Posted on 07/29/2012 9:16:20 AM PDT by marktwain
Given the recent appalling events in Aurora, Colorado, there’s been a renewed call for greater gun control and a ban on assault weapons.
I’m in favor of tighter gun control and a ban on weapons that are unnecessarily powerful but I’m afraid that technology will soon make any legislation that limits the availability of any kinds of guns ineffective.
To understand why this might happen, you need to understand a technology called 3D printing.
3D printing allows you to build things that are, as the name implies, three dimensional. A few years ago 3D printers were very rare, hugely expensive, and hard to use. But as with anything that can be driven by computers, 3D printers has become cheaper and cheaper to the point where, today, you can buy a 3D printer, off the shelf, for as little $500.
Using either free or low cost computer aided drafting software you can create digital 3D models of pretty much anything you can think of and, with hardly any fuss, your 3D printer will render them as physical objects.
The only contraints on what you can print are that the size of the printed object (typically a maximum of 6 inches by 6 inches by 6 inches unless you spend more money on your printer ; the bigger the final object you want, the more you’ll have to spend), the material printed (all of the low end printers can, at present, only print with thermosetting plastics; very high end printers can print with ceramics and metals), and the resolution of the printer (for current low end printers this is typically around 0.1mm).
So, can you print a gun? Yep, you can and that’s exactly what somebody with the alias “HaveBlue” did.
(Excerpt) Read more at forbes.com ...
I have thought along these lines as well, but an insurgency does not need very many rifles that can make head shots at 300 yards, and they are one of the most common and least likely to be controlled items in the U.S. citizen arsenal.
An insurgency, I suspect, can use a lot more pistols and sub-machine guns. Those can be assembled rather cheaply and quickly with a lot less knowledge than you possess.
Still, it is rather an academic discussion, because the U.S. civilian supply of rifles, shotguns, and pistols is enough to meet the insurgency demands for the foreseeable future.
We have won the debate on an armed population. Now we need to win the war to uphold the Constitution.
The Second Amendment serves as a clear guide to differentiate between those who wish to follow their oath of office, and those who disdain the restraints of the Constitution.
This thread completely underestimates the power of Government. Worry about that not gun size, power and availability.
I perhaps over-simplified this: The steel for the barrels is quenched/tempered at the mill, but the bar stock, as delivered to the barrel makers, isn’t usually heat treated beyond that by the barrel makers. It gets drilled, then reamed, then the rifling is cut/broached/etc and then (on the high end barrels), the bore is hand-lapped with a lead lap.
So you’re right in that it came from the mill Q&T, but my point is that the firearms industry doesn’t do a bunch of heat treatment on it - the way they do on receivers (for example). The bolt head and locking lugs on bolt action receivers are heat treated after they’re machined, for example. Those areas, even with MIM or 3DP, are going to absolutely need heat treatment. Or you’ll need to 3D print a different action than a bolt or AR-type action.
Even dead soft 4140 would be more than strong enough to contain modern smokeless powder, if you used enough radial thickness around the chamber. The gun buyer would have a hissy the first time he dropped his rifle, but the barrel wouldn’t let go under fire.
But let’s say you did want to heat treat the result. No big deal. Use an air-quenching alloy for the print, put an induction heating loop on the output side of the process, push the result through and wha-la, you’re done.
One of the reasons why barrels are made from 4140 or 416 is the ease of machining, not just the strength or heat treat properties. If we get rid of the machining requirements because we’re squirting goo out of a printer... well then, we could use all sorts of new alloy or material technology that might not require a heat treatment because we don’t need to worry about machining it.
This 3D printing stuff is going to radically change the manufacturing sector. Once you liberate your mind from the requirements of “subtractive” machining, and start thinking of material science without regard for the older ways of turning out a product... you suddenly see the skies part and trumpets blair. But more importantly, the entire process becomes as very repeatable for people who are more computer-savvy than machine savvy. In the future, it could be as easy as “pour 3D ‘ink’ in here, load program, press ‘go’ button, and wait.”
Let’s just say, as a retired engineer, I used to be a skeptic. Two years ago in a machine tools technology department at the local college, someone called me into their office and said “We can print plastic ball bearings that roll with this printer. We’re just doing this as a prototype, soon we’ll be able to make real bearings.”
I said “Bullcrap.”
He said “OK, sit down, let’s have a cup of joe while the program runs and I’ll show you some product lit from some companies...”
This we did.
30 minutes later, I had to eat my words.
It’s coming. For real. It might not be fully here yet for the average home hacker with a less than $10K budget, but it’s sure as heck coming - and quite quickly.
Okay. I will defer to you on it. If true, maybe I can print me up a Ma Deuce! Haha.
Okay. I will defer to you on it. If true, maybe I can print me up a Ma Deuce! Haha.
Yes, you can.
But CNC machines of the size that can work on gun parts will go between 4,000 pounds to 12,000 pounds, require three phase power and a bunch of room.
3D printing? Nowhere near as much room.
I can’t stress enough how disruptive a technology 3D printing will become. It will be to manufacturing what the Internet was to the mainstream media. There’s plenty of new sources of information on the Internet - decentralized, local, topic-specific, with deep expertise, rapid updates, responses, two-way dialogs, etc. All hugely disruptive to the old print media, which I’m sure you’ll agree, is on it’s last legs.
This 3D printing stuff promises to be the same, IMO, to the “subtractive” machining industry - including the companies that make CNC mills, lathes, grinders, etc.
If I were Gene Haas, I’d have a team of engineers and techs working on a 3D product line right the heck now.
Well, funny you should mention a Deuce.
If there’s ONE barrel you could have picked that does have a component therein that’s as hard as the Hinges of Hell, it’s a M2HB barrel. There’s a section in the barrel forward of the chamber for about 1/3rd of the length that’s lined with stellite. If you don’t know what stellite is, google it. It’s ferociously tough stuff. It’s the reason why a M2HB can withstand some serious rock-n-roll time. Rc’s in the mid-40’s and up.
But if we’re talking just civilian .50BMG barrels for single/semi-auto rifles, we’re back in the realm of “normal” barrel steels.
If ignorance was bliss this author would be one happy man.
The AK-47 is no more powerful than a 30-30- Winchester.
The M-1 carbine is no more powerful than a 32-20 Winchester rifle.
The M-1A with military ammo is less powerful than a bolt action rifle with .308 hunting ammo.
The AR-15 is more powerful than a .222 Remington varmint hunting cartridge, but LESS powerful than a .222 Magnum Remington varmint cartridge, and 5.56 MM ammo should not be fired in .223 chambers. Same for reverse.
To understand what I am saying, check your warranty info. If you use HUNTING AMMO in some military style rifles it voids the warranty as there is a minor but serious difference between military and hunting ammo.
***So far, no one is man enough to fire a .75 caliber rifle.***
No problem in other nations! A 12 guage shotgun shell will fit a .75 inch pipe very well. You can make a nice slam fore shotgun out of them!
But then, the women will again have to start going to the croc infested water holes for water.
Here is a thread with a picture of a functioning printed lower in .22LR based on the AR form.
LLS
Good luck with printing springs and screw threads. Some things need particular material characteristics where a thermoset plastic just won't do. It would be better if you could build your model with dental wax and then use the "lost wax" casting process to produce metal parts for things like receivers, frames and slides. It would be easier to make a barrel from steel round stock or tubing for a shotgun. It would be more costly then hand tools but a small lathe/mill would go a long way toward the necessary precision.
There are even CNC machining centers available for around $7000. Yes that's expensive but I'd bet most hobby fanatics spend more then that on their secret pleasures. Add a table top computer with a solid cad program and a post processor to output P code to drive the CNC and you can forget about the 6"x6"x6" 3-D printer and go direct from drawing to metal part for about $10,000.
I was the system manager for our engineering department CAD/CAM system for almost 15 years and got involved with "instant prototyping" for the last five years. We used Pro-E for modeling. Most of our stuff was made from castings and so the "prototype" was usually the pattern work for producing the finished casting. You just drew the part to required dimension then dialed in the shrink factor for the material and any draft, add the core prints, the program then finished the model and output the P code.
Regards,
GtG
I still have my “FirePower” magazines from the early 80’s. One of their writers (legally) made a STEN type 9mm submachinegun from scratch. Only took him 2 or 3 days, as I remember. I think a welder and a drill press were the extent of his power tools.
Very interesting. In a way, this sounds like a point between old machinging tech and full blown nanotechnology. Can you expand on the advantages of printing tech vs. machining or investment casting/machining? Do you think printing tech has an overall economic advantage? After all, the raw material cost of most things is a pretty small percentage of the entire cost.
I can see where printing tech might save some material costs... but the special “ink” likely will cost much more than raw steel, aluminum, or nylon.
Are there discussions on the net that are geared toward where this technology is heading, and its advantages?
Perhaps a quibble, but 3/4 nominal galvanized pipe has an actual inside diameter of .824 inches. 1/2 inch nominal has an actual inside diameter of .622. These are for the most common schedule 40 size of galvanized pipe.
BTTT
Quite a nice selection of paintings you have on your homepage! I can paint a wall, but that’s about it.
Somewhere I have a copy of “Edge of the Anvil”, but have never done as much with blacksmithing as I’d like.
So, 3/4” G.I. or black iron pipe would make a 12GA barrel? What about 1” mechanical tubing, 0.120” wall, wrapped with piano wire & brazed/soldered? That’s about 0.760” bore - 12Ga is 0.729”, so maybe too loose? Shells split?
I guess some use black water pipe. I personally would prefer to use heavy wall seamless pipe. If I fired one of those I want to make sure I still have hands and fingers left.
Looks like the site is is still up:
Check out the Four Bore rifle:
http://www.riflemagazine.com/magazine/article.cfm?magid=44&tocid=553
I know someone who has made two of these. They’re not cheap - like $25K and up custom rifles.
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