This is related to my past ESC troubles. See link for some flight history.

I tried the recalibration as suggested by ifconfig, which sadly didn't work. But now the motor will not go above 2/3rds thrust(slight improvement), no matter the calibration range. I did do one calibration where I used full throttle as max and the center as none, and the ESC would stop working once I got above 2/3rds of the calibration range.

What it is not;

  • ESC overheating/overloading(it is cool to the touch and I even ran it in our deep freezer, same results)
  • broken ESC(I used a new ESC as well as an old one I fixed. Both have the same problem)

What I'm not sure about;

  • the receiver has been in some crashes, perhaps it got shaken around and is messing with the signals?
  • the transmitter is cheap so it might be messed up, but it was working fine before.
  • motor might be broken but I don't think so, it's not even scratched up.
  • battery(charger) might be to blame. The charger I have (also cheap) has 3 lights for the cells, and the cell 1 light never turns green(ive left it charging overnight, still red). I just thought the charger was broken, but maybe cell 1 isn't getting charged?

hardware specs;

  • ESC is rated for 30A, uses T-plug to connect to battery.
  • Battery is a 3S 2200 mah 30C from Mirahobby
  • Motor is 2200 kv, is using a 9050 prop(slightly outside plane and motor recommendations)
  • Plane is an FT Spitfire from flitetest
  • The only modifications I have made to any of these pieces is when I globbed some hot glue onto the antennae on the receiver to strengthen it some

What do I need to fix to get the motor/esc to work properly? Do I need to replace any of my hardware? Should I just build a lighter plane that only needs 2/3 thrust?

  • 1
    $\begingroup$ Do you have a multimeter? If so, could you test to make sure that a fully-charged battery is 4.2V*[cell count]? $\endgroup$
    – ifconfig
    Commented Dec 9, 2020 at 18:10
  • $\begingroup$ @ifconfig, I used to have a multimeter, but it broke when i used it to test an electric fence(tip; don't do that). I have yet to purchase a new one. also I will add in the cell count, thx for reminding me of that. $\endgroup$ Commented Dec 9, 2020 at 18:39
  • 1
    $\begingroup$ Okay, well you could also check the transmitter endpoints to confirm that the TX/RX are outputting full-range values. $\endgroup$
    – ifconfig
    Commented Dec 9, 2020 at 18:55
  • 2
    $\begingroup$ A possibility is that one of the cells of the battery is damaged and cannot supply enough current which results in the ESC cutting out when it draws too many amps. $\endgroup$
    – Jacob B
    Commented Dec 10, 2020 at 4:00
  • 1
    $\begingroup$ You really need to try a different battery, especially as it's not charging properly. Maybe even a 12v car battery? $\endgroup$ Commented Dec 10, 2020 at 8:32

1 Answer 1


It was the battery.

Bought a new battery, charged it, all 3 lights turned green, and motor/esc has no trouble going to full thrust. Lots of power now, so that should really help the plane fly.

Problem solved!

And on the bright side, I get to tear apart the broken 3s battery and see how to fix it or turn it into a 2s. I'll probably put a question on electrical engineering SE about that later.


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