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Bench testing the Cinestar

Discussion in 'Cinestar 8' started by Dave King, Dec 26, 2012.

  1. Dave King

    Dave King Well-Known Member

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    Guys

    I have my Cinestar 8 on my bench with a 12V adjustable power supply that I have set to 16 volts. I have the props off and I set the gyro's like I normally do however when I turn on the motors they stop almost instantly. I don't have a battery here where I am to check this but I wanted to know if this is normal? I know that the motors take a lot of current and the bench supply only puts out 1.5 but it should be enough to keep them at the slowest speed?
     
  2. Steve Maller

    Steve Maller UAV Grief Counselor

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    If you're using MK boards, do you have the Navi board set to require a GPS signal? That's got me a few times when I've tried doing things indoors.
     
  3. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Dave also emailed this to me, but so others can see the response:

    There are a number of things that could be doing this:
    1. Have you calibrated the compass?
    2. Have you calibrated the ACC?
    3. Do you have enough current available from the bench supply? The motors spinning fairly slowly take about 5 Amps -- but the problem is that as they spin up, they drag the voltage down. Most power supplies have an over-current "crow bar" protection that will shut them off and that might be what is happening here.

    With MK Tool connect up to the Navigation Control board, when you first start power up the Cinestar, do you see any error conditions in the center green display?

    The fact that they start up at all indicates that you at least have radio control of them, so think that might exonerate the RC setup.
    Andy.
     
  4. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Dave also emailed this to me, but so others can see the response:

    There are a number of things that could be doing this:
    1. Have you calibrated the compass?
    2. Have you calibrated the ACC?
    3. Do you have enough current available from the bench supply? The motors spinning fairly slowly take about 5 Amps -- but the problem is that as they spin up, they drag the voltage down. Most power supplies have an over-current "crow bar" protection that will shut them off and that might be what is happening here.

    With MK Tool connect up to the Navigation Control board, when you first start power up the Cinestar, do you see any error conditions in the center green display?

    The fact that they start up at all indicates that you at least have radio control of them, so think that might exonerate the RC setup.
    Andy.
     
  5. Dave King

    Dave King Well-Known Member

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    Update: when I got home and put a battery on the cinestar it worked fine so the Cinestar's motors really need a lot of current just to keep the motors going at even the smallest RPM motor speed.
     
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Wait until you do a "scalded cat take-off" and see 80+ Amps being pulled out of the battery! :)

    Andy.
     
  7. Steve Maller

    Steve Maller UAV Grief Counselor

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    Not that I'd ever try it, but do these big LiPo batteries have enough current to start a car? I mean, if my math is right, a 3S 30C LiPo should be able to crank a gas engine, right?
     
  8. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Yup! I believe Johnny Beavers actually did use an old 4s to jump-start his car on a remote shoot when his battery died.

    Josh
     
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  9. Steve Maller

    Steve Maller UAV Grief Counselor

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    I wonder how many it would take to power my Prius (or my Ford Escape Hybrid)? :D
     
  10. Arthur Vieira

    Arthur Vieira Flight Squad

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    Dave,
    I know I'm a little late on this but... I have the same setup in my bench, the only difference is that my power supply can output 3A.
    With the 14x4.7 props on the CS8, when I start the motors the spin but I get the low voltage alert, if I remove the props this doesn't happen, also if you want to check things at home I always recommend that you remove the props and try to avoid using Lipos inside the house. Always play safe ;)
     

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