Roll much more stable now! #facepalm

Discussion in '2 Axis Gimbal' started by Steve Maller, Apr 17, 2013.

  1. Steve Maller

    Steve Maller UAV Grief Counselor

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    I have noticed in the past several flights that my 2-axis gimbal's roll has been shaky. I checked Radian gains, balance, and all the regular stuff. I also noticed that the roll servo appeared to be slightly bent, meaning that the pulley was not perfectly parallel to the large wheel. So I figured that I had bent something on one of my rougher landings.

    I almost went ahead and ordered a new servo, but this morning I checked the play, and realized that the hex screw that holds on the pulley was loose. Not only a little. But at least a full 360° turn loose. Oy.

    Just flew in a really stiff wind, and it's way more stable. Sigh.

    IMG_6711.jpg
     
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  2. Gary Haynes

    Gary Haynes Administrator
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    Nice catch Steve. My roll was a bit loose and the tilt more so.
     
  3. Steve Maller

    Steve Maller UAV Grief Counselor

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    "Pictures or it didn't happen"
    Proof. Much more stable, even in a 15-20MPH wind.
     
  4. Howard Dapp

    Howard Dapp Active Member

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    Good to see roll is a bit more stable but what I see is what others here are experiencing...slight roll jitter. Has anyone solved this yet?
     
  5. Steve Maller

    Steve Maller UAV Grief Counselor

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    My gains were set too high because I didn't change them from where I had them for the 5D Mark III. If the wind calms down a bit, I'll try a few different settings. I'm pretty confident that I can get it pretty well dialed in. I suspect the roll jitters have something to do with a subtle resonance between the vibration isolators and the Radian, so I mixed blue and red bands on mine in the hopes of killing of some of that. We'll see.
     
  6. Dave King

    Dave King Well-Known Member

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    Looks better Steve
     
  7. Brad McGiveron

    Brad McGiveron Active Member

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    With the CX cameras you should be able to get it almost perfect.
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    I just found that the bolt holding the pan pulley on the servo was also pretty loose -- the visual cue was that the pulley on the servo was at a rather jaunty angle -- I was just checking for belt tightness when I noticed that... I can see some Loctite in my pulley's future....

    Andy.
     
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  9. Shaun Stanton

    Shaun Stanton Active Member

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    I had the same thing with my pan pulley. In fact my pan pulley started to bore out is center diameter to a point where the pulley started wobble even when it was tightly screwed down. I swapped out servos and pulleys and that solved my pan woes. I still get bobbles. I am going to go back to blue dampers to see if that fixes it.
     

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