Skip to comments.Surprising Tools of Modern Gunmaking: Plastic and a 3-D Printer (NYT)
Posted on 01/29/2013 5:01:19 PM PST by Brad from Tennessee
A man in Wisconsin viewed it as a technical challenge. Another, in New Hampshire, was looking to save some money. And in Texas, a third wanted to make a political point.
The three may have had different motivations but their results were the same: each built a working gun that included a part made in plastic with a 3-D printer.
What they did was legal and, except for the technology and material used, not much different from what do-it-yourself gunsmiths have been doing for decades. But in the wake of the shootings in Newtown, Conn., and the intensified debate over gun control, their efforts, which began last summer, have stoked concerns that the inexpensive and increasingly popular printers and other digital fabrication tools might make access to weapons even easier. . .
(Excerpt) Read more at nytimes.com ...
Sounds fun but in California it would be classified as a “zip gun” which is illegal (who would have thought?). The plastic AR-15 lower would work the best as it doesn’t have to deal with any stress (that’s all in the upper receiver which isn’t considered a gun by the ATF, only the lower). Still wouldn’t stand up to too much use but would do in a pinch.
The reality is that neither will do you much good if you can’t get bullets and you can’t practice with it. If guns are made illegal what are you going to do? Most likely hide them or bury them. Ask the Scott’s how much good that does (they still find claymore’s in roof thatching every once in a while by the way).
Without some kind of organized resistance there is no resistance and just like in the old CCCP the police (and their informants) are everywhere. This is why modern police states typically do not fall until they have economically collapsed, because as long as they have money to pay for the thugs (police in this case) to keep on beating down the population the lid will stay on the pressure cooker. As went the Soviet Union so will go the USSA, but what comes after may not be any better and could be a lot worse than what comes before.
This printing a gun crap is just ridiculous. Printing the plastic parts is not printing the gun. You could whittle the plastic bits from wood - who cares. Try printing the 4140 steel parts, you useless geeks. Have we reached a univeral retardedness or what?
the plastic lower receiver does not have
look exactly like its metal counterpart.
is there some reason that the part can’t be beefed up
where needed, to make it usable?
Print me a lead bullet and some gunpowder you complete fools. I’m done with this geewhiz print a gun crap.
What is the best way to invest in 3-D gun printing, to keep the technology going?
I agree that the plastic printing stuff is limited in practicality (though it is perfect for testing new parts for fit before using the same data files to run the CNC machine tools). I do like the fact that these 3-D image files are flying around the internet. It helps the goal of the left - full disarmament of the people - slip further from their grasp.
zagger, you seem to be missing the point.
all the parts of a ar-15, can be ordered mail order,
without needing a FFL,
except the lower receiver.
Plastic 3D printed lower with metal parts for completion works well with a 22 cal AR-15 upper. When 3D printers that uses less brittle and bit more rubbery plastics are available for home use, printed AR-15 lowers would be more resilient to handle 5.56mm or .223 cal. Right now one can with a CAD program thicken the stress points of the original AR-15 lower without interfering with the moving parts and upper functions is possible to make the design more resilient with ABS. Problem with plastic is the heat generated from excessive and sustain firing can melt the lower plastic receiver. I do not know how well these ABS plastics can survive cold storage without it shattering under stress. Metal sinter 3D printers are available but very expensive to own privately. IMHO 22 cal AR-15 is possible with a 3 D printed lower. Anything heavier would have problems.
I designed some involute spur gears a few years ago on a 3D CAD system and had some SLS rapid prototypes made. We used SLA (stereolithography) back in the 90s, but it was kind of brittle.
The SLS gears ran fine, but they were not near strong enough to transmit any real torque.
Until these 3D printers use engineered firearm polymers, the idea of making firearms this way is absurd. Then, there is the steel component issue you brought up. That makes the idea of 3D printing a gun with current technology practically useless.
The original gears I redesigned were ABS. It’s not very strong, and UV light severely weakens it’s mechanical properties.
The production gears we used were made from PBT, which is about 4X stronger than ABS.
What if the ABS part was painted with Durocoat, would that block out the UV affects?
“What if the ABS part was painted with Durocoat, would that block out the UV affects?”
It probably would. There are UV stabilizers that can be added to plastic compounds.
I just think there are better plastics than ABS, and firearms’ plastics are specially engineered, not generic general purpose plastics like ABS and acetal copolymer.
Print me a sausage & pepperoni pizza with everything on it!!
You are absolutely right. Something I've been saying is that the politicians are going after stupid 3D printers, that are going to put maybe 20 plastic toy guns out there to be played with by hobbyists. Meanwhile, gangs and punks are getting real guns easily and don't obey any laws. Politicians are hurting the rights of honest citizens and ignoring the punks and their crimes. This news about plastic printers is a waste of time.
How about printing suppressors?
I seriously doubt that would work. Suppressors need to be metal to handle the heat and pressure.
Original stereolithography prototypes were made for “show and tell” marketing demonstrations. My company made some SLA rotors for a flowmeter that we actually tested, but they did not have the long term wear properties for production use.
3D printers can make functional parts now. However, I do not think they can currently make parts strong enough to make something like an engine or a firearm that would be durable enough to have an acceptable lifespan.
They do have metal sintering 3D printers now, and some engines use sintered, or “powdered metal” connecting rods.
A 3D printer can make a part like that, but I’m honestly not sure if it would have the mechanical properties to be strong enough to work.
Perhaps a freeper out there could enlighten us?
Perhaps you could answer some basic questions for me.
I get the concept of directing the laser in three dimensions, but after the ‘soup’ is mixed how does the process proceed.
What holds the first transformed molecule in a fixed position within the ‘soup’, allowing precise and accurate continued ‘building’? Assuming that heat is generated at the point of creating the solid are aspects of fluid dynamics at play at that scale? Is there an armature of sorts that’s seeded?
Is it possible that a carbon fiber wire frame form can be used as an armature upon which layers are added all around, thus providing reinforcing.
Interesting that you closed with “...would be durable enough to have an acceptable lifespan.”. Might well be that acceptable life span could be altered by having the means for production at hand. Barring catastrophic destruction one might accept a shorter product life span knowing that you’ve already got another one in the oven.
And there are scenarios where early catastrophic failure is a positive feature much in the way battlefield weapons are left booby trapped.
I have read that the points are measured in microns so the lasers and the plastic dispenser meet at a very finite point. The 3D is plotted in the x,y and then repeated in the z until each layer is complete.
Theoretically you could lay in some kind of nano-fiber to strengthen the layers similar to the way fiberglass can strengthen cement.
I think the end result will be some form of the above in conjunction with a radical redesign of the firing mechanism.
I think because because early designers were working in steel, the designs didn’t give much attention to the forces created by the bullet.
I think that there are possible designs that could severely limit the impact of the bullet recoil on the frame of the gun resulting in a metal barrel / coil / piston / plastic frame hybrid that would stand up to repeat firing... not going to work using current gun designs though....IMHO
3-D printing is here to stay. 3-D printing in metal is a rapidly evolving industry. Whether or not 3-D printing of weapons parts is restricted by law the science will remain intact somewhere.
If the part that the ATF considers a gun can be easily made in the home - then the other collection of parts can be purchased without any paperwork.
The lower receiver is the “gun,” according to ATF.
There are machines that can print stainless, Inconel and Ti alloys with excellent material properties. Granted, these machines are waaay out of the individual’s price range, but still, the technology is there.
“Print me a sausage & pepperoni pizza with everything on it!!”
Yeah! And print me a beer while you are at it!
I can tell you that the old SLA parts were made up by adding very thin layers one upon another creating the solid part. That is why these parts all appeared to have a rough 125-250 RMS machined finish on them, unless they were polished by another process.
As far as lifespan, a fragile engine would be of no use to anyone.
A fragile firearm that could be shot some without breaking or blowing up could be useful as a “throwdown”.
“There are machines that can print stainless, Inconel and Ti alloys with excellent material properties.”
Wouldn’t the metal grain alignment of a hammer forged barrel still be superior to a printed one?
I guess they could make some printed 4140 or 4150 barrels and do some c.u.p. testing on them.
Thank you guys for the replies.
Seems I’m guilty of not keeping up with the 3D tech. Based my question on a remembered report published in Smithsonian or Nat’l Geo when liquid polymers were being used. The photo of lemon-lime tank lingered in my mind, hence the reference to the ‘soup’. Seems to be a dry process not that far removed from Xerox copier tech.
As far as being suitable for such high temp/high stress constructs they do have a ways to go. But imagine all the little light duty parts that can be re-manufactured at home rather than sending stuff to the dump. I can also see customizing new parts for performance, ease of use, or just to make it look better to my eye.
New vistas yet to be revealed.
Mike, as far as high strength steel parts you’re probably aware of the CAD/CNC controlled cutting tables that allow for a variety of cutting heads. I was looking into purchasing such several years ago in conjunction with CNC mills. Laminated plate components such as the adjustable wrenches are now within reach of the small shop, home or commercial. Assembling a revolver frame from such is not a complex operation. And finally after half a century of acquiring tools and time spent in arch metals I can say that no one machine will do every thing. Nice to think of such, but like the multi-mate tools one subordinates the needs of the project to the tools at hand, not always the best or optimum approach.
Anyway, thanks for the response and the goad to do my own homework.
I’m not a metallurgist (my area is automation), but I would imagine there would be differences in the grain structure and properties. I don’t know if those differences would preclude there use in high pressure applications like barrels, or if those differences could be mitigated by some type of post processing. Still - it is possible to print fully dense metal parts, and that’s a start.
What is a good way to invest in the 3-D printing developers?