Escs Keep Breaking -- How do I fix it?
« on: August 16, 2016, 05:56:38 am »
Hey guys--

I just finished my first ever quadcopter build, and am having some esc trouble. I am using the Emax Simonk 12a escs that I got in a kit off of amazon. I decided to use Libre Pilot software on my drone's CC3D onboard computer. I clicked on the Libre Pilot software install wizard, and everything was going fine until the esc calibration phase. I did the first step (the one that involves checking boxes and plugging and unplugging the lipo), and then on the step after that, everything went haywire. I replugged my lipo battery in, and pressed the start button (this is on the step where you find where the neutral point is for your motor) and started slowly moving the dial up. Immediately, my esc started smoking. I quickly hit stop, but it was too late -- parts of the circuit board were melted and the esc was obviously ruined. I was surprised, and figured that I must have just recieved a faulty esc in my kit. So, I went online and ordered another of the same esc off of amazon for $9. I soldered it into my build nicely, and got to the same point in the setup wizard, and the motor for the new esc started up slowly. Then, the esc made a small popping noise and will now no longer work. (I should add that I progressed onto the steps for the calibration of the other four motors' escs, and they worked fine.)

Am I doing something wrong, or did I just have the incredibly bad luck to get two faulty escs? Or is there a compatibilitiy issue? Thanks, help is appreciated greatly.



  • *
  • 1018
Re: Escs Keep Breaking -- How do I fix it?
« Reply #1 on: August 16, 2016, 06:52:11 am »
It sounds more like it's either wired wrong or that motor is bad.  If three of the ESCs work then compatibility and proceedure isn't likely to be wrong.

One thing you might check is the screws that hold the motor to the arm.  Sometimes they're a little long and short the motor windings.

I deleted your duplicate post, it's considered wrong to post the same thing twice.

Re: Escs Keep Breaking -- How do I fix it?
« Reply #2 on: August 16, 2016, 06:51:34 pm »
Thanks! Sorry for posting it twice- didn't know that wasn't allowed.

Do you think it's a good idea to try my current motor #1 with one of the escs that I've already established as working? Or should I just order a new motor?


Re: Escs Keep Breaking -- How do I fix it?
« Reply #3 on: August 16, 2016, 09:18:06 pm »
hwh is spot on with this one I think.  Really sounds like a short or wiring problems somewhere from the ESC to the motor.

Do you think it's a good idea to try my current motor #1 with one of the escs that I've already established as working? Or should I just order a new motor?

I think if you've gone through 2 ESC's as of now, I'd be hesitant to move the motor to a new working ESC.  I'd suggest trying to verify where the problem is and either fix the problem or replace the faulty part. 

I bet if you use a multi-meter, you could test the resistance across the positive/negative cables going from the ESC to the motor.  I'm not sure what a 'good' reading should be, but I would think you may find a short between the positive and negative leads to the motor.  I'd try getting readings from both the known good motor and the suspected bad motor.  Hopefully there is a difference in reading between the 3 good ones and the 1 bad one. 

At that point, try to isolate the problem.  As hwh said: check the screws going into that motor.  Check wire connections and any solder points on that circuit.  Also remember that if its a carbon fiber frame, they are conductive so check for bare wires touching the frame. 

If you find there is a short somewhere in the motor or its wiring, but you can't easily resolve it, it may be best to buy a replacement motor.  If those motors are directional, make sure to get their right direction! (Clockwise/counter-clockwise)

If you can't find exactly where the issue is, I'd suggest purchasing a new motor and see if that resolves the issue.

« Last Edit: August 16, 2016, 09:33:13 pm by crof2003 »

Re: Escs Keep Breaking -- How do I fix it?
« Reply #4 on: August 27, 2016, 05:31:11 am »
It's also possible that you used an ESC protocol that isn't supported.  I wouldn't expect smoke from that, but I guess it's possible.  Know what protocols your ESCs support and use the fastest one.  If I was in doubt, I'd use PwmSync which isn't the fastest, but is generally OK.


  • *
  • 2
  • Build-Fly-Crash-Repeat
Re: Escs Keep Breaking -- How do I fix it?
« Reply #5 on: September 14, 2016, 05:31:45 pm »
Woow, i think we're on same boat.
I got this kit from my confused-friend who wanted my help to finish his 250.
This config was:
- CC3D with Librepilot
- 4 x EMAX 12A ESC BLHeli series BEC
- 4 x EMAX MT2204 2300 KV Brushless Motor
- 4 x 5030 Nylon Props
- LiPo 3S 2200 mAh 25C
- TxRx Flysky i6 & iA6.

I use Librepilot wizard for setup and it was ok.
But when I tried the throttle response without propeller, one of ESC burned (NW Position).
Then I change it with the same spec ESC.
Reconfig and test flight. When I tried to fly it and flipped it, another ESC burned again (SW Pos).
The burning happened after some flippings action.

I am so confused now if there is something wrong with this config because this config actually a generic config of ZMR250.
I check the PDB and it is all OK, no short circuit or cold soldering.
Were the ESCs amperage too low? What if I change the ESC to 20A?

Need y'all advice, please

Re: Escs Keep Breaking -- How do I fix it?
« Reply #6 on: October 14, 2016, 10:41:36 pm »
Hi all --

After listening to your advice, I bought a new motor this time. I did not screw it in, so that there could be no possibility of the screws shorting the motor out. I got to the phase in the setup wizard where you calibrate the motors just fine. However, when I started upping the current for the motor #1, the #1 esc caught fire and melted.

I am very confused and can't figure out what is wrong. The Pdb is fine, and this was a new esc with a new motor. Does this mean that my CC3D is broken/flawed?

Thanks so much,

Re: Escs Keep Breaking -- How do I fix it?
« Reply #7 on: October 19, 2016, 12:57:10 am »
If there is a bad wire, connector, or motor; the motor will not start, and adding power to try to get it to go when it doesn't want to will cause things to burn up.

One thing you can do during testing to completely avoid any burn outs ever (during bench testing) is to insert a 12v automotive bulb in series with your flight battery.  That will limit the current.  It doesn't matter a lot what kind of 12v automotive bulb.  I usually use #1156 which allow about 2 amps at full short.  Connect PDB minus directly to battery minus, but connect PDB plus through the light bulb to battery plus.  With this set up you will be able to run all 4 motors slowly or one a little faster.  Any more current than that and FC voltage will drop and the FC will reboot.  You can even flash the wrong ESC firmware.  If you test it with this you will not burn an ESC or motor.

I haven't had that problem in a while, but when testing your motor / ESC you should give it the minimum throttle stick to get it started.  If it doesn't run smoothly, but is jerky, stop immediately and test more carefully.  (If testing with GCS and going one increment at a time, it may not run smoothly at the first number, but it will at number+1.  If not, stop immediately!!!)  Do not add more power to get it to spin.  That is where it will burn.  One helpful test is to check continuity from each of the three motor leads to the other two (ESC unplugged).  They should all test like straight pieces of wire.  If any are open circuit (no connection), you have a bad motor that will blow an ESC.  This test can be fooled.  Open is definitely bad, but closed is not guaranteed to be good.  If you have a meter that goes down to hundredths of an Ohm, you can reliably read if the motor is bad.  All combinations of motor leads should read the same.  If one set shows somewhat higher (like more than 10%) then you have a burned wire in that motor.

I had some issues with some SimonK ESCs I bought from eBay.  They had to be started slowly and were jerky in flight but never burned up.  I flashed a later SimonK and the issues went away.

Attached is a picture of a #1157 bulb with leads.  The #1157 has a 2 amp filament and a 0.25 amp filament.

#2156 is about equal #1156 and #2157 is about equal #1157.