Posted on 01/23/2013 12:17:32 PM PST by Manta
Please throw me a link to a machine that will print in metal suitable for a gun that will not self destruct on the first shot.
It seems that 3d metal printing a 100x more expensive than conventional manufacture. 30 years from now who knows?
One need only engineer the gun specifically to deal with the recoil and shock of igniting the primer. The barrel and chamber will still have to be made of steel. The rest of the gun could be made of plastic and off the shelf parts that are legal for purchase now.
Different scenario. Counterfeiting is illegal, making guns, even without a license, is not. Now if they were to ram through a law violating our civil rights by criminalizing manufacture, that would be another story....
For printing something that one can buy in a store, additive manufacturing will almost always be more expensive than the mass produced part. However, if they go around banning things, then suddenly the economics gets better, because available but expensive is better than unavailable.
If they start making models for drug accessories as well as weapons, then half the people in America will buy one.
As you say...
Sure you can. You will pay usurious prices.
I went shopping and decided I didn’t need a Black Gun as I already have plenty of Semi-Automatics.
The fact that the shelves are bare of uppers and lowers as well ammunition demonstrates the polls where they claim 90% of gun owners want more restrictions such as universal background checks is a flat out lie and manipulation.
I know several people who buying something they never thought about buying before for the sheer reason this administration, many governors and state legislators are proposing or have passed onerous restrictions on gun ownership, magazines and ammunition.
FK em.
He may well have printed a select fire receiver, since manufacturing a machine gun does not require a FFL.
Sure, that is your standard manufactured AR-15, but remember that the AR-15 was designed as a fully auto weapon and can easily be converted back into one. This guy is printing his own receivers, so he could have easily and legally done just that.
“In the case of an AR15 the upper is the regulated part which requires a firearm manufacturers license to make.”
I think you can manufacture it with no license, as long as you are not intending to sell it.
“I don’t see anything in a gun that someone could not make on a current metal printer, except maybe the spring.”
Springs are cheap though, and pretty impossible to regulate. The real problem is the barrel. You might be able to print a metal barrel with the correct geometry, but it won’t be strong enough to use in an actual weapon. It may last a while, but eventually, that part will fail.
This is why I think that trying to manufacture an ordinary firearm with current printing technology is the wrong track. Instead, they should focus on a design that can function reliably for a short time, say a few hundred rounds, while being cheap enough to throw away after that. Just use it until it starts wearing out, then print a new one.
Yes, I have written this on other threads, the beauty of 3d printing is that you get to customize your own design. You don't need to copy a commercially available product if you don't want to, and that includes weapons as well. If they can't make a gun barrel, I'm sure they can make other weapons that people haven't thought up yet.
Gun barrels that can be used in a 3D printed receiver would be childs play on a modern CNC machine. Make pistol barrels about 4 inches long.
I bet a 20,000 dollar machine could turn out hundreds a day.
take a look at the design of the Zip22. Simple, and it uses very common .22 rifle (1022) magazines.
You can make guns for your own use without a manufacturer's license, but not NFA items.
OK, there’s lots of fretting about the barrel issue.
Right now, it is nowhere near cost-effective to “print” a barrel. But making a barrel isn’t some deep, dark witchcraft. The machines to do this aren’t new.
For people who wonder “How DO you make a barrel?” Watch this video:
https://www.youtube.com/watch?NR=1&v=kvnKSfDUCWY
OK, the rifling machine you’re watching there, painted in bright green, is an old Pratt & Whitney “sine bar” rifling machine. The name of “sine bar” is taken from the bar that controls how fast/tight the twist of the rifling is. If you freeze the video at 2:29, and then allow it to run forward to 2:36, I can describe what’s going on.
The green bar on a slant to the axis of the machine is a “sine” bar. Under that bar, which is set at an angle to the longitudinal axis of the machine, is a slot. There is a follower on the blue cross-slide under the green bridge/sine-bar that pulls the blue cross-slide across the long axis of the machine, and that linear motion of the blue slide is converted into a rotation of the cutting tool as it runs down the barrel.
The cutting tool is a wee little scraper in the head end of the rod that keeps poking it’s head out of the end of the barrel. They’re set up to cut on only one direction of the stroke, typically on the pull.
The barrel is rotated by a fixed about in those chucks every time the cutter emerges from the end of the barrel.
The cutter’s engagement into the wall of the barrel is increased every so many passes through the each groove in the barrel - but the advance in the depth of cut is by like a tenth of a thousandth per increase. Increasing to cut something like a thousandth instead of a tenth would result in too much material in the bore for the cutter to clear.
OK, lots of you guys who might shoot guns, but not work on guns or in machine shops are looking at that machine and saying “How old is this technology? How old is that machine?”
You guys sitting down? You might want to.
That machine, the P&W sine-bar rifling machine, was first made in the 1890’s.
Not only before WWI - but a pretty long time before WWI.
The best shooting barrels in the country are made on machines like this. Krieger, Bartlein and other single-point-cut barrels are made on P&W machines like this *today* - right now.
OK, what’s my point?
Someone with a lathe and some get-up-n-go can accomplish the same thing on an old lathe. I’m not going into tremendous detail how to do it, because it would require a long write-up, but suffice to say I could make a machine that would rifle a barrel in the same manner on some old, cheap lathe like a South Bend 13” swing machine, especially one with a longer bed. The leadscrew would be disconnected from the headstock gears and the spindle in the headstock would be used to hold the barrel. The leadscrew would be driven by a servo motor. The rotation of the spindle (with the barrel through it) would jump from groove to groove, then a sine-bar mechanism mounted out on the end of the bed would control the rotation of the cutting tool. The advance/retract of the cutting tool would be done by powering the leadscrew with the servo motor.
The same lathe could be used to deep-hole drill the barrel, then ream it.
Harry Pope used to make barrels on a modified lathe with a single point cutter.
The patents for Eugene Stoner's AR-15b rifle developed for Armalite asa subsidiary of Fairchild Industries subsidiary of Fairchild Aircraft, were for a fully automatic weapon.
It wasn't until around 1962 that Colt Industries, by that time manufacturing the AR-15 design as the XM16 rifle for USAF and U.S. Army contract consideration, began the manufacture of a semiauuto-only version, known as the SP-1.
I think it can be done, if not likely at 50,000 CUP. I believe I'd begin with a printed launcher for the GyroJet cartridge, produced by AAI and others, or a smaller version of the high-low pressure cartridge as used in the 40mm ammunition for the M79 and M203 grenade launchers. Even a single-shot low-cost *printed* 40mm blooper would be formidable. And of course it could be a one-shot disposable item like the WWII German Panzerfaust 60 or the American M72/M72A3 LAW family.
You are aware that during WWII, the British firm of Lines Brothers developed a process of stamping a barrel out of flat sheet metal plate, after which rifling was engraved upon it by means of diagonal milled grooves, followed by rolling the flat along a mandral and then fusion welding the barrel seam closed.
If not terribly elegant or traditional, the process resulted in a barrel suitable for use with the 9mm Sten submachinegun, and lowered the production costs for that weapon down to the vicinity of $6.00 U.S. each, less than the seven magazines that accompanied each guns.
Most of the Lines Brothers Mark III guns were airdropped to friendly partisan forces or used as secondary armament in Brit fighting vehicles. But there are those who reckon the Mk III design is considerably more reliable than the predecessor MKII despite the manufacturing shortcuts.
Ran an 80-ton L&J myself.
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