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My idea for adjustable gimbal damping

Discussion in 'Phantom FC40 Discussion' started by lake_flyer, Apr 12, 2015.

  1. lake_flyer

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    My Walkera G-2D plastic gimbal always vibrated a little, even in hovering, and no matter what i did, I couldn't get rid of it.

    I changed the gains, calibrated the props, used different props, changed damping balls......
    There always remained some vibration, and because the temperature changes a lot, there's never a solution that works in all conditions.

    Until I tried tie wraps through the damping balls. I found that compressing the balls gave a lot more damping and less, to almost zero vibration or shaking (when flying or ascending max speed).

    The only thing I wanted to change about it was adding the possibility to adjust the compressing ratio of the front balls, so I could find sort of a ball park for every occasion.
    My solution is very simple. I took 2 nylon break bolts (light) that are used to attach wings to RC gliders and planes, they come in different sizes. I used some I still had left from my old glider. With nuts and washers they make the compression freely adjustable to any situation.

    I only made the front balls adjustable. The rear ones are still compressed with tie wraps.
    Wished I could try it out right now but there's a fresh SSW breeze with some nasty gusts, expected to become a real storm later tonight.
    20150412_153741.jpg 20150412_153731.jpg
     
  2. 2nd2non

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    Curious to see how this works and if you don't introduce jellowing with the restriction on the balls
     
  3. lake_flyer

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    I believe jello is induced by the shutter speed of the camera in combination with the shadow of rotating props in direct sunlight. Has nothing to do with the gimbal or the vibration of the quad. Although I might be wrong here. I only have that waving image, early in the morning with low direct sunlight on the front props. The rest is purely vibration that can be dealt with mechanically.

    As I said before, with tie wraps it works beautifully, can't imagine this wouldn't work even better.
    When the weather permits I'll shoot a few clips with and without and post them here.
    [edited...jello...not yellow]
     
    #3 lake_flyer, Apr 12, 2015
    Last edited: Apr 13, 2015
  4. lake_flyer

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    weather is ok now, light to moderate breeze.
    If I find the time I will take it for a spin today.
     
  5. lake_flyer

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    Don't bother....
    It doesn't work.

    Tried it with and without bolts and nuts. The weather was worse than expected, a slightly heavier breeze with nasty gusts. Both flights were pretty shaky and the clips full of vibrations.

    The bolts seem to transmit the vibrations from the upper to the lower Gimbal plate, bypassing the rubber balls. Although a higher compression of the dampers help a bit in dealing with the heavier bumps, the vibration remains the same.

    Although it was a slight improvement over no bolts at all, simply a cable tie loosely through each of the front balls turns out to be the best solution.

    It was worth a try though.
     
  6. Noël

    Noël Guest

    That's how we do it with a Taco RC gimbal (see: http://www.phantompilots.com/threads/taco-rc-gimbal-ear-plug-vibration-jello-fix.15441/ )

    Currently I'm also testing the Walkera G-2D plastic gimbal and am also having a "vibration" issue.

    Today I tried the nut/bold trick and did not find it to work any better than stuffing the rubbers full with ear plugs.

    This is the vibration issues I'm currently having with a modified Phantom 2 vision, G-2D and a SJ4000 (wifi) camera.

    (nothing exiting to see... Just testing the setup in manual mode.)


    I've tested other gimbals with this Phantom, and they all showed the same vibration problem!
    The props are all balanced.

    I've got another Phantom 2 Vision here, and will test the G-2D on this one too.
     
    #6 Noël, Apr 13, 2015
    Last edited by a moderator: Apr 13, 2015
  7. IflyinWY

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    Do you have access to soft, medium and hard balls? I've seen where some are much more ridged than others. It may be a hit and miss thing, depending on your particular setup.
     
  8. Noël

    Noël Guest

    Me.. I'm using medium balls at the moment stuffed with ear plugs.
    The soft balls were definitely not a go.
     
  9. IflyinWY

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    Have you found a better way yet?
     
  10. lake_flyer

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    Yeah, my P2 as well as FC40 both have the same vibes, nothing to do with prop balancing. The 8" props do ease out the vibes on the FC40 though. As soon as I put on 9443's or 9450's the vibes are more pronounced.

    I found that 4 tie wraps, slightly compressing the balls works quite good.
    I will however trie the earplug method soon, looks promising.

    I have also been thinking about a layer of silicone jello instead of balls
     
  11. IflyinWY

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    That sounds interesting. I mean for reducing the jello in the video. ;)
     
    lake_flyer likes this.
  12. Noël

    Noël Guest

    Is it easy for you to disable the video transmitter?
    If so, can you please try a recording with out the VTX on?
    This "shake" might/could come from some kind of RF interference!

    I would love to test this, but my VTX in build inside the "P2", and can not be turned off easily.

    Please report back...
     
  13. lake_flyer

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    Nothing to do with the transmission I'm afraid.
    I flew quite some time before I had the 900Mhz FPV transmitter on the FC40. Besides, on my P2 I have 5.8GHz transmitter.
    It's definitely mechanical vibration. Not jello, induced by rolling shutter.
    But today I tried the 4 tie wraps, and a new circular polarised UV filter for the gopro, with a lot of wind, and I think I nailed it! The vibes are gone.

    Now I have to find a solution for the, now front heavy, gopro :)
    A coin at the back of the gimbal seems to do the trick.
    With the filter, the picture is more vivid with deeper contrast and colour. And no rolling shutter jello. It also helps as a lens shade.

    I'll post a example video tomorrow if the weather permits.
     
  14. lake_flyer

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    I'm using the black walkera balls now. Better, but still need extra compression.
    I found a pack of 4 sets of different grade balls for the zenmuse on Banggood for around 5$.
     
  15. lake_flyer

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    Haha, I mean the jelly stuff, but you know that,
     
  16. Noël

    Noël Guest

    make_flyer. Does your vibration look the same as seen in my video? If so I'll need to get a polarized UV filter for my SJ4000.
     
  17. lake_flyer

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    Noel, the vibrations I see in your video are all too familiar. Exactly the vibes I always have in my clips. It's just the natural vibration of any Phantom. I don't see much jello if any. Don't think the filter will lessen those clearly physical vibrations.

    I think, with the tie wraps, I'm getting where I want to be. I might make them a little bit tighter.

    I found after several flights that the vibes became less and less, the more I tightened them.
    As you see in my clip, shot yesterday, just before noon, the vibrations are quite small and sometimes even hardly noticeable. The NE wind was 8-10kn. You see the prop shadows when I turn into the sun. The light was very bright and normally I would have had some jello in this situation. The Polar/UV filter I use, deepens the colour and enhances the contrasts. Maybe it pronounces the prop shadows a bit that way. But there's no rolling shutter or jello visible. Just a tiny bit of lateral vibration that gets less when I tighten the straps a bit further, I hope.


    Notice the formation of four old Fokker planes appearing in the distance at the end of the clip. The 'Fokker Four' always practice over the lake on Sundays. It's a low fly zone so they are allowed to fly as low as 300m.
     
    #17 lake_flyer, Apr 20, 2015
    Last edited: Apr 20, 2015
  18. lake_flyer

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    In lower light conditions the vibrations are less noticeable. That's why I always love to fly at dusk. The shutter speed of the gopro is getting very high in bright sunlight, so there's no motion blur, and every tiny movement is sharp and clear. A neutral step down filter will help tremendously in this bright sunlight.
     
  19. Noël

    Noël Guest

    Thank you for the info.

    Before the Walkera G-2D I had a cheap Chinese gimbal, and this was showing exactly the same symptoms.
    I was kind of hoping that the Walkera G-2D would fix this.. I guess I was wrong.

    Will give the tie wrap trick a go and report back.
     
  20. One_crazy_dude

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    Any new news? Are the zip ties still working. I went from a eBay gimbal with a hard jerking in it to the walkera with the jitter. I have changed the lil dampening balls to hard oner and used ear plugs where the mount touches the phantom. This helped a lot but still is not as smooth as the last video posted here. ImageUploadedByPhantomPilots1434502705.224149.jpg ImageUploadedByPhantomPilots1434502764.898593.jpg