Improving on the 3d printed lower

[FastRope71]

I'd be interested in hearing your ideas on improving the design of the AR15 lowers for 3d printers.

Here's my idea:
The weak point seems to be the strength in the thin area of the receiver where the buffer tube connects.
My thinking is that there is no need to use the same dimensions currently used. Make the area thicker, and extend the supported area further back. this will require either a longer rear pin detent spring and, possibly, a different method of attaching the plate that hold the spring and detent pin in place, but that could easily be accomplished by drilling a hole in the plate and a screw. additionally you could use a set screw from the side or bottom and a shallow divot in the tube to prevent the buffer tube from rotating. These changes would amount to a minimal change in the design and would only change a few of the parts, used. What say you guys?

[Yogimus]

Yea that front pin sustains most of the force. It COULD be made "fatter"...

[FastRope71]

Hmmmm.....

Yeah, I guess there isn't much to be done to fix that other than improving the material. I suppose a longer pin and making it fatter as Yogi suggested is as far as one could go within the confines of 3d printing. if you changed the disassembly of the rifle to eliminate the tilt of the upper receiver, you might be able to reinforce the area better. That's kind of a stretch, though. I doubt it would result in any substantial improvement.

[Highspeed]

What is the price differential between a mini mill and a 3D printer ? you can mill an AR-15 lower from an 80% casting. Or you can fabricate one. Plenty of blueprints out there.
I'm not sure why the 3D printing thing has captured so many peoples imaginations. Hipsters I guess - they seem to have inherited the spirit of the 'Anarchist Cookbook' ( AKA the blind leading the blind )

And why the AR-15 ? if you want a resistance weapon then look at the Sten, it's a crude piece of shit but it got the job done.

[randy]

I think part of the hype is the how much the idea of peasants printing weapons is causing the anti-civil rights crowds to wet their pants.

A printer is something they understand as opposed to a mill, stamping press, etc. Buy a "printer", download the blueprints, and someone with no knowledge of fabrication techniques can make a useable weapon (according to the press). It's so simple that even an idiot like Feinstein or Biden could do it.

No choke points at FFL dealers. Done in the privacy of your home with no interaction that could be spotted and tracked until it's "too late".

And to them the AR-15 is the poster child of evil weapons. Most them wouldn't recognize the word "Sten", nor know it's production history (Dutch bicycle shops, etc).

I figure it's a meme that's worth encouraging just because of who it's pissing off/freaking out. Personally I'd have more faith in a Sten than the current crop of printed weapons, but I'm a traditionalist.

[Highspeed]

I agree Randy. I'm an old school file and hacksaw guy though.

Edit - there were leaflets detailing how to covertly make the Sten dropped into occupied Europe for the resistance guys. I have never seen one of those and I would love to get a copy. Just for historical ( and machinist nerd reasons ) , I have the Sten blueprints already.

[Jered]

I think part of the hype is the how much the idea of peasants printing weapons is causing the anti-civil rights crowds to wet their pants.

It's awesome because of this.

[slowpoke]

You listed the reason for 3d printed weapons. I'd like to add my thought. The AR platform is nice in this regard because the barrel uses an extension that the bolt locks to, this takes the stress of firing. So what is needed is to come up with a rifle design using the AR barrel with extension and bolt where nearly everything else is printed in plastic, ideally semi auto and bonus for using AR mags. That would really cause some serious gnashing of teeth.

[Old Grafton]

It's not an exact correlation but the printed weapons immediately brought to mind A.E. van Voght's "Weapon Shops of Isher". The whole concept gives liberals the fantods.

[Dub_James]

Based on their latest video, it does appear that they have in fact added material in the rear of the receiver, just below the buffer tube.