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FC40 throttle issues after installing T-Motor MN2214 motors

Discussion in 'Phantom FC40 Help' started by jezric, Apr 17, 2014.

  1. jezric

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    Hey guys, I have a Phantom FC40, had a crash about 5 flights in which resulted in a motor breaking.

    So, I figured I would use this as an excuse to upgrade to the T-Motor MN2214 Anti-Gravity motors and carbon fiber 9" blades.

    I followed the instructions to the T when installing, the motors are marked CW and CCW, I installed all 4, tested them out without blades, and they are spinning in the right direction (consistent with the diagrams on the phantom). So, I put the new carbon fiber blades on, calibrated the compass and tried a little test flight in my shop (good thing it wasn't outside). After waiting for the LED to blink consistent yellow (in ATT mode), I turned on and throttled up a little to take off. It started to take off and then the throttle went to full and it shot up and hit the ceiling, it was unresponsive to throttling down, I killed the motors (corner sticks), it fell, and one of the new CF blades broke. :(

    So, I took off the blades and when I test it just sitting on my bench without blades, sure enough when I throttle up a little , it just goes full throttle by itself, unresponsive until I kill the power.

    Anyone have any idea what the problem here is??

    One side note: the T-Motor MN2214 motors are a set of 4 where 2 are CW threaded and 2 are CCW threaded, they are installed in the correct positions and are spinning in the right direction, but the threads go in the opposite direction than what the stock ones went. meaning if I put the self tightening stock blades on that came with the FC40, they blow air up instead of down. It's almost as if the T-Motors are mislabeled? Anyone else notice this?

    Any help would be greatly appreciated.
     
  2. DeweyAXD

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    Re: FC40 throttle issues after installing T-Motor MN2214 mot

    Two things that could be happening here.... Firstly check you don't have a batch of reverse labelled T-motors like I did (discovered earlier this week!):

    http://www.youtube.com/watch?v=WjS3TME-vRM

    I very much doubt you do because if you have fitted thread props it wouldn't fly at all (because it would be trying to push its self down, not pull it up into the air).

    So with that confirmed can I ask what TX you are using? Is it by any chance a non stock one like a Futaba, Spektrum etc? (anything that has trim control)?
     
  3. jezric

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    Re: FC40 throttle issues after installing T-Motor MN2214 mot

    Hey thanks for the reply.

    Other than the motors, everything is stock FC40, so it's the stock Phantom 1 TX, the newer one with the self centering throttle stick.

    There is some major confusion out there on these T-motors and how they're labeled. I think the intent of the labels are to convey the thread direction. Therefore, when you install them, the one labeled CW should go in a CCW position. The wiring is the same either way (1>3,2>2,3>1 and so fourth), to set the motor to spin CW or CCW. So, they spin in the correct direction the way I have them now, but the threading is backwards. The self tightening DJI stock props thread on backwards so yes, using those, it just pushes air up = no flight. However I also with the motors, got a set of CF props, which aren't self tightening, so I used the provided T-motor nuts, but they would self loosen instead of tighten. Anyway, I just need to swap the motors and that will be solved.

    The big worrying problem I am having is this throttle issue.

    When on the bench with no props, the behavior is: turn on the motors, they turn on at idle speed. I give it a little throttle and then center the sticks and it goes back to idle (I would think it would stay at hover speed thinking that it's in the air), if then I hold the throttle at full for a few seconds, it ramps way up to full throttle, then if I put the stick back to center, it just stays at the high/full throttle speed and never comes back until I either hold the throttle all the way down (at which time it goes from full throttle to killing power completely), or I do the diagonal sticks to force the motor kill.

    It really seems like the Naza is confused. Or perhaps the altimeter is messed up or it's trying to GO HOME, like it loses contact with the controller after you put it on full throttle or something. Really frustrating.

    Is there some sort of factory defaults reset procedure that one should follow after a bad crash? In the Naza software, I see normal behavior for stick movement (i.e. it doesn't stick on full throttle or anything). I did the advanced calibration but it didn't change the behavior.

    ...and I just got my Fatshark Pv2 FPV system in the mail... but no functional copter to attach it to. :(
     
  4. Boozshey

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    Re: FC40 throttle issues after installing T-Motor MN2214 mot

    My motors were also reversed... But it wouldn't take off until I swapped them. Opposite problem.
     
  5. jezric

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    Re: FC40 throttle issues after installing T-Motor MN2214 mot

    So, turns out it was the props I had put on. I got a set of high efficiency 9" carbon fiber props on ebay and this is what I initially used when it seemed to fly out of control.

    Well, got it all back together, the motors swapped to the right positions and the stock props (self tightening and yes they do fit the T-Motors) and the phantom is flying fine now (after an adv calibration). So, I again, tried the new CF props and sure enough the thing shot up seemingly out of control (good thing I had it on a tether this time).

    So... Is there something I need to do to adjust for these new 9" CF props?

    Thanks!
     
  6. Jgrimberg1979

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    Re: FC40 throttle issues after installing T-Motor MN2214 mot


    Just bought a set a few days ago and found I have the same issue. The freaking labels on the motors and the labels on the nuts were backwards so I had to switch and resolder. What a pita

    Sent from my HTC6525LVW using Tapatalk
     
  7. Jgrimberg1979

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    Re: FC40 throttle issues after installing T-Motor MN2214 mot

    Just bought a set a few days ago and found I have the same issue. The freaking labels on the motors and the labels on the nuts were backwards so I had to switch and resolder. What a pita

    Sent from my HTC6525LVW using Tapatalk