Mini Goes Mad!

[BushWacker]

This doesn't look like a yaw error ...

Would like to take a look at the mobile device .DAT log ending with FLY024.DAT also ... if it's not erased.

If it was a Yaw error, what would that mean? Where is the FLY024.DAT file located? I can't find it so maybe it's gone.

 

[Amorotor]

Did you power up the drone near steel objects ? In my case, it was the steel reinforcement in the balcony floor. As the result, the compass became way off ( almost by 180 deg ). The consequence :

I had problems calibrating my MM while wearing a steel watch band. As soon as I took the watch off and placed it in my pocket the calibration proceeded normally.

 

[slup]

If it was a Yaw error, what would that mean? Where is the FLY024.DAT file located? I can't find it so maybe it's gone.

A yaw error, mostly due to that the AC is powered on in a magnetic disturbed area, cause a flyaway in a straight or a toilet bowl shaped path (depending on how much the compass was thrown off) ... and that isn't what we see here.

Instead I think one prop blade from the left front motor was broken off or was damaged in some way.

Everything went well in the flight until approx 36sec ... the AC had then been piloted over the street & the house roofs there, turned around & was piloted back. The markers in the chart below is placed at 36sec ... all the time before that you commanded it over the street by means of elevator stick inputs (purple) & every time the AC answered with a speed increase (blue).



Just over the house (where the red circled star with the green bar is in the sat pic below) the AC start to rotate CW & at the same time pitch down & roll over to negative side (left).



Here below how yaw, pitch & roll change after 36sec...



Looking at the pic below we see that with a lost propulsion from either front left or rear right we lose one of 2 in total that torque the AC CCW, that means that the 2 CW gets the upper hand & the AC start to rotate CW ... that points to either the front left or the rear right.

As the AC initially pitch down, the front left looks most likely ... this is then confirmed by that the AC rolls over to the left. Both these motions due to a lost lift from the front left.



If the mobile .DAT log still was there (see post #16 where it should be) we could probably see there how the FC had commanded the front left to 100% rpm's & lowered the other props in an attempt to balance out these uncommanded motions of the AC ... but it was doomed anyhow as only 3-3,5 props can't keep the Mini airborne anyway.

The bounce after it hits the roof makes me think that only one blade breaks & then you give full positive elevator stick into the wall in the end (see the first chart & the purple graph) ...

 

[BushWacker]

Thank you very much for the analysis, although I must admit I only understand about 1/2 of it. The rail around the balcony is made of wood and I don't know if the flooring is made of metal, although it very well could be I just don't have any idea. It's a rental that my son just moved into a few days prior. The gentleman next door sitting on his balcony watching was so polite, he said sarcastically: "Is that the way it supposed to fly?"

What I'm hoping for is some evidence that I did not crash it into the roof of the building across the street so I can make a Warranty Claim as opposed to a Care Refresh Claim. I assure you I did not push the left stick down until it crashed onto the roof, the aircraft did that on its own. I also did not fly it back into the building I launched from, it did that on its own also. I did use the left stick full up trying to keep it from hitting the roof across the street and I try to bring it back towards me and then let go of both stick when it came full speed back at me crashing into the building I launched from.

Where is the mobile .dat file located on an Android? I will look for it.

 

[slup]

The rail around the balcony is made of wood and I don't know if the flooring is made of metal, although it very well could be I just don't have any idea ...

The incident was most likely not a yaw error coming from powering on the AC near a magnetic object ... everything so far points to a broken prop or possibly a motor failure on the left front.

Where is the mobile .dat file located on an Android? I will look for it.

See post #16, the one that belongs to this flight have FLY024.DAT in the end.

I assure you I did not push the left stick down until it crashed onto the roof, the aircraft did that on its own. I also did not fly it back into the building I launched from, it did that on its own also. I did use the left stick full up trying to keep it from hitting the roof across the street and I try to bring it back towards me and then let go of both stick when it came full speed back at me crashing into the building I launched from.

No need to assure me anything, all your stick commands are clearly shown in the .TXT log ... The incident started as said approx at 36sec (beginning of the chart below, left side). The AC clearly lose height uncommanded, below represented by the Red VPS sensor graph which shows height to things below the AC ... & the Black graph coming from the barometric sensor & are relative the height of the HP.

At approx 38sec you try to counteract the sinking AC with the throttle stick, Blue graph (left stick forward), which is released at 41sec. At 42sec you start to apply full positive elevator stick, Green graph (right stick forward) ... the AC have then bounced off the roof & is located above the driveway belonging to the house on the other side of the street. That stick isn't released until just a tenth of a second before you crash into the wall on your side of the street. That last elevator stick command drives the AC speed from 2m/s to 9m/s shown by the Light blue graph.

What I'm hoping for is some evidence that I did not crash it into the roof of the building across the street so I can make a Warranty Claim as opposed to a Care Refresh Claim.

It depends ... if you can provide the correct mobile device .DAT log & that shows a motor failure, then you have a stronger case towards DJI. If it shows a prop failure it will be harder as the reason for the failure can come from a number of pilot related thing's ... like abuse with micro cracks or badly mounted screws etc.

If the .DAT log is gone ... then I'm afraid, all will end with what I've shown you so far.

 

[JohnWF]

I have used My mini and Air2 launching from a steel ship, taking off from a steel deck with a new calibration and without, both drones have operated perfectly, close by and a kilometre away. the total No. of flights is over 50. I cant see how a compass error would cause any problems. As GPS would keep things on track and Drone knows where forward is, so all stick movements would not change.

 

[slup]

... I cant see how a compass error would cause any problems. ... and Drone knows where forward is...

First of all, this incident hadn't anything to do with a yaw error due to a thrown off compass when the AC was powered on ... but with that said,

... if you think the compass can be disregarded & a magnetic interfered power on spot have no influence on yaw errors & flyaways you might read the 2 posts below ...

A short explanation of compass function, calibration and errors.

Compass error demonstration

I have used My mini and Air2 launching from a steel ship, taking off from a steel deck ...

The truth is that you've been lucky so far ...

 

[BushWacker]

Thank you for such an informative explanation. This is a very accurate description of how the flight went. I might have broken a prop when the AC crashed into the roof across the street, there were several broken props when I recovered it but I can't say as to when they were broken. I went back and looked for the .DAT file but it is gone, I only have 1 file there from a flight I took a few days ago with another Mini I have. Too bad, it's in the hands of DJI now, I'll provide an update on what they have to say. All of this is very helpful to me and I hope to others also....

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No need to assure me anything, all your stick commands are clearly shown in the .TXT log ... The incident started as said approx at 36sec (beginning of the chart below, left side). The AC clearly lose height uncommanded, below represented by the Red VPS sensor graph which shows height to things below the AC ... & the Black graph coming from the barometric sensor & are relative the height of the HP.

At approx 38sec you try to counteract the sinking AC with the throttle stick, Blue graph (left stick forward), which is released at 41sec. At 42sec you start to apply full positive elevator stick, Green graph (right stick forward) ... the AC have then bounced off the roof & is located above the driveway belonging to the house on the other side of the street. That stick isn't released until just a tenth of a second before you crash into the wall on your side of the street. That last elevator stick command drives the AC speed from 2m/s to 9m/s shown by the Light blue graph.

View attachment 108233



It depends ... if you can provide the correct mobile device .DAT log & that shows a motor failure, then you have a stronger case towards DJI. If it shows a prop failure it will be harder as the reason for the failure can come from a number of pilot related thing's ... like abuse with micro cracks or badly mounted screws etc.

If the .DAT log is gone ... then I'm afraid, all will end with what I've shown you so far.
[/QUOTE]

 

[BushWacker]

Well good news! Thanks to the great support and advice I received here DJI is sending me a new drone covered under Warranty and I don't even have to use my last Care Refresh claim. I sincerely thank all who have taken their time to help me with this...