High Temperature Warning

Discussion in 'Electronics' started by David N Atkisson, Feb 5, 2013.

  1. David N Atkisson

    Joined:
    Nov 24, 2012
    Messages:
    73
    Likes Received:
    0
    Okay Andy I'll get the rare unsigned one but when I next visit Portland I would like to have the celebrity signing session option as well. LOL
     
  2. Ben Freedman

    Ben Freedman Member

    Joined:
    Jan 11, 2013
    Messages:
    119
    Likes Received:
    1
    Hey, David...

    When I flew the same stock CS8 with my 5D, it really felt to me like it was near the top of its weight capacity. However, in a hover, I would normally be drawing around 50 amps. I felt the C8 was MUCH better suited to flying something like a CX550 or NEX6, which would hover at just below center stick...

    70-80 amps seems VERY high for a hover. Can you perhaps remove the camera, and fly with just the gimbal, then tell us how much amps its drawing in a stable hover?

    Best,

    Ben
     
  3. David N Atkisson

    Joined:
    Nov 24, 2012
    Messages:
    73
    Likes Received:
    0
    I did a weigh in on my copter and it weighs in with all batteries and accessories at 14 lbs.
     
  4. David N Atkisson

    Joined:
    Nov 24, 2012
    Messages:
    73
    Likes Received:
    0
    I will go out without the camera and do a few minutes of hover and upload the gpx file soon.
     
  5. David N Atkisson

    Joined:
    Nov 24, 2012
    Messages:
    73
    Likes Received:
    0
    Okay folks,
    Here is a gpx file hovering around but not camera.
     

    Attached Files:

  6. David N Atkisson

    Joined:
    Nov 24, 2012
    Messages:
    73
    Likes Received:
    0
    By the way does anyone know how to get my time up to date. I notice that the time stamp on my gps files do not correspond to the actual time here in California.
     
  7. Steve Maller

    Steve Maller UAV Grief Counselor

    Joined:
    Oct 30, 2012
    Messages:
    3,979
    Likes Received:
    807
    14 pounds sounds about right. Here's mine, loaded for bear.
    IMG_6300.jpg
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
    Staff Member

    Joined:
    Jul 31, 2012
    Messages:
    10,369
    Likes Received:
    1,162
    GPS time is always Zulu Time (GMT to you squire!)

    Andy.
     
  9. David N Atkisson

    Joined:
    Nov 24, 2012
    Messages:
    73
    Likes Received:
    0
    Oh Course! I should have known that. haha
     
  10. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

    Joined:
    Sep 20, 2012
    Messages:
    581
    Likes Received:
    44
    Hello to all the Bl and motor temperatures are an always concern specially for the many MR pilots that live in warm whether locations me
    S Florida where the average warm temperature is around the range of 86-90F (Josh L and a few others may know this very well they get even higher than 90F "OMG" ) my thought is that this considerably contributes to increase the BL,s and motors temperatures, assuming that you are flaying a perfectly balance copter and the other technical aspects like bad connections etc. are in check, we will reach this high temperatures faster than the folks that fly at cooler locations, some of the aproaches that I am testing are:

    1 Heat sinks on top of every Mosffet on the BL.s Ctrl ( Quadrocopter has them)
    http://www.quadrocopter.com/Aluminum-ESC-Cooler-for-MK_p_324.html

    2 Heat sink on the 4 side plates off the distribution board (octo)
    (http://www.readymaderc.com/store/index.php?main_page=product_info&cPath=11_15&products_id=1040

    3 Simply If I can fly (example) with one 4S 8000mHa Lipo for 5 minutes cut that to 4 minutes and let the bird cool off, Directors and producers will have to know and agree this before hand.

    4 I asume that in Hover flight the heat increases because there less airflow than in motion flight

    5 Im going to try to add a little more space between the top copter plate and the Dist board and the Mk FC so to allow more air to flow trough


    IMG_1855.jpg
    I am always reminded that this configuration of MR components where and are originally design and tested in northern cooler climates, where the average temperatures are in the 30,40 50,F

    Questions:

    1 Any one using heat sinks also on the bottom Mosffets? of the BL,s ?

    2 whats is the highest recorded Bl temp that lived (landed) to tell the story

    3 What exactly happen when a Bl reaches the the top temp does it simply stops working

    4 is there an alarm for this, I guess Graupner talking lady screams and curses at you

    any other suggestions ?
     
  11. Gary Haynes

    Gary Haynes Administrator
    Staff Member

    Joined:
    Jul 6, 2012
    Messages:
    5,211
    Likes Received:
    460
    Yes to putting them on the bottom mosfets.
    On an over temp the BL will throttle down or shut off (can't remember which but I think it is a throttle down. Andy will know)
    Yes you will get a warning from the Graupner.

    If you constantly see high temps, 100c, it's time to think about a different combination of ESC's, Motors, etc.
     
  12. Josh Lambeth

    Josh Lambeth Well-Known Member

    Joined:
    Jun 29, 2012
    Messages:
    1,313
    Likes Received:
    214
    I can say that I have flown in temps here in Phoenix where the outside temp was about 110*F. I had a BL hit the 116*C mark during that flight. I promptly landed and was done flying for the day. If you keep the copter moving around (not hovering) you will see a significant decrease in temps. Sometimes as much as 15*C but if you start hovering your temps will almost instantly climb to the unsafe limits.

    Josh
     
  13. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

    Joined:
    Sep 20, 2012
    Messages:
    581
    Likes Received:
    44
    Thanks guys I will do the bottom mosffets as well
    I notice that the motors to the touch seam to have lower temperatures if I change props from the standard APC SF 14.4.7 to the Xoars 14.4 props any comments on this
     
  14. Gary Haynes

    Gary Haynes Administrator
    Staff Member

    Joined:
    Jul 6, 2012
    Messages:
    5,211
    Likes Received:
    460
    Typically less pitch (if you meant 14x4) means less work/power draw. But that is offset for a given weight that they won't have as much thrust. But the only way to get a real answer is to try it on your setup.
     
  15. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

    Joined:
    Sep 20, 2012
    Messages:
    581
    Likes Received:
    44
    What do you guys think of placing a small electronics fan in the middle of the kopter shooting air up to the FC and the Bl's
    would this affect the Pressure sensor or any thing else ? a constant directed flow of air has to help
    thanks
     
  16. Gary Haynes

    Gary Haynes Administrator
    Staff Member

    Joined:
    Jul 6, 2012
    Messages:
    5,211
    Likes Received:
    460
    I think Josh gave this a try but I don't remember how it worked out.
     
  17. Steve Maller

    Steve Maller UAV Grief Counselor

    Joined:
    Oct 30, 2012
    Messages:
    3,979
    Likes Received:
    807
    Seems to me that one possible fix is to relocate the BLs out onto the booms underneath the prop wash.
    That'd provide a good source of airflow.
     
  18. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
    Staff Member

    Joined:
    Jul 31, 2012
    Messages:
    10,369
    Likes Received:
    1,162
    I wondered about that, Steve. Is there a downside? Would the I2C bus work with really long wires like that -- you'd have a total of about 16 feet of wire running out to the booms....I don't know enough about how noise resistant the I2C bus is, or whether the increased capacitance of the wire would cause a problem?

    Andy.
     
  19. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

    Joined:
    Sep 20, 2012
    Messages:
    581
    Likes Received:
    44
    And the fan Idea, wold it mess up the sensors ?
     
  20. Steve Maller

    Steve Maller UAV Grief Counselor

    Joined:
    Oct 30, 2012
    Messages:
    3,979
    Likes Received:
    807
    I'd be willing to try it, although my copter doesn't run particularly hot where I usually fly.
     

Share This Page