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Strange motor issue

Discussion in 'Phantom FC40 Discussion' started by Mattsimok, Mar 21, 2015.

  1. Mattsimok

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    Recently installed a gimbal, took it for a test flight flew great, realized I had put the top on backwards, took it off switched, went to fly the next day, my M3 motor is spinning like something is stuck in it, took the top off to look at it and all connections appear fine, can't see anything wrong with it. No clue what I can do, any ideas?
     
  2. Case29247

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    I'm sure you have checked, but have you looked closely to see if the motor's rotor is rubbing against the plastic housing? The clearance is pretty close.

    If you don't get the interlocking top and bottom housings aligned properly, the top might be out of alignment enough to rub the motor rotor.
     
  3. IflyinWY

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    Is it possible you used too long of a screw? If you did, they say, you need a new motor.

    Will it spin as freely as the other motors?

    Maybe something fell into the motor. Try blowing it out.

    FYI, You're not the first one to put the top on backwards. ;)
     
  4. Mattsimok

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    I know I began screwing the wrong size screw in to the set below the prop guard, but I soon realized that and took them out.

    No it does not spin freely, it spins, but is a choppy movement.

    New motor :shock: ...is that install a complicated one?
     
  5. J.James

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    Even a good motor will have some of a choppy feel to it if its been run at all recently and the wires are hooked up. Due to resistance. But even if you did some how damage the windings with a screw being to long the longer screw will not make it any harder or any less harder to turn the motor being that only the out side bell housing moves so the screw will not physically stop the motor from spinning. BUT if it did crush the windings and shorted them out it can make it feel like its harder to turn from the resistance in the motor. as you turn the motor it actually makes electric and if there is a short it will flow to the other poles and make it harder to turn. BUT you really have to also feel the other ones and see if its different to really know.

    Or have all 3 wires disconnected then it should always spin completely free with no resistance from the magnets in it at all unless its still got an internal short in it. Even if you take a good motor thats not hooked up at all and touch the wires together and try to turn the motor its pretty stiff. compared to if the wires are not hooked together.

    Tho as to the ? of how hard it is to change a motor that depends on if you can solder or not. IF so its super easy its just the 4 screws and soldering the wires to the esc in the same spot each one is wired to already.. Tho some people if they cant solder have replaced motors by just cutting the old wires and then using a crimp connector to reconnect the new wires to the old ones.
     
  6. Mattsimok

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    It's not that it feels physically hard to turn it turns with the same ease as the rest of them, but when powered it stutters and looks as if something is caught. I'm now fairly certain its the screw I misplaced, I ordered a new motor, my brother is an electrician and should be competent in soldering, thanks for the response.

    Although I'm a little confused as to the 4 screws you're referring to? I thought I'd simply disconnect the old motor and reattach the new one in the same spot?
     
  7. micknick

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    I had something similar a while ago so took prop off and unscrewed the motor from underneath and found a tiny screw between the windings and motor housing fortunately didn't cause any damage
     
  8. Mattsimok

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  9. Mattsimok

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    There is nothing actually preventing it from turning. It turns physically with as much ease as the rest of them
     
  10. TuT

    TuT

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  11. IflyinWY

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  12. J.James

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    only if you have a real good one that has a setting for testing frequency or Hertz

    a bad ecs will usually still put out voltage accost any 2 of the 3 wires going to the motor BUT will not have the right htz on all combinations of 2 of the 3 wires or will be off from what the other known good escs are putting out.

    another way is if you are handy with a soldering iron. one way to tell if its a bad motor or a bad esc is to take out the motor and swap the opposite motor that you know is good to that spot and see if its still not working right. If the known good motor still dont work right then you know its a bad esc. OR if the good motor works then you know it was the motor. and then you can get a new one and put it back in were you took the 1 good one from.

    Tho if there was a screw inside the motor between the housing and the windings more then likely if the motor turned at all with it in there its going to mess up the motors windings. all it takes if for one of them fine wires to break or even just scratch off the enamel insulation on the windings wires and the motor will e shorted out on the winding that is damaged and cause what eer pole that is shorted to work differently then the other 2 and the motor will stutter when its running.
     
  13. IflyinWY

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    Thanks J.James,

    I'll check into the real good meter.
    Sounds like most of us need to do a motor swap to find out which component is the issue.

    I think I will color code my motor mount screws by painting the long ones red :oops: and the short ones green. :mrgreen:
     
  14. Mattsimok

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    Completed the motor swap last night! Beyond nervous, I wanted to cry when the wires were snipped from the old motor.

    It was sooooo incredibly simple! Simply cut the old wires, cut half of the new wires from the new motor, did a western union attachment of the wires, put heat shrink band over the wires, soldered, moved the heat shrink up and viola! New motor! Flew perfect!

    Definitely color coordinate your screws!

    ~Thanks all for the help!
     
  15. IflyinWY

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    Very cool, a happy ending.:)

    Did you look real close at the motor you removed? I'm wondering if it's possible to see the damage done by the screw.
    We are thinking it was too long of a screw, aren't we?
     
  16. Mattsimok

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    Short of taking it apart I looked that thing over countless times I literally cannot see any signs of damage what so ever, I can with certainty confirm I placed the wrong screw inside of it. I never started it, because as soon as I realized it wasn't flush with the groove I took it out and put the proper one in, I guess that was enough to ruin it. I learned my lesson that's for **** sure
     
  17. IflyinWY

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    You can use it as a centerpiece on your "Wall of Shame". LOL