Use Freefly with larger R/C servo

Discussion in 'Radian' started by Kris Orban, Oct 23, 2012.

  1. Kris Orban

    Kris Orban New Member

    Joined:
    Oct 23, 2012
    Messages:
    6
    Likes Received:
    0
  2. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
    Staff Member

    Joined:
    Jul 31, 2012
    Messages:
    10,357
    Likes Received:
    1,161
    Wow. Now that is a Real Man's Servo.
    I'm afraid I cannot answer your questions -- perhaps JohnC can.

    I do have to ask what you're planning to move with that servo? California? :)

    Andy.
     
    AerialVisioneering likes this.
  3. Josh Lambeth

    Josh Lambeth Well-Known Member

    Joined:
    Jun 29, 2012
    Messages:
    1,313
    Likes Received:
    214
    Holy crap!!! Thats awesome!

    May I ask what got photoshopped out of the picture on the left? lol

    Josh
     
  4. Tabb Firchau

    Tabb Firchau Administrator
    Staff Member

    Joined:
    Jun 28, 2012
    Messages:
    911
    Likes Received:
    472
    Hi Kris,

    From looking at the documentation a few questions for you:

    1. Did you modify the servo for continuous rotation with a resistor in place of the pot?
    2. I believe this should run with 1500uS pulse width per the specs.

    Best,

    Tabb
     
  5. Tabb Firchau

    Tabb Firchau Administrator
    Staff Member

    Joined:
    Jun 28, 2012
    Messages:
    911
    Likes Received:
    472
    Kris,

    The Radian has not failed...you are trying to use it with a non modified servo with a potentiometer. It is designed to be used on a servo setup for 360 degree continuous rotation with no potentiometer (5K resistor instead). The Radian shutting down is a failsafe feature. It will try and 'drive' the servo 3 times and if it does not get the behavior it expects it kills the motor drive.

    I would be very careful driving such large servos from the Radian. I am not sure what the current draw the Radian can handle is but you are well outside the intended operational envelope with your current setup.

    Best,

    Tabb
     
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
    Staff Member

    Joined:
    Jul 31, 2012
    Messages:
    10,357
    Likes Received:
    1,161
    Tabb:
    I believe the servo has its own 12v supply (see first posting in this thread) so I'm inferring that it would not rely on the Radian as its motor power supply -- otherwise, if it did I wouldn't be surprised if it became an ex-Radian sensor and the smoke would come out of the wires.

    Also, with the resistor, I believe it's actually two 2.4K resistors in series with a center tap in the middle that "fakes" a potentiometer perpetually stuck in its center of rotation, isn't it?

    Andy.
     
  7. Tabb Firchau

    Tabb Firchau Administrator
    Staff Member

    Joined:
    Jun 28, 2012
    Messages:
    911
    Likes Received:
    472
    OH ok, that makes sense.

    On the resistor...5K refers to the pot the resistor is replacing, the resistors we use are exactly as you describe. You can also use a pot locked to a center point and decoupled from the camera mount if you wanted to.

    Tabb
     
  8. Tabb Firchau

    Tabb Firchau Administrator
    Staff Member

    Joined:
    Jun 28, 2012
    Messages:
    911
    Likes Received:
    472
    Hi Kris,

    The Radian cannot work with standard non-modified servos.

    Is the small HiTec servo modified for 360 continuous rotation? If not the Radian cannot work properly on it. My hunch is that there is nothing wrong with the Radian, just that it needs the servo modified for 360 degree rotation in order to function as intended.

    This might be a case where a video is worth a million words.

    Thanks

    Tabb
     
  9. Howard Dapp

    Howard Dapp Active Member

    Joined:
    Aug 18, 2012
    Messages:
    977
    Likes Received:
    111
    Kris, can you please confirm that you've modified the Hitec servo for 360-degree operation. Has the Hitec's internal potentiometer and mechanical stops been removed? Have you replaced the potentiometer with resistors? We'll then move to working out the issues with the Seiko once we've confirmed the Hitec is in fact 360 ready.

    Thanks
     

Share This Page