DJI Crash footage with strange noise

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mdr1031

Member
Was able to recover the wreckage and footage after this crash. Wondering if anyone has seen or had the same issue. After looking at the wreckage it looks to me that the balance lead on the battery came unsecured and was chopped up by the prop. Therefore cause multiple shorts. Wondering if that might be a sound theory and the cause of the noise and spooling of the motors.
Side note this footage is cut down to just before and through the event. There was a good 6-8 mins of solid uneventful flight before hand. Also the initial nose dive was intentional to loose altitude quickly then eventually level off, but obviously that didn't go as planned. Any thoughts will be greatly appreciated. Running E300 power system and naza m v2.

https://www.youtube.com/watch?v=V2HXKf8Cs2U


 
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C

cootertwo

Member
Wow! That is a bummer, and strange. I'll be watching to see if you ever discover what it was. Ain't it a ***** when all you can do is watch your rig plummet to the ground, while your butt is eating a hole in your shorts! Looks like the left front motor was cutting on and off, and when it comes on, it's overpowering the right. Loose connection or short somewhere? It that the same sound your ESC's make when you power up?:black_eyed:
 

M

mdr1031

Member
Yeah what makes me think it was the shorting out of the balance lead wires is I initially lost video signal. After waiting a couple seconds and moving my ground station around with no result I hit the failsafe. But now thinking back on it as soon as the video signal went I remember the taranis repeating , "RSSI critical...telemetry lost...telemetry recovered" almost in time with the results in the video.

also after look over the wreckage the only prop broken was the rear right. Which if the balance lead was chopped would have been the one to do it. Only half of the prop was missing too which could explain the yawing...again just theories.
 

Av8Chuck

Av8Chuck

Member
I think its more likely that the damage to the balance lead was a result of the crash. The sound is too mechanical for a short, if the problem was a result of the lead being damaged in flight it would have been more likely that it would fail altogether.

But no matter what the cause this is the first time I've seen this. I guess that's some sort of consolation?
 


M

mdr1031

Member
DJI e300 esc, motors,and props. Haven't had a chance to individually test escs and motors. Don't think it was low voltage only had 1500 mah consumed out of 5000. Unless two of the balance lead wires contacting some how tricked the escs into thinking the voltage was lower than it really was. But that's just speculation...
 

Amerly

Amerly

Member
One of the smoothest crash I've even seen (from that height) ! How many flights have you got from this bird before the crash ?
 

M

mdr1031

Member
Tell me about it. Despite the looming uncertainties the beauty of them spooling like they did kept it from hitting at freefall or close to it. Really the only damage I saw without testing electronics is a broken bottom plate, two arms, and the one prop.

I'd say I had somewhere between 30-40 flights on it conservatively without an issue.

Good excuse to upgrade to the Discovery frame I've always been putting off.
 


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