Disconnect Motors During Setup!!!!! (WARNING: GRAPHIC!)

3689424243?profile=originalNow let me start off with YES I have read the manual where they state millions of times disconnect the motors, or take off the props whenever you are making certain changes.


I would consider myself well-versed with the entire APM, but I have chosen in the past to not get into the discussions on the forums, which is likely to change.


So I haven't had any problems with the motors spinning up AT ALL during the initial setup phase for any of the distributions. I have been flying and setting up this quad since early July of this year, and trust me, I'm absolutely hooked. Today, however, was an entirely different story. I was having some problems with ALT_HOLD pulsing in the most recent release, so figured might as well test out 2.0.42 and see how that faired for me.


I loaded the code for 2.0.42 (through the arduino software, which I have lots of experience doing with other arduino projects in the past) and then opened GCS in order to do the initial setup of my Quad. Reset the thing fine, and moved onto my controller calibration (neglecting to take off the props, or disconnect the motors).


Here I pressed calibrate, and tried calibrating my radio, but nothing was showing up, weird. Hit save, and realized my controller was off, turned that on, and before I could even blink I heard the whirl of my quad taking off at 100% throttle. Still connected to my computer via USB, and without direction from me. Without even looking I reached my hand out to prevent liftoff, and, well, too late.


It took off in my living-room, tore through my hand, across my laptop, and ultimately smashed into the couch, still running.


Now keep in mind this was a custom build of mine (The original Aeroquad frame directions) with 350w 910kv Motors. A little overpowered to begin with:




So here are the results of me attempting to stop my quad from taking off in my living-room (WARNING: GRAPHIC):






This one sure goes down in my own record books as my most expensive whoops so far.

New MBP Screen

New MBP Keyboard

One Motor, 2 Props

Frame looks okay

APM Board got caught in my bloody crossfire, but cleaned it and should function fine.

12 Stitches and 3 hours in the hospital! Woooo!

Thankfully no tendon damage, but you can see a small portion of it on the left side of that open wound :)


So what did I learn from this:

Clearly my quad is not an indoor flyer

RTFM and Listen to it!

And props HURT.......BADLY

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  • Thanks everyone for the support! Today my hand feels much better, but I was instructed to not remove the gauze until later tonight.


    After a couple of quick fixes, my quad is back up and flying on 2.0.42! Now time to get my ALT_HOLD tuned properly!


    Thanks again everyone! I really appreciate the support!

  • good to know

  • Hope u didn't have any tendon injuries, and recover soon.
  • Thanks for posting.  I find it thoughtful of you to share your misfortune with us as a safety reminder.  Hope you heal up well.

  • Distributor

    Jordan, I have to say you're not alone, I'm guilty of not removing the props, and I got a little
    "bite" once!

    I now don't connect the LiPo in these stages, I use a 5 volt battery pack to power RC system and USB power for the APM, no power to the motors / ESC's any more unless I'm outside and ready to fly.

    I hope you make a swift recovery & we all learn the lesson from your experience!




  • Developer

    Yikes. wish I hadn't clicked that! 

    RC hasn't put me in the hospital yet, but Snowboarding has three times. Sometimes the most dangerous things are the most fun.

    But, Yes, disconnecting the signal to the ESCs is a great way to stop them from spinning up. I'm religious about it. 

    Also, those APC props are especially dangerous compared to the breakaway props I use. 


  • 3D Robotics

    Jordan hope you get better, like Sam said, I know what that feels like. I got something like 55+ stitches on 4 fingers :S  I still dont have all feeling back on a couple of them, but I can use them all :D. Since then, no props inside or when Im doing anything other than actually flying the quad.

  • Moderator

    Good post. Hopefully this will save someone else from a similar or worse injury, it is a very worth thing to do, sharing this. It may well be me, as I have been more and more cavalier about spinning props. Thank you.

  • Yep, safety first. Thanks for posting, Jordan, this is a very good reminder. I had the same accident a few years ago. My finger was hurt by nitro engine prop. It was really painfully.

    I hope you recover soon.

  • Ouch, sorry to hear that, but seriously thanks for posting the wound picture. I've seen many wounds from 450-size collective pitch helicopters, but never from a quad. Not as bad, but definitely not something you want to happen. A good reminder about safety.

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