Requesting post crash analysis (video)

[skiddyfisk]

So, earlier today I experienced an unexpected auto-landing while the drone was out of sight. Video cut (as happens at that range) and I looked away to pet a dog, and when I looked back it wasn't hovering anymore. Found it pretty quick, but it was behind a fence and took some doing to actually retrieve.

What concerns me is why it auto-landed. This was 13 minutes into the flight, so the battery shouldn't have been low, and if it was it should've tried to fly home (it usually does this when I run it out) - also, the camera continued recording for an additional 25 minutes while it was on the ground, and was still going when I shut it off.

The entire flight video is here:

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Skip to 12:30 or so for the leadup and descent. It drops in a controlled manner but MUCH faster than I've ever seen it go before. Then skip to 38:40 unless you feel like watching blurry grass blow in the wind for 25 minutes.

When I cleaned it off and replaced one broken prop, the motor of that prop would no longer spin - it just sits there twitching when the other three spin up. I've already ordered a new motor and ESC, but what I'm wondering is this - did the crash fry the motor, or did the motor croak, causing the auto-land? Does it have that level of fault protection?

I mostly want to know if there's likely to be any other issues I should look for.

 

[a31burgervan]

The footage seems very Shakey from the start and the horizon seems off level, was the quad calibrated ok, windy?


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[skiddyfisk]

Wasn't super windy. I haven't done any calibration since I got it last month. It's always been about that shaky; I haven't flown any other drones so I don't know how it's supposed to be.

I was thinking it was tilted to the right a little, but wasn't sure.

 

[PageSide]

At 12:43 there is a sudden jerk backwards. Was it one of the rear motors that failed?


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[skiddyfisk]

Nope. Front right.

 

[Ryan Hanscom]

That footage is not normal. The amount of shake is a dead giveaway that it has a serious issue. Motor perhaps? Bad prop which is causing extra strain on motor? Although I have to admit I would still think the gimbal would absorb some of that.


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[skiddyfisk]

OK. If people are saying the footage is remarkably shaky I'm definitely thinking the motor caused the crash.

Thanks for the feedback. We will see on Friday if the new motor and controller improve things.

 

[skiddyfisk]

New parts installed, here's a short video of a test flight in my parking lot:

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The video from the drone is uploading, but is it obviously acting weird in any way?

I don't know how stable it's *supposed* to be.. the drone video is solid enough, but it does exhibit the odd wobble in the video above.. or I could just be obsessing now that it's had an issue once.

Drone video is live:

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Second liftoff at 2:10 is the one recorded in the previous video.

 

[Ryan Hanscom]

I might have misspoke....I just saw that you have a phantom 2. I dont know how thise should look but if it was a p3 it is really bad. Sorry for the confusion someone with a p2 needs to chime in.

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[skiddyfisk]

This is a 2 vision with the single axis gimbal.

I'm personally happy with the stability of the video by itself, just concerned about it signifying an issue I need to fix.

 

[Phantom_Dazza]

Currently uploading a 2:31 off a take off and landing of my P2V+ as u will see the video is stable and drone lifts off straight up and quality is stable
I would say that their is defo a problem somewhere , i would have replaced all 4 motors because it then gets rid of any miss match

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[Phantom_Dazza]

Hope that little video helps wind was blowing at 10 mph with gusts of 15 mph

 

[skiddyfisk]

I can compare a recent video with one from January and see it's definitely shakier. How can I narrow down the issue without just shotgunning new motors? (I don't have that kind of cash)

The front right motor/esc are brand new, and the esc is a 2.1 as are the ones already in it.

Video from 1/19:

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Video from 2/28:

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The only significant crash between the two is the one this topic is about.

 

[Phantom_Dazza]

not so much, i had my Gimble pointing straight down .. Your P2V should be quite stable in the air ... When u launch are you pushing on any sticks apart from the left one as i have noticed it lurches forward or back on Launch
When was the last time u calibrated the compass ?

 

[skiddyfisk]

not so much, i had my Gimble pointing straight down .. Your P2V should be quite stable in the air ... When u launch are you pushing on any sticks apart from the left one as i have noticed it lurches forward or back on Launch
When was the last time u calibrated the compass ?

Sticks: sometimes I give it a little juice away from whatever nearby object if I don't have an ideal takeoff spot, not always, and I can't recall in which videos I did or didn't
I calibrated the compass a couple weeks ago while attempting to diagnose this very issue and it didn't do much.

 

[Phantom_Dazza]

are all 4 props of the same brand ? ...
Think what i would do first is get get 4 DJI props $30 might fix your problem, I had a problem with my P2v+ once there was a very small piece missing from one of my props and it caused chaos to the flight of it

 

[skiddyfisk]

They're what came with it, secondhand. COULD be knockoff props, I don't know.

I have a set of four new DJI props, but they're for a p3. Same shape and threading, any reason I can't use them?

 

[Phantom_Dazza]

P2 and P3 Share the same props 9450's also look close at the bottom of the drone around the motor mounts/Screw holes for cracks to the case

 

[skiddyfisk]

Just this on the left front motor mount area:

https://i.imgur.com/CRHllGs.png

I took it to an empty field to see if I could get it to mess up in a controlled manner:

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Twice it does the thing that bothers me - it jukes right and down.

Theory based on my minimal comprehension of how quadcopters work: It's losing power to one or both right-side motors, thus tilting (and moving) right; left motors slow down to try and level out, resulting in loss of altitude. Does this make sense? And would one fuckity motor like that be causing the other wobbliness I'm seeing?

Additional detail: I suck at soldering so the joints attaching the right front ESC and motor I replaced are less than stellar. Could a crappy connection on one of them be causing this?

 

[Phantom_Dazza]

Do u have DJI Vision assistant ? if not try getting it and plugging the drone in see if your new esc needs a update ... and just run threw the initial set up process again ** IMPORTANT ** make sure u remove your props before doing this just in case they fire up