Pan Problems

Discussion in 'Radian' started by Bob Wojda, Nov 2, 2012.

  1. Bob Wojda

    Bob Wojda Member

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    My pan module seems to be acting up. It will be working fine and then, with out warning, begin spinning without input from me. To stop it I flip the mode switch and then when I turn it back on I get no response from the pan servo. The tilt and roll work fine. The radian module is flashing and won't go solid. The only way to fix it seems to be unplug the power and restart (hard to do in the air). I've hung it up in the shop and had it do the same thing so I'm wondering if there is a problem in the Radian unit for the pan. Any ideas or anything else I should try?

    Bob Wojda
     
  2. Joe Azzarelli

    Joe Azzarelli Active Member

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    Hey, post some video of spinning without input. ;)
    Just kidding. First thing that comes to mind is not enough power for everything so volts drop and radian goes into automatic confused mode.

    Good luck!

    Joe
     
  3. Bob Wojda

    Bob Wojda Member

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    Could be a voltage issue but I had it happen on (what I think was) a fresh battery in the shop. Do you know what the minimum voltage requirement is for the radian, and what happens to the gimbal in "automatic confused mode" for you?

    Spinning wildly in the air isn't my favorite mode of flying.

    Thanks,
    Bob
     
  4. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Can you connect up the programming cable to the pan module with the C8 suspended and try and capture an image of the state of the diagnostic window when it starts to spin, please Bob. It'll give us an idea of what's going on.

    I find that if I feed the programming cable up from directly under the hub, the cable will twist when the gimbal turns but nothing bad happens beyond that.

    What I'd then try doing is:
    1. Make a note of the current settings in the Pan sensor.
    2. Power the gimbal off.
    3. Power the gimbal back on.
    4. Reset the sensor back to factory defaults by selecting Pan-1 and doing a Write (without any preceding read).

    Then see if it still does it.

    If not, then change the settings away from the defaults as you original had them and do a Write (without a preceding read).

    This will at least determine whether a "factory reset" changes the problem.

    Andy.
     
  5. Bob Wojda

    Bob Wojda Member

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    Andy,

    Nice to hear from you. Good idea on resetting back to factory and trying from there. I will work on it Monday morning and take a few screen grabs as well if it still has issues. Have you seen this kind of reaction if the radian has low voltage? What is low for it?

    Thanks,
    Bob
     
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Bob:
    I'm afraid I've not seen this reaction before. I'm not sure what the voltage has to fall to for the sensor to get confused....I can speculate and say, oh, below 4.5 volts but that's just a guess.

    It would be worth checking to see what the voltage actually is before you change anything....

    Andy
     
  7. John Cunningham

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    Just FYI, the Radian sensor operates normally down to about 3.2 volts. Below this, the IMU sensor may reset and then the system behaviour can be affected.

    The main task is to prevent the voltage spiking below this due to servo load or whatever.

    There is a known issue with firmware 1.02 where the pan axis will be active if the gimbal powered up but with the radio off. If the gimbal is on the ground (not suspended) then it will start to spin as it tries to stabilise.

    This will be fixed in firmware 1.03.
     
  8. Bob Wojda

    Bob Wojda Member

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    So, still having issues with the Pan. Here's what I've checked and done so far: Checked voltage - 5v - looked good. Reloaded firmware 1.02. Set everything back to factory defaults. What's still happening: Occasionally the pan begins spinning without input from me and won't respond. I can switch modes to stop it from spinning but the green light is blinking and I can't get it to solid again. I think that maybe the pan module is losing connection while the servo is engaged and won't come back. The rest of the servos are working as expected. Any ideas on troubleshooting this? I am thinking about swapping servos maybe the pan and roll, reprogramming both of them and seeing what happens?

    Bob
     
  9. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Bob:
    I think swapping the servos is a good place to start.
    If that doesn't change anything, I'd swap the Radian sensors too.

    Andy.
     
  10. Bob Wojda

    Bob Wojda Member

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    Andy,

    Sorry, meant to say I am going to change the Radian modules, which I did. It really seems that there is a problem in that one module as now the tilt is acting up and the Pan is good. I already ordered a new module and will exchange the old one. Hopefully that comes in fast.

    Bob
     
  11. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Bob:
    Understood -- glad you helped narrow it down.

    Andy.
     
  12. Justin John

    Justin John Member

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    I'm having an odd jerk issue with my gimbals. One is brand new and one is 6 months old. Pan and Roll seem to sporadically twitch violently during flights mostly during but not exclusive to 2nd operator input. It does not matter if I'm carrying a RED or a GH3. The gimbals are well balanced and it seems to be happening more frequent. I have to turn the gimbals off then on via 3 position switch to get any input back after the violent and unpredictable movements. When I do get some input back i'm usually battling a constant force in any given direction. They also twitch less violently when the 3 position switch is set to off and the radians are not active.

    I suspect that one of the servos may be toast but its odd that the brand new and the older gimbal are both doing this. What is the best way to test servo health ?

    Any insight on this issue would be greatly appreciated.

    Things i've tried.
    - Switched from DX7 1024 to DX8 (DSMX) - I unchecked the 1024 button in the radian software.
    - Replaced All radians
    - Upgraded radians to 1.03 firmware
    - Replaced BEC
     
  13. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Justin:
    That sounds like you might have an electrical noise problem in the system. Certainly the symptoms are consistent.
    Can you describe the electrical system you have on the gimbal?

    Andy.
     
  14. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Justin: Sorry -- hit Post Reply too soon.

    Do you see this happening on the ground at all? If so can you connect up the Radian software and verify:

    1. There is no corresponding twitch on the channel monitor? (That is, nothing coming from the Rx to trigger the twitch.)
    2. Is the tilt axis also twitching?

    The "probably noise" thought I described above is because more that one Radian sensor is affected -- do they twitch simultaneously or independently?

    Thanks
    Andy.
     

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