Super bumpy in the wind: OK?

Discussion in 'Cinestar 8' started by Steve Maller, Jan 21, 2013.

  1. Dan Coplan

    Dan Coplan Member

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    Bryan - In an earlier post you said you couldn't get decent results out of your 5D. Why not? For this much money and technology, we should all be getting great results. You also mentioned dynamic motor and prop balancing along with what I'm assuming would be "static prop balancing"? How do you balance motors, how necessary is this, and what's the difference between static and dynamic prop balancing? I'm only familiar with prop balancing by putting it on a hub and weighting it such that it stays in place no matter what position it's rotated.
     
  2. Bryan Harvey

    Bryan Harvey Member

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    Dan,
    I know it's possible, but I have not been able to get there yet with any camera that is not BOSS stabilized like the Sony CX760. Maybe I am expecting too much and my 5d footage just needs to be post-stabilized. Not sure what is considered acceptable. I wonder about how much post stabilized footage I'm seeing in flight demo reels. Would love to see a good example of un-post-stablized raw footage from a 5dmarkII flight, just so I know what is possible.

    As for balancing everything, after the props (prop hubs too), I do think it is also very important to balance motors. There are different ways to do it, but like the props, it involves adding weight to one side or the other to minimize vibrations. Here's a video:


    There is a Vibration iphone app some people use, but I just spin up my motors on the boom arms with the props off and lightly touch them with my fingers to feel vibration variations between the motors. Easy to determine the ones that need work. The best ones feel like they are not even spinning. Then just trial and error add small pieces of metal tape to one side of the motor, re-spin, and repeat until you find a combination that minimizes vibes. Then there's the ziptie method...

    whole bunch of links on the topic here:
    http://www.rcgroups.com/forums/showthread.php?t=1617156

    And then to take it one step further, after you've done all that, you can balance the prop to the motor. This is dynamic balancing. Tighten the prop down, spool up the motor to hover speed, measure vibration, then shut it down, clock the prop 45 degrees, and repeat, incrementally - basically testing to find the optimal position for the prop on the motor regarding minimum vibration.
     
  3. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Bryan,
    Here is a video showing raw footage from my copter. No post. This also was the first time I have flown solo running both copter and camera (I hate flying that way btw haha)

    THis was shot on a 5DMKII with 20mm lens WITHOUT the use of image stabilization on the lens.


    Josh
     
  4. Dan Coplan

    Dan Coplan Member

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    Josh - that looks really good! I would be psyched if I could get those kinds of results out of my T2i (may as well be a 5D). Any tips or tricks for the stability you managed to get in that video? Actually, I think my only problem is with the Radians and I'm otherwise in good shape.

    Poll: How many of you are flying strictly line-of-sight vs FPV? I've never flown FPV but after seeing some videos online, I'm getting pretty excited about it.

    Dan
     
  5. Brad McGiveron

    Brad McGiveron Active Member

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    Yup footage that isn't camera stabilized (Boss etc) in most cases has to be stabilized in post to some degree. Some IS lenses have just about as good results but mainly to a lesser degree. In most cases a two axis mount will yield better results as far as the roll and tilt are concerned.
    When not out working a gig I test A LOT and with just about everything I can get my hands on and I can safely say there is no perfect solution in this price range... only degrees of success. This is why some folks jumping into this at a RTF level are having mixed results and lowered expectations due to the fact there is so much tweaking to get 2% better. Lets not even start talking about wind!

    Bryan... I don't think your going to find much that is actually raw. There is no magic setting that delivers Zenmuse quality on a larger form factor unless it is direct driven full size helicopter grade stuff.
    Kopterworx don't have that special formula... they do however have Premiere.:rolleyes:

    This was stuff I posted a few months ago. Stock CS8 no Stab and no IS lens. Also zero wind.
    Similar results to Josh's. Make sure you download folks Vimeo flying shots. It looks much more like it should.



    This is similar but different machine and again no wind. No IS lens.



    This with IS lens and select shots. There are a few moments not shown that were less than ideal. The smoothest footage I have got by a long stretch, with the 5d3 and 360 gimbal. Zero wind.



    I would love someone to post up the raw smooth footage on 5D2/3 that makes us awe inspired. I'll be upfront gathering notes and asking questions:D

    There is a challenge...
     
  6. Bryan Harvey

    Bryan Harvey Member

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    Brad and Josh,
    Thanks! This is great to have as a reference. Pretty darn smooth...I guess if I flew my 5dMII on a totally windless day I might be a little closer than I thought. I seem to have this jitter that I cant get rid of, but usually flying in 5-10mph.
    What color bumpers are you running with the 5d series camera, and Josh, did you also do a gimbal plate mod like Brad did? Brad, did you notice a big difference in image stability after your gimbal plate mod? Would love to know your Radian gains for the 5d series as well, if you don't mind sharing...

    thanks!

    Bryan
     
  7. Gary Haynes

    Gary Haynes Administrator
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  8. Brad McGiveron

    Brad McGiveron Active Member

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    As Gary mention my settings are in the spreadsheet.:)

    The gimbal plate mod for me is a major improvement with heavier cameras. I will eventually get a square piece of CF and replace the plywood I used but it has worked well and stayed together so I left it.
     
  9. Bryan Harvey

    Bryan Harvey Member

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    Copy that on the spreadsheet. It's just that when people list multiple cameras, I'm not certain which camera their Radian settings pertain to. Or are you not changing the settings for different cameras?
    I think it would be great if there were separate setting entries on the spreadsheet for each camera flown.

    Brad, why not just buy another gimbal plate and bolt them together, making it double the thickness? You're thinking a structural advantage to a big square piece of CF?
     
  10. Josh Lambeth

    Josh Lambeth Well-Known Member

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    That video was running all BLACK o-rings that Tabb sent me to try out. I did not have an extra gimbal plate at that time but I do now.

    Ill post a quick RAW video from a very windy day... only difference is the lens does have IS. BUT it's still really really good for how dang windy it was...

    Josh
     
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  11. Brad McGiveron

    Brad McGiveron Active Member

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    Ya the double works for sure... I think there is even more with a square because each arm of the star is attached to another on each side, if you get what I mean. Probably a circle would be best. I didn't have enough extra stuff around to try a circle. The double might be enough for medium camera weights like the 5D. Josh and others who use the double can answer that for sure.

    Yes I will upload my other copter settings but generally the heavier the camera the lower those Radian numbers go. By a little :)
     
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  12. Ryan J. Rowe

    Ryan J. Rowe Member

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    I'm still begging my CS8 for buttery footage with the 5dm2 as well. The CX760 with BOSS is almost a gimmie, but would rather use the 5d. I did more testing today and will do the stiffer plate mods that everyone seems to like along with the black o-rings. One small thing that did help was tying the copter booms to the gimbal very tightly. This in a sense stiffened up the plate by not allowing it to flex. I fly solo with 3-axis tho so this obviously won't work for everyone.
     
  13. Dan Coplan

    Dan Coplan Member

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    Can someone point me to whatever thread describes Brad's gimbal plate mod? Thanks.

    Dan
     
  14. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Here's my video of my windy flight... accidentally posted it in the wrong thread earlier :rolleyes:



    Josh
     
  15. Ryan J. Rowe

    Ryan J. Rowe Member

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    Hey Dan,

    I think this is what you're looking for. Scroll down and you'll see his plate mod.
    http://forum.freeflysystems.com/index.php?threads/roll-shake.302/page-4

    Also here is another great but expensive way to stiffen up the plate from Quadrocopter.
    Go to 3:20 in the video to see it.


    : ) Ryan
     
  16. Bryan Harvey

    Bryan Harvey Member

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  17. Bryan Harvey

    Bryan Harvey Member

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  18. Brad McGiveron

    Brad McGiveron Active Member

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    Nice one Josh!
     
  19. Ryan J. Rowe

    Ryan J. Rowe Member

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    Hey Josh,

    Thanks for posting that. Was this windy flight before or after stiffening up the gimbal plate?
     
  20. Josh Lambeth

    Josh Lambeth Well-Known Member

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    This was after.
     

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