Hackaday Links: September 25, 2022

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Looks like there’s trouble out at L2, where the James Webb Space Telescope suffered a mechanical anomaly back in August. The issue, which was just announced this week, involves only one of the six imaging instruments at the heart of the space observatory, known as MIRI, the Mid-Infrared Instrument. MIRI is the instrument on Webb that needs the coldest temperatures to work correctly, down to six Kelvins — we’ve talked about the cryocooler needed to do this in some detail. The problem has to do with unexpectedly high friction during the rotation of a wheel holding different diffraction gratings. These gratings are rotated into the optical path for different measurements, but apparently the motor started drawing excessive current during its move, and was shut down. NASA says that this only affects one of the four observation modes of MIRI, and the rest of the instruments are just fine at this time. So they’ve got some troubleshooting to do before Webb returns to a full program of scientific observations.

There’s an old saying that, “To err is human, but to really screw things up takes a computer.” But in Russia, to really screw things up it takes a computer and a human with a really poor grasp on just how delicately balanced most infrastructure systems are. The story comes from Moscow, where someone allegedly spoofed a massive number of fake orders for taxi rides (story in Russian, Google Translate works pretty well) through the aggregator Yandex.Taxi on the morning of September 1. The taxi drivers all dutifully converged on the designated spot, but instead of finding their fares, they just found a bunch of other taxis milling about and mucking up traffic. Yandex reports it has already added protection against such attacks to its algorithm, so there’s that at least. It’s all fun and games until someone causes a traffic jam.

It may be hard for the normies out there to imagine a coffee table book of electronic components, but if you’ve followed along here much, you’ll no doubt have seen some of the beautiful cross-sections that Eric Schlaepfer, aka TubeTime, has come up with. Eric has teamed up with Windell Oskay from the Evil Mad Scientist Laboratories blog and created “Open Circuits: The Inner Beauty of Electronic Components.” You’ll definitely want to check out the first chapter, which is available as a PDF for download. Bunnie also did a glowing review, which you’ll want to check out at least for the coupon code — Christmas is coming, after all. Windell and Eric talked about the book on the Embedded.fm podcast too, if you’d rather hear them talk about the book.

We’ve all likely heard the horror stories of 3D printers catching fire in the middle of the night, and while the relative risk is probably small — it’s definitely non-zero. So a little prudence is probably indicated, which for most of us has some practical limitations. It’s just not easy to organize your day around babysitting a print, especially one that goes 24 hours or more. Utilities like OctoPrint can help, but at the end of the day, if you’re minutes away when seconds count, all a camera is going to do is document the destruction. But here’s an idea that might actually do something about a fire. It uses a product we’d never seen before, which is an automatic fire extinguisher for car interiors. They apparently self-activate above a preset temperature, spewing out some sort of dry chemical to put out the fire. We’ve got our doubts about how well this would work in a car, but inside a 3D printer enclosure, it might actually work. If anyone has experience with these things, sound off in the comments.

And finally, if like us you’re always feeling behind the curve on understanding quantum mechanics, you could be in the market for our friend Jeroen Vleggaar’s latest video on quantum fields. It’s pretty clever — he uses his recent bathroom remodeling project as a launching board for the discussion, which honestly we only got about halfway through before zoning out. That’s a consistent problem for us when dipping a toe into the quantum pool, and honestly getting that far is doing better than average. So hats off to Jeroen for attempting to explain things, and for the sweet bathroom upgrade. Oh, and on a related note, Sabine Hossenfelder just dropped a video on the “Nine Levels of Nothing,” which you might want to check out once your mind is in the proper quantum state.

15 thoughts on “Hackaday Links: September 25, 2022

  1. The first link to “Open Circuits” appears to be malformed; it is instead Bunnie’s blog post link with the No Starch link appended.
    Feel free to delete this comment.

  2. Cause: Watched videos.
    Effect: Time is lost, and I now exist in a negative energy state.

    Yet time still exists, and in the morning there will be coffee.
    So, that’s something.

  3. In our apartments we have these “Stovetop Firestop” hanging from a magnet over the stove- they’re similar little fire-suppression canisters you can get at the hardware store or online. Makes perfect sense to throw one in your 3d printer, under the hood of your car, etc.

    1. I wonder if you could enclose the 3D printer in a sealed (or at least very close to sealed) container and then vent some CO2 out of a canister into the enclosure to displace all of the air (include an outlet valve at the highest point on the enclosure), to ensure that there is no oxygen inside that a fire could start from. The CO2 cost might get expensive if you print a lot, especially for larger printers, but it seems like it could be a really solid preemptive option if you know you are going to be away for a while.

      I’m thinking a Plexiglas box with an open bottom and a bead of silicone or some foam rubber to get a seal on the desk, so it’s easy to put on even when the printer is in the middle of running a job. Hmm, maybe this is how I should do my replacement for the current (rather destroyed, because kids) box my laser cutter is in… An open bottom would be really convenient…

      1. Should have spent 10 more seconds thinking before posting, because now I have an idea that is cheaper and simpler than CO2.

        Put a little tealight candle in the enclosure, ideally it should be elevated (CO2 sinks and might put it out before all of the oxygen is consumed), but not so high that it burns the top of the enclosure. Wait for it to consume all of the oxygen, and then you are good to go. This way you don’t need the CO2, the outlet valve, or the setup for injecting the right amount of CO2 into the box. You just light the candle, put the enclosure over the candle and printer, and then wait for the candle to go out (specifically, wait for it to start smoking, as it might be hard to see the flame near the end, even though it is still burning).

  4. My list of 3D printer fire precautions, from trivial to advanced:

    1. No flammable materials near the printer. Most electronics materials by themselves are self-extinguishing. Though printed parts and the filament spool will burn.

    2. Test that firmware thermal runaway protections work: take the thermistor out of hotend, and see if the heating stops.

    3. Enclosure made of non-flammable material, such a glass or steel.

    4. Smoke detector that automatically cuts power. You can e.g. connect an SSR relay in parallel with the smoke alarm loudspeaker and have it connected with a resistor in between mains and ground, to trip GFCI outlet.

    5. Automatic extinguisher such as linked above. They activate by temperature, so it’s probably useful only inside a non-flammable enclosure.

    1. Re: #4. The two big smoke detector manufacturers in the US (that I’m familiar with) both sell detectors that can trigger other detectors when they are activated. This, combined with a compatible relay module, gives you the option of not even needing to modify anything.

      I have a First Alert, along with their RM-4 relay module. It gives me a contact closure for normal and another for alarm. I combined this with a latching relay and an IoT power strip thingy that takes a low voltage signal as an indication to power on.

      Smoke detector goes off? Latching relay cuts the low voltage to the power strip, which in turn cuts the 120v to the printer. Sure, I could have skipped the latching relay, but I didn’t want there to be any chance of the smoke clearing, power restoring, and the fire hazard starting again.

  5. I wonder if that car fire extiguisher is of the powder type, not only killing the fire, but also all the other thing the stuff touches. It is a kind of salt, corroding everything in its neighbourhood. And I think this powder is emploid with pressurized gas so the isolating hood of the printer will also be blown off. In a car it will kill a fire, but also the complete interior with its chemicals, making for a total loss anyway.

    1. good point. The link that does not work here (too much tracking and advertising stuff i don’t want to enable), but i assume it’s dry powder simply because thats the most effective fire extinguishing agent (generally speaking). I would not use this or as a last ressort only. Better cut power to the printer and then fill the enclosure with carbon dioxyde. Fine droplets of water (isn’t this called “mist” in english?) would also do but will probably kill the printer too.

    1. My coffee table book is a 1988 Texas Instruments TTL logic data book. In it’s exciting pages is low power TTL, Schottky, and low power Schottky. It’s a long read at about 1240 pages. Boy howdie, some of the schematics of shift registers and decade counters will keep you entertained for hours on end!!!

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