Using Camera ops Tilt in FIXED POSITION STABILIZED mode?

Discussion in 'Radian' started by Chris Newman, Oct 18, 2012.

  1. Chris Newman

    Chris Newman Member

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    Is it possible to let my camera op control the tilt while in Fixed position Stabilized mode?
     
  2. Tabb Firchau

    Tabb Firchau Administrator
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    No, only in slew stabilized.
     
  3. Tabb Firchau

    Tabb Firchau Administrator
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    Hold on, you could setup 2 different mode switches so that tilt could be in "slew" stabilized while pan and roll are in "fixed position"

    I am wondering why thought? What is it that you are after?
     
  4. Chris Newman

    Chris Newman Member

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    I was having issues with jittery panning, think my pan servo has issues. I was hoping I could flip on fixed position so the pan isnt and issue and have my opp tilt. I have a shoot today so I just switched the pan and tilt servos for now and I am having better results. Thanks for the response!
     
  5. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    I'm noticing "jittery" panning too - I'm at 50% gain and the "jitter" looks to be at the natural frequency of the gimbal. But, as Tabb says, you could use separate Mode channels and have Stabiilized slew be selective so that you've got separate switches to control pan and tilt/roll.

    The jitter on pan that I see happens when the pan slew control has no Expo on it -- if I add lots of Expo (like 60%) then the shooter I work with doesn't induce the oscillation.

    I'm going to continue researching this pan jitter -- it may be that altering the servo ATV (see footnote) might be the best way to tame it (as I think Tabb suggested in another thread).

    Andy

    Footnote: Futaba-speak:
    ATV/EPA
    Adjustable travel volume, or end point adjustment. Adjusts the total travel in each direction of servos 1-8 regardless of their control assignment. For example, ATV adjustment to AIL channel will adjust only the servo plugged into channel 1 regardless of any flaperon, elevon, or other programming set-ups.
     
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  6. Chris Newman

    Chris Newman Member

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    Thanks Andy I will try your suggestions!
     
  7. Joe Azzarelli

    Joe Azzarelli Active Member

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    Andy
    Describe "jitter" for me: Are you having oscillation or is it panning in like "steps"?

    I am able to use a pan gain of 80 with my latest and very acceptable vibration isolator mod. But that pan belt needs to be TIGHT or I experience oscillation.

    Best
    Joe
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Joe:
    Yes....panning in steps -- the gimbal moves, overshoots slightly, moves back slightly too far, then moves forwards again -- to those with a mechanical background it's what I would call damped harmonic oscillation. I've got the pan gain down to 50% with a Sony CX760 on it, so I suspect the gain needs to be lower. I've got the standard vibration isolators on the gimbal with all the standard O-rings mounted. Temperatures when I've flown and seen this have been from 72F to 80F (22C to 26C).

    I've experimented with the Futaba 8FG by putting in 60% expo so that the shooter won't over drive the pan slew.... but if he ever accidentally flips the switch to go back to zero expo, hoooo boy....you can hear the oscillations as the motors try to dampen it....

    Thanks
    Andy
     
  9. Joe Azzarelli

    Joe Azzarelli Active Member

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    At one point i flipped the belt over to the smooth side because I felt the belt teeth were "popping" into the servo pulley rather than smoothly meshing. But, the back side is too smooth. The belt would need to have a course surface to let friction do the job the teeth are doing.

    I am rambling...

    Joe
     
  10. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    You're not rambling, Joe. It's very helpful to other people to know what experiments you've tried and what the outcomes were.

    Andy.
     

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