I killed a Freefly servo

Discussion in 'Camera Mount Misc' started by Nick Wolcott, Dec 2, 2012.

  1. Nick Wolcott

    Nick Wolcott Member

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    The servo for my roll axis stopped working. It now has way more resistance than it used to. It didn't sustain any trauma that I know of. It was working fine, I packed it into the backcountry in a backpack and when I reassembled my Cinestar it didn't work. The Radian is supplying it power, I plugged in an old Savox servo and that fired up. Any ideas on what may have happened? Is there any hope for it? Can it be repaired or should I get a new one? It's not that old it has just a handful of hours of use.
     
  2. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Nick:

    I would take it apart and see whether something bad has happened inside. I fried one in an arboreal encounter (it kept trying to keep the gimbal level when it should have been trying to tilt the tree ;)), so there's a small black mark on the insulating paper where a small IC fried itself. You can easily get to the top part and check the gears too.

    I suspect you'll need to get a new one, but keep the old one for spare parts.

    Andy.
     
  3. Nick Wolcott

    Nick Wolcott Member

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    Hey Andy,

    Thanks for the quick reply. I dissected the servo, I didn't see any fry marks and checked out the gear box, the gears spin fine until I reassemble, now it's completely locked up. So if it wasn't broken before it definitely is now. Ha. I'll order a new one.
    How'd you end up in a tree? Just curious, it's something I'd like to avoid.
    Also, what's up with the user name change? Am I OK or should I add a space?
     
  4. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hey Nick: So you broke it? <evil grin>
    Hmm. That doesn't seem quite right that it should lock up completely. Did you try rotating the gears when you had the top cover off? It's almost as though the bearing's seized up, or one of the gear shafts is dislocated. Weird.

    Yeah. I'm afraid that's the only way out now. The electronics are probably still good, so you might want to hang on to it.

    This tree jumped out into the flight path, ya see.....
    Oh.
    Not buying that, eh?

    I was flying on a demolition site (actually they were demolishing a dam on the White Salmon River in Washington State) and unbeknownst to me, the beta Radian tilt servo (which was stuck on with double sided tape) was coming unstuck -- I'd knocked it off the previous day and stuck it back on and I thought it was secure.

    I think the dust from the demolition site had inflitrated the double sided tape too. Anyway, sensor came off in flight, camera started waggling like crazy. Cinestar started waggling like crazy. I got the bird back to the landing zone, but just could not control it -- I'm a crap pilot when it comes to copters and "recovering from unusual attitudes" (as they called when I got my full sized self-launching sailplane rating in the UK) so the C8 ended up yawing like crazy and flew into a tree. Which sounds bad, but the construction side was littered with huge concrete blocks, 30 ton chunks of steel culvert etc. The good news is that if you have choice between concrete or a tree, pick the tree. Busted props. Soiled underwear. And one fried servo. That was it. 5D Mk III and (cough) rented lens were completely unharmed. The boom clamps on the C8 absorbed energy by shifting around the booms rather than breaking anything. Genius design!

    See the thread here for the explanation. The spambots were creating lots of fake user accounts and it was impossible to tell which were real and which were not. So, given that this board has thus far shown an unusually high level of professionalism (kudos to all of the members!), one of the solutions to the problem was to ask folks to use their real names -- then we can more easily tell spambot from human. Hugh has also added some "IQ tests" to try and discern spambot/human. I've not taken those tests as I'm concerned that I would fail.

    If you don't mind changing your name from nickwolcott to Nick Wolcott, that would be preferable....

    Andy.
     
  5. Nick Wolcott

    Nick Wolcott Member

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    Yeah it's strange the gears spin fine until I close the box, you might be onto something with a gear shaft being out of place.
    Sorry to hear about the mishap, glad it wasn't catastrophic, like at the bottom of White Salmon. I imagine you've programmed a mode-off switch now. Checking my Radians are secure.
    I was filming at that site just a couple weeks ago sans dam. funny.
     
  6. SteveWilson

    SteveWilson Member

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    That's very interesting Nick. My roll servo appears to have died the other day as well. No trauma. Same symptom of high resistance to rotation.
     
  7. Nick Wolcott

    Nick Wolcott Member

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    Steve- That is interesting. When did you notice that it died? What were you doing?
    Andy- I was just told my user name is already taken, I think my old name is too similar to my new name, or somebody is pretending to be me?
     
  8. SteveWilson

    SteveWilson Member

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    It's a back-up gimbal with very low time, I was setting it up to use a new Sony Camera we are trying out - a little CX580V. So it wasn't even flown between being good and going bad, just time on the ground idling. Friday I plugged the Sony zoom into the Tilt AUX and balanced the camera on the gimbal, etc and everything was fine. I fired it up yesterday just to make sure everything was good before heading out to fly and I get a fast orange light flashing on Roll. I checked it over and noticed the very high resistance then.

    For what's worth, I power it with 5.0v off a Castle BEC.
     
  9. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Oh. Let me work the problem.
    Andy.
     
  10. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    This is very high resistance when the Radian sensor and servo is powered off, right, Steve?
     
  11. SteveWilson

    SteveWilson Member

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    Right.
     
  12. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hmm. That really does suggest a bearing/gear misalignment if every spins fine with the case open....

    I've learned a lot since then. ;)
    The other thing worth observing -- and it may sound obvious is that human vision just doesn't work well when it comes to distance perception at distances more than a few yards away. So I really need to learn to fly using an FPV display (not goggles) so that I don't overshoot into distant trees (which accounts for tree #2).

    But you're right: Be sure to add a mode switch -- and use it -- I had a mode switch on the camera op's TX but forgot to ensure he'd switched the mode to Off. My mistake.

    Andy
     
  13. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    OK. Thinking. I'll ask Tabb if he's got any ideas.

    Andy.
     
  14. Nick Wolcott

    Nick Wolcott Member

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    Andy- You're right about depth perception, it's really difficult, especially when it comes to wires, wires scare the hell out of me. I recently rigged up my monitor to a backpack so I can be mobile with it and spin around and such, it looks goofy but I really like it.
     
  15. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Wires are indeed scary but they don't leap out at you like trees do! :rolleyes:

    I've now got two FPV cameras on boom #1 -- one looking forward and slightly down, and the other looking straight down, with a video switch on my TX so I can change views quickly. I just wish there was a good HD FPV system that also has an OSD....maybe there is one now?

    Andy.
     
  16. Nick Wolcott

    Nick Wolcott Member

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    Andy I made you a little vid of the gears spinning in case you didn't believe me.
    Do mind sharing how you wired the switch to change cameras?
     
  17. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Oh, I believe you Nick! I'm just puzzled as to what it could be....

    The two FPV cameras feed into this two way video switch, then into a Smart Electronics On Screen Display and then to the Lawmate 1.2Ghz video downlink.

    Edit: I just realized I didn't answer your wiring question. Here are the instructions for the switch.

    Andy.
     
  18. Steve Maller

    Steve Maller UAV Grief Counselor

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    Must scribble that down under "Andy's Axioms".
     
  19. Gary Haynes

    Gary Haynes Administrator
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    I use the DPCAV switch and it toggles between my FPV view which also shows the OSD data and my HDMI board. I never did get the OSD overlay on the HDMI side to work well so don't route that into the HDMI side. Image overlay was really bad, fuzzy, etc and didn't feel like trying to adjust that only to have issues with my FPV view.
     
  20. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Whose OSD board are you using Gary? I've been looking and hoping for an HD FPV (as a pilot of full size aircraft it's my dream form of FPV). But I've not seen anyone with such a working system that I felt comfortable buying....

    Andy.


    @Steve: I think the axiom should perhaps be restated: "When it comes to copters, trees beat concrete any day."
     

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