

Let’s entertain the thought. How would one identify what is a gun part being printed, and what is a tube, a mechanical latch, or whatever else. Heck, I printed a plastic replica of a movie prop once. Would that be illegal?
I mean, I’m not in the US, and I know how to drive three steppers according to a list of extremely basic instructions that never ever represent anything “final part-y” looking, but the question remains. How do we go from “lots of gcode” to “yep, that’s definitely illegal” without saying that everything is illegal?


That’s… not applicable here. Like, at all. To reproduce a printed document, you input it. To make a 3D print, you produce tailored list of operations depending on many, many settings. Usually, the file that reach the printer have little in the way of knowing what is printed, aside from expensive reconstruction that would only give the general shape, if even that. And even if you can send actual 3D model files to a printer that would do the slicing locally, there’s no “absolutely required” fingerprint there. A tube is a tube.
And, just so you know, there’s a slew of public printers and scanners that will just plain not recognize any of this, too. There’s also some “protection” pattern in some official document; large office printers would choke on them, where a home scanner was fine. This is, at best, only enforceable in the flimsiest of ways.