video shaking while in the air

Discussion in 'Cinestar 8' started by Albert Chang, Oct 9, 2014.

  1. Albert Chang

    Albert Chang Member

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    guys...
    i know i am no expert, and i don't have all the right terms for what happened... but here is what's going on...
    the video link attached is a recent footage we took (Passcode: 1009)

    notice the video twitch at 1'25", 1'49", 2'12" and 2'43"...

    we are desperately trying to figure out what was the cause of the shaking,
    setup as following:
    M5, 70D, 16-35L, Octo with DJI A2

    here are some speculations:
    a. the Tilt is only set at 12.. (don't know why is so low, but any higher we will get vibrations)
    b. the Roll is turned on
    c. Wind?

    at the same time, we get disconnect with the movi remote, Movi will automatically reset to level and then reconnect...

    we are hoping to get some idea on how to improve the footage...

    thanks a lot in advance...

    albert
     
  2. Brad Meier

    Brad Meier Active Member
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    What type of Octo frame and how is the M5 mounted? To me it looks like vibration in the way its mounted to the frame.

    Post a photo of your setup please
     
  3. Albert Chang

    Albert Chang Member

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    i am using the standard Tarot S1000 frame... see photo (not my actual setup, Octo is at office, so i used a most similar photo from web).
    iron-man-rtf-731.jpg

    but also i installed an vibration isolator device (also see photo) in order to reduce copter's vibration to M5.
    70310054_14.jpg 70310054_11.jpg


    does these photos help? really appreciate the help...

    thanks

    Albert
     
  4. Gustavo Rios

    Gustavo Rios Member

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    One of the things that I see and produce some oscillations is the separation of o-rings, you have four in each vibrator dampener but separate, together have more support.
     
  5. Albert Chang

    Albert Chang Member

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    gustavo,
    are u suggesting to add more rings? the photo is an illustration, in fact my setup has more rings than it show with the gopro setup.

    do you suspect the "jello" effect is cause by the o-ring?
    and if so, more stiff or less stiff? which direction should i take?
    there are Red and Blue O rings and red is more stiff than Blue...

    thanks
     
  6. Gustavo Rios

    Gustavo Rios Member

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    My suggestion is based on the picture you posted, the jello effect could be caused by alignment of engines or propellers balance.
     
  7. Albert Chang

    Albert Chang Member

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    hummm... we are curious... if the prop is unbalanced, shouldn't the video continues to experience jello?
    the part that we r trying to diagnostic is why sometime is has jello and sometime it wont...

    we looked at video over and over again, we noticed when ever we tilt the camera down, the jello effect show up more frequently.
    does anyone thing that could be a problem?

    thanks
     
  8. Gary Haynes

    Gary Haynes Administrator
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    Albert please post photos of your vibration damper setup. Photos of something similar, while interesting, don't really help troubleshoot your specific situation.
     
  9. Albert Chang

    Albert Chang Member

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    understood.. will do so after tomorrow step into the office... i should take more photos while i can...
     
  10. Gustavo Rios

    Gustavo Rios Member

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    my suggestion, first try of o-rings, this can eliminate your oscilations (2:43), put them together. The tilt, calibrate again and check the balance of camera, also the battery charge.
     
  11. Albert Chang

    Albert Chang Member

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    ok, guys... i manage to get some photos and get a chance to take apart the shock damper.
    i think i may found the reason why the video jiggle "sometime" and not all the time...
    and share with you what i have done trying to correct it...
    hoping you guys give me some idea and suggestions.

    here is the actual setup _T3P0856-1.jpg

    and here is the original damper _T3P0855-1.jpg

    base on some suggestion, so i start to swap out some of the orange rings and replaced with blue
    _T3P0862-1.jpg

    but while i was doing it, i noticed something else other than rubber rings...
    the screws that secure the booms are protruding the base plate and it's kinda in the way... and 2nd photo show exactly what i am worried about...
    _T3P0857-1.jpg
    _T3P0863-1.jpg

    while the flyer in the air trying to fly forward or changing direction, the damper was flexing to compensated but it tilting angle was too big and the screws is in contact with the damper itself.
    i think this is the reason why some footage is shaking and some are stable.
    (the rubber rings has been changed to a different combination)

    this is a little rig i did... i position 3 additional rings in between the plates and drastically reduced the tilt angle...
    i realized that this could reduce the agility of the Octo, but i am hoping this will at least keeping the footage smooth and calm.
    after all, that's all it matter...
    _T3P0864-1.jpg
    i have not yet have the opportunity to try due to bad weather. but i m really hoping it would fix the jello video footages...

    any suggestion is welcome.

    thanks
     

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  12. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hmm. On both my Cinestar 8's the screws through the boom clamps have the socket head underneath -- the opposite way to the way that you have them so there is no thread sticking down towards the vibration isolators. The other thing you might consider is that I believe FF sells M3 x 37mm bolts that do not have exposed threads when fitted to FF boom clamps: http://store.freeflysystems.com/collections/cinestar-hardware/products/m3x37-socket-head-screw

    Which vendor's boom clamps are you using, by the way?
    Also, which vendor sells the plates above and below the vibration isolators...that whole setup looks very different -- you may find that you have too much isolation -- that is the whole assembly allows for too much deflection of everything below the toad-in-the-hole.

    Andy.
     
  13. Albert Chang

    Albert Chang Member

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    Andy,
    the reason that the screws are so long is due to that we need to "take apart" the Octo for easy transport. it just simply too big to travel with the unit, so the booms are designed to be "retractable". the screws are longer is for quick release without drop out of the frame set. so at this point, the shorter screws are not used in this case.
    the vibration isolator is locally designed by a vender and he was using it for the FF setup as well, but he does not have the protruding screws issue, therefore i think once i correct that, it may help.
    the deflection angle can be changed by using a with stiff sets of rubber rings... again, i am trying out many different combination and see if i can find the best combo...

    thanks for any suggestions
     
  14. Mark Harris

    Mark Harris Member

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    Before digging too far into the vibration isolator (the vibration isolator is a patch.. you need to fix the root)... have you balanced your motors and props? You will always get some vibration transferred to the arms as the props pass over, but unbalanced props and motors cause far more issues than this.

    Also, as you have removable arms, please ensure they are locked down super tight so there can be no movement at all in any direction when they are on, they should be rock solid.
     
  15. Albert Chang

    Albert Chang Member

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    Mark,
    we understand the importance of a balanced flyer is. and we tight down the booms very tight so it has very little wiggle room.
    due to the length of the booms and the size of the Octo, it's really hard to eliminate all vibration, especially the higher frequency vibs.
    so the vibration isolator is used, yes, as a patch.
    the motor is all leveled with a leveler and before take off, all prob is "numbered" so it matches the motor to go with.
    we are going to give it a test fly sometime this week and see if this modification makes any difference at all...

    will keep everyone watching this posted...

    thanks
     
  16. Mark Harris

    Mark Harris Member

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    Albert, Sorry if i came across as saying that you shouldnt use a vibration plate, I really meant that many people I see use the vibration plate to mask their lack of effort in setting up their copter - which is not good for the flight controller electronics either. I absolutely agree with the use of a vibration plate, as even the most mechanically perfect copter will receive vibration form the air pulse as each prop blade passes over the booms and these cannot be avoided.

    Many non-RC users dont understand prop balancing, or dont realise that it is needed :)
     

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