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Radian Stabilize help please

Discussion in '3 Axis Gimbal' started by Kirk Williams, May 14, 2014.

  1. Kirk Williams

    Kirk Williams New Member

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    Hey Guys,
    Trying to get the best I can out of this radian while my bank account replenishes itself enough to get a brushless setup. But--- for now, here's what I'm working with. Any help to get better stability is greatly appreciated.

    Aircraft Type: CS8
    Gimbal: 3 axis radian
    Power: 1200mah
    Radio: Graupner MX-12 HOT
    Communication; Believe it's a PPM but radian software has S.Bus checked??

    Roll Sensor:
    1. Input from PAN
    2.
    3. Out to Tilt
    4. Roll Servo

    Tilt Senor:
    1. Input from Roll
    2.
    3.
    4. Tilt Servo

    Pan Sensor:
    1. Input from GR-12
    2.
    3. Out to Roll
    4. Pan servo

    Symptoms: Lack of hair from pulling it out while tuning... but also slight jerkiness and slightly delayed reaction on ROLL axis. Pan is jerky when moving-especially at slower speeds. Tilt has slight jumps i think

    Steps taken: Camera Balanced near perfect, checked belt tension, tried various gain settings on ROLL from 80-130. all looks similar. Added zip-ties to vibration isolators even though i have a GH4 12mm camera (which is pretty light), balanced props, checked motor alignment. Messed with slew rate a bit for camera operator- can't seem to get them smooth (changed expo in MX-12 to help smooth out transitions). Checked for slack in servos-all good.

    NOTE: video is the middle mode (Gimbal on but no camera operator control except for the quick second when it tilts up looking at us)

    Password: Smoother

    THANK YOU

     

    Attached Files:

  2. Tim Joy

    Tim Joy Active Member

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    What servos do you have on it? Have you tried 200Hz instead of 400? What does the video look like with the gimbal off?
     
  3. Gary Haynes

    Gary Haynes Administrator
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    Kirk tuning the Radians to get maximum results entails doing a series of flights. From the point you are now and to isolated the issue do a flight with only one axis powered at a time. Try to do the same flight pattern one after another. Then take a look at the video. Try to isolate which axis is causing vibration. Make changes to one axis, re-fly with that axis and check the video again. Through a methodical testing sequence you should get it down to where on smooth days it is nearly flawless and on windy days is still good but might need 3-5% in something like warp stabilizer.

    Trying to guess which one to adjust when all of them are running, well you may be chasing it for a long time. Also see this spreadsheet. https://docs.google.com/spreadsheet...F2ZXZLQm5zM2hfci1tN1pPdlE&usp=drive_web#gid=0
     
  4. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Kirk: One thing that bit me was that the small hex bolts on top of the servos (that hold the small pulleys on) had started to work loose, so I put some Loctite 222 on them and retightened them up.

    You didn't actually mention it but have you balanced the actual gimbal (not the camera on it), but suspend the gimbal by itself from the center point and make sure it hangs level. The pan axis is best balanced on the copter with the copter rotated so that the booms are in a vertical plane -- then remove the pan belt and ensure that the gimbal can be rotated to any angle and will stay there.

    Apart from that, Gary's right -- one axis at a time...

    Andy.
     
  5. Kirk Williams

    Kirk Williams New Member

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    Awesome! Thank you guys for such a quick response! Sorry I couldn't do the same. Been slammed over here. Going to re-adjust and try your suggestions tomorrow. Will keep you posted.

    -Kirk
     
  6. Kirk Williams

    Kirk Williams New Member

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    Some progress. Does anybody use 200Hz? Should i take the zip ties off the stabilizers?
     
  7. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Kirk: Your questions are both valid and unanswerable, I'm afraid. Well, the answer is: "Try it and see..." Which is as good as unanswerable. :)

    The reason is that you're dealing with a complex mechanical system with so many variables that it's not even funny. As Gary said above, you just need to do a bunch of experiments and only change one thing at a time to avoid confusing yourself and/or masking the effect of whatever it was you just tweaked.

    Andy.
     
  8. Kirk Williams

    Kirk Williams New Member

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    Tis true... Thank you!
    One more question. We balanced the tilt with the camera plate at an angle (quadrocopter said it should be fine as long as the radian matches the lens angle). Any reason not to? Increased vibration? see pic

    Off to the testing fields....
     

    Attached Files:

  9. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    The Radian knows nothing about the camera angle (shhh.....don't tell it). It only knows about its own angle. :)

    Andy.
     
  10. Kirk Williams

    Kirk Williams New Member

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    There's light!!! But one quick question... In PAN mode on the Radian software, the receiver is set to PPL as I use Graupner... But in every other axis the receiver is set to S.BUS and I can't change it? Won't let me check the box. Everything seems to work fine but want to make sure it isn't messing anything up. Idea's??
     
  11. Gary Haynes

    Gary Haynes Administrator
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    Kirk the communication between the Radian's is s.Bus. Only the Radian connected to a receiver has a selection choice available.
     
  12. Kirk Williams

    Kirk Williams New Member

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    Thanks Gary and Andy! Headed to my first paid shoot tomorrow! shhhhh don't tell anyone...

    A couple more questions....

    I'm in the process of learning what to look for with my Cinestar 8. I want to be able to understand how hard the motors are working, temperature, amperage and everything else that is key and making sure the craft stays in the air.

    1. If I have upgraded the flight controller, do I need to erase the old settings on the SD card in the copter? I have never removed it and don't know how to look at and or what to look for with the data. Any tips here are great!

    2. On my Graupner receiver it tells me that amperage coming from the telemetry. At certain times I'm pushing upwards of 68 A (short burst- normally closer to 60A) with a normal cs8 non-heavy lifter w Mikrokopter V2.0 ESC Board. Is that okay? What range should I look for? What exactly is that measuring? I'm not carrying a heavy camera (GH4) but I have two 5000 mA 4s batteries running in parallel.

    3. Where do I go for temperature readings? What is a good temperature range to be flying?

    4. What else do you suggest monitoring closely to make sure everything is operating okay? I will be traveling from San Diego to the high Rockies and flying everywhere in between.

    Thank you very much!


    - Kirk
     
  13. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    I'd recommend that you learn how to use MK_GPXTOOL (just do a Google search) and look at every flight's GPX file so you get to learn what is "normal" and can then more easily see what is not.

    Delete the SETTINGS.INI file from the MicroSD card.


    "Normal" depends on the weight of the copter, but 68A is not unreasonable with a 4S battery. If you break 120A, that's probably bad news -- you might go that high in an emergency climb.

    Again, pretty hard to answer because it depends on ambient air temperatures. But greater than 80C would be questionable.

    You're not going to like this, but monitor everything! Even down to how things look and sound. Many times a failure will "telegraph" long before it happens....well, at least "some time before!"

    Andy.
     
  14. Kirk Williams

    Kirk Williams New Member

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    Thank you much!

    Will do and I've already learned to keep more than a close eye on this thing. ;)

    Will deleting SETTINGS.INI in the micro SD loose all my current settings in MK Tools? Would I need to reload them back to the copter?

    Thanks

    -Kirk
     
  15. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Kirk:
    No. The SETTINGS.INI file is only for parameters like how often the GPX file gets log data written to it. Actually, it's just a plain text file, so you can open it with a text editor and see what it contains.

    Andy.
     

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