no longer use it.

 

[davemorts]

The loc8tor will definitely affect compass as has metallic innards and a battery.

Look in DJI go at the compas calibration screen which shows interference. Move the loc8tor to and from the site you had it fixed and see what interference you get.

Any time you add anything like that to the mavic calibrate with it in place, and again if you no longer use it.

Thanks for that advice Callum. I will try that when I get it back from DJI.

 

[BudWalker]

I took a look at some of the other .DATs from the tablet. There were 3 or 4 from the Spark that didn't have any useful data because a flight didn't occur. From the Mavic flights there was on additional flight - FLY033.DAT. It exhibited some of the same behavior as the incident flight, i.e. magYaw and Yaw would separate.after rotating.


When you get your Mavic back maybe we can do some experiments with the LOC8TOR.
1) calibrate the Mavic
2) do a "fake" flight where the Mavic is rotated 2 or 3 times by hand - don't start the motors and fly
3) attach the LOC8TOR
4) another fake flight
5) calibrate
6) another fake flight
.......