Pan Troubles of another kind...

Discussion in '3 Axis Gimbal' started by Scott Loeschner, Nov 29, 2012.

  1. Scott Loeschner

    Scott Loeschner New Member

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    Has anyone had their 3 axis gimbal continuously pan? I cannot get my camera mount to sit still. As soon as I hook the power up to the camera mount, it starts to pan to the left at a rate of about 4 degrees/sec, or about a full rotation every 90-120 seconds. It seems to slow down a little, but only after a long while... 15-20 minutes of being powered up. I use a DX-8 to operate the camera mount, and I am able to go into the sub-trim settings to get it to sit still. However, if I do that, I am only able to pan to the left at about 1/10 of the normal rate (way too slow for all practicality), and the pan to the right still operates normally.

    Any suggestions?

    Thanks!

    Scott
     
  2. John Cunningham

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    Scott, are you just using a 360 degree modified servo direct from the Rx ?.

    Your problem sounds like it might be the resistors (or internal pot if it is mechaincally disconnected and still used) is not balanced so that the null point of movement is not at the servo pulse centre point.
     
  3. Josh Lambeth

    Josh Lambeth Well-Known Member

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    He is using a secondary MK FC to operate his gimbal so everything is plugged into that..

    Josh
     
  4. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Can you post a screen image of how the FC board is set up -- specifically the Camera window in MK Tool, and also provide details of how the various servos are connected to the second MK FC board, Scott?

    Thanks
    Andy
     
  5. Scott Loeschner

    Scott Loeschner New Member

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    Thanks Andy. I'm away from my copter for a few days right now, so it might take me a little while to get back with this stuff.

    Also, I'm still new to all of this... I'll have to do some research over the next couple of days to see what you mean by a the Camera window in MK Tool, servo connections, etc.

    I appreciate your help! Up until now, I haven't had a hiccup with my system. Everything has been working great since it was built. Maybe I should just upgrade to the Radian to save the trouble :)
     
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    MK Tool communicates from a PC to the MK Boards. If you switch it to expert view, it will show a series of buttons across the top. One of them is for the Flight Control Board's settings for camera control -- which is implicated by virtue of the problems that you are having, so I thought it would be a good place to start checking things.

    Post it when you get a chance....no rush from my point of view!
    Andy.
     
  7. Scott Loeschner

    Scott Loeschner New Member

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    Thanks for that, Andy!

    On a similar note, I just want to say how impressed I am with this community. It's amazing how much people are willing to help out... especially the help for the newbies, like me. Hopefully I will be able to return the favor some day!

    Scott
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    You'll soon transition from being a newbie to an oldbie.... (if there is such a word -- I guess there is now....)

    Andy.
     
  9. Scott Loeschner

    Scott Loeschner New Member

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    Here is the camera settings. I messed around with the compensation values a bit, but they did not affect the gimbal's persistent rotation.

    image.jpg
     
  10. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Scott:
    Thanks for the image -- sorry for the delay in replying...your response didn't seem to trigger an email alert to me. Not sure why.

    As to the Camera setup, it raises one question: Can you check the Easy Setup window -- have you got that set to Octo2 for the Mixer? I can see from the Camera setup what appears to be a quadcopter (which is the default setting).
    If you can post an image of the Easy Setup, I can check those settings.

    It would also be good if you can describe how each of the three servos are connected to the FC board you're using for gimbal control.

    Thanks
    Andy.
     
  11. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Andy,
    This is a second FC that is not actually flying the copter. It's only purpose is to run the gimbal.

    The servos are plugged in according to this diagram:
    [​IMG]
    Servo3 controls the 360* pan servo.

    Josh
     
  12. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Oh, right....sorry....I didn't go back to the front of the thread (being lazy as I was accessing the forum on an iPhone!) :rolleyes:

    Even so, I noticed where the "front of copter" is in the lower right hand corner of the Camera screen capture. Is that correctly pointing to where the front of the aircraft is?

    @Josh: It sounds like you have either seen this set-up or have talked it through with Scoot -- is your take that everything is set up as it should be? If so, then I wonder whether the likely culprit might be the DX8 and the way it's set up?

    Andy.
     
  13. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Andy,
    I was the one who helped Scott build his copter. Everything on his gimbal is setup the same as mine was which worked well.
     
  14. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Scott: Did you check the terms of the Lambeth WorldWide Warranty? ;)
    Or is it the "30 seconds or 30 yards whichever occurs first" kind of warranty?

    That aside, the choices appear to be:

    1. The Flight Control board is bad.
    2. The pan servo is bad.

    You can eliminate #2 by swapping either the tilt or roll servo with the pan servo.
    I also would double check the setup on the DX8 just to be sure that everything is set symmetrically in terms of expo, servo ranges, etc. -- I suggest this more to eliminate the possibility that it's the DX8 -- in which case, it then points the finger back at the Flight Control board.

    Andy.
     
  15. Josh Lambeth

    Josh Lambeth Well-Known Member

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    We think it's something to do with the controller settings... He is in SD, CA so I can't look at it. Next time he is in Phoenix I will be taking a look at it if he hasn't gotten it fixed before then.

    Josh
     
  16. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Scott: Based on what Josh is saying, you might want to make an note of the Channels/Camera settings and then click on the red triangle with the exclamation mark at the bottom of the Camera window -- this resets everything back to their default settings. Write that out to the FC board. Then make your custom settings in Channels/Camera and write those out.

    See if that helps.
    Andy.
     
  17. Scott Loeschner

    Scott Loeschner New Member

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    Thanks for filling in, Josh... and for all of the help, Andy. Somehow, I am don't receive emails for this thread anymore.

    My gimbal was working fine when it was setup. I haven't changed a thing with ANY of the settings before this little bug showed up.... DX-8 or in MK Tool. It has been working fine for multiple flights. I'm not sure when it started to happen, but it was working fine to begin with. When I get back to town, I'll swap out the servos to see if that's the problem.

    What's strange is that the camera mount stops panning on its own after about 15 minutes of power. It seems to slowly lose steam after a while.
     
  18. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Scott:

    Ah, well, then it's obvious, innit? The Flight Control board has become sentient, wants to show off, but after 15 minutes of twirling back and forth without any praise or positive feedback, it gets bored and loses interest..... ;)
    --
    Alternatively, something somewhere has failed as only electronics can do. My hunch is that the FC board is telegraphing (in no uncertain terms) that it would rather not be a Flight Control board. Sigh. They're not cheap....but try servo swapping first when you get a chance and let us know what you find.

    Andy.
     
  19. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Scott when are you coming back to Phoenix? I have a spare FC we can try out also.

    Josh
     
  20. Scott Loeschner

    Scott Loeschner New Member

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    So... I swapped the servos and I still have the same problem. The gimbal still rotates. On the plus side, I know it's not the servo. But I don't know where to go from here.... should I try a different FC board?
     

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