Smelly motor - how dangerous was this?

Motors r cheap. High amps burned the enamel off the windings. It will fail at a lower temp now and crash the bird. Replace it
 
Thanks, guys! I will order a new motor tomorrow and replace it when I get it. I will take the chance of playing with it in the meantime, though. It seems both from comments and my own thinking (very faint smell after a while, no visible discoloration of the coils) that the engine will work until I get a replacement. I'll just avoid flying over police cars and baby strollers! :D
 
Normally in such cases, currents are limited by the ESC but motor gets hot as there is no cooling. Winding insulation can Withstand high temperatures and the weak link is only the lubricant. I'm sure you must be getting smell out of the lubricant that got burned due to over heat.

If motor is running smoothly, you can use it. As the motors are cheap, it may be better to replace it with a new motor to avoid risk to your a/c.

You don't need to remove camera and any other part.
 
It's a $20 motor. Just get it over with and replace it. I changed one out in 30 minutes. 25 minutes to remove the top shell and 5 to replace it. U can get one from Amazon in 3 days. Just don't overheat the board. I cut the wires and soldered the wires. I used shrink tubing to cover the joint. Not sure that is recommended. Thoughts?
 
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It's a P3 so he can't replace just the ESC as they are integrated into the mainboard.

Is the smell coming from the motor itself? Look at the coils inside the spokes on the affected motor with a flashlight. Are they blackened compared to the other motors? If so it was cooking the coil insulation coating and some coils could have been shorted. Is this motor still running hot compared to the others? Replacing a single motor isn't a monumental task if you are competent with a soldering gun. The hardest part is getting the shell open!

Right! It smelled because the ESC circuit board started to burn. That means components are dying. When you order a new ESC get the proper motor which you may have to replace.
 
Thanks, guys! I will order a new motor tomorrow and replace it when I get it. I will take the chance of playing with it in the meantime, though. It seems both from comments and my own thinking (very faint smell after a while, no visible discoloration of the coils) that the engine will work until I get a replacement. I'll just avoid flying over police cars and baby strollers! :D
Beware if you do the work yourself you'll void the warranty. There are a handful of shops that are authorized to do work on craft without voiding the warranty. You'll need to check with DJI to find an authorized shop if you want to maintain the warranty.

BTW, if anything like that happens again, remember how to do a CSC. That will shut the motors down immediately, versus the 3 second shutdown of holding the left stick down.
 
If the motor was blocked why would the esc be fried? Doesn't make any sense, esc is not a moving part. It just sends a signal to motor to run. If the motor cant run why would the esc be damaged.
 
Alirz, any electrical component can burn out if it's short-circuited. If you stop a motor from turning, it's almost the same as a short-circuit. If he had throttled up when the prop was blocked, it would absolutely burn out an esc but that's not the case here. Just burnt insulation in the motor.
 
Thanks for the replies, all of you! This morning I have been out in a soft meadow (well, as soft as a meadow gets in 14 F!) and frozen my fingers off for a ten minute flight. As a side note I'm impressed with how little the cold seems to affect flight time. After ten minutes of rather vigorous flight it was blinking on the third bar! I'm used to phones and other rechargeable stuff going close to half the runtime in that cold, but not this battery.

And it was a vigorous flight. To be honest I flew the sh!t out of the drone, after a relaxed start to see if anything seemed fishy. Then I began going full stick movements, full speed forward to full speed backwards, full speed down to full speed up, full speed left to full speed right, and combinations the rest of the time. Not a problem at all. No heat from the motor (well, in that temperature it's probably not that strange...), and no more smell, only the same, faint one. And I have had short circuits in electronic stuff before and been able to smell that for years after the part has been replaced.

Something puzzles me: I looked at the flight log, and I can't find an error on the flight where the prop got blocked. It's not recorded at all. Is there a separate error log I can find? Shouldn't there be something there with an error message? Also I had a flight indoors two days ago, and that flight isn't recorded in the log at all. Is that correct?

I have ordered a new motor, and I really liked Ted4797' s idea about soldering the wire instead of the board itself, and using shrink tubing. I would feel much more comfortable not soldering on a PCB that costs several hundred dollars! :D To echo him, does anybody else have thougths on doing it that way?

I have also looked very closely at the coil of the motor, and there is no discoloration at all to see, even with flashlight and magnifying glass.

There are no shops in my area, I live far out in the sticks, so I'd have to send it away to get the motor replaced. But I do know a guy who has experience with drones, so I will ask him for help. I am really mostly worried about taking the thing apart, to be honest. The process in the YouTube video I saw, was rather complicated. Not the screws, but splitting the body.

Finally, how could I best strap it down to do a load test? It sounds like a very smart way to check the motor, running full power when the drone can't move. Should I simply use small straps in a cross over the body, connected to screws in a heavy wooden plate, or something like that?
 
Why not let it run for a while with the props off and see if it gets smelly again? Saver then flying when you are not sure...
 
Pim-K, I had it hovering very low for a while first, yesterda evening, before I started to get creative between the trees when there were no problems. I have now done three trips with it (one with really brutal flying, at least to me it seemde brutal), and it hasn't skipped a beat. I am going to replace the motor, I just need to get it here. :) But I'm now around 95 % sure that it will work well until it gets a too heavy load, but it would be nice to test it under a heavy load, hence the strap down test.
 
By the way, talk about a bipolar evening yesterday! From "oh %!¤!%&", to "maybe I reacted wuick enough to save it" to "several hundred dollars for a &%!/! ESC board?!" to "it seems to be only a motor for 20 dollars that should be replaced soon, rather than later" was one of my life's most stressing roller coasters! But to be honest I'm glad I got a scare this early, that should keep me from doing anything too crazy, I hope...yeah, right! :rolleyes:
 
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IMO - terrible idea to run a brushless at no load for significant periods of time.

I cannot find any corroborating info on this and have done it for years with my CP-Heli motors to drain batts. and other testing.

There may be a concern with 'inrunners' as they could potentially sling a magnet but not for 'outrunners'.
 
Well, I'm done with my third mission since the problem. On this mission I learnt something: Trees that are far away can very sonn be a lot closer when the drone is pointing the opposite way of what I think it is! I narrowly escaped and didn't damage anything but my rather substantial ego (which sort of goes with a rather substantial 210 lbs me...) since I was flying like a panicked rooster there for a few seconds, but lesson well and truly learnt. I also found out that I have to be careful with sun in the face. For a while I had no idea where the bird was, but I knew it wasn't close to trees, so I let it hover and walked to another angle. Going back later today to make a new attempt at getting the "full beach in one shot" that I was planning, only this time I'm going to take it the other way around, with the sun in my back and the drone well within sight and even further from the trees.
 
I had this same exact scenario play out. Clipped a tree, the P3P fell to the ground slowly and jammed my rear right propeller for 5-8 sec before I could turn it off. There was smoke coming out of the motor and the burning electric smell you are referring to. The drone is still running fine, however:
1) I conducted a hover test at low altitude for an entire battery to make sure the motor wasn't weaker or burned out
-It seemed fine so I went on to step 2
2) Load the motor to try to make it fail. I ascended and descended quickly at relatively low altitude and "shuffled" left to right at low altitude to load the engine with regular flight stresses
-it seemed fine so I continued
3) I monitored the engine temp relative to other motors after both tests with a UV thermometer and the motors all seemed ok, so I took it out for a regular flight over a field. This flight also went well

Ill be honest, I am very nervous about what happened that day however from everything I can tell, the P3P is ok. I believe I got lucky. That being said I am skeptical of its long term endurance abilities and am nervous now to push the limit (ie- 2 batteries worth of flying simultaneously). I hope I didnt ruin it and from what I can tell replacing the motor is easy, but I am still hesitant to open her up if she is working well.

This was my experience. I hope yours woks out too. Lets hope the motors dont fail one day while flying !! Be cautious.
 
Trenman, not far from what I did, except for that I was a bit less patient (hovering only a few minutes) and a bit more primitive (checking the motor temp with my fingers, not a UV sensor). And now I'm off to make a second attempt at that beach shot, without getting too close to trees!

Btw I have no idea what it is with this forum, but if I let the tab be open in Firefox, it takes crazy amounts of CPU power! 20 % of the CPU on my i5 Microsoft Surface. Usually, Firefox takes around 5-6 % with at any time 10-20 open tabs. So there's something whacky going on with the forum page. Maybe it's the blinking green dot (Flash?) that shows that somebody are online?
 
Me again , the guy who had the same problem as you mastiff...I flew again yesterday and I'm carrying

Modded p3 battery
2 hyperion 1800 mah 4s
Battery brackets
Headlight
Gimbal guard
Prop guards

Again. .....I have had no problems with that motor that hit the fence , stopped,smoked, and made the aqueel noise .

Ps I also tried a small stress test when it first happens by sticking a broomstick through the legs of the p3 ..behind the camera and a small dumbell 5 pound....on each side of the broomstick...worked well.
 

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