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Massive Jello after installing ImmersionRC 600mW

Discussion in 'Zenmuse H3-3D/H4-3D GoPro Gimbal' started by erek, Sep 28, 2014.

  1. erek

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    Hello, after replacing my AVL58 with Cloverleafs with an ImmersoinRC 600mW (stock antenna) and a Black Pearl 7-channel (stock antennas) I am seeing a significant amount of Jello.


    Here is the previous layout where I had the anti-interference board on top of the AVL58

    [​IMG]


    I replaced the AVL58 with the ImmersionRC 600mW in the same spot as the AVL58 in that picture, and also had the anti-interference board mounted on top of the ImmersionRC, I noticed severe Jello, so I tried mounting the anti-interference board on top of the iOSD Mini (it's current location now) instead, and the Jello is still there. Could wind be a significant factor here?

    Here is a video with the AVL58 setup (two weekends ago):

    [vimeo]106703502[/vimeo]

    Here is a video with the ImmersionRC 600mW setup with the anti-interference board mounted on top of the iOSD Mini (this weekend) :

    [vimeo]107358787[/vimeo]


    I am considering going back to the AVL58 using upgraded Antennas on both the vTX and also my 7-channel Black Pearl from FPVLR. What do you guys suggest? I am not really interested at this time in moving the FPV Hub / iOSD Mini / Anti-interference board inside the phantom 2 yet.
     
  2. csivet

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    hi,
    have you ever think that you can put your iosd mini, anti-interference board and even cam bus inside the phantom 2 very quickly.
     
  3. erek

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    planning to avoid that for now
     
  4. smallman28

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    The problem might be two fold.
    Is the whole gimbal noticeably wobbling when you look at it?
    Does the Phantom sound different?
    Normally when you start adding extra weight you need to alter the gains.
    My F450 flew fine "naked" but as soon as I put the gimbal on it was wobbly as a jelly,I went way down on the gains and ironed out the vibration.
    Also it is a brighter day in the second video so the Gopro tends to run at a higher shutter speed and that causes problems,on the second video it is a lot less bright and you have long shadows,looks like late afternoon/early evening.
    It is worth fitting a neutral density filter that in effect tricks the Gopro into using a lower shutter speed to compensate,this also has the effect of very slightly blurring everything which also helps.
    I have noticed a huge difference since fitting one.
     
  5. erek

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    I will have to wait to check on the sound of the phantom 2 and also look at the gimbal to see if it's wobbly. which gain settings do you recommend adjusting? I have modified the gain for the Gimbal Tilt Control. Brought it way down, but that's all that I touched in terms of gain settings
     
  6. ianwood

    ianwood Taco Wrangler
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    You're not adding enough weight to need to touch the gains. Something has changed during your install. You need to look very closely for anything else that may have been disturbed or changed during the install.

    And I wouldn't put anything on top of the vTX as it is a transmitter with an amplifier that will introduce noise and interference to anything right next to it.
     
  7. erek

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    With the Anti-inferference board now mounted on top of the iOSD Mini should I look into replacing all of the cables going into the FPV Hub that may have been stressed from all of this fiddling around?
     
  8. ianwood

    ianwood Taco Wrangler
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    Doubtful the cables are damaged. I would first look for anything that may be loose or could vibrate while flying. Put it in a hover close to the ground and take a close look. Then I would look at the way the gimbal is mounted, the dampeners, the anti-drop pins. Is anything rubbing on the gimbal?
     
  9. Away Point

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    I've fought with jello problems too, and after two Phantom 2's and three 3D gimbals, over a couple hundred flights, FWIW, here are my conclusions...

    First off, I agree with smallman28 on both counts. Brighter conditions are more likely to suffer jello, and some tweaking of the gains can help. I find it helpful to judge just how much vibration is going on by hovering in front of myself (using all the necessary precautions!) and observing both visually and by touch. You shouldn't see the base of the landing struts vibrating, and the landing struts should feel pretty smooth to the touch.

    I suspect it is a good idea to separate the anti-interference board from other components as much as possible. Seems "noise" from the iOSD module may contribute to the problem.

    Balancing the props is a must! Get yourself one of those CNC'ed rods for the P2 props (r/h treads on one end, l/h on the other), and a good prop balancer. A half inch square piece of scotch tape can make the difference!

    Unfortunately, the most frustrating and serious culprit in the jello issue is the gimbal itself. If yours buzzes or makes noises, I think this can be a factor in either triggering or exacerbating jello issues. Making sure the camera and gimbal are balance precisely as possible, and all the P2 calibrations are done as thoroughly as possible, as both help the situation.

    The reality is, in bright conditions, at least some of your shots will have jello, in my experience. Also, the fact that light and wind conditions are different on every flight, make troubleshooting very tiresome!
     
  10. wkf94025

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    I have owned, flown, enjoyed and crashed a number of P2's H3-2D's, and H3-3D's. Seen jello come and go on various configurations, and have spent hours reading others' fixes, frustrations, theories, etc. My current P2 + H3-3D is shaking pretty bad in hover, more than I remember in other similar ships, and jello is unfortunately fairly common on this rig. I am trying to carve out a few hours this weekend to find a solution, or at least reduce magnitude and frequency of jello. Background on this rig:
    (a) I am using an ND filter always
    (b) I counterbalanced camera+filter in lateral dimension with solder affixed on right side of gimbal with double stick tape; camera+filter tilt downward when limp/off
    (c) see pic of long "rattail" extension of CP antenna. It helps longer range FPV reception, but perhaps a contributor to vibration?
    (d) components outside shell: iOSD mini + FPV Hub + ImmersionRC 600mW vTx
    (e) white balls on gimbal; no retention ties or zip ties on gimbal mounts
    (f) anti-interference board NOT installed (too lazy/busy)
    (g) Props are stock, new and no damage, but have never balanced them
    (h) stock gains with firmware (3.06, I believe)

    One possible clue as to what's going wrong here is a high-pitched hum/buzz that is always there on my videos, even if P2 is idling before takeoff.

    Theories about possible causes of vibration and attendant jello:
    1. props out of balance, despite stock new clean props
    2. gains wrong/too high
    3. rat-tail antenna setup causing bad harmonics
    4. lack of anti-interference board
    5. juxtaposition of VTx and FPV Hub, or VTx and iOSD
    6. VTx and FPV Hub and iOSD mounted with Velcro, not double stick tape; source of bad vibes?
    7. just bad luck on a bad P2 and/or bad H3-3D; **** happens, according to Murphy

    Looking for wisdom from those high on the mountain. Which of (a) through (h) seems like most likely vibration/jello culprit? Which of 1 thru 6 would you try first, second, etc. Thanks any/all.

    Kelly
     

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  11. wkf94025

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    Pleased to report that dropping all gains substantially in the Assistant greatly reduced the visible shaking in the bird, and the resultant test flight, albeit on a cloudy day, had virtually no jello. Gains are now set to 100/100/100/100/150/150. I tried adjusting Attitude Gains only, and that was insufficient. Basic gains are critical, and that makes sense if one is seeing substantial shaking when bird is hovering right in front of you with no stick input. I disregarded the advice of 10% at a time, and just decided to make substantial jumps on all settings. Instincts paid off. There were two clues that basic gains were part/all of my problem: 1) if I replaced my long rat-tail extended CP antenna (see pic in prior post) with a shorter non-extended CP antenna, shaking was substantially reduced (but I want that long tail for long range FPV clarity); 2) by unplugging gimbal power at the FPV hub, so I had same physical load, but no gimbal controller fighting with flight controller, vibrations were greatly reduced.

    Two other facets of the morning based on other advice on this forum:

    1) I downloaded Android app "Vibration Monitoring" by Mobile Tools, and set phone against motor housing with props running; no obvious smoking guns from that. Numbers jump all over the place. Method was to hold left edge of phone against end of P2 arm with motors idling, and watching X value (lateral phone movement). Since no discernible outliers, I am concluding no bad motors (or all equally bad ;-).

    2) With props on and P2 idling on the table, rotated P2 so that I could view each prop in its plane, with a clear background. Point being to judge how coplanar (or not) the two blades of each prop are. One of the CCW props was substantially out of plane relative to the others, so I replaced it (before gain adjustments mentioned above). One of the CW props was VERY planar, more so than the rest. Would like to get more props like that one. I think we collectively need more tools and techniques for dynamic motor and prop balancing. Static prop balancing isn't enough, IMHO.

    I didn't play with adding AI board, or moving FPV/OSD components around, or replacing Velcro with double-stick. Tweaks for another day...

    Hope this is helpful to anyone out there with shakes/jello due to gains too high.

    Kelly