Crash, how can you protect yourself from this happening?

Looks like it was a cold solder.

 

HI Nick

Sorry this happened but I"m glad nothing was seriously damaged. Looking at the picture of the power leads it looks to me that the ends of the cables were not pre-tined good enough and a little too long. It looks like a 1/4" or even 5/16 of an inch of insulation was cut of the tip. Having that much insulation off can cause problems. On your picture you can see the very ends of the copper of the wire without solder. Even though its been melted it should have some solder flow on it still.



I cut 3/16 of an inch of insulation of the wires. I pre-tin the ends very well. Did I mention they need to be pre-tinned well? I rotate the wire and pre-tin all the sides of the exposed copper strands so that the entire end is tinned very well. Once the bowl of the connector pin is filled with solder I keep the solder iron on the connector pin and then slowly force the wire into the connector pin straight down from the top. Using a vice helps put the entire exposed part of the wire into the pin. This leaves hardly any exposed copper part of the wire that's not in the connector pin. At this point my connector pin is screaming hot and I use needle nose pliers to put the connector pin into the connector. While hot, I then use one of 3mm Hex drivers and force the pin into the connector until I hear a little pop and the pin is perfectly seated inside the connector. Having the pin very hot really helps put the pin in the connector that extra little 1/64" of an inch that really gives a perfect seal. Once its finished I pull hard on each wire and its rock solid.

 

My power leads are 10 gauge. I wouldn't try soldering any power leads until your certain your soldering is up to snuff. If you need a parallel cable to run 2 batteries you can purchase it on the Quadrocopter website. They can also solder your main power wire to the PDB too. Riley does excellent work.

 

Hey Nick, when I was building my CS from the kit I was terrified of soldering that distribution board... Being aware of cold joints, I sent it into QC and it took about a week to two weeks, but the shop soldered all my leads and BL connectors. Cost me about 300$. Might be something you'd be interested in, Riley is beautiful...at soldering. And I trust their solder joints much more than my proficiency. (At least on mission critical spots like the main power leads)

 

I normally use deans but hearing horror stories i may move to EC5 connectors, my question is why put it in hot? Are you not worried about melting the connector, or at least making the mating hole a bit to big and now you have a lose connector?

 

OH YES!!! I had an X8 that was pull near 100 amps on punch out and about 30-40 on normal hovering and i didnt realize the wire I used for its connector was to small and while flying one time i noticed it get a bit sluggish and suddenly i saw smoke coming from it. Lucky i was only about 3 feet off the ground i set it down and disconnected the batteries. But the insulation on the positive side was completly gone and the negative was almost all the way through.

 

Seeing this absolutely amazes me how quickly those connectors heat up to a degree that they will melt the solder! From takeoff to meltdown only few seconds. Scary! I've seen some aerial crew doing some public flying recently - very low and over quite a few people and in quite a bit of wind .... They need to see this and rethink their directives to get the shot! I've had one prop smash my hand and can only imagine the damage it can cause a youngster in a crowd of innocent bystanders.
Be safe people!

 

flying over crowds all comes down to Risk management. Is your bird thoroughly tested, do you have spotters, how close and how many people are there? I did a shoot in February for the Polar Plunge here in Virginia Beach, there was 3000+ people there. As often as I could i made sure to not go over peoples heads, but there was one shot i did when they initially ran into the water. I took off and was filming them run in and slowly backing the bird away, once a large majority was in the water I stayed outside of the Police Rescue Swimmer line and ONLY went back over to land for battery swap. I also had 2 Spotters with me, one who watched the bird at all time and another to watch the ground so if i did have issues they could both run out and clear a spot for me to land. In a worse case i would ditch it in the ocean, I would rather lose $5000 worth of gear then injure someone.

 

Ive lost a quad to the waters as well, Threw a prop, got to see it tumble and heard a splash. Ripped my goggles off but the waters were calm couldn't find a ripple. I went back later with dive gear and a sonar from work, helps to have access to these things , but i couldn't find it. Really sucked as it had a NAZA, GoPro2, and a 1watt 1.3 transmitter about $1000 gone!
As for the crash, it really sucks but I do a FULL teardown on any bird that crashes. It's a lengthy process but a needed one because I've found things that could've failed in flight and resulted in a major wreck.

 

No. I did several overflights with my Cinestar to survey the treetops, but didn't see anything. It was that my hope that the lost copter's "return to launch" would have used a 15m altitude to come back home, but one of the things I noticed in my SmartOSD was that the treetops weren't that high (about 10-12 meters max), so my theory was just magical thinking. Sigh. Fortunately, the only real loss was the GoPro I had on there, because the copter had been a free door prize at the UAS conference a few weeks ago. Not that it didn't sting...I liked that little quad.

 

I would've found it to, i can find mines in pitch-black with that thing. But it was a boat canal leading to the atlantic so i think the current got it before i could dive.