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(solved) No response from Futaba T8J VR knob

Discussion in 'Phantom 2 Help' started by GearLoose, May 24, 2014.

  1. GearLoose

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    I'm using a Futaba T8J and Tarot gimbal on a P1.5. Suddenly the gimbal does not tilt -- but when powered on the Tarot does remain level, both in roll and tilt. The gimbal is enabled in the NAZA Assistant but there's no response in the X1 channel, using the VR knob (channel 5) on the Futaba.

    I had also set up switch G to auto-tilt the gimbal. This switch does show a response from the X1 channel in NAZA Assistant but the gimbal doesn't react.

    I'm not sure if this is a Futaba problem or the gimbal??
     
  2. Gizmo3000

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    Re: No response from Futaba T8J VR knob

    If you're seeing activity in the X1 when you rotate the VR knob and/or use the switch G to auto-tilt, and the gimbal is turned on in the NAZA (and things were working, then not..), odds are high that it's either the servo wire to the T pin that might have come loose (possibly inside the Phantom as well?), or something perhaps changed in the Tarot software. (you're running v1.4 or more I presume on the Tarot?). only connected to the F2 and T-pin?

    I believe you can also hook up your computer to the Tarot and monitor if there's RC input.
     
  3. GearLoose

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    Re: No response from Futaba T8J VR knob

    Thanks, Gizmo -- the servo wire to the gimbal pin appears to be ok. I wonder if it is possible to detect a signal on that connector, to avoid having to open the shell?

    I haven't attempted to use or upgrade the Tarot software for a long time. I have VMWare with Win XP2 and was never able to get a stable connection to the Tarot software. Perhaps I'd better try that again....

    Any further clues on how to hook the Tarot to a computer to check RC output? I hadn't heard that suggestion before.



     
  4. GearLoose

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    This turned out to be a genuine head-scratcher involving compounded errors.

    First of all, I discovered that the tiny Radio Shack switch I'd used on the gimbal power leads was bad. I not only had a cold solder joint on one lead but the switch failed internally.

    I connected power directly to the gimbal but it still didn't respond to the VR knob, though it did hold the camera level when manipulating the Phantom.

    Next: opened the shell and ran a new servo lead to the "T" pin on the gimbal board.

    No joy....

    Replaced the little board on the back of the gimbal as I just happened to have an extra.

    No joy....

    Disassembled the gimbal and prepared to replace the entire board. That's when I noticed that I'd connected the servo lead to the wrong pin on the board, the pin opposite of the correct "T" pin. This mistake was actually made earlier, before I discovered the problem with the gimbal switch, so in changing servo leads I'd continued to reconnect to the wrong pin.

    The gimbal now works just fine.