3D printed AR Lower

>>31445950
It's the upper you need to worry about. What with it being the part that contains an explosion and all

>>31445968
The upper is from PSA, nothing unique. I'm just asking about a 3D printed lower.

>>31445950
Sounds like SLS printers, and those make pretty good quality parts. I'd say it should work, yeah, I don't think it'll pose any issue, AR lowers are plastic anyways, aren't they.

>>31446020
What lowers are you talking about?

>>31445950
Which fortus do they have?

>>31446020
Nah fortus are fdm printers.

>>31445950
>making a firearm
>on campus property

No way this could end badly...

>>31446061
he could make an 80%

That way if he gets in trouble with school management at least he hasn't actually made what would be legally considered to be a firearm

>>31446020
Ar lowers are billet aluminum.

>>31445950
id be more worried about printing scary salt rifle parts with school property and on school property than i would be about it grenading senpai

>>31446046
The ones in the OP

>>31446055
Who the fuck pays 200k for an FDM machine? What can it do better in terms of raw printing that my 300$ off-brand chinese ripoff can't after a 20$ upgrade?

>>31446069
Shit, goes to show how little I know about ARs. What bits are plastic then?

Just pay $70 for a real lower you won't need to worry about

>>31446085
>What bits are plastic then?
Stock, hanguard, grip

Stratasys Fortus is a FDM machine - it extrudes a plastic filament and places it to make the part. The resulting meta-material is strong along the filament, but weak perpendicular to it (it's orthotropic, steel is isotropic=same strength in all directions), hence it has a tendency to break between filaments. Hence FDM is a bad choice for such a part, especially the part where the buffer tube screws into will break easily, as it is thin and the stresses don't have a preferred direction. SLS is better, as the small powdered plastic has randomly oriented material interfaces, hence it is on average isotropic.

>>31446020
> AR lowers are plastic anyways, aren't they.
I don't know thats why I made this threar
>>31446051
450mc
>>31446061
>>31446077
Half the stuff printed is drug paraphenelia, it's a bit of a joke, I'm not gonna flaunt it around campus, not too worried
No one would recognize it as a firearm part anyway

>>31446144
>No one would recognize it as a firearm part anyway

The guy who manages the 3D printers is generally an engineer or "scientific" technician of some sort. They can tell.

>ask me how I know

Just do it and post results

i would not advise this -- no polymer cad-print system will give you a 'quality' cut and tolerated design/build. only time advise is to makeshift the geometry by measuring the tolerance to the microns, then assuage all is well in regards to qc, build/cut with a matasura or metal cnc using proper grade-aluminum or base cxk8-steel variant.

just my 2 cents... i have many cads for ar uppers and lowers if you want them. they are shaded and correct to the micron-per-bill*^2

You have to get the plastic reinforced near the part of the receiver that the buffer tube and stock are at. That's where it's most likely to break if you do a 1:1 print of a metal receiver.

You can probably find modified plans to print out one that will properly work in plastic.

Granted if your school has that shit, shouldn't they have a CNC machine somewhere so you can make some real funs?

Granted, it wouldn't surprise me if they don't. Numales and betas love 3D printing but hate real material crafting.

>>31446203
can someone explain this more to a non-technical person?

seems like this anon is saying you have to be careful when measuring, use an actual cnc designed to cut metal, use quality metal, double-check your parameters?

>>31446164
The 3D printers are mostly student run. The last I was there some stoners were retrieving their new bong. Only the CNC mills and PCB printers have employed engineers running them.
And how do you know?
>>31446129
So if the part that the buffer tube screws into fails ill be decapitated by the spring right?
>>31446212
They have CNC mills, but students can't use them. You give blueprints to an employed engineer that does it for you. I'm worried that they'll recognize what it is.

>>31446164
Since resin and PLA are the medium, you can print what you wanted in a series of pieces and join them later. The person who manages it wouldn't know what they were unless they were looking for it, and even then you could make a series of false creations that would make it nearly impossible to tell what you were really doing.

>>31446203
I call bullshit, FDM printers may not be capable of the tolerances necessary but SLS definitely is, and I have a feeling you're inflating the tolerances.

>>31446267
by-all-means be selective it will probably work

>https://www.youtube.com/watch?v=zz8mlB1hZ-o

will it last? probably not... will we ever see torlon casts and molds? i hope so... would i fire a torlon ar15? yes i would.

>>31446246
Dimensional tolerances be wack, yo.

>>31446259
Multi part reciever doesn't seem like it would be strong enough.

>>31446299
It won't last as long, sure, due to the material and printing technology, but it'll live long enough is my guess.

OP Here
What I'm going to do is print the lower sometime next week and come back to /k/ with some detailed photos and see what you guys think. If it seems okay enough I'll slap an AR together with it and see how it turns out.
If it doesn't work out at least it was a cool project.

Guys, 3D printed lowers have been a thing for a good while. Even using shitty bargain-bin printers and ABS.

Download the FOSSCAD megapack and thank me later.

>>31445950
doesn't 3d printer plastic have a low melting temp so it flows easy and dries fast?

at least with the injection molded shit you can use high temp plastics.

the barrel would melt your upper i think

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>>31445950
i only know from that vice video a few months back. but those would break at the buffer mount like after 30 rounds.

>>31446488
Not printing the upper, only the lower.
>>31446524
Thats the only worry I have.

>>31446524
>>31446552

That's why the lowers in the FOSSCAD pack have reinforced buffer towers or incorporate the buffer tube into an integral stock.

>>31446564
Is there any feedback on how the FOSSCAD lowers hold up?

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>>31446638

Multiple test fire videos on youtube for various different designs.

Hell, there's even an AR-15 lower receiver that was made to use a 3D printed FCG based on the AK's.

>>31445950
>Will it grenade on me after a few rounds?
yes

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>>31446655

File: warfairy charon p90 ar lower.jpg (595KB, 1920x1080px) Image search: [Google]

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Speaking of 3D printed funz: Has anybody seen Warfairy recently?

>>31446683

Last seen on the FOSSCAD IRC about a month ago.

>>31446707
Then that may be where OP should go next. This is right up his alley.

>>31446655
>>31446683
>>31446707
Where do the FOSSCAD 'experts' congregate in case I need some info? A forum?

>>31446735

The IRC.

>>31446748
How spergy are they?

>>31446762

Just so you know, a lot of them spend their time on /k/, so you're not really making that great an impression by asking that.

>>31446801
I spend a lot of time on IRC, it's honestly a valid question with some of the communities. I used to frequent a lot of /g/ channels and some of them were ridicuously clichey.
Not trying to offend anyone.

>>31446801
>>31446940
WTF, it's fucking 4chan. Why the fuck do we suddenly care about offending people and feefees all of a sudden?

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'u gon' get comfy.

>>31446085
Yes they have plastic AR lowers don't let anon tell you otherwise most are aluminum though. They even have plastic LPKs (a few metal parts still)

>>31447270
99.9% are fucking aluminum

>>31447291
Yep that's why I said most are aluminum

>>31445950
The only plastic lower I've ever heard of holding up to long term use is the GWACs one that has the stock integrated into it. The main point of failure tends to be the threading for the buffertube.

>>31446085
Some fortus machines can print a life size pair of pants if you wanted to. At .1 mm layer height.

>>31446418
Make sure someone else has a camera because you won't be able to take pics after your hands are blown off

>>31446257
It'd be illegal for someone else to make your CNC lower for you anyways even if they did recognize it.

>>31448493
yes because a lower cracking will cause the gun to explode like a bomb

>>31449477
no it's not, a lower is not a firearm.

>>31445950
the best way is to use the 3d printed lower to make a mold, and then cast a lower from a stronger resin.

>>31449576
in the USA, the lower is the firearm