Hey guys, have a problem i need help with.  as mentioned in some prior threads, i have had 3 sudden prop stops in the past few months.  one was when i hit a tree with prop guards on (props stopped suddenly but didnt crash bounced off tree and kept flying).  second was my fingers (long story some of you already know).  third was VRS, fell 10ft into a tree, props hit branches, CSCd and dropped 10-15 ft to ground nothing broke.  so only that one 'crash' and it flew at least 2 times after that without any issues.

now i have the following issue (shown below with props off).  the motor (one of them) is intermittent forward/backward at idle.  the video doesnt show it too well but the motion is 2 or 3 pulses forward then 1 or 2 pulses backward, repeat.

the only thing that has happenned in between the last flight was that i, as i mentioned in another post, i was trying to get those tiny P00 screws off and it was sitting upside down on the rotor posts.  i did apply a good deal of downward pressure on those screws to avoid strippping.  i suppose i may have damaged the motor OR there is something wrong with one of my ESCs.


here is the video.  thoughts or suggestions would be appreciated.  


\

sorry for the vid quality, was on my phone and seems more lowres than usual for some reason...

I had the same problem after a sudden prop stop. Conventional wisdom is that it's the ESC, but I replaced both the ESC and the motor. After all, you have to unsolder the motor to replace the ESC, so for an extra $20 or so why not replace the motor, too?

My $.02. YMMV.

In 10 years flying electric, previously nitro, I have never had a motor failure even after a crash, it's always been the elecctronic speed controller,always.  I have always upgraded the  stock ESC where possible. Edit, should mention your problem is identical to when my ESC  fails,seen this many times unfortunately.

ok, thanks, im assuming that ill want to inspect my ESCs for version so that i can upgrade all 4 if necessary.  got this in december but not sure what ver they are, ill take apart this week and post pics.  appreciate the above and any other thoughts as well.  thanks fellas.

also, as far as ordering parts and such, anyone got a good US reseller?  i bought my phantom from dji direct but would have rather bought from one of the dealers around here (maybe Atlanta or Northeast?).  want to make sure i get the right ESCs from a knowledgeable and reputable shop.  price is less important to me than quality, ability and honesty.

gnixon2015 Posted at 2015-4-2 04:39
also, as far as ordering parts and such, anyone got a good US reseller?  i bought my phantom from dj ...

I would recommend B&H Photo or Atlanta Hobby.

>  the video doesnt show it too well but the motion is 2 or 3 pulses forward then 1 or 2 pulses backward, repeat.

That is the classic description of an ESC with a couple of cooked MOSFETs.  The failed MOSFETs are keeping one of the windings from being energized, so it will "hunt" back and forth between the permanent magnet poles.

As others have said, a motor failure is very rare.  I have replaced a couple sets of ESCs and motors on my P2V+, but the failure was always the ESC.  The original motors worked fine with the new ESC.

Replacing an ESC is not that difficult with numerous threads on the subject here.  Basically you just  need a soldering iron and amateurish soldering skills will do the job.

Good luck and hope you get it repaired soon.  And like many of us, learn to stay away from those trees!

Paul

tonyphantom147@ Posted at 2015-4-2 04:06
In 10 years flying electric, previously nitro, I have never had a motor failure even after a crash,  ...

so do you suggest upgrading the stock P2 ESC?

thanks na5n, good comments.  as i mentioned, ill post pics to determine if i have 2.0 ESCs instead of 2.1, but am i right in assuming that if i have 2.0s i want to get 4 and replace them all?  

if the LED is part of the ESC, why is there only 1 to order, if ordering 4 wouldnt i need to order 2 with green led and 2 with red led?  it looks like the part on amazon has no color designation:

http://www.amazon.com/Genuine-DJ ... product_top?ie=UTF8

gnixon2015 Posted at 2015-4-10 12:07
if the LED is part of the ESC, why is there only 1 to order, if ordering 4 wouldnt i need to order 2 ...

Here is a video of the ESC on the backside in the video.

gnixon2015 Posted at 2015-4-10 12:07
if the LED is part of the ESC, why is there only 1 to order, if ordering 4 wouldnt i need to order 2 ...

Good question, I wonder if those LED's are a Dual color or something, I could not see anything anywhere indicating Red or Green,,,,

picture from the video. 3 leds.  On the big triangles. one is red, 1 is green. if they flash together, they make yellow.

red flash and green flash together make yellow

so the ESCs are all the same and the wiring from the MB (main board for all you acronym junkies ) is what tells it whether to flash green or red based upon whether it is installed on the front or back motor yes?

gnixon2015 Posted at 2015-4-10 19:19
so the ESCs are all the same and the wiring from the MB (main board for all you acronym junkies  ...

That is what I am thinking.  I watched the lights very closely last night, the red flashed on the inboard triangle and the green on the outside triangle, when both flashed, I got yellow before I went blind.

color lights

this is the place I use.....uavdirect.com. ESC - $19.00. They also repair Phantoms.

http://www.uavdirect.com/DJI-Phantom-2-ESC-p/djisp-p2v-esc.htm

ray, thanks, ive already ordered and received my ESCs, (i am replacing all 4 even though only one went bad), what i was concerned about was that i had ordered 4 and not specified front/back (red/green) but sounds like im all set.  thanks for the info folks, now on to the soldering.

Ok, good luck.....

I have to say I am really worried bout these esc. are they easy to change/ did you do yours yet?

hadnt finished yet, ive taken it apart, gotten all my soldering supplies in just in the last day or so.  im a bit concerned about the soldering work as it has been 20+ yrs since i did it last.  the soldering of the motor wires to the esc im not as concerned about as the soldering of the esc wire to the MB.  frankly, if esc failure is as likely/common as it is with prop stalls, they should make them modular (engineered with plugs or connectors instead of solder) to make replacement easier.  ill post up results when done, hoping to get to it this weekend.

gnixon2015 Posted at 2015-4-17 19:22
hadnt finished yet, ive taken it apart, gotten all my soldering supplies in just in the last day or  ...

Can't say I blame you. I'm not a big fan of soldering either......too tedious. I guess they saved a few pennies by not putting connectors on the wiring and headers on the ESCs.

While they saved a few bucks by soldering and not using connectors, when done correctly soldering is a better connection.  I under stand folks may be a little worried about soldering. I recommend getting a soldering iron with temp control and practicing. The aux cables that power the lights on my Phantom are soldered directly to the power cables on one of the ESCs.

great replaced the ESC (wasnt easy or fun but got it done) and the problem still exists exactly as before.  im packing it up now and shipping to dronefly for repair.  i know it is probably just the motor (in addition to the ESC) but at this point i'd rather have someone that knows what they are doing fix it.  ill post back up here when i get it back.  FML.

ok, got my drone back today, dronefly found it needing a new motor (which is what i fig'd above).  they replaced the motor (and shipped the old one back in the box) and were pretty good turnaround and service along the way.  i know it was simple soldering but im glad to have had someone else look at it.  i have to reinstall my RP so all i did today was insert a battery and confirm that the motors all ran 'normally' turned on with no props.  the errant motor seemed to work just like the others.  in the next few days ill put things back together and get a test flight in.  im lucky that my esc and motor didnt fail midflight but in between flights instead.  i was also very pleased with dronefly, will certainly use them again if i need it worked on.  thanks for the posts above and hopefully ill have some more news in the coming few days.

ok, everything reinstalled, test flight of 10mins went well.  they replaced 1 motor and with 7-9 sats during test flight, it did drift a bit even with little to no wind.  im afraid an IMU calibration is in order because of the new motor install, but not really looking forward to doing that.  up to now, my drone has flown flawlessly in about 20 flights and ive only ever done maybe 2 compass calibrations and never done an IMU calibration.   with the mixed results from imu calibrations (some getting better, some staying same, some getting worse), im a bit anxious about doing it but i dont think i have much of a choice.  

im also concerned whether 2 of my 4 batteries sitting there for over 4 weeks at nearly 100% charge may have caused permanent damage.  while the drone was in transit getting fixed, i check the battery status after about 12 days and it went from like 100% (4green) to 3green1flash, so i think my batteries are not the ones that self discharge even though they were all purchased directly from DJI and all purchased after Dec'14, i would think those would be fairly new but maybe not.  

at least im back in working order and can start doing some more test flights in the next week.

Glad your up and flying again. Also glad to hear that Dronefly performed their service well. Hope I never need them but it's good to know there is a place to get repairs.

gnixon2015 Posted at 2015-5-6 20:21
ok, everything reinstalled, test flight of 10mins went well.  they replaced 1 motor and with 7-9 sat ...

Gnixon,
What solder tip would you recommend using for an ESC? I blew one today and ordered it along with a heavy duty solder iron...I hate soldering.

I hate it too.  from what i read, everyone said narrow tip ( like a pencil ) would be best.  what i liked about that tip was that it seemed to keep the heat focused and away from other components (it seems tight to solder on the esc and main board of the phantom to me at least).  what i didnt like about that tip (compared to what i read of the broader tips (that look more like a flat head screwdriver than a pencil) is that they brought the heat to the wire/board/solder faster and more efficiently.  i did find the pencil tip seemed too cold sometimes (which wasnt because i skimped on the power of my iron).  all in all i got the job done but the solder joints were clearly not as good as the factory ones (that looked stellar to me).  good luck...