
3D printers have ‘fingerprints,’ which could help trace guns, counterfeit goods - rbanffy
http://www.buffalo.edu/news/releases/2018/10/030.html
======
anilakar
3D-printed guns are not a problem that needs solving. They're mostly dangerous
to the user. I'm more worried about companies trying to shut down legit spare
part manufacturing & repair (think Apple but in another context).

~~~
cthalupa
>3D-printed guns are not a problem that needs solving.

Agree.

>They're mostly dangerous to the user.

Kinda disagree.

Several reasons why:

1) On the AR-15, the lower receiver is the "gun" portion that is serialized.
It actually doesn't take too much abuse - you can 3D print one without much
difficulty and have a firearm that is not traceable.

2) FDM materials that are basically just enough plastic to bind metal powder
in place exist and can be fired in a kiln after being printed on your 3D
printer, and you get a metal component.

3) DMLS printers will someday become cheap enough for home use. Patents are
starting to expire here, so this will likely happen soon - over the next 10-15
years.

But guns also aren't particularly difficult to build at home with more
traditional means either, so I don't think it makes much sense to worry about
the 3D printing aspect.

~~~
chrisseaton
> you can 3D print [a lower receiver] without much difficulty and have a
> firearm that is not traceable

I thought it was the barrel that added traceable marks to the bullet, through
the rifling?

How does changing the receiver, which does not change the rifling, make it not
traceable?

~~~
vesrah
Probably just in terms of serial number / manufacturer stamp / etc which are
what live on the lower.

~~~
chrisseaton
Well if you're planning to trace weapons by their serial number then you're
already going to be defeated by a simple screwdriver, let alone 3D printing.

~~~
function_seven
You'd be surprised how well a serial number can be recovered even after it's
been filed away. The stamping process that imprints each digit affects the
metal underneath as well. Even when the physical characters have been filed
away, the serial is readable using some advanced techniques[1]

[1] [https://www.washingtonpost.com/national/health-
science/scien...](https://www.washingtonpost.com/national/health-
science/scientists-develop-a-technique-to-find-serial-numbers-that-have-been-
filed-off/2015/05/11/45e76fce-d489-11e4-8fce-3941fc548f1c_story.html)

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defterGoose
I skimmed the article and can confidently say this is garbage science. The
microscopic parameter changes inherent in every print (across printer types)
means that any sort of unique ID (the type of ID which would be required in a
court of law) on a single printer would be impossible. Using the word
"fingerprint", which is essentially a UUID for humans, as a stand-in for
"identifying a class of printers" is hugely misleading

~~~
CapacitorSet
"The microscopic parameter changes [are] inherent in every print" seems like a
weak argument for claiming that the article is garbage science. No two
fingerprints are pixel-perfect, and DNA samples can get damaged, but this
doesn't mean that such methods are invalid - in fact, they can be valid even
in forensic contexts.

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dogma1138
The problem with 3D printed guns is that countries that you would be hard
pressed to find a gun in legally are countries where you can’t buy an ammo at
your local BigBox store.

Ammo control is the only gun control 3D guns need. Now if we’ll get to a point
where will have a printer that can print on a molecular level and print the
ammo with the gun we can discuss the dangers of 3D printed guns until then a
shotgun shell 2 pipes from the plumbing store and an end cap would make a more
useable weapon than a fully printed gun.

~~~
dleslie
Er, paper ammunition is definitely a thing. It's not beyond reason that one
could forge/press the copper components oneself, either. The tricky part,
which isn't all that tricky, is manufacturing the combustion mechanism.
Charcoal, potassium and sulfur; or saltpeter, sulfur and charcoal. There's
more than a few sources of instructions online.

~~~
dogma1138
Anyone who can make cordite or cellulose gun powder at home, die press casings
and make the primers and the bullets will be able to manufacture a complete
gun without 3D printing, and better one at that.

Heck some high end air soft guns are made from the exactly the same material
as an AR15 some even use real receivers with modification to prevent the drop
in of parts converting those to a real gun would produce a more reliable
weapon than most current 3D prints.

The “danger” of 3D printed guns isn’t about people with the will and skill but
about trivializing it to the point where your idiot parking lot weed dealer
can break into a maker space hit print and come out with a SAW and ammo to
boot and were probably 50 years off from that point.

~~~
dleslie
I think you're over-estimating how hard these things are; especially in this
day and age of online video tutorials. Try googling how to make gunpowder,
you'll come up with many viable tutorials.

The rest isn't that far out of reach, either.

IE, here's an image sequence of an amateur creating a 37mm slug launcher,
ammunition and _most_ of the components; some is 3d-printed, some isn't:

[https://i.imgur.com/kXsM5Ax.jpg](https://i.imgur.com/kXsM5Ax.jpg)

[https://imgur.com/a/3piHH](https://imgur.com/a/3piHH)

[https://imgur.com/a/EUA5Dp0](https://imgur.com/a/EUA5Dp0)

[https://imgur.com/a/0XPSZ](https://imgur.com/a/0XPSZ)

[https://i.imgur.com/bpAZr5B.jpg](https://i.imgur.com/bpAZr5B.jpg)

And have you seen the Shovel AK?

[https://www.northeastshooters.com/xen/threads/diy-shovel-
ak-...](https://www.northeastshooters.com/xen/threads/diy-shovel-ak-photo-
tsunami-warning.179192/)

~~~
dogma1138
I think you’re underestimating how stupid people are because of the group you
socialize with.

People with the will and skill can make one this isn’t trivial even with all
the videos in the world it will take weeks of practice and will require a good
understanding of chemistry and basic engineering.

Most common criminals wouldn’t know how to measure correctly, use a caliper,
heck most of them won’t be able to multiply add or subtract correctly.

Yet alone hammer forge an AK receiver out of a shovel.

Even if you discount career criminals as the only risk group most people can’t
wire a power socket, switch a lock or fix a leak you want them to forge
recievers and cut grooves in barrel blanks?

Not to mention that any substantial delay would reduce the likelihood of these
guns being used there is a huge difference between a kid that would have to
spend 2 weeks banging a gun out in his garage and a kid that can go into the
school workshop and 3D print a gun on the spot.

~~~
dleslie
I don't live in the valley; I live in, and grew up in, a low-class blue collar
community.

None of what has been posted or mentioned thus far is beyond the skill and
scope of the hardware hacks that I've witnessed from relatively uneducated
neighbors.

Frankly, you're woefully underestimating the ability of the blue collar
masses.

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justtopost
A quick wipe with acetone will solve most of that. I think nanoparticles in
plastic stock for tracing will be the future here, and in many recycling and
corprate dumping issues.

For now, the most effective tracing would be localized nozzle temp effects,
inferring equipment and software by toolpath, and basic composition analysis.
However, just particulate dust embedded in the plastic may be enough to
determine something useful about mfg location.

Somehow, I doubt it will be anything basic police work can't uncover. Treating
3d guns as easier to produce than with hardware store parts does not reflect
the current state of affairs. A trip to home depot will produce a superior
slam fire shotgun with no welding, or machines beyond a drill and file. Its
alarmism and fear mongering.

~~~
therein
I mean, what would you do to trace to the printer if it were printed with 100%
infill and then just lightly touched with a butane torch, put into the oven
for a few minutes or even lightly sanded on the surface?

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ocdtrekkie
Sure, you might be able to confirm a gun came from a given printer when you
have both to look at. But the main issue with 3D printing is you can make a 3D
printer in your basement. Cheaply.

Presumably if you don't want the gun traced to the printer, you destroy the
printer. Or disassemble it and rebuild it which probably adjusts the various
imprecisions that create that unique "fingerprint".

~~~
edanm
> But the main issue with 3D printing is you can make a 3D printer in your
> basement. Cheaply.

I assume you mean "you can make a gun" cheaply. [Edit: actually, I probably
misunderstood - seem further comments below and feel free to ignore this
comment].

Which is not really true today? I mean, you can't get anything near a real-gun
equivalent, and 3d printing really isn't that cheap compared to mass-produced
goods (nor is it likely to be - things are mass-produced for a reason).

~~~
radarsat1
> > But the main issue with 3D printing is you can make a 3D printer in your
> basement. Cheaply.

> I assume you mean "you can make a gun" cheaply.

No, he means you can make a 3D printer easily. So you can make one that
doesn't have whatever restrictions or fingerprints the article is talking
about.

~~~
edanm
Oh that makes much more sense. Thanks.

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delecti
All of the features they use are easily changed in software. And not "an
expert can get to hidden settings to change those aspects", they're as
fundamental to the process of printing a model as selecting single or double
sided is when printing from a conventional paper printer. Depending on what
I'm printing I'll choose anywhere from ~.04 to ~.24mm layer heights, increase
or decrease the speed or temperature, choose from any of ~10 spools of
filament I have in a drawer, vary the infill density or pattern, (or somewhat
less commonly) change the top/bottom layer pattern.

It's not like a Star Trek replicator where you push the "gun" button, you have
to find the model and tweak your settings, and there won't be any single set
of settings consistently used on any printer unless the user is only printing
a single model repeatedly.

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binomialxenon
Tangentially related, but it seems pretty creepy how all LaserJet printers
purposely print uniquely identifiable information on every sheet. I expect
more and more things are going to be like this, although it may be technically
difficult in 3D printing.

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zeure
This is almost guaranteed to be used as a tool to hurt innovation in modified
IP.

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exabrial
I really really really don't understand all the fear around 3d printed
firearms. You can "make" a "firearm" from parts at Ace Hardware that will
discharge more times before failure than the plastic 3d printed firearms. The
whole debacle really demonstrates the misplaced fears and intentional FUD.
Nevertheless, this is fascinating, makes me think of all the machined items
around me and if they too have unique signatures

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alsadi
Seriously! It would be much easier to get an effective ak47 from black market
than printing sub-par plastic useless gun.

~~~
blackbrokkoli
The difference is that you can get a 3D-printer without doing anything shady
whatsoever, as opposed to contacting a black market. This makes no difference
if you're a drug cartel, but for lone-wolf shooters it does.

~~~
tokai
If you are afraid of lone-wolf shooters, the gun show loophole is much much
much more problematic than 3D printed guns.

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alkz
not a reliable method, one could just change the nozzle and/or print with
different parameters

~~~
comboy
Yeah, this article is full of s..tuff. Database of 14 printers and it's not
even clear if it's the same model and manufacturer. So yes, you can tell
something about the settings from the print..

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newman8r
I assume this specific method is only applicable to filament-based printers,
haven't read the study though.

