Wow, you guys dug this out of the archives  : )

Just to be clear, I have no interest in actually using an AR receiver that was 3d printed. As my username indicates, I am a machinist of some years, and it would be easier and faster for me to machine something that would fire a round than it would be for me to print it out. My OP was more of a chance to test the waters here and see if folks would be opposed ethically to firearms files being posted on the forum.

I'm no firearms expert, but I will say this; while firing high power ammunition out of your 2nd amendment-protected elk rifle is great, there is a guy in an oppressed, developing country who had to build his gun out of parts he found at the junk yard. I don't think printing critical structural components for firearms is the best use for 3DP. I do think that it will eventually allow the oppressed in other countries to build better firearms for themselves and their fellow citizens. They can build stocks, magazines and grips as well as covertly manufacture replacements for procured weapons or other miscellany used for fighting.

Since I first got my SD2, I have used it to make everything from medical device prototypes, all the way to an ar-15 magazine. I'm also designing a custom butt stock for my son's CQB airsoft m4.

The magazine that I printed out could send me to jail in some states. This is America, remember?

Now, for folks in other countries, 3d printing democratizes not only the manufacturing of cute crap you can sell on Etsy, but it also democratizes the ability to stand up against your oppressors. Everyone thinks it great when a tribe in Africa starts making bamboo bike frames for spoiled hipsters to buy at top dollar, but the smiles all get a little uncomfortable when those same people start making weapons to stand for what they believe in, whatever it may be.

So did you ever get it to print properly from your SD2? I'd like to print one, just to put on my shelf!

I do think that it will eventually allow the oppressed in other countries to build better firearms for themselves and their fellow citizens. They can build stocks, magazines and grips as well as covertly manufacture replacements for procured weapons or other miscellany used for fighting.

+1

If that's your question, then the real problem is figuring out how to get more printed guns in their hands before they've had a chance to breed.

Just to be clear, I have no interest in actually using an AR receiver that was 3d printed. As my username indicates, I am a machinist of some years, and it would be easier and faster for me to machine something that would fire a round than it would be for me to print it out. My OP was more of a chance to test the waters here and see if folks would be opposed ethically to firearms files being posted on the forum.

I'm no firearms expert, but I will say this; while firing high power ammunition out of your 2nd amendment-protected elk rifle is great, there is a guy in an oppressed, developing country who had to build his gun out of parts he found at the junk yard. I don't think printing critical structural components for firearms is the best use for 3DP. I do think that it will eventually allow the oppressed in other countries to build better firearms for themselves and their fellow citizens. They can build stocks, magazines and grips as well as covertly manufacture replacements for procured weapons or other miscellany used for fighting.

Since I first got my SD2, I have used it to make everything from medical device prototypes, all the way to an ar-15 magazine. I'm also designing a custom butt stock for my son's CQB airsoft m4.

The magazine that I printed out could send me to jail in some states. This is America, remember?

Now, for folks in other countries, 3d printing democratizes not only the manufacturing of cute crap you can sell on Etsy, but it also democratizes the ability to stand up against your oppressors. Everyone thinks it great when a tribe in Africa starts making bamboo bike frames for spoiled hipsters to buy at top dollar, but the smiles all get a little uncomfortable when those same people start making weapons to stand for what they believe in, whatever it may be.

you should really read into the techs I posted above

I might make the same suggestion. This may be helpful in understanding some of the basics. I'll quote a few paragraphs from the following link:

http://www.madehow.com/Volume-1/Revolver.html

<<<Forging the components
• 1 The major components of most revolvers begin as a group of steel or stainless steel blanks that are forged into close approximations of the desired parts. The basic shape of each part is formed by placing a heated blank of material into a forging press and impacting it with several hundred tons of force. This impact forces the metal into the forging die, a steel block with a cavity shaped like the part being produced. Sometimes, multiple strikes by the press are required, each with a more precise die than the previous step. The resulting part is both extremely strong and very similar to final shape.

Annealing and machining
• 2 After forging, the flow patterns of the metal must be stabilized by heat treating. This procedure consists of reheating the parts in a controlled atmosphere to relieve internal stresses without reducing the metal's inherent strength.
• 3 Machining can now begin on the frame, cylinder, and other component parts. Most modern revolvers are manufactured on automated, computer-controlled machining centers and lathes. However, a number of manufacturers have had such excellent service and results with some of their machines that they continue to utilize fifty-year-old equipment. Regardless of whether older or modern equipment is used, the basic process actions of milling, drilling, and tapping are essentially the same. The tolerances on this machining must be held within one or two thousandths of an inch. All of the components, from the screws to the trigger, are machined using similar processes.
• 4 To effectively machine the raw forging, a worker clamps it into a holding apparatus that secures the part during machining. Properly designed fixtures also contain tool guides and bushings to support the cutting tool and increase accuracy. Many of the operations performed will require several specialized fixtures. Cylinders, screws, shafts, and barrels are made on lathes while frames, sideplates, sights, and triggers are made on a milling and machining center.>>>

Truly, there is a lot more to it than making hot puddles out of powdered metal.

DePartedPrinter wrote:

SLS, DMLS, and EBM technology is all perfectly suitable for building functional firearms. You might consider it brain dead media hype but as the cost of this technology comes down the feasibility of functional 3D printed firearms increases.

Even if you accept the proposition it may eventually be possible to print a gun of better quality than current printing technology permits, I don't see that as the question that should be answered. The question that should be answered is if it will ever be possible to print a gun of such high quality that it would be in some way superior to even a budget class of modern firearms.

It is possible on current technology. Milled firearms have limitations...you should really read into the techs I posted above.  Initial cost of the machine might be prohibitive at the moment but time should take care of that...

SLS, DMLS, and EBM technology is all perfectly suitable for building functional firearms. You might consider it brain dead media hype but as the cost of this technology comes down the feasibility of functional 3D printed firearms increases.

With all due respect, I would suggest persons interested in the idea of 3D printed guns take some time to study SAMMI specs for things like cylinders, chambers, and gun barrels.

Without exception, these parts are made of specially tempered, high grade carbon steel, developed exclusively for those parts of a gun that MUST stand up to the high pressures developed in modern firearms so they don't blow up in your face.

When you cut through all the smoke, mirrors and hype on printed guns, what you have left is nothing more than what used to be referred to as a "zip gun". Constructing a device that will cause a cartridge to detonate isn't exactly rocket science. Unemployable highschool drop outs have been doing it for at least a century. At the end of the day, what it comes down to is the difference between a firearm you can safely, accurately and reliably put 20,000 rounds of ammunition through without any problem, and one that may take your hand off the first or tenth time you try to fire it.

In a typical year I'll go through several thousand rounds of ammo in target practice and plinking. I know guys at the range who shoot competitively who go through more than that in the average month. On a good day I can consistently shoot groups under an inch at 100 yards from a benchrest. On the day someone comes along who does the same with a plastic gun they whipped out on a 3D printer, I'll listen respectfully to anything they have to say on the subject. However, until that day comes, you'll have to pardon me for being skeptical on the whole printed, plastic gun thing.

If a person isn't a criminal and wants to own a gun, there is no shortage of acceptable to excellent quality firearms to choose from, at prices that will fit any budget. In all seriousness, what possible use would anyone, not a criminal, have for a plastic gun when they may walk into any gun store and buy a safe, quality firearm at an affordable price, that is so far superior to anything you could make on a printer that there is no comparison?

Even if you accept the proposition it may eventually be possible to print a gun of better quality than current printing technology permits, I don't see that as the question that should be answered. The question that should be answered is if it will ever be possible to print a gun of such high quality that it would be in some way superior to even a budget class of modern firearms. Keep in mind that a top of the line firearm is manufactured to tolerances measured in the fourth decimal place, out of materials that will easily withstand pressures well over 100,000 PSI, with which a world class marksman may use to accurately hit a target a mile and a half away. When that can be done with a printed gun, not only will I change my mind on the subject, I will be be more than a little bit impressed.

If you want a gun that's mostly made from plastic, buy a Glock.

Among other considerations, even a low power, sissy round like the .223 used in AR 15s produces 50,000 pounds of pressure per square inch. It it were safe and practical to make lowers from plastic, you can bet your last buck Armalite would have been making them out of plastic for the past several decades.

It's also worth noting that under Federal law, the lower receiver IS the gun. Unless you have a Federal license to manufacture firearms, you may want to weigh whatever short term joy you'd experience from trying to build a gun on a printer against a long and unpleasant stay in a Federal prison.

And, seriously, you can pick up a stripped lower receiver for under fifty bucks that is made out of materials that will last practically forever. If you can legally own a firearm, why would you want to fool around building one out of breakable plastic parts?

If you will pardon me for being frank rather than diplomatic, while I have a very high opinion of the Second Amendment, I have a very low opinion of stupid. There's a good reason guns are made out of metal. It's because making them out of plastic is stupid.

On top of everything else, the whole printed gun thing is nothing more than brain dead media hype. If you want to manufacture firearms from computer files, trade in your over priced 3D printer for a milling machine. If you want to get into the illegal arms trade, you can cut an AR lower from a block of aluminum a lot better, faster and cheaper with a CAD file and a milling machine than you can with a CAD file and a 3D printer.

About the only practical application for 3D printing and guns is a person might be able to do some interesting things in the way of custom grips and stocks. If you come up with a good design, you might even find a real market for them, and without having to worry about the Feds busting down your door at three in the morning.

SLS, DMLS, and EBM technology is all perfectly suitable for building functional firearms. You might consider it brain dead media hype but as the cost of this technology comes down the feasibility of functional 3D printed firearms increases.

I too have been wondering why nobody is 3D printing custom pistol grips for target pistols like High Standard etc.

I have seen a few for 1911 on thingiverse.
Personally, I never liked the polymer bodies. All metal handguns always had a nicer balance IMO. Personally, I see absolutely nothing wrong with shared files for grips, mounts, etc. I love my guns and I love me some printing, but I can easily see how sites like DefCAD can be abused.

If you will pardon me for being frank rather than diplomatic, while I have a very high opinion of the Second Amendment, I have a very low opinion of stupid. There's a good reason guns are made out of metal. It's because making them out of plastic is stupid.

+1, plus i'm too fond of my fingers and face to want to fire a printed gun.

If you want a gun that's mostly made from plastic, buy a Glock.

Among other considerations, even a low power, sissy round like the .223 used in AR 15s produces 50,000 pounds of pressure per square inch. It it were safe and practical to make lowers from plastic, you can bet your last buck Armalite would have been making them out of plastic for the past several decades.

It's also worth noting that under Federal law, the lower receiver IS the gun. Unless you have a Federal license to manufacture firearms, you may want to weigh whatever short term joy you'd experience from trying to build a gun on a printer against a long and unpleasant stay in a Federal prison.

And, seriously, you can pick up a stripped lower receiver for under fifty bucks that is made out of materials that will last practically forever. If you can legally own a firearm, why would you want to fool around building one out of breakable plastic parts?

If you will pardon me for being frank rather than diplomatic, while I have a very high opinion of the Second Amendment, I have a very low opinion of stupid. There's a good reason guns are made out of metal. It's because making them out of plastic is stupid.

On top of everything else, the whole printed gun thing is nothing more than brain dead media hype. If you want to manufacture firearms from computer files, trade in your over priced 3D printer for a milling machine. If you want to get into the illegal arms trade, you can cut an AR lower from a block of aluminum a lot better, faster and cheaper with a CAD file and a milling machine than you can with a CAD file and a 3D printer.

About the only practical application for 3D printing and guns is a person might be able to do some interesting things in the way of custom grips and stocks. If you come up with a good design, you might even find a real market for them, and without having to worry about the Feds busting down your door at three in the morning.

+1 I too have been wondering why nobody is 3D printing custom pistol grips for target pistols like High Standard etc. make a file that you can punch hand measurments in for specific pistol and print.

Among other considerations, even a low power, sissy round like the .223 used in AR 15s produces 50,000 pounds of pressure per square inch. It it were safe and practical to make lowers from plastic, you can bet your last buck Armalite would have been making them out of plastic for the past several decades.

It's also worth noting that under Federal law, the lower receiver IS the gun. Unless you have a Federal license to manufacture firearms, you may want to weigh whatever short term joy you'd experience from trying to build a gun on a printer against a long and unpleasant stay in a Federal prison.

And, seriously, you can pick up a stripped lower receiver for under fifty bucks that is made out of materials that will last practically forever. If you can legally own a firearm, why would you want to fool around building one out of breakable plastic parts?

If you will pardon me for being frank rather than diplomatic, while I have a very high opinion of the Second Amendment, I have a very low opinion of stupid. There's a good reason guns are made out of metal. It's because making them out of plastic is stupid.

On top of everything else, the whole printed gun thing is nothing more than brain dead media hype. If you want to manufacture firearms from computer files, trade in your over priced 3D printer for a milling machine. If you want to get into the illegal arms trade, you can cut an AR lower from a block of aluminum a lot better, faster and cheaper with a CAD file and a milling machine than you can with a CAD file and a 3D printer.

About the only practical application for 3D printing and guns is a person might be able to do some interesting things in the way of custom grips and stocks. If you come up with a good design, you might even find a real market for them, and without having to worry about the Feds busting down your door at three in the morning.

As to the AR receiver, cut of the part that sticks out the most (the ring) and print, then superglue it onto the main part.