Fell out of sky, Mini2

[Deleted member 103366]

My Mini2 has reported "motor unable to rotate" messages just about everytime I attempted to fly in "cool" temps since receiving it from DJI in early November. The right rear motor would not start. Definitely felt resistance of that motor when spinning manually. The other 3 motors spun freely. No visible misalignment of motor shaft. No crashes or near crashes - happened since brand new.

After spinning the right rear motor manually and re-attempting takeoffs, the Mini2 would fly normally. But same resistance and "unable to rotate" message if I brought the AC down, changed battery, and attempted to fly after a 5 minute "rest". Once airborne, there has been no issue, but I have not flown in temperatures below freezing.

My situation indicates a direct cause & effect relationship on cool weather/temps. I am suggesting a possibly similar situation for the OP's AC -- colder temps at higher altitude (150 feet) and in snowy conditions chilled the AC motor and caused motor's failure to rotate.

Just a suggestion.

My AC is on it way back to DJI for assessment. I specifically mentioned to DJI that I was concerned about a motor failure or unable to rotate situation once the AC was airborne. The OP's incident strikes me as exactly what I feared would happen to my AC.

Does it? That I see you make no mention of having tried it in warmer temperatures.

 

[slup]

...I am suggesting a possibly similar situation for the OP's AC...

The OP had a bent motor shaft.... if you didn't have that your case isn't similar. If you want to know what might be your issue, post your log in your own thread, unnecessary to confuse & mix up the OP's incident with others.

 

[Wumpus_NJ]

The OP had a bent motor shaft.... if you didn't have that your case isn't similar. If you want to know what might be your issue, post your log in your own thread, unnecessary to confuse & mix up the OP's incident with others.

No worries. I was merely suggesting a possibly similar situation. As I have sent my AC to DJI, I'll await their assessment, so there is no intent to confuse or mixup anyone.

 

[zetetic]

... and to get that chart you feed in the downloaded .CSV file from PhantomHelp into the free software CSVview which you can download here --> CsvView Downloads

Excellent. Thanks!

 

[goldensky]

yeah, no icing involved in this failure, Mini2 was flip flopping all the way down into a snow bank, and it was very dry out and above 0 C.

it's actually very hard to see the wobble in the motor bell, but if you place it on a table, and shine a light around the gap in the motor , it has just the slightest amount of clearance as you turn it, then the gap gets tighter, then opens up a hair. the amount of drag isn't alot, but you can feel it compared to the other motors. the two front motors feel very loose and free, while the left rear is a bit notchy, and the right rear is smooth but draggy

 

[Chaosrider]

Where can I find the log file on my Samsung Galaxy S20 Note?

Thx,

TCS

 

[slup]

Where can I find the log file on my Samsung Galaxy S20 Note?

If you use the DJI FLY app ...

Device internal memory/Android/data/dji.go.v5/files/FlightRecord

 

[Quadcopterer]

Yours appears a separate problem to mine but non the less similar, see here Downward Vision Sensor Error (Logs)

 

[slup]

Yours appears a separate problem to mine but non the less similar...

And in what way do you mean your vision error is similar to the OP's incident ... besides that you also have a Mini 2?

 

[Quadcopterer]

i Didn’t read the whole thread, my mistake

 

[TRogan42]

Looks like you started with cold battery at 50%, MM wil lforce land at 3.5V as this is 0% of battery, you hit 3.3V at one point, below 3.5V on individual cel MM2 will act funy as it has built in logic to emergency land. I had exact same thing happen to me once also with cold battery.

 

[Meta4]

Looks like you started with cold battery at 50%

If your battery has been sitting around and self discharged, the % indicator will not give an accurate indication , and the real capacity of the battery may be significantly less.
Don't launch with a partially discharged battery.

 

[goldensky]

definatly lithium sucks in cold weather , i know all about it, thats why i keep my bird warm in the car with the heater at 70 degrees


the QC on the motor install sucks is the problem here

Mini 2 tight motor

One motor tighter than others. Loosened up a little after Taking off and flying for about 30 seconds. I don’t know if I should fly it any longer. It didn’t seem to feel hot after that short time. Maybe I should just fly a little longer and see if it gets warm? Any suggestions? Oil or what type?

mavicpilots.com

 

[slup]

Looks like you started with cold battery at 50%, MM wil lforce land at 3.5V as this is 0% of battery, you hit 3.3V at one point, below 3.5V on individual cel MM2 will act funy as it has built in logic to emergency land. I had exact same thing happen to me once also with cold battery.

All what you speculate have nothing to do with what happened in this incident ... Go here & read, all there is based on the log content --> Post #19 ... then add in what the OP discovers here --> Post #30

Further more ... the low battery auto landing is height dependent ... all DJI crafts will start to auto land much earlier than at 0%.