Spin & crashed!

[cheddarman]

I've got this issue in the hands of BudWalker as he is the developer of the programs that read this data. I thin k it's a Mac issue, not fully compatible maybe!

 

[Fly Dawg]

@Gizmoh ...according to the .txt log in your original post. You need FLY147. I suspect that FLY148 and FLY149 are continuations, being the fact that FLY149 appears to be while the aircraft is on the ground upside down without the motors running. You were still looking at over 50% Battery at that point.

 

[cheddarman]

Oh dear, no idea where I'll find FLY147. Just did a computer search and not on mine!!

 

[Fly Dawg]

Oh dear, no idea where I'll find FLY147.

The OP only posted one DAT file in Post#23.

 

[cheddarman]

Ah, OK. @Gizmoh can you find FLY147 for us??

 

[Gizmoh]

The OP only posted one DAT file in Post#23.

@cheddarman

Got FLY147, here it is

Gofile - File sharing platform, anonymous and free

OR

easyupload.io

easyupload.io

easyupload.io

OR

1fichier.com: Cloud Storage

1fichier.com

 

[Ansia]

I have to say that after 18 months lying on a shelf I would calibrate. In fact t I calibrate at any new location I go to. It's an individual choice.]
]
At no time was he flying above 90 feet over all those houses. I wonder if there was some sort of interference somewhere along the route?
He started to lose height at 0.43 and just steadily dropped to the ground.
At the latter part of the flight the battery cells were showing some deviation but still at 95% capacity.

I'd still like to see the data file if it is still there.
I am in a steep learning curve analysing data and would be interesting to see what the ESC's and motors were doing.

My v2.0 requires calibration when you travel more than 50 kilometeres or if you haven't done a calibration for more than 30 days. DJI told me, this is standard for that model. So I'm stuck doing the dance every other day.

 

[sar104]

@cheddarman

Got FLY147, here it is

easyupload.io

easyupload.io

easyupload.io

OR

1fichier.com: Cloud Storage

1fichier.com

Your file download options are horrible, so I haven't looked at the DAT file. However, the data in the txt log are pretty clear. Firstly, it wasn't a compass or IMU issue - this was almost certainly a CW motor failure - probably front left - leading to rapid CW rotation and descent:

Why did you ignore the repeated "motor blocked" warnings that began as soon as you started the motors?

 

[cheddarman]

My v2.0 requires calibration when you travel more than 50 kilometeres or if you haven't done a calibration for more than 30 days. DJI told me, this is standard for that model. So I'm stuck doing the dance every other day.

I love doing that! It's a prelude to explaining to people what the heck you're doing going in circles with a drone! I tell them I'm winding up the motor springs or something equally stupid! Amazing the reactions one gets

 

[Gizmoh]

Why did you ignore the repeated "motor blocked" warnings that began as soon as you started the motors?

Warning appeared only in logs.. No warning was shown in DJI app.


Gofile should be fast enough: Gofile - File sharing platform, anonymous and free

 

[cheddarman]

Bear with me, I'm practicing this from your FLY147 data file...........

At 18 sec and again at 26 seconds you put full left/right yaw (rotation) inputs and then after 36 seconds you appear to have put full left and then right yaw for some reason?
At this time all four motors appear to be working normally.

Not sure if this is relevant to anything but I'm enjoying the analysing!! I'm sure someone will correct me if my above is wrong? (I won't taker offence as I say, I'm practicing........

 

[Fly Dawg]

@cheddarman...Look at the rudder inputs. There were 2, but well before the 2 spins. Not relavent to the spin.

 

[Fly Dawg]

@gizmo To me this looks like an ESC issue. At the first 2 spins, the left front PWM spiked to 100% and subsequently the aircraft spun 360 degrees. It recovered after the first and second one, but got worse after that. That is not written in stone. Just what I am seeing. Not really certain why that spike would cause the spins, but could be the result of another factor. The motors were fairly stable in RPM.

 

[cheddarman]

@cheddarman...Look at the rudder inputs. There were 2, but well before the 2 spins. Not relavent to the spin.

Yep, got that.........the left front motor/ESC behaving erratically pre crash?

 

[Meta4]

I love doing that! It's a prelude to explaining to people what the heck you're doing going in circles with a drone! I tell them I'm winding up the motor springs or something equally stupid! Amazing the reactions one gets

Maybe the reactions are because the onlookers understand what compass calibration actually does and why it's a waste of effort doing it before each flight.
Your compass really does not require recalibration every day you fly.

 

[cheddarman]

I get the message Meta4!!!

FlyDawg, what does PPMrecv stand for/mean in the CsvView Motor menu please?

 

[sar104]

Warning appeared only in logs.. No warning was shown in DJI app.


Gofile should be fast enough: Gofile - File sharing platform, anonymous and free

It was the front left motor, as I suspected:

Note that the ESC had been intermittently maxing out the PWM on that motor repeatedly after takeoff (hence the motor warnings). At 35 seconds it again went to full, but the motor speed dropped. That angular imbalance, with a CW motor running low, is what caused the CW spin. The lack of lift also caused the descent. It's either a bad motor or a bad ESC.

 

[sar104]

Warning appeared only in logs.. No warning was shown in DJI app.

Those warnings are being logged by the DJI GO app, so if they appear in the log then they appeared in the app during the flight.

 

[cheddarman]

YESsssss! Picked up the front left problem!!

 

[Fly Dawg]

That angular imbalance, with a CW motor running low, is what caused the CW spin. The lack of lift also caused the descent.

Thats the answer I was looking for. Wasn't 100% certain of the reason for the max PWM and motor slow down causing the spin. And agreed on the app messages as well. BTW, did you look at the event log? Specifically the first line here. Landing? Just curious. The remainder is after the crash I believe.