over temp BL controller

Discussion in 'Electronics' started by Jon Fredericks, Aug 10, 2015.

  1. Jon Fredericks

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    I'm getting an overtemp on a MK BL-Ctrl 2.0, on the #2 controller. I've cleaned with alcohol and did a run-up test again, and it is slightly out of temp with the other 8, hitting 112 C. Granted our run up test was severe conditions (HOT > 88 F; HIGH > 6000' MSL; & HEAVY > a human, holding it to earth!), but it is consistently happening on the #2 controller.

    Question: could this be indicative of a motor issue?
     
  2. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Jon: It's possible that it's a motor issue, but the real problem is that I think the MK ESC start self-protecting at 100C, and they do so by reducing power to the motor.

    The only real way to isolate whether it's the motor is to replace the #2 motor -- or, if you don't happen to have a spare with you, swap over #2 and #4, say, just to see if the problem follows with the motor.

    With the props off, if you use MK Tool to spin up the #2 motor does it sound pretty much the same as #4.

    I'm only using #4 as an example -- it just happens to spin the same way as #2. :)

    Andy.
     
  3. Jon Fredericks

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    Andy - I like your line of thinking. We are going to try a replacement motor and see what happens. At least one more step to isolate the source of the problem.

    It seems as though MK may allow to set the "temperature limiter" higher, but I'm not convinced this is a good idea, and just would conceal the real issue:
    http://wiki.mikrokopter.de/en/BL-Ctrl_2.0
     
  4. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Yeah....it's one step closer to "Here's how to turn your BL-Ctrl into a fuse." :)

    Andy.
     
  5. Jon Fredericks

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    The new motor appears to have solved the issue. Must have been a slight amount of excess resistance in the old one. Here's the stats after our (brutal) torture test:

    Motor1: 0.0 6.2 15.9 A Temp: 99 99 100 °C
    Motor2: 0.0 2.1 6.0 A Temp: 103 103 104 °C
    Motor3: 0.0 7.4 19.3 A Temp: 95 98 99 °C
    Motor4: 0.1 7.8 16.2 A Temp: 103 103 103 °C
    Motor5: 0.0 7.9 16.7 A Temp: 108 109 110 °C
    Motor6: 0.0 2.6 6.5 A Temp: 105 107 107 °C
    Motor7: 0.1 7.4 17.2 A Temp: 103 105 106 °C
    Motor8: 0.0 4.4 10.8 A Temp: 94 99 101 °C
     
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Nicely done.
    Probably the bearing has gone on the motor. They can easily be replaced, so don't pitch the motor into the ocean just yet. :)

    Andy.
     
  7. Jon Fredericks

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    Thanks for the timely feedback Andy! Always good to bounce ideas...
     
  8. Jason Smoker

    Jason Smoker Active Member

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    all your temps are really high! whats the payload your carrying? whats your set-up?

    you might want to consider upgrading to the v3 cool board and bigger motors and props. I used to see temps in the 90 degrees in summer now it barely breaks 50 even on the hottest of days ;)
     
  9. Jon Fredericks

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    Yes agreed Jason, the temps were high intentionally - we purposely subjected it to a torture test.
     
  10. Jason Smoker

    Jason Smoker Active Member

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    oh i see yeah it probably is the bearings they are the first sign of high temps
     

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