Never had this happen before!

[RTRyder]

In the years I've been flying multirotors I've had a lot of weird things happen while flying but this is a first. Charged up a battery and went outside for a little night flying with a Multiwii Quad, cold out there but no wind and otherwise perfect conditions for flying. About a minute and a half into the flight I notice what I first thought was frosty air being blown down by the props followed by an OH S**T! as FLAMES appeared about half way down the left front arm! The frosty air was actually smoke :surprise:


Fortunately it wasn't far away so I brought it back as quickly as I could and landed then grabbed the battery leads and killed the power. The cause? The LED strip under that arm caught on fire...

As I said, I've had a lot of weird things happen while flying but seeing the left front arm burst into flames is definitely a first. Odd thing is this quad has a bunch of hours on it with these LEDs having been on there for most of them, no idea why it just all of a sudden decided to flame up


Ken

 

[Bartman]

gnarly.

 

[hjls3]

wow, any chance of some snow getting to it on the ground and causing this to happen? all in all though - great save!

 

[Benjamin Rowland]

Dang. Now my LEDs are making me nervous. Let us know when you figure this one out. Voltage issue maybe? Just throwing out a guess.

 

[RTRyder]

I doubt that I'll find a cause, it's all charcoal now and no way to determine what happened. It certainly wasn't snow or water, the LEDs are encased in clear shrink tubing with no way for water to get in there short of landing in a pond. Ive put an aerobatic quad in a stream before but never tried to water land this one. Matter of fact without the shrink tubing it might not have been nearly as pyrotechnic since there wouldn't have been much to burn other than the LED strip itself

I do know this, it's cold enough outside that a different flight controller did some really odd things earlier until it fully acclimated to the near single digit temps, it's entirely possible that the cold caused something to contract enough to cause a short, what that might have been I'll never know but it sure as heck was impressive to see, wish I'd had a video camera going!

Ken

 

[Emowillcox]

Are those hobby king LEDs

 

[SleepyC]

Following the burn, it seems to almost come from the two soldiered leads, into the LED strip. Any chance the soldiering "bubbles" where the wires are connected were a bit heavy, and the dryness of the weather caused an arc? Sometimes when it's below freezing, it gets crazy dry and electronics can do weird things.

 

[bordhead]

I had that same thing happen..good thing you saved it..

 

[kloner]

was that on 4s?

 

[RotorFilms]

Kloner,

I was thinking exactly the same thing, these strips are normally meant to be supplied with 12v so a 4 cell pack which sits at 16.8v when fully charged will make the led's shine brighter but it will also cause the little buggers to run much hotter.

Regards,

Andre

 

[Benjamin Rowland]

We run our led strips off a 4S. Now you've got me thinking about dropping that voltage.

 

[gadgetkeith]

heres a thought could the leds against the carbon have caused a short

carbon fiber fishing rods are fantastic lightning conductors

if you shink wrap the tubes then add leds then shrink wrap over the top again the first layer would act as an insulator

just a thought as carbon fibre does have some conductive properties under the wright situations

keith

 

[kloner]

I had swapped out some motors on a carbon frame, for whatever reason when i put the ezuhf antenna on the flat of the nut didn't sit flat to the frame and it almost touched. When i fired up the heli i smelled smoke, thought i fired an esc. Saw a faint smoke a few times, i was freakin out. next thing i know i saw light emiting from between the sma and the frame, it was sizzling

 

[maxwelltub]

Seems like they shorted out some how. The led strips have positive and negative leads exposed every 3 LEDs. I don't run long strips but I do use silicon or liquid electrical tape to cover exposed leads. On the bright side you saved most of quad. Thanks for sharing.

 

[seattle_helo]

Ken, I had something similar happen on a much smaller scale. As I was building a machine and testing LED's one of the strips had a gap in the adhesive backing that happened to line up with a set of the soldering pads. The bare copper dots made contact with the CF arm and shorted, creating some smoke and charring a small portion of the arm and strip. Because I was testing it was quickly disconnected before anything more could happen. As a result I now use adhesive trim backing anywhere I use LED's to help ensure safety. My front booms have always had blaze orange trim and on the rears I use some white which also aids output/contrast just a little bit.

Glad you got it down and minimized the damage.

nick

 

[Efliernz]

I tested mine on 4S and while the brightness was awesome, the components got really hot - and they were in free-air, not sleeved!

I run mine off the same 12V ubec as the a/v TX.

Pete