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  • Hi All,

    I had some strange motor behaviour today

    One motor would only twich at low throttle settings while the others spin up just fine

    Suspecting a fault motor I swapped it for a new one - no change to the 'bad' behaviour

    This led me to suspect a bad ESC or bad ESC calibration - I did a couple ESC calibrations - no change

    So I did a few run up tests in the back yard - powering up to a low hover - hoping to see what happened

    During one run up the 'bad' motor stopped dead and I heard the familiar ESC boot up beeps

    After the ESC reboot the motor ran OK (apart from the twitchy behaviour)

    So I pulled the thing apart to swap the ESC - damm that power board is buried deep inside!

    The one difference with 'bad' ESC when compared to the others is that it is the one supplying the APM through its BEC (in my quad it is the 'back' motor - this is what you get following the wiki constructions instructions)

    I'm about to fit an external UBEC and new ESC but it leads me to wonder if some of the problems people are seeing with the same motor burning out more than once and others with un-explained in flight 'flips' could be related to drawing APM and receiver power supply from one BEC on one ESC.

    Do we know the start up current from all the bits we put on an Arducopter (APM, Xbees, Sonar, RX etc)?

    Do we know that the standard JDrones / 3Drobotics ESC BEC can handle the load without some form of 'brown out' that may 'burn' a motor?

    For the people with 'burnt' motors was your motor powered from the ESC that also supplied power to the APM?

    regards

    Andrew

     

     

  • I've also seen the motors act funny in the following situations:

    - Using the reset button on the sensor shield or board

    - Connecting from USB (in particular with the ArduCopterConfigurator but also the Arduino monitor and CLI)

    - Uploads

     

    It doesn't seem to be related to the software code at all since I've seen this happen with both many versions of the old Arducopter code and 2.0.16.

     

    During resets it seems to depend a lot on the ESCs as well. Some of my ESCs (I have different versions of the same no-name thing) first emit a warning saying that the signal has gone out of bounds in the upwards direction right when I press reset, then shortly after it does another warning that the signal was lost entirely (flatlined) and then a notice saying that the signal has been recovered. This happens on every reset, always - easily reproducible - and takes around 1-2 seconds total. Others just move the motor a bit and get hot to touch if you reset 3-4 times in a row (didn't try more than that).

     

    During flashing I have no clue what is going on. I noticed some of the motors moving a bit and getting hot once and tried different things. It seems that setting "soft start" on the ESCs will remove the heat problem but instead it will sometimes randomly spin up a propellar for a few seconds, then lose the signal and spin it down again. Sometimes it works flawlessly, though, and other times it is a weird mess of beeping and spinning propellars. It is not really a problem because the documentation clearly states that powering the motors should be avoided when connected to a computer, but some people seem to take safety warnings as a challenge - in this case me included ;)

     

    In short: For me it works to enable "soft start" until the problem is solved. Most ESCs have different levels of soft start, I just used "quick"... - it doesn't affect flying at all like the "slow" one does.

  • I have also had this problem crop up with various other FC's so it is not just an APM problem. In every case it was the ESC that was at fault. Only last week I had a brand new TURNIGY PLUSH 40 amp that would not start properly I have also seen that happen with the HiModel copy. Nearly all of that type of controller are made at the same factory, essentially it's the same controller rebranded with a slight firmware change. Both are 400 hz. There is a high proportion of faulty components out there. Unfortunately once you shorten the wires or put a soldering iron on it then warranty goes out the window, so It pays to check them first before installation.
  • I'm really glad to see this getting some attention now, i've made several posts about this since the release of the first beta kits last year and not really managed to get any traction despite a few posts since December its always been dismissed. Its always been the same motor for me (on the 1280) connections are always soldered and have tried multiple ESCs, but am out the cost of several motors so far. Lets hope this gets resolved soon.
  • Probably a new PDB design with Optos + 5v regulator and a separate battery for APM would be a nice solution.

  • This may be off topic, but is the APM Mission Planner working with Arducopter with the traditional heli?
  • I tried using the Pulso ESC which are optically isolated.  The only problem was that they auto-calibrate which meant that they were useless on my quad.

    Make sure that the ones you choose can be manually calibrated fro throttle end points etc.

     

    Philip

     

  • hi there

     

    see: http://diydrones.ning.com/forum/topics/motor-grilled-up-in-smoke

    Front right motor burned out without any warning sign while setup. The ESC was grilled as well.

    had exactly the same problem.  Due to missing ESC's in the shop i replaced all 4 ESC's with another product: When connected to USB i get wild turning and spinning up of the motors as well. No more" spastic" trmbling.

     

    thx

  • As a rule I always use a separate battery for the control section + a BEC If needed, and for quads I also recommend Opto-isolator for each ESC.
    ONLY with the control battery plugged you can upload firmware, program, play without any risk. Then when you are ready to fly or understanding the risk plug the monster battery.
    And a plus. If the main battery, PDB or any ESC have any problem you will continue having “control” so is possible to cut all motors or even use telemetry to find the model.

    The battery I use is:
    http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=...
    30g for security reasons is not too much weight.

    Regards,
    Vicente A.
  • 1280

    Fah Pah kit ESC

    smoked one motor after a second or two of jittering, the motor continued to work for several flights after this, but eventually died. I do not recall what arm it was on.

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