Hackaday Links: September 9, 2018

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Octoprint is one of those must-have apps for 3D printers. All you need is a Raspberry Pi, an SD card, and a USB cable, and you can control your 3D printer from anywhere in the house. Of course, some people take it too far and open up their Octoprint to the greater Internet. Gizmodo reports thousands of people are doing so, with possible dire consequences. Choice quotes: “Imagine waking up in the morning to find that your 3D printer was used to produce a gun” and “Once again, 3D guns come to mind”. Yes, they referenced 3D printed guns twice in a story. Call me when you can 3D print bullets. Or when bioprinters can print airborne HIV, which was also suggested in the story.

ARS Electronica is going on in Linz this weekend, and it’s the largest new media art festival where cyber artists are recognized for their innovations. One of the more interesting exhibits is [Sarah Petkus]’ Noodlefeet. Its [Sarah]’s kid, that’s a robot, that’s made out of pool noodles. She’s talked about it at the Hackaday Superconference, and now there’s an entire exhibit behind it. You can check out her ‘making of’ post right here.

A mirror is a useful survival tool, if only for signalling people. Here’s a video showing long-distance mirror signalling, over a distance of 27.5 miles. The mirror used was 330 x 254mm, but the real challenge here is pointing the mirror in the right direction. For that, [Andy] used a bamboo pole a few meters in front of the mirror. By reflecting sunlight onto the pole, he knew it was going in about the right direction. Accuracy versus precision, or something like that.

Last week, a slow leak was detected aboard the International Space Station. The leak was quickly traced to a 2mm hole in the upper orbital module of a visiting Soyuz spacecraft. prompting call of micrometeoroid damage and plenty of speculation on what would have happened if this hole appeared anywhere else on the station. Now, it looks like this hole was put there by a drill, probably during assembly or testing, and was somehow plugged until the Soyuz was in space for a few weeks. Why this hole just magically appeared one night is anyone’s guess, but there you go.

64 thoughts on “Hackaday Links: September 9, 2018

    1. Hmm. Assuming choked (maximum) flow, a 2mm hole would exhaust around a gram per second of air (in reality, it’s probably less). The total volume of the ISS contains around 1.5t of air, so that leak would ’empty’ the ISS in around 1.5 million seconds, or a couple of weeks or so. Urgent enough to divert resources to find it pronto, I suppose.

      It makes one wonder how they would detect and find (and pathc) a similar meteor hole hidden behind a hard-to-access location.

      1. Detection is easy because the air pressure is closely monitored. Finding a leak seems harder though, maybe something as simple sealing modules one by one to identify the general area, followed by as a colored aerosol or smoke?

        1. Yah I don’t know why just squirting a few droplets out of a waterbottle and following them wouldn’t work, unless the recycle intake and equipment fans just make far more air movement.

          You’d think also that if rate of loss was known before hole was found, that kinda relates to the size of the hole, and the size would relate to a particular sound frequency range, so you could rig audio filters and hunt with a mic.

          1. “zero-g” environment without any forced ventilation is very dangerous for people (exhausted CO2 and warm/hot air has no reason to move away from you), life support systems keeping a constant draft is wanted side effect for this very reason…

          2. Does air exhausting into a vacuum make a sound? Obviously air escaping a pressure vessel makes sound *in the volume it’s exhausting TO*. But can you hear sound from inside a pressure vessel if there’s a hole from it into vacuum? Seriously. Since (by definition) air is going the speed of sound through the hole, sound can’t propagate backward through the escaping air. It can’t propagate through the surrounding vacuum and back through the walls. So is it silent? Will (say) an ultrasonic leak detector even work?

          3. Yah I was realising a majority of the sound is projected outwards and in this case immediately damped by vacuum, but was expecting some amount to be transmitted to the material around the hole and thence to the interior volume.

        2. Maybe sprinkle a few air pressure sensors around, should produce a map with the likely location of the leak right at the lower-pressure bit. You could do it using simple little PCBs with some sort of mini-radio mesh and a cheap pressure sensor. Since it’s not life-or-death it doesn’t need to be tested quite as excessively as other space stuff.

          There’s the issue of the radio causing interference, but I get the impression the computer stuff up in the ISS is a good bit behind what’s down on Earth. So interference not too high a risk. You could even power them with batteries, with low-battery being one of the messages they can send. Then you just need one of them to interface to a computer somewhere that the crew can access, stick the others up with blu-tack, and that’s about it.

          Or else they could do it the NASA way if they wanted to, up to them. Still, I think having a few extra pressure sensors would be useful in locating a leak.

          Another option would be to have loads of them, but only deployed when a leak is detected, the rest of the time they’re kept in a case. When there’s a pressure warning, you scatter them about, and a little flashing LED lets you find them easily to pack them up again after.

          1. AFIK the pressure drop is near uniform throughout the cabins, unless in a sudden fast leak. Ultrasonic sounds may be used to trace the source of leak?

            In zero G heat does not rise from a hot chip or board, the poor thing just soaks in it’s own heat. So there are fans everywhere and in everything. Noise aside the dust and human stuff just gets into everything like the dust bunnies in PC’s. Turning off things to watch a smoke trail drift might be hard.

        3. Maybe FLIR cameras on the outer hull or the Canada arm? I expect a plume of habitat-temperature air has got to stand out against the background of space. And some parts of the station are probably only sealable from the outside in any case, despite the risk of spacewalk.

          1. Not warm at all? Got any sources on that Paul, or are you just assuming? Sure, it’ll drop in temperature, but last time I checked depressurising by a mere fifteen PSI won’t chill air from a comfy 24°C to the exact and frigid -270° of deep space in an instant. It should still shine like a beacon in infrared.

            It’s not like in movies where everything instantly freezes solid the moment it goes out the airlock; in reality, it takes a long time to lose heat in space because the only vector for it is radiation.

          2. TGT: You’re right. I was thinking how effective Joule-Thompson coolers are, but they require high pressure to work. From 100 kPa, even into a complete vacuum it’s only going to be a few degrees drop for nitrogen/oxygen. Thanks for catching that.

          3. That said, what’s the optical depth in the infrared of that diffuse plume of air? Its effective surface brightness will be very, very low. It would be interesting to know whether a ‘normal’ FIR camera can detect it. Can a good FLIR camera see even ambient-pressure warm air against a cold background?

          4. Good point Paul. It would maybe need a modified IR sensor of some sort to deal with low temperatures, and I don’t know how it would be affected by how sparse the molecules would be. And I should be mindful that if it’s a viable solution, somebody at NASA or one of the other space agencies has probably already considered it.

            I know they can see a warm or cold plume of air at least in atmosphere; I thought of using FLIR because lately I’ve been working with detecting methane leaks at wellheads for the oil and gas industry. Apparently it’s a great tool, and shows escaping methane very clearly even from a great distance despite it mixing with the air and assuming close to ambient temperature. Pretty cool stuff, I got to play with a very fancy and expensive FLIR camcorder :)

          5. The methane detection task is a perfect one for FIR cameras: Methane has a monstrous absorption band around 7-8 microns that makes it really stand out against ambient thermal background.

    1. A healthy imagination indeed. Do we have a multi-extrusion printer loaded up with smokeless powder filament ready to go somehow? Primer? spring steel for a sufficiently strong firing pin? Are the projectiles themselves PLA or lead? Even assuming these fantasy spools actually exist, sounds like the machine was specifically configured to print “3d guns” from the start.

      Side note, I love how the article genuinely uses the term 3d guns. As if there are 2d guns for flatlanders, which must of course be muzzle-loaders or else they would be bisected by the barrel in a similar way as flatlanders themselves are bisected by their own digestive system.

      Oh no! Somebody is gonna print a shitty, plastic, disassembled gun on my machine, minus ammunition and hardware! So essentially a block of PLA with a hole in it. The horror! Obviously the only real threat is that somebody would 3d-print me a house fire.

  1. Gizmodo is just fear mongering for clicks, the worst outcome is mentioned by octoprint’s website itself in such that protections can be disabled and the printer could burn your house down.

      1. I was referring to the 3d printed gun being mentioned twice and the printed HIV reference. The article is a non-article because the worst possible outcome currently is mentioned on the Octoprint website as a legitimate warning, something that any Octoprint owner could easily read when looking for information on how to hook it up to the Internet.

        Some things should just NOT be networked, and even more should not be put on to the open Internet

        1. They didn’t really claim somebody could print HIV did they? FFFFF!!!!

          While there are DNA printers, they do short sequences. It’s been demonstrated that yes, you can join these chunks together. But that’s still a million miles from a viable virus. And HIV isn’t a simple one.

          They also cost a bleedin’ fortune and live in labs surrounded by dozens of PhDs and their assistants.

          I’m genuinely more worried about grey goo, right now. And I’m not worried about that at all.

  2. “Imagine waking up in the morning to find that your 3D printer was used to produce a gun”

    I’d be annoyed that somebody had wasted my hard-earned PLA to make some really crappy gun parts, I guess. Is there supposed to be something else significant about finding harmless pieces of plastic stuck to the print bed? Does this Gizmodo-writing hack think those bits of plastic are going to detach themselves from the printer, self-assemble, conjure up some ammunition, and shoot my cat or something?

    I mean, I’d worry about a gun lying around where my cat could reach it. She’d shoot me in a heartbeat just for shits and giggles. But she lacks the opposable thumbs to assemble the gun, and she probably doesn’t have any ammunition handy (probably), so I think I’d still be okay.

    1. These are the sorts of people that don’t understand guns aren’t alive. I won’t say “Guns don’t kill people” (They do) but they require an outside something to interfere with it. Something a lot of anti-gun people seem to have trouble understanding.

      Finding the parts to a 3d printed gun isn’t exactly going to be any sort of dangerous event. It’s on par with leaving a disassembled .22 caliber pistol lying around without any ammo nearby. Not exactly a smart thing to do but it’s not going to shoot someone in that state.

      1. A 3d-printed plastic gun is about as effective as a block of wood with a .22″ hole drilled through it and a cartridge stuffed into one end. Where are the people fomenting fear about cordless drills? One could produce “guns” at a hundred times the speed and volume of a 3d printer, and they don’t even need an outlet! Clearly this is the true menace.

      1. Yeesh. Y’all can find a way to shoehorn politics into anything. It’s gizmodo, they’re very stupid and the 3d-printed gun statement is more a dumb buzzword with little to do with politics or those dastardly “SJWs” y’all go on and on and on about yet which I never seem to encounter IRL. It’s the weirdest and least-threatening version of the boogieman.

        If somebody utters that term I instantly know they’re full of horse turds and hot air and are a person to be ignored.

        1. Gizmodo and their entire company are so poor at journalism I feel like they are only hurting their cause and ruining the credibility day after day. I read a lot of their material to understand how a lot of my friends think……………….. maybe I need smarter friends……………………….

  3. This is like worrying about internet-enabling curtains in an opening in a house between the kitchen and living room

    Sure, someone could do nefarious things with it(morse code swear words!), but where exactly is any of it going to go?

    At the most, it’s an annoyance. Until they break into the house to get to the internet enabled object, there’s no physical issues.

    But using the printer to gain access to a network to steal information from other devices on the same network, now that’s a definitive nefarious reason to not internet enable a printer.

  4. The security folks here aren’t reporting imagined scenarios, they actually found and connected to 3,759 3D printers which didn’t have any authentication.
    If nothing else that means someone can deliberately break your expensive printer.

    1. yes, Its one thing to report on thousands of Internet printers accessible on the Internet but then they inflate the issue to say that someone could print “3d Guns! 3d guns i tell you” ™ as a dog whistle in order to get people to be concerned about their reporting. That isnt security anymore, that is marketing social outrage, real security people would note the number of devices affected, how to solve the problem and the REAL consequences of the issue instead of saying “OMG the GUNS!”. Real professionals do not need current hot topics or dog whistles in order to get their point across.

      Note: notice how i didnt ascribe this to either side of the isle, because BOTH right and left uses these methods to rile people up, they just use different topics. This crap should be called out on both sides regardless of who you prefer to vote for.

      1. Yeah, well I’m only referring to the security folks referred to by [Snide]. They did reference 3D printed guns, but only as an example of something that could be tampered with during printing in a disastrous way, i.e. fouling the print in a way that couldn’t be observed by eye, but would cause the gun to malfunction. They also referenced 3D printed drone components in the same way. So I wouldn’t say the real professionals used current hot topics.
        The Gizmodo writers are a media outlet and they will, of course, reference every hot topic going. I’m surprised they didn’t bring Kim Kardashian into it.

    2. I’ve personally seen many of these with no security for several months now. Just figure out what to search for on shodan.io, and you’ll see them too. They even have webcams that are accessible. The options to actually print anything seem to be grayed out in the examples I’ve seen, but then, I wasn’t exactly trying to be evil or anything. It’s obviously a potential opening for an attack.

  5. “Octoprint is one of those must-have apps for 3D printers. All you need is a Raspberry Pi, an SD card, and a USB cable, and you can control your 3D printer from anywhere in the house. Of course, some people take it too far and open up their Octoprint to the greater Internet. Gizmodo reports thousands of people are doing so, with possible dire consequences. Choice quotes: “Imagine waking up in the morning to find that your 3D printer was used to produce a gun” and “Once again, 3D guns come to mind”. Yes, they referenced 3D printed guns twice in a story. Call me when you can 3D print bullets. Or when bioprinters can print airborne HIV, which was also suggested in the story.”

    Thats cause everyone who writes for Gizmodo and its parent company is a litteral communist afraid of anything having to do with freedom. The 3D printed gun hysteria is old, code is free speech now deal with it.

  6. 3d printing a gun is scary depending on where you live, but only because it is ilegal and potentially traceable by ip address or isp. I can see proving in court that someone else did it to frame you would be a real hassle.

    Besides that it’s just wasted plastic.

    Or the real threat of them trying to burn your house down.

      1. USA =/= The Whole World.
        I’m actually impressed; like everyone else here I dismissed the zomg 3d gunzzz hysteria but [raukk687] has raised a decent point. The gun itself isn’t a problem but there are plenty of countries where possession of a gun-esque item brings serious legal problems even if it is far from functional.

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