My number came up yesterday (crash!)

Discussion in 'Cinestar 8' started by Steve Maller, Oct 20, 2014.

  1. Steve Maller

    Steve Maller UAV Grief Counselor

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    My KDE motors are due back today or tomorrow (love those guys!), but I'm in the middle of a busy streak with photo/video shoots back to back to back so it'll probably be a couple weeks before I can get Humpty Dumpty back together again. I'll keep y'all posted.
     
  2. Steve Maller

    Steve Maller UAV Grief Counselor

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    Well, I now have my replacement parts (a couple new booms, new props, etc.) and I'm going to start putting Humpty Dumpty back together again. I decided that while she was all apart I'd update all the firmwares (and check that the power distro board and BLs were not damaged). Everything checked out, and now my boards are all updated. I also discovered a nearly severed pigtail coming from one of the BL pads and replaced it. It must have been cut by the CF boom that shattered in the crash.

    I ran motor tests and everything checks out. Unfortunately, I'm doing wall-to-wall photoshoots over the next two weeks, so this is as far as I can go right now. But it's good to know that once I have a day I can get her re-assembled and in the air! :)

    IMG_1197.jpg
     
  3. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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  4. Dave King

    Dave King Well-Known Member

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    Steve I recommend soldering the bullets to the board. It's super solid.
     
  5. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Isn't there a risk that any physical tweaking on the motor wires (e.g. a crash) will then pry the bullets and the pads away from the board (thus trashing the Double Quadro board), Dave? With pigtail wires, the bullet connectors become a "weak link" that should separate before damaging the board.

    I was searching to try and find out what MK recommends -- did you have any contact with Holger/Ingo that guided you towards soldering the bullets directly onto the board?

    Andy.
     
  6. Steve Maller

    Steve Maller UAV Grief Counselor

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    I'm with Andy. I like the added flexibility. In the case of this crash, that might have saved the PDB from damage.
     
  7. Dave King

    Dave King Well-Known Member

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    MK had several promo pictures that showed they added the connectors to the pads. If done right there should be absolutely no difference between having the bullets on the pads versus not as far as the motor wires pulling on the connectors. These pads are extremely robust and even the board that caught on fire had the pads intact. It does take a while to solder them to the boards because of the size and shape of the connector. I spend a lot of time laying out each wire so that it has absolutely no stress on the connector or pad and that it doesn't push or pull.
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Dave: Interesting re: the promo pictures. I must be searching using the wrong keywords because I couldn't find any.

    What I did was email Ingo (as Holger's still on vacation). His answer is that it's really a personal choice -- he did observe that each connection is another potential point of failure so there is an additional risk of failure with the pig-tail wires.

    Personally, I think I'll stick with the pigtail wires just for the mechanical reasons as I mentioned.

    Andy.
     
  9. Steve Maller

    Steve Maller UAV Grief Counselor

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    I've seen the photo Dave mentioned. What bothers me about that setup is that the mechanical force required to connect and/or disconnect the motor bullets (multiplied by 24) seems likely to eventually dislodge and/or weaken at least one of those connectors. The pigtails, however, are easy to repair/replace if something fails with their connection to the motor leads. So while there is one additional connection for each motor lead (3 per motor), it's a soldered connection that's not prone to much (if any) mechanical stress, except in the case of a severe crash, in which case there are probably greater concerns. :(
     
  10. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Funny you should say that, Steve. I could have sworn I had seen some images with bullet connectors soldered directly on to the pads (maybe they were images of Dave's setup on the forum?).

    I agree with your assessment. Those are large pads and with a suitable soldering iron, you can make a good solid connection to the pad for the pig-tail wire.

    Andy
     
  11. Steve Maller

    Steve Maller UAV Grief Counselor

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    MK did post some photos showing female bullets soldered directly to the pads on the BLs, and I know they support that as an option. I just worry that for those folks who set up and break down their copters often for transport, you risk damaging the board with repeated use.

    The Castle 3mm bullets I use require a pretty decent amount of force to disconnect.
     
  12. Dave King

    Dave King Well-Known Member

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    Not sure how it would be another potential point of failure? Don't see what the difference is between soldering a connector to the versus a wire. It's not adding another connector into the mix you are simply eliminating the pigtail. I have had several pigtail connectors come loose before I started using the 4mm castle creations connectors. Not one issue since I started using the connectors directly to the board.
     
  13. Dave King

    Dave King Well-Known Member

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    \
    IF soldered properly the CC connectors are not going anywhere on the pad. They do take some time to solder them on the boards though. Trying to get them square with the pad is a pain. I use some tape to hold it place and solder around it.
     
  14. Dave King

    Dave King Well-Known Member

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    Same with the CC 4mm bullets.
     
  15. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    I think you may have inverted what I said! :)
    Ingo was pointing out that *with* the pig-tail wire, there was another point of failure: "each connection is another potential point of failure so there is an additional risk of failure with the pig-tail wires."

    Andy.
     
  16. Dave King

    Dave King Well-Known Member

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    Sorry. I invert a lot!
     
  17. Thijm le Grand

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    This happened with soldered bullets to the pads if you have an faulty connection
     

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  18. Steve Maller

    Steve Maller UAV Grief Counselor

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    Oops I meant the 4mm.
     
  19. Wayne Mann

    Wayne Mann Member

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    WOW, I see three pages of post crash investigation with everyone trying to figure out what went wrong with the machine and nothing about what went wrong with the pilot that led him to fly in xxxx conditions at an "EVENT" directly over hundreds if not thousands of people. I find that utterly amazing. This is just as irresponsible as flying a Phantom out over a commercial airport watching jets land underneath you. This is the kind of crap that makes true professionals look really bad and will most likely, ultimately lead to the end of using UAVs for aerial filming. How many times does the expression "No amount of money is worth the risk" have to be repeated. That machine could have just as easily came down in the middle of the crown of runners.

    Sorry for the rant


    Wayne Mann
     
  20. Dave King

    Dave King Well-Known Member

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    Wayne

    I know Steve personally and I know that he values safety, more than most people. Steve is not like some young punk who flies 1000 feet in the air or like flying at an airport. Your comparisons are way out of line. Steve takes extra safety precautions into every flight. He is far from irresponsible, in fact he's one of the most responsible people I know. If every phantom owner was like Steve you wouldn't be seeing the kind of irresponsible cases over and over again that we see.
     

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