Syma X5C gear issue

Discussion in 'RTF Modification & Repair' started by ack214, Dec 30, 2017.

  1. ack214

    ack214 Member

    I got the Syma X5C for Christmas. A small gap has opened between between the two gears on the bottom side of the drone, underneath one of the propellers. Since the gears don't touch (or barely touch), there is not enough contact from the motor gear to turn the propeller to get it airborne. Any ideas how to fix this?
     
  2. Bradmadison

    Bradmadison Member

    Just a thought try lining up the gears by pushing down or up on the small gear on motor.
     
  3. Jeff Neese

    Jeff Neese Well-Known Member

    Do they not mesh vertically, or horizontally? Is it more like this _- or like this _ _?
     
  4. ack214

    ack214 Member

    It is more horizontal. The propeller has a little more wiggle than the others - when I manually turn the propeller and angle it just right it makes contact with the motor gear. Is it possible something got bent inside? We have only been flying it inside due to weather so I don't think it has taken hits that are too hard.
     
  5. Jackson

    Jackson USA member at large

  6. Jeff Neese

    Jeff Neese Well-Known Member

  7. ack214

    ack214 Member

    Thank you all for your help! We are looking at the replacement parts.
     
  8. Rick M

    Rick M Absent-minded professor

    While you're buying parts, buy some X5HC props for it. They perform better than the stock ones on the X5C. The X5C is a great learning quad, and even if/after you move on to more sophisticated quads, you will probably still fly it pretty often. I do mine. :)
     
    ack214 likes this.
  9. Jeff Neese

    Jeff Neese Well-Known Member

    Rick, I saw one person report that those props make the X5C-1 prone to wobble or instability. What has been your experience? In stock form the X5C-1 seems almost immune to wobble of any kind.
     
  10. Rick M

    Rick M Absent-minded professor

    I haven't seen that, and I'd suspect prop balance issues in his case.
     
    Davey59 likes this.
  11. ack214

    ack214 Member

  12. ack214

    ack214 Member

    Update - we replaced the gear and the motor. The gears are lined up now but it won't fly. Any other suggestions of what might be happening?
     
  13. Gyro Doctor

    Gyro Doctor Electronics Tech for over 45 years

    Can you be a bit more specific ?
     
  14. ack214

    ack214 Member

    Three of the four propellers seem to work fine and start to lift off the ground. The fourth propeller that we have repaired (new gear and motor) spins but doesn't seem to have enough power to lift off.
     
  15. Davey59

    Davey59 Member

    Is the new motor spinning the correct direction? direction marked on the arm. Are you using the same props?.
     
  16. Gyro Doctor

    Gyro Doctor Electronics Tech for over 45 years

    I would check these things in this order:
    Make sure the prop isn't slipping on the shaft by holding the gears and (not too forcefully) pushing laterally on the prop.
    Manually spin the suspect motor by the prop and compare it's "feel" to the others (similar cogging effect or not and/or any slipping).

    Barring any useful indications at this point open the shell, turn on the quad and run with throttle at about one third power, and gently load
    down each motor one at a time (by pinching, but not holding, the pinion gear on the motor) to "get a feel" for the difference between the "bad"
    motor and the other good ones. Next swap the leads at the circuit board from suspect motor with any other motor and test again running and
    loading down the motors to see if the problem has changed location.

    If it HAS NOT, and a known good motor now exhibits the same symptoms in that same location, you'll know it's a problem with the driver section
    on the circuit board for that motor's location.

    If it HAS changed location then you know it's a problem with that motor and/or wiring that was just replaced. Double check the motor to be sure
    it's the same as the others and check the soldering connections at the motor. ;)

    IF you determine it's a fault with the PCB then be sure to keep the bad one for parts (mark or remove the bad components) and just replace the
    whole board (about $10). That way the next time something like this happens (fried driver) you can make repairs to your board.
    These toy grade quads have everything on one PCB in them (unlike hobby grades where there are different boards for each function).
    What would normally be thought of as the ESCs are just single MOSFETS and their accompanying diodes. Here are some pics identifying them
    for you.

    [​IMG]https://postimg.org/image/c5rwq2k7f/

    https://postimg.org/image/774ebkizf/
     
  17. ack214

    ack214 Member

     
  18. ack214

    ack214 Member

    Thank you - does anyone know if it is normal for this drone to have trouble this quickly? He got it on 12/25 and flew it maybe 6 times before it started having problems.
     
  19. Rick M

    Rick M Absent-minded professor

    Not typical for Syma quads in my experience and that of the people that I know that fly them. However, they are inexpensive and mass-produced, so anything is possible. The typical experience is to have to replace one or more motors once in a while. Make sure if the quad runs into anything that prevents the props from turning, that he cuts power immediately. Not doing so is the easiest way to take out a motor.

    If you fly quads, you will end up doing repairs, which sounds intimidating but needn't be. You can find YouTube videos covering just about any issue you will have and showing you how to do anything you need to do. The hardest part of replacing the board (if you end up having to do that) is soldering the motor connections.
     
  20. Gyro Doctor

    Gyro Doctor Electronics Tech for over 45 years

    You're very welcome :)
    No, these things usually last longer but anything can happen.
    Whatever caused the initial problem which required the replacements may have also damaged the drive circuitry to that motor.
    When these motors are at a forced stop (obstruction of the prop or damage to drive train) the circuits often get fried.

    My MJX X101 got stuck in a tree once and (foolishly) insisting on "flying it back loose" I fried it's drive to one of the motors. :(
    Aftering buying another PCB for it (and later frying it too ... lol) I eventually went online to Mouser Electronics and bought a handful of higher
    capacity rated FETs for it. After upgrading the PCB with those heavy duty parts it would (and did) start frying motors before the board would
    give out. That quad eventually flew away on me (as they are prone to do) and was never to be seen again. :p
     
    Rick M likes this.

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