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  1. #1

    Join Date
    Apr 2016
    Location
    Green Bay, WI
    Posts
    328

    Probably I damaged the BEC

    So I connected my 25mW camera directly to the Rx servo pins to pull the needed 5V from the BEC on the 40 amp Emax ESC. I'm pretty sure that it has a 3 amp switchmode BEC on the ESC. I have the standard (4) 9 gram servos. I'm using a 3300 mAh battery that is at least 30C.

    Here is the ESC:
    http://www.headsuphobby.com/Emax-Sim...EC_p_1394.html


    I have flown the plane many times before with no issues. Now, after connecting the camera, I took off and was able to make it halfway around the pattern (30 seconds?) and the Rx browned out resulting in a spiraling crash.

    I know that the camera was probably too much for the BEC to handle resulting in the crash. No problem, I'm a big boy and will own up to my own dumbness. Since I have removed the camera and everything tests OK on the ground. But now I take off (no camera, just 4 servos and the Rx on the BEC) and it is fine for climb out. As soon as I reduce the throttle the ESC goes into programming mode. I can hear it beeping the sequence for all of the programming parameters. I cannot get any power from the motor but have full control of the plane and am able to complete a forced landing.

    I believe that the BEC is flaking out and the ESC is resetting and seeing the full throttle on startup causing it to go into program mode.

    I suspect that I will either need a new ESC or install a dedicated BEC to power everything independently. I was just wondering if anyone else has come across this or can think of a fix.

    Thanks,
    Gazoo
    78% of the facts that I make up are loosely based on a guess...

  2. #2
    Old and Bold RC PILOT
    Join Date
    Aug 2016
    Location
    Brisbane, Australia
    Posts
    2,002
    I would test the operation of the ESC etc before replacement.

    A copy of the test methods I use to see if a brownout, (loss of BEC), is likely was posted on another thread just recently.

    See - http://forum.flitetest.com/showthrea...ng-RX-Brownout

    Also check to ensure that you have adequate ventilation for the ESC. I have had a couple of designs that "leaked" air but over time as the paper swelled and with a few repairs it became almost airtight and the ESC started cooking up! Made a few ventilation holes checked the items posted above and she is back flying reliably again!

    Just what works for me!

    Have fun!

  3. #3
    Obsession, not hobby TazRC's Avatar
    Join Date
    Dec 2016
    Location
    Phoenix, AZ
    Posts
    321
    I'm sure you're over max current of the ESC's 3A BEC circuit with 4 servos, RX and AIO camera. Try running the AIO from a simple voltage regulator from the flight battery (ESC side) or a separate 1S battery if it can run on 3.7V. With the original ESC, I would try going through the programming to make sure it's setup correctly. Maybe even try it with another battery, RX and motor on the bench before calling it dead.

    http://yinyanmodel.com/EMAX%20User%2...ries%20ESC.pdf
    On the ol' Interweb: tazrc.com

  4. #4

    Join Date
    Apr 2016
    Location
    Green Bay, WI
    Posts
    328
    Thanks for the advice. The ESC is not vented that well. I'll punch some vent holes for it.

    I will program it again. I suppose that it could have wonky parameters if it went into program mode and I was moving the throttle stock attempting to get power.

    I moved the cam to one of the cells on the balance plug but I don't think it's a good idea (on a different plane). One cell will be under more load and I'm just asking to kill that cell and the whole battery. I noticed that as I gave full throttle on the last run, the cam feed died and then came back.
    78% of the facts that I make up are loosely based on a guess...

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