Early studies show that 3D printers may leave behind similar toolmarks on repeated prints.

  • Cyv_@lemmy.blahaj.zone
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    1 day 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.

    (This is ignoring changing print settings, nozzle diameter, filament type, print temp, etc)

    • CmdrShepard49@sh.itjust.works
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      1 day ago

      You don’t have to buy it for them to convince 12 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.

    • Postmortal_Pop@lemmy.world
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      1 day 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.

    • remotelove@lemmy.ca
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      1 day 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 and repeatable errors.

      • Cyv_@lemmy.blahaj.zone
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        1 day 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.