FYI to engineer dude, these are not 400 Hz stepper motors, they are variable frequency 3 phase motors with corresponding VFD's for 'esc's'.  I got a good laugh from this whole thread as it is just like 'Outsourced'!

to all you pilots there with this engine issues, did you guys have bumpers installed?

DJI-Dboy Posted at 2014-12-20 14:33
Hi, Paul,
Thanks for your detailed description in technical. It is our customers' support that mak ...

DJI-Dboy and others,
Here's a few photos and information specific to my premature V2 ESC failure to pass on to the DJI R&D team.  From the forum discussions on ESC failures, I'm sure the failure is similar to others.

Observations:
1.  New motors are causing excessive current to flow through the motor wiring, melting the insulation.
2.  Melting insulation on the motor wiring is evident -- even on the still functional ESC boards (failure nearly imminent).
3.  Motors clearly need a larger wire guage for the current, and with high temperature teflon insulation.
4.  Motor wires should come off the motor end of the ESC board for shorter wires, ensure their separation (don't touch when hot) and lower the inductance presented to the MOSFETs when sinking current (fly back).

In my case, I believe the failure was caused by the red motor wire insulation melting and fusing into the black motor wire forming a short, forcing the MOSFET drivers to source the full battery current (5A) into the short, causing the dramatic destruction of the MOSFET ICs.  Fortunately, the P2V+ was on the ground, just landed after an 18 minute flight (38% battery remaining) and just as I was powering down the motors.  As stated, the remaining functioning ESC boards also all show signs of excessive heat stress and melting insulation.

Operational conditions:
Flown in New Mexico between 4,600-5,000 feet above sea level, temp mid-60s F (20C) 15% relative humidity.
ESC failure occured less than 2 weeks after I purchased it, on the 16th flight with only about 3-4 hours on the motors/ESCs.
The P2V+ has never crashed or had a hard landing.

I love my P2V+ and impressed with the well thought out engineering.  However, it does appear the V2 ESC board and wiring falls a bit short to properly handle the increased power (current) demands of the new motors as the photos show.  An easy fix with larger guage motor wiring and perhaps a little more robust ESC/MOSFETs.  Some additional motor demands are no doubt made at higher altitudes over sea level.

Paul

na5n@zianet.com Posted at 2014-12-21 06:25
DJI-Dboy and others,
Here's a few photos and information specific to my premature V2 ESC failure t ...

is that the v3 vision plus?

jarek33@hotmail Posted at 2014-12-22 02:05
is that the v3 vision plus?

Yes.  The latest new version.  The only real noticeable difference I see from older P2Vs is the  improved GPS shielding, pointed out on one of the photos, and of course the new motors.

na5n@zianet.com Posted at 2014-12-11 11:31
Never saw the wiring in the original P2Vs, but they do appear to be heftier in photos.  The motors ...

Just some thoughts on wire size.  These motors are 3 phase brushless motors, the ESC sequentially drives the motor windings one at a time (very fast) to spin the motor.  The current flow is less in the 3 motor wires than the supply line into the ESC and that's OK because the current is divided between them.  Dr Turbo, who designs these motor systems is a PHD and really knows his stuff so I trust his designs on wire sizing etc.

What I'm seeing in these photos looks more like ESC/motor installation quality issues.  There is potential for serious shorting if the motor wires are stripped back too far and they are bent or routed in a way that allows them to touch where they shouldn't.  ESC shorts by wire or FET failure are usually catastrophic as the pictures show.  Also there have been some warnings about using older ESCs with the new motors, but if they had the DJI installed firmware that maybe they would be OK.  My thought is that the ESCs are fairly cheap so I opt for all new, current pieces to my upgrades.

I'm an electronics guy and a real stickler for clean wiring.  I would probably open my Phantom to inspect the wiring, if I didn't do the installation myself.

I've purchased the new ESCs and Motors and will be retrofitting two of my Phantoms this week so I'll see for myself soon enough.

So here is my case: New last month Phantom 2 Vision Plus (Not a V3).  Upon powering up to idle, one motor will twitch, however at 50% power it will spin as normal and at full throttle will take-off as normal.  All flights seem to be normal. Does this sound like an ESC / motor issue or something else?

Same thing happened to me. Got tired of waiting for a response from DJI, so I ordered a new ESC from HeliDirect. Got it in 2 days, repaired, and now flying.

By the way, got a response from DJI the day after I fixed it telling me to contact service center

na5n@zianet.com Posted at 2014-12-9 15:49
One of my motors failed on my 16th flight just as it was landing (new version).  No crash, just a  ...

Did the motor fail in the air, or did it land, tip over, and stall the propeller.?I would think that the resultant EMF from a stalled motor could cause all the damage you describe.

john@johnc.org. Posted at 2014-12-13 01:22
I have just received my new Vision 2 + Version 3.
Props attached, I tried to spin up the props as t ...

I also see the same problem with my new Phantom 2 Vision +.  One prop is not going as fast as the others, and completely stops for a split second as it is rotating.  Will get a replacement.  

swinden@prodigy Posted at 2014-12-30 22:46
So here is my case: New last month Phantom 2 Vision Plus (Not a V3).  Upon powering up to idle, one  ...

I would say there is an issue, all 3 motors should be spinning at about the same speed.  On my Phantom 2 Vision Plus V3, one motor is going slower and actually stopping for split seconds, and never gets up to speed, so that it can get off the ground without just flipping over.

jtrager@carolin Posted at 2014-12-31 02:12
I would say there is an issue, all 3 motors should be spinning at about the same speed.  On my Pha ...

So reading up on this site has been really informative....thank you.

In my situation I was flying normally, and I landed the copter in the grass....during landing the copter tipped over while the motors were running.  When I ran over and flipped the copter over one motor was spinning less than the other three.  I assumed it was a piece of grass, or something odd since the tip over was so mild and not long in duration.

I set the copter upright and throttled slightly and the lagging motor matched the RPM of the other three, so I took off to a hight of ~20 feet. Upon the conclusion of the test and when I started to descend, the one motor shut off completely and she came down like a rock. Now there is severe shell damage and the one motor will not function, other than a slight struggle to spin.

I have ordered a new replacement shell, and two new motors (for what I anticipated as spares) in an attempt to repair.  I purchased the item in order to capture important moments, one of which is occurring next week, so there is no time to send in for diagnosis.

Does this sound as though I will also need and ESC board as well, and if so does anyone have a PN: associated with the correct one to order?

Spin the motors. If they all feel the same, it's the ESC boards!

porschett Posted at 2014-12-31 10:20
Spin the motors. If they all feel the same, it's the ESC boards!

The one motor is definitely not spinning freely as the other three.  It is also on the arm that took the brunt of the sudden stop on the concrete (also cracked), so I'm holding out hope it is just the alignment of the motor in the assembly.

On the chance I would need to replace the board, are these readily available for aftermarket purchase at a hobby shop?

Got mine through Helidirect.

Subscribing

Part number for the ESC is DJI-PHV-P07

This is very interesting and worrying to read. I have contacted my dealer to get an advice on what to do and not to do with this issue.

I've ordered a new motor and ESC board even tho I cannot see any damage, here's my vision plus v3

na5n@zianet.com Posted at 2014-12-9 15:49
One of my motors failed on my 16th flight just as it was landing (new version).  No crash, just a  ...

thanks for the heads up ... will be tearing into mine this weekend to check for signs of imminent failure

skburnett@hotma Posted at 2015-1-2 18:23
I've ordered a new motor and ESC board even tho I cannot see any damage, here's my vision plus v3
ht ...

Are they 2.0 ESC or the 2.1 ESC?

Hi aaronshirt, how would I find out? complete noob here :S

I think they are V2 ESC ? also check out the damage, I eventually found it :S

na5n@zianet.com Posted at 2014-12-9 15:49
One of my motors failed on my 16th flight just as it was landing (new version).  No crash, just a  ...

Paul,
That's a good report.   I would propose that either the wiring must be smaller than 22 awg, or the surge current far exceeded 5A, since 22 awg can carry way more than an amp.  Here at NASA/GSFC, we derate single 22awg wiring to 4.5 amps and 2.5A when in a bundle, but that assumes a hard vacuum which limits convective cooling.  I have no idea what these little LiPo batteries can source instantaneously, but it likely is more than 5A.

Thanks for the report.

skburnett@hotma Posted at 2015-1-3 05:18
I think they are V2 ESC ? also check out the damage, I eventually found it :S

On the ESC board, end farthest from the motor, look for the large electrolytic capacitor.  The version number, "V2," is printed on the board next to the capacitor.  It is quite visible in your photo.

tmansonusa@msn. Posted at 2015-1-3 06:51
Paul,
That's a good report.   I would propose that either the wiring must be smaller than 22 awg,  ...

I have made numerous measurements, current and temperature sensors on the drive wires, etc. over the past week, including replacing the MOSFETs and intentionally blowing them up to see what can cause a sudden MOSFET/ESC failure.  Any sudden interruption of the motor rotation, like a tip-over or striking a small tree branch, will immediately blow the ESC.  I'll be posting more details shortly, along with some O-scope waveforms.

Thanks for your comments and insights.  I no longer believe the motor wire size is the main culprit.  I thought they were about AWG22-24 wires coming from the motors.  Turns out, they are the actual wires from the windings; two solid wires from each motor winding covered with colored shrink tubing.  After 15-20 minute test runs at full throttle, they only climbed to about 40C - enough to make the shrink tubing "spoungy."  However, the MOSFETs get very hot after a 15-20 minute hard run.  The best safeguard is to ensure the motor drive wires are not touching each other and lifted above and away from the hot MOSFET chips.

Paul

I have also had an ESC Failure and it is only 2 weeks old, DJI Phantom 2 Vision+ V3, see YouTube video link

http://youtu.be/ezNo3Tt7ur8

That sucks.

na5n@zianet.com Posted at 2015-1-3 09:35
I have made numerous measurements, current and temperature sensors on the drive wires, etc. over t ...

Hey Paul,  
It just dawned on me that in one of your images I saw an identification of a "V2" marking on the ESC.  I'm really curious if there is a way to substantiate that these are the new version of ESC rather than the old (original) V2 ESC.  If the new motors are being driven with the old ESCs, it is very likely that the MOSFETs will overheat, potentially short, and allow excessive current through the motor wiring when there is a high demand from the motors.

Does that make sense to you?  Is there any chance that the ESCs are of the old variety while the motors are the new version?

skburnett@hotma Posted at 2015-1-3 05:18
I think they are V2 ESC ? also check out the damage, I eventually found it :S

No sir. The v2 next to the capacitor is there on all models. The firmware or version should be on the white sticker. If it says v2.0 or v2.1 you have the last version of not you have the old one. As from what I can see in the pic they are not the latest one. May I know when you bought your phantom?

na5n@zianet.com Posted at 2015-1-3 09:35
I have made numerous measurements, current and temperature sensors on the drive wires, etc. over t ...

Paul, you are a star! speaking with data does it every time!  
Your statement "Any sudden interruption of the motor rotation, like a tip-over or striking a small tree branch, will immediately blow the ESC." is the best case I have heard for prop guards.  So many burnt out esc's here after only a small tip on landing.

Thanks for all your research , you should be commissioned to work for DJI as their technical guru!
Cheers!
Rod

hello all, just adding to the list of people with motor issues. I got my dad a P2V+ and took it to his place to try it out. Had a quick fly for maybe 30 seconds to make sure it all worked and then landed. Upon trying to fly again one of the CCW motors refused to work properly and stutters as it tries to spin regardless of how much throttle is applied. I've emailed the closest DJI support centre but being holiday time i've yet to hear back. To say i'm disappointed is an understatement.
https://www.youtube.com/watch?v=NnUNzf9A3M4

w00dsy Posted at 2015-1-4 16:16
hello all, just adding to the list of people with motor issues. I got my dad a P2V+ and took it to h ...

W00dsy,
Your Youtube video, with the props hunting back-and-forth, are the classic signs of a blown ESC, not the motor.  It typically occurs when experiencing a slight tip-over on landing.

See my recent post "Causes of motor/ESC failures. Test Results" for more information and recommendations.  If you've ever done a little bit of soldering, you can replace the ESC board yourself.  Many have done it.  Contact the vendor you got your P2V+ from to see if they'll send you a new ESC under warranty, or can repair it in a timely manner.  Or, just buy another one to do yourself.  They're about $20.

Paul

Has DJI responded to anyone about this widespread issue yet?

na5n@zianet.com Posted at 2015-1-4 16:43
W00dsy,
Your Youtube video, with the props hunting back-and-forth, are the classic signs of a blo ...

This is not a dig at self repairs.

Should'nt Dji sort these problems out? why should anybody have to repair an almost new machine and incur costs?

tricky908@iclou Posted at 2015-1-4 09:37
No sir. The v2 next to the capacitor is there on all models. The firmware or version should be on  ...

Yeah Tricky, the wife got it two months previously for my birthday which was the 30th dec
I'm going to start a new thread, feels like I've hijacked the OP

Hi all,
Try to fly for the first time in a few days today and found out my one month old v3 has a busted motor. SN is ph645465921, if anyone can help with finding out if it has a wrong esc/motor combo. It was bought end of December in Indonesia.
Am not sure what to do now to be honest as I have never soldered anything myself...

Yea looks like I'm gonna have to learn to solder if i want to keep this hobby. Makes you rethink the entire point of buying a vision +

na5n@zianet.com Posted at 2014-12-21 06:25
DJI-Dboy and others,
Here's a few photos and information specific to my premature V2 ESC failure t ...

Wow...Thanks for the great photos and labelling.  People like you should rule the world :-)

Hi, I just bought a Phantom 2  (Version 3)  with H4-3D about 2 weeks ago. I did some practice before actually having my Gopro4 on board. During my initial practice, when I first turned on the motors, I had the Phantom tipped over a few times, which I thought was normal because I was just learning. I finally had the Gopro4 on board. The weather was nice and I had 1 run with full battery, landed safely, I let the motors cool for about 10 minutes before going for the second run on a freshly charged battery. The second flight was also nice but as I was on my way to land, the battery was 32% on the FPV, and the Phantom was about 10 meters above the ground. I was landing very slowly and hovered to record the parking lot when all of the sudden the Phantom fell to the ground. I felt like there's a force pulling the phantom to one side. It went sideways on the air and crashed (I will discuss about this later). The gopro4's mainboard was bent and the USB port became unusable, basically I ruined my gopro4 but the Phantom was ok, only a cracked body right under one of the motors and damaged Red LED.  I even tried another flight about 10 minutes after the crash and the Phantom flew perfectly.

Ok, so I took it to the dealer to have it checked (Phantom still flying normally). Later they called me and said that one of the ESC boards was damaged and needed to be replaced. So I let them replaced it. Today I finally had the time to try again. I tried flying indoor with enough space. First time I turned it on was ok but the second time the phantom tipped over to one side again. This time I noticed that one or more motors spinned faster than they should, creating too much force pushing to one side causing the tip over. Now it all makes sense to me after reading this post. I believe one or more of the motors spinned faster or even stopped during my landing approach.

Last note, by now I have a pretty good knowledge on how to start the motors so there's a minimum chance that I started the motors incorrectly. This is quite a terrifying experience for me. I plan to just sell my phantom and do a cut loss rather than having another crash, who knows where it's going to crash next.

Any suggestion? Thank you!