Surely a blown light bulb can’t kill a microwave oven, right? You might not expect it to, but that was indeed the root cause of a problem that [mikeselecticstuff] recently investigated; the cascade of failures is instructive to say the least.
While the microwave that made its way to [mike]’s bench wasn’t exactly engineered to fail, it surely was not designed to succeed. We won’t spoil the surprise, but suffice it to say that his hopes for a quick repair after the owner reported a bang before it died were dashed by an arc across the interior light bulb that put a pulse of mains voltage in places it didn’t belong. That the cascade of failures killed the appliance is a testament to how designing to a price point limits how thoroughly devices can be tested before production runs in the millions are stuffed into containers for trips to overseas markets.
Even though [mike] made his best effort to adhere to the Repair Manifesto, the end result was a scrapped microwave. It wasn’t a total loss given the interesting parts inside, but a disappointment nonetheless unless it forces us to keep in mind edge-case failure modes in our designs.
If you lived through the Y2K fiasco, you might remember a lot of hype with almost zero real-world ramifications in the end. As the calendar year flipped from 1999 to 2000 many forecast disastrous software bugs in machines controlling our banking and infrastructure. While this potential disaster didn’t quite live up to its expectations there was another major infrastructure problem, resulting in many blackouts in North America, that reared its head shortly after the new millennium began. While it may have seemed like Y2K was finally coming to fruition based on the amount of chaos that was caused, the actual cause of these blackouts was simply institutional problems with the power grid itself.
I believe higher quality learning happens from sharing failure than from sharing stories of success. If you have set your mind to living on contract, I present this cheat sheet of some of the most simple and effective ways to muck it all up that have surprisingly little or nothing to do with your technical skill, knowledge, or even deliverables.
The previous installment of Life on Contract discussed how one might find clients as an engineering contractor or consultant while also taking a bit of time to pull apart the idea of whether life on contract is appropriate as opposed to, for example, bootstrapping a business instead. Assuming you are set on working as a contractor, let’s talk about what happens after you have found a prospective client (or perhaps more likely: after they have found you.)
WARNING: this article features an utter lack of success tips and tricks. Partly because those can be found in any seminar or business self-help book, but mostly because I do not have a foolproof recipe for success, and cheat codes to unlock easy mode still elude me. But I have witnessed (or committed) and reflected on many excellent ways to fail at contracting; or at the very least succeed in not being invited back.
Just because I won’t be sharing success stories doesn’t mean success has no learning value. Got a success story, or a better way to fail? Tell us about it in the comments!
[CNLohr] is kinda famous round these parts; due to some very impressive and successful hacks. However, for his 20k subscriber video, he had a bit to say about failure.
Of course glass circuit boards are cool. Linux Minecraft things are also cool. Hacks on the ESP8266 that are impressive enough people thought they were an April Fool’s joke are, admittedly, very cool. (Though, we have to confess, posting on April 1 may have added to the confusion.) For a guy who puts out so many successes you’d think he’d talk about the next ones planned; hyping up his growing subscriber base in order to reel in those sweet sweet Internet dollars.
Instead he shows us a spectacular failure. We do mean spectacular. It’s got beautiful intricate copper on glass key pads. He came up with clever ways to do the lighting. The circuit is nicely soldered and the acrylic case looks like a glowing crystal. It just never went anywhere and never worked. He got lots of people involved and completely failed to deliver.
However, in the end it was the failure that taught him what he needed to know. He’s since perfected the techniques and skills he lacked when he started this project a time ago. We’ve all had experiences like this, and enjoyed hearing about his. What failure taught you the most?
We put a lot of trust into some amazingly cheap components, sometimes that trust is very undeserved. Long gone are the days when every electronic component was a beautifully constructed precision lab instrument. As [Rupert Hirst] shows, this can be a hard lesson to learn for even the biggest companies.
[Rupert]’s Nexus 5 was suffering from a well known reboot issue. He traced it to the phone’s power switch. It was always shorting to ground, even though it clicked like it was supposed to.
He desoldered the switch and pried the delicate sheet metal casing apart. Inside were four components. A soft membrane with a hard nub on the bottom, presumably engineered to give the switch that quality feeling. Next were two metal buckles that produced the click and made contact with the circuit board, which is the final component.
He noticed something odd and busted out his USB microscope. The company had placed a blob of solder on the bottom buckle. We think this is because steel on copper contact would lead to premature failure of the substrate, especially with the high impact involved during each switching event.
The fault lay in the imprecise placement of the solder blob. If it had been perfectly in the middle, and likely many phones that never showed the issue had it there, the issue would have never shown up. Since it was off-center, the impact of each switching event slowly deposited thin layers of solder onto the copper and fiberglass. Finally it built up enough to completely short the switch.
Interestingly, this exact problem shows up across different phone manufacturers, somewhere there’s a switch company with a killer sales team out there.
Some of our more dedicated readers may remember me as that promising and talented new writer who disappeared after only a couple of months last fall. Or, alternatively, that moronic new writer who had no idea what he was talking about. But, I’m just going to go ahead and assume it was the former in order to protect my ego. In either case, if you remember me at all, you may have wondered why I left. Was it cholera? Was I drafted into a top-secret CIA program? Did I join a circus as a fledgling trapeze artist?
No, it was none of that. That would be absurd. What would make you think I had any trapeze skills at all, much less circus-worthy ones? The truth is a lot more straightforward, but was also a lot scarier (and more exciting) for me — I started a business. The astute readers among you have probably already put the dots together and figured out that I failed. The title was a pretty strong hint, right? This isn’t a story of bootstraps-pulling success, or a heartwarming underdog tale. This is an opportunity for me to talk about the lessons I learned as I failed, and to give the entrepreneurs out there something to consider when they start their businesses. We’ll laugh together, we’ll cry together, and maybe we’ll even learn something together. Ready? Alright, let’s dive right into the heart of it, starting when I was seven years old…
[Jay] out of the River City Labs Hackerspace in Peoria, IL cleared out a jam in his printer. It’s an operation most of us who own a 3D printer have performed. He reassembled the nozzle, and in a moment forgot to tighten down the grub nut that holds the heater cartridge in place. He started a print, saw the first layer go down right, and left the house at 8:30 for work. When he came back from work at 10:30 he didn’t see the print he expected, but was instead greeted by acrid smoke and a burnt out printer.
As far as he can figure, some time at around the thirty minute mark the heater cartridge vibrated out of the block. The printer saw a drop in temperature and increased the power to the cartridge. Since the cartridge was now hanging in air and the thermistor that reads the temperature was still attached to the block, the printer kept sending power. Eventually the cartridge, without a place to dump the energy being fed to it, burst into flame. This resulted in the carnage pictured. Luckily the Zortrax is a solidly built full metal printer, so there wasn’t much fuel for the fire, but the damage is total and the fire could easily have spread.
Which brings us to the topics of discussion.
How much can we trust our own work? We all have our home-builds and once you’ve put a lot of work into a printer you want to see it print a lot of things. I regularly leave the house with a print running and have a few other home projects going 24/7. Am I being arrogant? Should I treat my home work with a lesser degree of trust than something built by a larger organization? Or is the chance about the same? Continue reading “Ask Hackaday MRRF Edition: 3D Printers Can Catch Fire”→