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Pan servo wheel clearance.

Discussion in '3 Axis Gimbal' started by Tristan Twisselman, Aug 7, 2012.

  1. Tristan Twisselman

    Tristan Twisselman Active Member

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    I attached a few pictures. I noticed in one of Tabb's gimbal videos it showed him installing spacers which would be the fix for my issue I think but my kit did not come with them. Not sure if it was supposed to or not. Thoughts? It just barely barely is touching the head of the mounting bolt to the wheel.

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  2. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Mine does this too when it's on the ground. As soon as it's in the air it spins freely without hitting it.

    Josh
     
  3. Tristan Twisselman

    Tristan Twisselman Active Member

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    That's why I thought. Thanks :). I just need to quit having my spin while on the ground. Darn hover fly board
     
  4. Tabb Firchau

    Tabb Firchau Administrator
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    Yes, clearance is tight...but should be OK once in the air!

    Tabb
     
  5. Tristan Twisselman

    Tristan Twisselman Active Member

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  6. Brad Meier

    Brad Meier Active Member
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    I found one solution is to tighten the booms down at the center clamps first then put some pressure on the outer ends while tightening the other clamps to get yourself an extra mm or so. Alternatively if you tighten all those down with any kind of weight on the structure it would go a mm or so in the opposite and definitely hit the servo wheel
     
  7. Bob Wojda

    Bob Wojda Member

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    I have the same issue. The clearance is too tight and the head of the bolt just touches the wheel. If everything is dead even it's free but if the cinestar is not perfectly level, like on a windy day, the four bolts hit the gearwheel as the gimbal moves around. In the shop I can recreate it by leaning the cinestar to one side. I think is shouldn't do this. Any ideas on spacer for this or is there another solution somewhere?

    Bob Wojda
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Bob:
    Check out this thread.

    Andy.
     
  9. Ros

    Ros New Member

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    I am also experiencing the same problem with the servo wheel still hitting one of the 4 bolts at times during flight. Is there a way to give myself enough clearance to be sure this will never happen?

    Cheers,
    Rory
     
  10. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Rory: That's very unusual for it to hit during flight. Normally, once you get airborne the weight of the gimbal extends the silicon O-rings and there should be more than enough clearance. You can verify this by picking the Cinestar up by the booms and panning the gimbal -- or have you already done this, please?

    I'm really puzzled why it should be hitting when the copter's airborne....

    Andy.
     
  11. Ros

    Ros New Member

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    Hi Andy,
    It definitely hits during flight and when suspended. Could the mount not be symmetrically connected?
    It only hits on one side of the gimbal cross plate, I only have about 1 kg of weight on the gimbal, however I still want to find a way to eliminate this issue even with a small load on the gimbal.

    Rory
     
  12. Brandon Loeser

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    To fix this issue... when you tighten the tension on the pan belt.... rotate the servo slightly. Sometimes the tension is too tight and it causes the gimbal to flex in the middle and it sags. You can also double up on the center plate and that helps keeping the plate from sagging. No need for glue just double it up. You can see in the top picture how the servo is slightly turned down.


    IMG_0480.jpg

    IMG_0478.jpg
     
  13. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    As Brandon suggests, doubling up the star plate will provide extra rigidity -- but it's not clear to me why the star plate only hits in one position. If you look at it from the side, does either the small pulley or the large pulley appear to be canted over? Or is one of the arms of the star plate bent downwards?

    Andy.
     
  14. Ros

    Ros New Member

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    Hi guys,
    Now you mention it the plate does appear to maybe be bent. I guess I will take it apart and put it on a table to tell for sure.
    Cheers,
    Rory
     

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