3D Printing Patterns Might Make Ghost Guns More Traceable Than We Thought

Comments

• otter@lemmy.dbzer0.com ⁨1⁩ ⁨hour⁩ ago

  NGL, my favorite way that independent artists are watermarking their SLA sculpts is sublimated in the model itself. Both the file and its prints have telltale ciphers at a specific plane, all but nullifying the “washing” tactic. Still, if the rule of law means nothing, it’s all pretty moot. 🤌🏼

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• maxwells_daemon@lemmy.world ⁨9⁩ ⁨hours⁩ ago

  Re-slice in different positions, use a few different slicers and printers, got it. Thanks for the pro tip 👍🏻

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  • Zetta@mander.xyz ⁨5⁩ ⁨hours⁩ ago

    Just change nozzles every print, you can get cheap Chinese nozles for less than a $1 a pop.

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  • IAmNorRealTakeYourMeds@lemmy.world ⁨8⁩ ⁨hours⁩ ago

    I think there was a study that showed every 3d printer leaves a sort of fingerprint, and they can identify which printer printed what object.

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    • Ulrich@feddit.org ⁨5⁩ ⁨hours⁩ ago

      In a lab, probably. In reality? No. Print nozzles wear over time time and their patterns will change accordingly, and they are entirely replaced often.

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    • GrumpyDuckling@sh.itjust.works ⁨7⁩ ⁨hours⁩ ago

      Yeah you can see the slop in the prints when the axis stops. You can just change print settings and it won’t look the same between prints. You can also use chemicals to smooth the outside of the print.

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• dual_sport_dork@lemmy.world ⁨8⁩ ⁨hours⁩ ago

  All of this represents a deeply flawed understanding of how such “tracing” works. In order for this to accomplish anything you have to have both the printed gun part and the printer that made it already in your forensics lab, which means whoever you’re trying to hassle has already been caught. This might help secure a conviction after the fact by being able to conclude that, yes, part A was probably printed on printer B. It absolutely will not allow any random beat cop to grab any random printed gun off the street and be able to proclaim, “Ah, yes. This was printed by Bob Smith at 123 Maple Street,” or whatever hyperbolic fantasy these authoritarian types are always wishing for.

  The risk here is cocksure but incompetent investigators inevitably generating a shitton of false positives and charging/convicting the wrong people just because they happen to own a 3D printer, and judges and juries believing them. This kind of thing already happens in established fields of forensics all time and if they couch everything in enough authoritative sounding language nobody who doesn’t already know a whole bunch about the topic is going to be able to call them out on it.

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  • cecilkorik@lemmy.ca ⁨7⁩ ⁨hours⁩ ago

    This kind of thing already happens in established fields of forensics all time and if they couch everything in enough authoritative sounding language nobody who doesn’t already know a whole bunch about the topic is going to be able to call them out on it.

    Bingo, the goal is not to actually trace 3d printed guns, it’s to add another piece of evidence they can slap onto the target of their investigation to improve the chance of getting a conviction. Whether the accused is actually guilty of anything is truly irrelevant to the intended purpose of these kind of things, they are in practice assumed guilty by the prosecution unless proven innocent. The point is simply to make a convincing case to a judge or jury.

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• Cyv_@lemmy.blahaj.zone ⁨9⁩ ⁨hours⁩ ago

  I’ve seen this before and I still don’t entirely buy it. If you’re talking about the pattern left by the nozzle rubbing the print, that will not be a reliable identifier.

  Most nozzles are brass. Soft metal. It wears down and the pattern in the plastic will change. Because they wear down anybody doing regular prints is gonna replace their nozzle from time to time. New pattern in the plastic.

  This is assuming they don’t change a new $2 brass nozzle, print a gun part, then toss the nozzle in the trash. Or the whole printer. My printer right now is probably $150 used at this point, if I was to sell it.

  Imo this isn’t gonna do much, and for the people who would do nefarious things it will be easily avoided.

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  • CmdrShepard49@sh.itjust.works ⁨6⁩ ⁨hours⁩ ago

    You don’t have to buy it for them to convince 8 average citizens that they used wizardry and science to definitively prove it’s ‘real.’ See bite mark analysis, fiber analysis, hair analysis, etc, etc, etc. Court rooms are full of pseudoscience because it helps convict more people.

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    • Arghblarg@lemmy.ca ⁨3⁩ ⁨hours⁩ ago

      And ‘Lie detectors’. Don’t forget those frauds.

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  • Postmortal_Pop@lemmy.world ⁨9⁩ ⁨hours⁩ ago

    Hell, you’re not even gonna get that far. I don’t think there’s a forensic lab within 2000 miles of me that could do this kind of work. All that funding goes to guns and cover ups.

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  • remotelove@lemmy.ca ⁨9⁩ ⁨hours⁩ ago

    You could probably map resonance artifacts, but you have to isolate layers that were printed at the same speed and direction. However, the second you tighten a belt or screw, that pattern will change and I am not sure how consistent resonance patterns would be on a bed slinger. (The quantity and density of printed plastic may change the resonant characteristics of the entire printer. This may be less of an issue on a core xy.)

    Thinking waaay outside the box… In some cases, I have seen extruder gear marks on the filament create artifacts on a print. Every gear pattern should be unique, but measurable differences would probably be micron or sub-micron.

    Maybe you could map the surface of textured beds as I seriously doubt that those patterns would be consistent and more prone to randomness from the factory.

    There are a ton of conditions that could generate unique artifacts on a print, now that I think of it. Hell, even a printers PID tuning can leave visible errors.

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    • Cyv_@lemmy.blahaj.zone ⁨8⁩ ⁨hours⁩ ago

      I think my issue is practicality in testing. They have to have the print, and the printer. To test they likely need the file, modified with the same slicer settings as set originally. There are just so many factors, I have a hard time seeing them get all the required pieces, get them all in working order (especially the printer), then have the means to print the same thing in the same way. After all of that, now they have to measure some patterns and prove they’re the same across prints.

      I feel like the complexity of the problem introduces more chances for false positives, or just enough of a shift in how the printer is tuned, how the file is set up, etc to make the process unreliable at best.

      I guess we’ll see, but idk. A poor tool still has potential for abuse even if it doesn’t work as originally intended.

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• kayzeekayzee@lemmy.blahaj.zone ⁨5⁩ ⁨hours⁩ ago

  oh boy can’t wait for printer manufactures to start encoding metadata in every print like 2d printers do

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  • XTL@sopuli.xyz ⁨1⁩ ⁨hour⁩ ago

    I half expect Bambu labs to already do and be furiously trying to come up with a scheme to monetize it.

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• spitfire@lemmy.world ⁨9⁩ ⁨hours⁩ ago

  Sounds like a very American “problem” ;)

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  • Arcka@midwest.social ⁨5⁩ ⁨hours⁩ ago

    ^ Obviously uneducated about the topic.

    At least read up on JStark and the FGC-9.

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