What was your biggest project Disaster? We are asking e14 in our Join, Share & Win Competition

Not a project, but when I got transferred to Germany many years back, I was setting up my US computer and forgot to change the voltage switch on the power supply.  I put the plug adapter on and shoved it into the socket.  POP!  Bzzzzzt!  Smoke.     Swearing.     The next day at work - ordering a new power supply.   Three weeks later, I was finally online.

Could have been worse...

Top Secret!  "...here in E Germany we use 220 volt..." 

https://www.youtube.com/watch?v=xZzO6thDkkY&t=86s

One time we went oversees to capture radar data.  Just before the trip someone assessed the three RF cables we were planning on taking and flagged one as being bad and took the further action of quarantining it.  When I started assembling the setup at our destination I noticed to my horror that there were 3 cables.  Someone had packed the quarantined cable.  I assembled two cables together and took a cursory look at the first bit of data that was collected.  It looked fine and I counted my blessings for getting the cable combination right the first time around... or so I thought.  When I got back to the home office someone a little more knowledgeable had the opportunity to scrutinize the data and he didn't mince any words.  "There was something clearly wrong with your setup.  This data is useless.  What a waste of a trip."  I wanted to crawl inside a hole.  It took me a while to get over that episode.

Every field experiment has a few disasters.  The funniest one was when I downloaded video files from a site camera and saw pictures of the hotel room and trip in the car to the site, but nothing from the experiment days.  They must have been confused with the On/Off procedure.

Another time I spent several days constructing a 16 channel micro temperature probe using 40 AWG thermocouple wire that was supposed to measure temperature gradients just above and below the surface of a lake with a 0.5mm resolution.  As soon as we deployed the probe, a dragonfly landed on the top probes, and some little minnows started nibbling on the bottom probes, impossible to get any data.

Similar tale of woe, I arrived in the Hyderabad India hotel all jet lagged and set my PC case vertically on the edge of the bed.

As I walked away , in a frame by frame slow motion,  the PC case leaned over and slapped a perfect belly flop onto its side onto the concrete based tiled floor. 

The hard drive didn't survive. 

I was visiting my employer's Hyderabad engineering office to get with global members of my team from there, and altho the company's global PC service and SW center  was also in that building, it still took 3 weeks to get the hard drive replaced and reloaded. I got the PC back up and running the day before I returned back to the US.   

Early on in my traveling robotics club road show, I had made a Halloweenish radio controlled and Arduino controlled contraption, an animated skeleton sitting in a plastic chair with wheels, a lightweight poor man's wheelchair.

He could drive around convention hallways remotely, an FPV camera was mounted in his eye, and a walkie talkie in his shirt pocket.   

Oooo what fun. The RC part had its own battery, Arduino had its power circuit, the FPV had its own battery, walkie talkies had their own batteries. 

I usually fuse my robot projects, tho this time I neglected that detail on one section. 

The inevitable happened at a robot STEM event at a university gym of all places - I see a sliver of smoke rising from the skull jaw - power lines shorted at a connector.

Luckily it wasnt moving and I was standing next to it, quickly pulled the plug. No major damage.

The lesson - always include a main power fuse and main disconnect switch when batteries bigger than a button are involved !   

I guess in a way you were a human fuse.

I guess once you get away from from a controlled environment like a lab all manner of things can go amuck.

The fire extinguisher :-)  Which reminds me of another story attending a Chili Festival. There was a guy running around with a "far" extinguisher, "far" which is a southern word for "fire". If your tongue was on "far" from chili , he'd extinguish it with a squirt from the extinguisher, which was filled with marguerita ! I need to remember to carry on of those to robot and amateur radio events. :-)