Fuck jigs and fuck drilling it myself because I'll probably fuck it up. I'm going to UGA next semester and was wondering if any of you know if I would be able to use the school's CNC mill or know what I would need to do to use it. I'm sure I can find plans online to use, just need the machine.
Also thoughts on the ghost gunner? $250 ($350 with shipping) doesn't seem bad for a cnc machine.
>>28334732
If you have access to a legit CNC machine why start at 80%? Start with a titanium billet or sum cool. You can make a 10/22 reciever or aluminum hi power frame. 80% lowers are for garage hobby people. You can do anything with the big boy equipment
>>28334832
Because I have an 80% already that I bought out of impulse
>>28334838
Well add some material back and make it 0% again, I generally use some super glue
>>28334732
>$250 ($350 with shipping) doesn't seem bad for a cnc machine.
That's because it doesn't cost $250, it cost ~$1400. That $250 is just a deposit.
>>28334876
good idea :^)
>>28334881
Oh fuck that
>>28334832
Forged lowers are objectively stronger than billet, so unless you're going for some cool looking billet lower that prioritizes form over weight + function, milling out a lower from a billet doesn't make sense. Some people like 80% lowers because they're pretty neat to make and you can get a gun with no rollmark or manufacturer info engraved on it. Others like them because it's the only way to build your own AR from scratch, such as in California.
>>28334732
I believe atf requires you to own the tools used to make the receiver. Or some shit along those lines
>>28334952
Can we get a citation on this? Ive heard that you can use someone's tools to do the milling yourself and that seems legit. Could be fuddlore though
You probably won't be able to use their $50K+ machine for your little projects until you're atleast a junior, know how to program and setup the CNC, know the people that run the shop, do it after hours, and even then...making guns on school equipment doesn't usually sit well with anyone there. I know people that have done it at the colleges I've gone to, so it can be done.
It would be way easier to use the manual bridgeport than some CNC for that simple of a machining.
>>28334732
I doubt the school will let you make a gun
>>28334996
Does the Bridgeport work in the same way?
>>28335040
Not at all, bridgeports are manual, no computer control like CNC
>>28335040
Its like a Super complex drill press in idiot terms. It would be easier to just walk up to and start learning. Sooooo it accomplishes the same result in a different way? I'm not sure what you are asking. The CNC is more like a metal drilling cutting milling robot cabinet.
>>28335040
It's literally the same thing, only with manual controls instead of a computer.
>>28335066
>>28335067
I'd still need a jig then and Id rather just let the cnc mill do it. I have access to a drill press but I'd rather not buy a jig that I'm going to use once
>>28334995
https://www.atf.gov/file/11711/download
>>28334732
> I'm going to UGA next semester and was wondering if any of you know if I would be able to use the school's CNC mill
>or know what I would need to do to use it. I'm sure I can find plans online to use, just need the machine.
Heres a tip, if you want to violate your campus rules you probably shouldnt do it with an incredibly expensive cnc machine you dont know how to operate
This annon >>28334996 has it right, Get your hands on a manual mill and operate it easily. If you didnt live in armpit tier georgia I would loan you my mill.
Try to find a local hackerspace or go the drillpress route. Drillpress + router is pretty retard proof. But be prepared to fuck up atleast one 80%.
>>28335040
>Crank wheel one direction, mill moves that direction
>Crank wheel in reverse, mill moves backwards
80% milling is basically a square at two depths, it isnt the kind of milling you need to be a rocket science to do.
>>28335091
>Buy jig
>use it once (more like three times since you will fuck up)
>sell jig
OR
>make like 10 or so lowers so you dont need to buy one ever
Pic related, Mill master race
>>28335091
You shouldn't need a jig. Just get the blueprints and measure twice/cut once. Clamp the workpiece in the mill and remove material slowly. The mill will hold everything securely
>>28335098
Thanks man.
>>28335091
>Id rather just let the cnc mill do it
I hate to say it but you're starting to be a little naive. Learning how to program a CNC mill is going to take some time to learn, and you will still fuck up the first few tries. It's not like you press a button and let the machine do the work, it takes knowledge of the machine to program everything right, which takes time to learn. Unless you buy the ghost gunner, then yes, you literally press a button and let the machine do the work, because it is programmed to do that one function. Your typical CNC machine is designed for a multitude of applications, and each job needs its own program. The jig+drill press/router option is by far the easiest route to take when making an 80%.
>>28334732
OP. Dont be a pussy, go get a 3/8" end mill ($25) chuck it in as big of a drill press you can find and 3,2,1, GO.
>>28334732
CNC machinist of 10 years here. Reading shit like this always gives me a chuckle.
Hey record it so I can see when you crash the sumbitch into your receiver scrapping it.
The stories of morons with no experience buying these machines and having no idea what it really takes to produce a real part is always great.
>>28335040
OP. dont fuck around with cnc. a bridgeport is better than drill press but unnecessary.
>>28335233
>>28335290
You guys are right. I didn't know shit about what a cnc actually took so I guess I'll just go with the drill press
>>28334732
no you have to own the tools you use to make a firearm.
no because more than likely it is illegal to have a firearm on campus
>>28335440
But he's not going on campus with a firearm, he's leaving campus with one though.
The wat to do's vs. the already have done's is strong in here/
>>28335404
Op dont drill with the drill press make it a mini brigeport and with the described earlier 3/8 end mill, MACHINE YOUR80%ER
What keeps me from finishing my lower on a manual mill is the lack of info on the exact place the FCG slot is in relation to the unmachined side of the receiver so that I can actually edgefind my way there properly without buying some kike's $80 slabs of aluminum with a few holes drilled in them.
I shouldn't need a jig, damn it. I just wish the AR-15 lower prints that are out there had more information on actual hole location.
>>28335506
This thread makes me want to do some drilling and milling. Do 80% lowers come with a threaded buffer tube loop already?
>>28335577
Why don't you just take a micrometer and measure a complete lower? Od - Wall thicknessX 2 = pocket size
>>28335609
Because if I had a complete lower I wouldn't be making one from an 80%.
I don't know anyone that owns an AR, either.
>>28335618
Fair point.
>>28335584
yes
>>28335462
yeap.
neat observation.
still has a firearm on campus.
My welding instructor was pissed when I made a 4winds
>>28335577
base every measurement off the takedown pin holes
for function the pocket dimensions dont really matter as long as the parts can move freely and you didnt break through a wall
the important part is the trigger and hammer holes
you dont need a safety its fine to fuck that measurement up
>>28335618
>>28335682
I got a more complete PDF here.
https://filetea.me/t1sKQaKJtzGSymxrMQ8nMibUA
>>28335462
Doing a service to the community. Remove dangerous firearms from college campuses .
>>28335699
Goddam senpai. that's a good drawing
>>28335759
I have a full CAM file somewhere...
>>28335699
eh mine has all the locations measured off the takedown pin locations which is important
you cant trust the externals on an 80
if you measure off the top edge shit will be messed up
>>28335773
For what controller, if I may ask? FANUC? Cincinnati? Okuma?
>>28335807
Good tip. Thanks anon
>>28335813
It can be opened by any CAM software. It's just a full model. It's up to the programmer to make his own tool paths using it.
>>28335682
Thanks a ton. Finally have a real use for that tiny edgefinder I bought.
>>28335843
Oh. When you said "CAM" I thought you meant already toolpathed and everything. But I'll ignore the semantics.
>>28335112
Implying that making a 80 percent is hard
I did three builds 2x ar 15 and one 1911 all of them work
I used the easy jig to build my ar 15s
If the ghost gunner was so cheap back then I would of went that route
But seriously never even used power tools boor but I manage to do iy
>>28335577
Look at metal maniac ar 10 build be did with schamatic and a home made jig
>>28336138
Never mind it is still expensive
Has anyone ever made receivers out of wootz steel or "fake"damascus patterned steel blocks?
>>28335773
well post it then!
>>28335290
I'm a pretty new CNC machinist, only 1 year experience at this point.
A little over a year ago I tried to teach myself some CNC shit by buying a cheap ass CNC mill kit... and that shit was awful. I didn't even learn any CNC coding on it.
BUT! It did manage to mill a polymer receiver for me. And that receiver recently snapped because polymer sucks for ar-15 lowers.
If anyone wants to try to CNC machine a lower, at least know basic g-code commands and proper machining methods. Learn how to calculate feeds and speeds.
AND DON'T BUY A DIY CNC KIT! Unless you already know what you're doing.
>>28334732
you act as if milling a 80%lower without a cnc/mill is hard and never done before.
>>28337778
I'm working on a tutorial on how to use an Easy-Jig with Harbor Freight tooling.
I've finished 3 receivers with that shit setup. And at least 2 of them work fine. I haven't built the 1st receiver since it was more of a test piece but my friend really wants to use it. So we're gonna build an AR out of that one in a couple weeks.
Here is a teaser on the major problems with using harbor freight. At least you can do it though.
>>28337778
lets see your product then
What do you guys think of this? Anyone used Mach 3?
http://www.automationtechnologiesinc.com/products-page/cnc-router/taig-gecko-cnc-mill-milling-machine-engraver-router
>>28335112
>grizzly
El oh el
I imagine +/- .020 is a tight tolerance for you
Grizzly has its place, for poorfags to buy at estate sales, but Bridgeport or Sharp are the only mills worth bragging about
>>28337886
Mach 3 is shit compared to actual controllers, but for a free torrent it's pretty good. You have to know how to set the program up correctly though.
That CNC router looks like it's going to give you comparatively shit tolerances. But anything under 15K is going to be shit for CNC machines.
HAAS is about as cheap as you can go for fully functional CNC mills. You could also jury-rig a Bridgeport mill with a computer controlled auto-feed system that will make it essentially CNC.
>>28338254
>anything under $15k will be shit
serious m8?
>>28337985
Grizzly makes some "okay" benchtop lathes, but yeah their mills are garbage. Like, HF-$30-drill-press garbage.
I've chambered a lot of barrels on a Grizzly 30x12" benchtop, have never had a problem holding it to half a thou. Will I ever try to chamber a benchrest gun on it? Hell no. But considering what I paid for it, it does perfectly fine for AR barrels (99.9% of what I make, since you can frequently get 2 from a single blank).
The one Grizzly blast cabinet I used was fine too. Eh blasts glass and doesn't afraid of nothing.
>>28334910
>hurr forged lowers are stronkest!
No. They're stronger than billet of the same thickness, but also tend to weigh about the same as a stronger barebones (IE, no fancy curves/designs) billet. But they're thinner.
Also, if you're breaking a billet lower you'd have also broken a forged lower. They take almost zero stress from actually firing so if you break one it's through negligence or a severe accident unrelated to firing.
>>28338606
Second guy here, absolutely agree.
>$30k machine
Assuming you set it up properly and don't use the chinkiest of chinkshit eBay mill bits, you can expect consistent 0.00005" tolerances. Maybe occasionally better, guaranteed to be no worse than 0.0001"
>$9,999.99 machine (not on sale)
Assuming you set it up properly and didn't use the chinkiest of chinkshit eBay mill bits, you can expect consistent and repeatable 0.001" tolerances. Maybe occasionally better, maybe occasionally worse. Also, it won't last 4 generations like the original Bridgeports have and all current Bridgeports (and a few others) are expected to.
>>28338606
Shit is anything that can't get a +/-.001 tolerance.
I work with machines that hold +/-.0001 tolerance and mill things to within +/-.001 inches... so... yeah. 15K is a pretty minimal amount for a proper CNC machine.
There are plenty of routers and engravers for well under 15k and can still hold tight tolerances but the spindles generally can't machine ferrous material or heavy amounts of aluminum and the cutting area is to small.
Like I said, you could just rig up a Bridgeport mill with some motors and a controller and you'll have a half-assed CNC machine that can hold a tight tolerance, but it's nowhere near a proper CNC machine like Mori-Seiki or HAAS.
>>28338739
>>28338766
what tolerances do you get manual milling with a jig/fixture?
>>28338947
If you're manual milling, you don't want a jig.
Just get a good engineering print like pic related.
How accurate you can get everything is really just a matter of how fine you can get you're own movement to be. Like, how close you can get the table to the nominal position without going out of tolerance.
Also, get good at planning your cuts. You should undercut by a few thousands until you reach final depth, then make a finish pass to reach you're desired dimensions.
TL;DR, just learn how to manual machine if you want to use a manual mill...
>>28339002
I forgot to add...
If you're going to mill using an easy jig, try not to use harbor freight. You can do it since I'm the one who did it 3 times but it's a terrible end product.
The trim router doesn't even hold the bit straight. It's canted by a few degrees.
If you get good shit, everything will be fine if you follow instructions.
>>28335066
Hmmm,Bridgeport makes CNC controlled machinery in addition to manually controlled machinery. You can retrofit Bridgeport knee mills as well. There are many knee mills without CNC control and some of those are branded Bridgeport.
>>28339249
When a person refers to a "bridgeport," they're usually referring specifically to their line of manual vertical milling machines.
