3DPrinting
3DPrinting is a place where makers of all skill levels and walks of life can learn about and discuss 3D printing and development of 3D printed parts and devices.
The r/functionalprint community is now located at: or !functionalprint@fedia.io
There are CAD communities available at: !cad@lemmy.world or !freecad@lemmy.ml
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I think that's the unspoken implication and I'm instantly suspicious of the entire premise. The entire field of forensic science is filled to the brim with things described as "fingerprints" that are not nearly as unique or consistent as the field would have us believe.
I’m rather skeptical as well, but if there’s a defect on the nozzle causing stations in the extrusion, that might do it.
Otherwise they might get lucky, but I doubt it.
Resin printers might have something else, but it’s hard to imagine what. (Maybe dead pixels?)
The nozzle? The one part that gets replaced almost as often as the filament?
My guess is if there's a defect somewhere on the z-axis so there's always a consistent slip at a certain height would be the only way, and even then, that's a replaceable part.
Yes. The nozzle.
The one part that puts a consistent pattern into the filament as it extrudes that can be corrected for variation from temps and materials and whatever else.
Unless you’re printing abrasives, your brass nozzles doesn’t wear that quickly and defects from the boring out during production will translate to patterns in the surface.
Most fdm printers might be accurate to .1mm, with the best getting to around .05mm in z and any measurement below that is basically random noise, so you have finite limits on how precise you can get measuring defects.
This means that well tuned printers will generally be close enough that it’s hard to differentiate between them.
Now imagine a pattern in an introduced by a warped lead screw, as an example. Sure this is cyclic. But its height is dependent on the lead screw’s thread lead. A T8x8 has an 8mm lead and this pattern will repeat every 8mm in height, with a consistent layer count between them.
As will basically every printer using a t8x8 screw. Printing at that same layer thickness. Which is pretty much every printer on the market. There might be some slop with backlash, but that’s not going to show up accurately enough.
And yes. You can swap out nozzles, just like you can belts and lead screws and every other part. Unlike most parts, though, the microscopic striations coming off the nozzle aren’t as inconsistent as say belt tightness.
I'll have you know that my magic wand is 100% accurate at least 50% of the time!