I got bit, badly...

[RTRyder]

One of those unforeseeable and ultimately stupid mistakes that could have been avoided, got me a quick trip to the E-R and 40 or so stitches in the side of my right wrist. Had just finished flying my Hoverthings FlipFPV frame with APM2.5 controller and disarmed the motors after landing. I was walking back from the landing zone when I bumped the radio hanging from a neck strap and unknown to me apparently re-arming the motors and shortly thereafter bumping the throttle stick to about midpoint. Graupner props are SHARP and spinning at half throttle it didn't take but a split second before it turned the side of my wrist to hamburger as I was in the process of slamming the quad to the ground to get the motors to stop ( I carry them upside down after flight ) and didn't quite manage to keep the fleshy bits out of harms way.

Lesson learned, ALWAYS disconnect the battery on landing which I hadn't done in this case because the plug was being difficult and not wanting to separate easily, figured I'd take care of it on the bench rather than squatting on the ground, big mistake...

So now I have a bunch of stitches, will have an impressive scar, and have limited use of my right hand for the next two weeks which pretty much means no flying for the duration. That will give me plenty of time to make sure all battery connections come apart easier than this one wanted to as well as setting up a throttle hold switch that will be used while plugging and unplugging batteries, going through this once is more than enough for me.

And no I'm not going to post any pictures, at least not yet, it's just too gory for me to even look at not to mention it's wrapped in surgical dressing for the next couple of days until the doctor opens it up to check on how it's mending.

Stay safe and stay alert, these things can bite!

Ken

 

[Bartman]

Sorry to hear it Ken!

THe good news is maybe we can get our 2013 Flight Control Assessment published soon?

Take care of yourself,
Bart

 

[dr427]

Ouch! Thanks for the story and tip!

 

[hjls3]

wow Ken thanks for sharing. Sorry to read it though. Will learn from your sharing - thanks and take care of yourself.

 

[DucktileMedia]

crap! I guess the beach towel tip only works if you throw it on the heli first. Sorry man. Perhaps it's good that Hoverfly added the annoying beeps for this very reason.

 

[RTRyder]

One other thing I'll be doing, changing the setup on all of my multis so that the motors are spinning while armed on all of them that don't already do it, that way there's no doubt as to what state the flight controller is in. Not that it would have made much difference in this case but in the future I'll know it's disarmed and safe to unplug the battery.

Ken

 

[maxwelltub]

Major bummer man, I got bit by my Trex 500 rotors once while it was spooling down. Its sucks because after you realize how if only you did "X" differently it wouldn't have happend. Wish you a speedy recovery.

 

[DennyR]

Sorry to hear this Ken I hope it heals up soon. I have often seen the heli guys pick up their models and while walking back from the flight line the throttle accidentally gets opened up. That should never happen as they all have a hold switch on the throttle to disarm it. But it does happen and the interesting thing is that although the rotors do have the kinetic energy to do some really serious damage, because the controllers are programmed to slow start the motor no serious damage usually results. Guess we should be looking for that as a regular feature on MR's.

 

[Efliernz]

Not good Ken. Heal quickly

btw - The latest firmware upgrade from Hoverfly makes the board beep continously when armed until over 7% throttle. Stories like this remind us why they chose to do that!

Pete

 

[R_Lefebvre]

Gah! Sorry to hear this Ken.

Have you considered using the external LED on the APM? It works well to give you external indication. All my machines use this. You can also drive a piezo beeper. This one is nice too, for audible indication of arming/disarming.

I use a little dielectric grease on the connectors to help them separate better.

Not to be preachy, but a couple things I try to do:

1) Treat the copter like it's a wild animal anytime it's "live".
2) Never carry the transmitter dangling from a strap. I use a tray, but I try to leave the transmitter set down somewhere if I'm not flying.
3) I use a "throttle hold" type switch. On a MR, it does two things. When "hold", throttle output is zero. When "not hold", throttle output is held up off the bottom range. This does several things. First, prevents arming the copter if the switch is up. This makes "going hot" a two step approach. You have to have it down, then arm, then raise it, then the motors start. There's really no in-between. It also prevents mid-air motor shut-down on APM which can happen accidentally.
4) I strongly prefer to have the APM on a separate battery from the motors. This allows you to boot up, program a mission or whatever you want safely. Carry it around, set it down, then plug in the motor batteries. If for some reason the APM is outputting a throttle signal when you plug in the batts, the ESC's should lock-out and beep at you.

 

[jfro]

Sorry to hear about mishap, but glad the damage wasn't worse...

Probably a stupid question, but after landing and having the throttle down, what happens if you turn your radio off?
Or maybe disarm and then turn radio off?

I am interested, because I might do the same thing if my battery connectors were hard to get apart..... Scarey thought.

 

[Tomstoy2]

Welcome to the 'scar club', buddy!
Happened to me on St. Patrick's day last year. Was doing stuff on my coffee table and pushed the wrong button on my transmitter. You know that button on Futaba radios that says, Servos on/off? Well, never, never just push it to see what it does.
Got both my fore arms and my left leg. My house looks like a crime scene. Spent 8 hours in the emergency room.

Unfortunately, safety is one of those things that we just never seem to talk about enough.

 

[ChrisViperM]

No clever words from my side.....I just wish you a quick recovery and uncomplicated healing process.

All the best

Chris

 

[R_Lefebvre]

Probably a stupid question, but after landing and having the throttle down, what happens if you turn your radio off?

I believe it'll disarm itself.

Or maybe disarm and then turn radio off?

I believe nothing will happen.

But realistically, this all depends on your Rx setup. The APM can only act on the signals it gets. And the signal it gets is dependent on your Rx Failsafe setup. If you have the FS setup as laid out in the wiki, then it should behave as stated. However, if the Rx does something else, then all bets are off.

I'm a little unsure how you could accidentally arm it. I'm more inclined to believe it wasn't disarmed properly? Bumping the throttle up is obviously easy.

 

[kloner]

sorry bro

no scars, no proof.........

get better

 

[RTRyder]

I believe it'll disarm itself.



I believe nothing will happen.

But realistically, this all depends on your Rx setup. The APM can only act on the signals it gets. And the signal it gets is dependent on your Rx Failsafe setup. If you have the FS setup as laid out in the wiki, then it should behave as stated. However, if the Rx does something else, then all bets are off.

I'm a little unsure how you could accidentally arm it. I'm more inclined to believe it wasn't disarmed properly? Bumping the throttle up is obviously easy.

Not all that sure myself how it re-armed but I do know it was disarmed. One thing I always do after disarming is to pop the throttle stick up and back before I even approach the multi, did that with the FlipFPV and no reaction, also looked in to see the LED wasn't indicating armed anymore, it was disarmed. I think what happened is the radio was leaning to the left off the strap and the throttle stick hung up on my jacket so it stayed there long enough to arm the board and the next bump brought the throttle up.

Fortunately the JR11X allows a throttle hold to be setup in both heli and acro mode so I'm going to use it for everything. I'm also going into the sketch on all the multiwii I currently have flying and comment out the motor stop so they spin as soon as it's armed, most of the rest already do that, MK, DJI WKM and Naza...

All it takes is that one time you DON'T do something you should, like unplug the battery before picking it up, to cause havoc, won't be happening again on any of my equipment.

Ken

 

[DucktileMedia]

Do you think these would interfere with my tx signal?

View attachment 10131

 

[mitmit]

chicks dig scars) get well!

 

[Benjamin Rowland]

Ken, sorry to hear it man. Hope you heal quickly. Thanks for sharing the story though as it is a good reminder for us all.

 

[JZSlenker]

Ouch, I hope you heal quickly. I think at some point you should try to take some pictures and post them. I think it's important. Some people actually want HF to remove the new beeping while armed feature. :upset: Safety should always be our first concern. The pictures might convince others to be as careful as possible.