Horizon not keeping level on a 360 pan ?

Discussion in '3 Axis Gimbal' started by Andrew, May 30, 2013.

  1. Andrew

    Andrew New Member

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    Hi Guys
    Have a 360 setup freeflight servos, pj760 cam,
    Radians on all axis
    Horizon is level but when paning left it tends to slant to the left , on returning back to 0 degrees the horizon is level again.
    Is there a way to keep the horizon level through out the 360 pan ??

    Any help appreciated
     
  2. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Happens to pretty much everyone... Things to help minimize it is makes sure the camera/gimbal is 100% perfectly balanced. Also mess with the gains on the RoLL specifically.

    Josh
     
  3. John Cunningham

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    Hi Andrew,

    This kind of issue is usually because the roll sensing axis is not perpendicular to the yaw axis - so as it turns, it picks up movement which it interprets as roll.

    Look carefully at the roll Radian and check it is square in relation to the pan axis in both directions : looking the side and also from behind.

    JohnC
     
    Janne Hoglund likes this.
  4. Janne Hoglund

    Janne Hoglund Member

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    Thanks John.
    Got any picture of the best way of mounting the Roll Radian?
    Is what you are saying that it must be mounted right, and the use of ¨angular correction¨ in the sw is a nono??
    regards.
    /Janne
     
  5. John Cunningham

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    Hi Janne,

    The angular correction is really meant for the final tweak to get the horizon perfect, but it won't help this kind of issue.

    If you imagine the gyro for the roll axis sensing rotation around the Radian, you want that axis as near as you can to be 90 degrees from the tilt and pan axis.

    I don't have any pics to hand, but the mounting is not so important as having it 'square'.

    JohnC.
     
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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  7. Janne Hoglund

    Janne Hoglund Member

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    Thanks John and Andy, thats the way mine is mounted, but is it ¨square¨??
     

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  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    It's hard to see from the image, but it looks like the right hand side of the Radian might be a little lower than the left hand side as shown in the image. can you use a spirit level and check with the boom absolutely level whether the Radian is also level.

    Also if you separate the gimbal from the hub/booms, can you check with the star plate level that the Radian Pan sensor is level?
    It's possible for that Radian sensor to rotate around the boom so that the label on the Radian is not absolutely vertical. In which case it's sensing something other than pan.

    I think those are the checks that JohnC is suggesting but I could be wrong....
    Andy.
     
  9. Sean Carter

    Sean Carter New Member

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    Also

    Are your cables causing friction/drag on the pulley and servo?

    Nothing to do with your problem(really) but its still better to avoide any contact.
     

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