roll shake

Discussion in 'Radian' started by JY Air, Oct 17, 2012.

  1. Philip Ellerbroek

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    Forum,

    I think I may have found the answer to the "roll twitch" or what some are calling roll shake where they see the horizon twitch in the video when the copter changes roll directions.

    My first thought that I was having this occur because I went to a heavier camera and that maybe the gimbal was swaying and causing an issue. I did the o ring replacement and other mods to eliminate the vibrations, but I was still having the roll twitches in my videos. I began to think of all the changes I did around the same time that I switched to the heavier camera because i first noticed this in the video that i took after i switched cameras. Well, the same night that I switched cameras I also upgraded to firmware 1.03.

    As I was looking at the radian software settings tonight, I all of a sudden had a memory that the 1.03 firmware sets each radian deadpan stick setting at 5%.

    Sure enough, my roll radian deadpan was at 5% ! What I'm proposing is that this small amount is causing the roll radian to direct the servo to delay or reduce corrective movement that is necessary to keep the camera level with the horizon. Since this deadpan adjustment is reduced, the servo is slower to correct when it does, it causing a "twitch".

    I nearly sure that all previous firmwares had no built in deadpan nor were you able to make adjustments. This is one of the great features of version 1.03, but for tilt and pan only!



    It's raining here, but if you are struggling with roll twitch, particularly when quickly changing the directions of roll, could you check your roll radian deadpan settings and If they are anything but 0%, would upon film a before and then after to see if this is correct?

    Phil
     
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  2. Howard Dapp

    Howard Dapp Active Member

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    Phil, looking forward to seeing your results.
     
  3. Philip Ellerbroek

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    Rain all day/weekend. Your initial thoughts?
     
  4. Brad Meier

    Brad Meier Active Member
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    Philip,

    From what I've seen in previous threads by searching "deadband", that setting seems to adjust the dead area around the stick position before input will be given to the servo by the Radian. Now that's great and all for tilt and pan but with most of our systems roll cannot be controlled by camera op stick movements. I wonder if that would have any affect on the Radian. It's a good theory that it could be influencing the Radian
     
  5. Brad McGiveron

    Brad McGiveron Active Member

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    Philip... if its deadband you are talking about? Then Brad is right. I didn't notice deadpan anywhere.
     
  6. Philip Ellerbroek

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    Hahah! It was really late when i posted. I meant deadband settings within the Radian calibration software. I'll do some flying and screen shots showing the software so people can see the location of the deadband adjustments.

    Phil
     
  7. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Phil,
    I am also wanting to try this... but since we both live in the same place... well we both have the same issue... also my copter is still torn apart from my last trip... Maybe I'll build it today and find a big warehouse to fly in. :D

    josh
     
  8. Brad Meier

    Brad Meier Active Member
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    I did a test at 0 and at 50 with no change. Its only able to influence transmitter to Radian and has no affect on the servo to Radian connection. Confirmed with Tabb
     
  9. Philip Ellerbroek

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  10. Brad Meier

    Brad Meier Active Member
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    Phil,

    What are your gains set at for roll and what camera are you lifting? If the roll is slow to respond in turns, that would indicated your gains are set too low. For an exaggerated example set the roll ridiculously low.. Say 20% and see how dampened and slow it responds compared to 130-140%

    I'm currently flying a Canon 7D at 150%. I can get to 190% with not much difference. I believe any shake I do experience comes from servo and belt slop as I don't get it with Radians inactive nor does it change with Radian gains. I recently replaced my roll servo as I had an extra for spares and noticed the shake is greatly reduced.

    Brad
     
  11. Gary Haynes

    Gary Haynes Administrator
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    Maybe this will help with all of the questions on the Radians. Since everyone is in different starting places, different cameras, etc it would be good to fill out this little form then we can all understand what you have for your setup and the settings you are operating.

    Please send the following so that the members can give you the best suggestions on helping you correct the problem:
    Aircraft Type:
    Gimbal Type:
    Camera being carried:
    Radian Type ( 1, 2 , 3 axis)
    Gimbal Power source:
    Gimbal Radio Type:
    Radian Communication Protocol (S.Bus, PPM, PWM, Spektrum)

    Connections: Change these to match your setup
    Roll Sensor:
    Port
    1. GR-24 receiver and power.
    2.
    3. To Tilt sensor
    4. To Roll Servo

    Tilt Sensor:
    Port
    1.
    2.
    3.
    4.

    Pan Sensor:
    Port
    1.
    2.
    3.
    4.

    Symptoms:


    Steps taken to resolve:


    Video of problem:

    Please also do the following:
    a. With the gimbal powered off, connect up the USB and adapter from your PC to the Radian sensor to which you have the receiver connected.
    b. Power on the gimbal and sensors with the transmitter set to the Off mode for the Radian sensors.
    c. Use the Radian software, connect the Radian cable to the Radian sensor connected to your receiver.
    d. Click on the Connect button to connect to the Radian sensor, and check you have a connection.
    e. Click on the Read button.
    f. Take a screen shot of the Diagnostic and Configuration windows and post it to this thread with your response to Question 1 above.
    g. Then connect up to the other two Radian sensors in turn, do a Read, and take a screen shot of the Diagnostic Window and Configuration Window and post those screen shots too.
     
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  12. Brad McGiveron

    Brad McGiveron Active Member

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    I personally think it would be helpful if freefly would post visually what can be expected from the Radians in the tutorial section so that people with issues can say "mine is looking like this or doing this compared to freefly's". I mean no "post" and no "best of" and just a full clean flight... because there's so little "approved" footage on the website, that for some it's hard to gauge where their setup stands between initial expectations after purchase. Some people are genuinely having issues and others who might be expecting more than they are going to get.
     
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  13. kjetil tønnesen

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    hello
    i have now balanced everthing one more time to see if a get rid off the mini twitch on the roll axe ,and i think it´s really good now:)
    roll gain 125
    tilt 150

    cinestar 8
    360 gimble
    radians 1-2-3axe
    13x6,5 carbon props
    sony hdr-cx730 camera



    what do you think?
     
  14. Brad McGiveron

    Brad McGiveron Active Member

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    Looks real good!
    I would expect the cx730 and other new consumer cameras with that optical stabilization to be very smooth.
    It would be interesting to see how it looks without the camera stabilization going? Or if that is without, it is indeed very nice!
     
  15. kjetil tønnesen

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    thanks when the rain has stopped i shall take a fligt without the camera stab and see how it looks

    that was a interesting idea:)
    i will post video her
     
  16. Philip Ellerbroek

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    Brad,

    I broke down and ordered a new servo after reading this post. What would you contribute the issue too? Stripped gears perhaps?

    Phil
     
  17. Philip Ellerbroek

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    Brad,

    I tried roll gains in increments of 15, starting at 80, all the way up to 175. Once I broke 145, I saw noticeable vibrations. Also, no of these settings eliminated the roll twitch I was experiencing.

    Phil
     
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  18. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Phil,
    Can you post a RAW video of the roll twitch? I want to see if it's the same as mine. Thanks.

    Josh
     
  19. Philip Ellerbroek

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    Josh


    Sure! I'll see if I have the footage , otherwise I'll try to get a flight in ASAP.
    Have you swapped out your roll servo? That's my next step.

    Phil
     
  20. Brad Meier

    Brad Meier Active Member
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    My old roll servo seemed to have a little more play so I swapped it out. I did some dissecting and found one of the larger gears to have some slop...

    Phil, id say install the new servo and make sure the belt is tight and you should see some improvement.
     

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