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Jerky Gimbal / Servo

Discussion in 'General Discussion' started by DomKane, May 8, 2013.

  1. DomKane

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    So... I have a cheap gimbal (the Jakub one) for my GoPro, and I've fitted the EMAX ES08MD servos to it. My problem is that the footage is basically unusable because it's so jerky! :(

    My props are balanced, my gimbal screws aren't too tight, and I don't really know what else to do. I've fine-tuned it as best as I can, and I can't seem to find anyone else's settings to work from, so in case someone finds this post by having the same issue, here are my NAZA M settings.

    OUTPUT FREQUENCY: 400Hz

    SERVO TRAVEL LIMIT:
    Pitch: 1000, -150, -850
    Roll: 1000, -200, -800

    AUTOMATIC GAIN CONTROL:
    Pitch: 50
    Roll: 30

    The gimbal seems to be holding the camera level, but it's all so jerky, I get way better footage without the gimbal.

    I know it's only a cheap gimbal, and I know it's not exactly brushless motors, so I'm not expecting "sub-pixel stabilisation", but this footage is so jerky it renders the footage useless, even when I slow it down 50% and stabilise in FCPX.

    I know that there's a bit of jello because I'm waiting for delivery of replacement rubber pads on my anti-jello plates, so they're DIY'd at the mo using bubble-wrap and wires. I also wonder if maybe the camera is wobbling on the gimbal, even though I've strapped it in tight with velcro straps.

    Anyway, here's some crap footage I'm talking about: https://dl.dropboxusercontent.com/u/10601699/Videos/JerkyGimbal.m4v
     
  2. tvpopta

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    I've got the exact same issues with the same gimbal and servos.. I removed the gimbal. Not sure if any settings can change anything about the jerky motion. Be sure to watch the servo limit settings; Using the recommended settings the servo rods might hit something.

    At rc-drones.com (retailer of the PhantoMount X2 Phantom Wide Gimbal) they recommend using a 6v harness, promising smoother motion.
    http://www.rc-drones.com/SBEC_harness.php

    I looked into alternatives too, like the futaba S3157 High-Torque/High-Speed Micro. Measurements are equal so it should be an easy replacement. They go on e-bay for about $30.
    http://www.futaba-rc.com/servos/digital.html
    http://www.ebay.com/itm/Futaba-S3157-Se ... 0673447355

    Speaking for myself, I'm a bit hesitant to spent more cash on this gimbal; the pitch extremes are quite limited; would love to invest in a gimbal that's known to work well, and can give me (near) straight look down. With the possibility of fpv in the future in mind :)
     
  3. DomKane

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    Cheers for the links... I've done a bit more research myself, and I think I'm slowly coming to the conclusion that any gimbal using servos is pointless. I don't see that an SBEC will change anything for me, since even holding the phantom powered up with motors off it's still jerky as I tilt it slowly with my hands. Which leads me to wonder why all the quadcopter shops are even selling these gimbals when they render all footage as useless.

    I'm yet to find any footage online from anyone using a similar gimbal/servo setup with good footage that isn't either jerky as **** or so heavily post-stabilised it's warped and distorted beyond belief. Seems like I've wasted a lot of time and a fair amount of money. :/

    So I think I'll be better off in the long run just buying a whole new brushless motor gimbal like the ARRIS CM2000 V2.0.

    I just hope I'm wrong! :)
     
  4. MX45OR

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    I have the Jakub V2.0. I must say my flying has to slow way down in order to get any usable footage at all. I can't use gps without a bunch of jitter in the recording' while it self corrects.
    I'm on the fence as far as using any bec. Do I need one for each servo?
    Is there a different arm length for the servo, in order to slow the movement. I'll have to post my Naza settings later when Im home. Id like to get this to work, by comparing notes
     
  5. DomKane

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    So now I'm half glad that it's not just me with this issue, but half mad that people are selling these things in a when they're not fit for purpose.
     
  6. tvpopta

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    True that; the sample videos showed a very different picture :roll:
    The Arris 2.0 gimbal looks like a pretty neat thing! I'll have to check if the gimbal can be controlled using the 7th channel on the phantom transmitter.. If thats a fairly easy fix I'll get one :)
     
  7. DomKane

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    Yeah, I'm looking at brushless gimbals now and I keep watching videos trying to look for hints of post-production stabilisation out of fear of getting conned again! ;)

    I don't know how much longer I can wait for DJI to put theirs out (and that's without mention of how long the waiting list will be!).
     
  8. jumanoc

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    Did you see this one? cheaper than expected Zenmuse (US$369.oo), and looks like performs same way ! Watch 2 videos:

    http://www.foxtechfpv.com/mastorg-brushless-gimbal-for-gopro-p-1017.html

    [​IMG]
     
  9. DomKane

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    I just ordered one of these: http://r.ebay.com/B6t3iL

    I think it's worth a gamble of £100 at least it means I can get some decent footage (hopefully) while I wait for DJI to come out with theirs to get the whole FPV and GoPro power supply etc.
     
  10. dbrack

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    I can't wait for the DJI one either. I need one right away! I pulled the trigger on the Hobby-wing.com one. "Arris CM2000" V2 (with Phantom compatible mount)

    Hoping it arrives this coming week. I'll post results!


    db
     
  11. Gizmo3000

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    I've had the Quadframe gimbal, it's sort of working, but like just about everyone else, I found it jitters a bit on the roll, and I was kind of hoping for a bit more pitch (so it could face downward). So while I'm somewhat disappointed, it's been an ok learning experience and I basically consider it only a slight tradeoff, as I've been able to get a few neat shots out of it.
    I run things thru a bit of post-stabalization which i think helps smooth things out further.

    I tweaked the gains way down (to 30,30) as well.

    But part of me wants to just go in and hack the thing up to make it a 1-axis gimbal that can tilt all the way down

    I kind of got into the first wave of the "gimbal" bandwagon when i got mine, .but think I'll hold off a bit and wait to hear what people think about the new wave of brushless gimbals, and compare prices in a few months once the dust has settled a bit and a true winner is announced.
    The Arris CM2000 definitely looks like the most promising of the bunch, in terms of value and design.
    .I'm very tempted, and can't wait to hear what you guys think about it.
     
  12. tvpopta

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    Looks good Dom! Dang I got sold by the sample movie of the Arris CM2000 v2.0 gimbal. Just looks too good to be true; Ordered it and hope it will get here soon. Still under a quarter the price of the zenmuse hero, so that saves some for an fpv set up in the future :)
     
  13. windcharger

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    very interested in this one, I await your review :)
     
  14. Gizmo3000

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    Hah! well I certainly have my fingers crossed on that one, as if it's successful they'll in the very least force DJI to price theirs somewhat competitively. I doubt they'll sell theirs for $1,000, especially considering the competition. my guess is that it'll be around $600-$700 top, otherwise they simply won't be selling many (except for the big spender with money to burn)
     
  15. DomKane

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    UPDATE: lol I just found out the weight of that £100 gimbal... 700g!!!!!

    Needless to say, I cancelled the order... The hunt continues...
     
  16. tvpopta

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  17. DomKane

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    Yeah that's what I thought! Must be made of iron or lead! lol

    €500? Hmmm, I wonder if that's a deposit or a loss-leader? If its a loss-leader I'd pay it right now!
     
  18. windcharger

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    :shock:
    That is disappointing
     
  19. tvpopta

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    Not sure either, but considering a previous retailer had it at 1000€, this will attract a lot of buyers; probably what they're after. And there really isn't much choice for dji with other gimbals promising the same level of stabilization at still less than half this price :cool:
    My worrie with the zenmuse is the remaining fpv connectivity; the back port is already in use it seems, and I'm not sure if there's a master-slave output with the gopro ports. That is, are options left to connect your own 5.8 ghz transmitter, or will you be forced into using an apple device for monitoring?
     
  20. Gizmo3000

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    wow, that's one heavy gimbal!
    obviously not made for Phantom!

    I believe the Arris one is advertised as 155g, which is pretty good considering it comes with an isolation mount (if that's included in the weight).

    My advice - stick with what you have for the time being, try turning the gain setting way down and do post-stabalization.
    wait it out until others report back on how well the Arris and other brushless gimbals work out.
    - let the early adopters do the beta testing (thanks guys!)