Has anyone here built a 80%-90% M4 lower with a Drillpress? I am thinking about getting a cross slide vise to use in milling w/ my drillpress w/ mill end bits. Can anyone give me some feedback on this idea?
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Has anyone here built a 80%-90% M4 lower with a Drillpress? I am thinking about getting a cross slide vise to use in milling w/ my drillpress w/ mill end bits. Can anyone give me some feedback on this idea?
Drill presses are not intended for side loading.
A vertical milling machine is.
I know and plan on drilling all the hole straight down and comeback with the cross slide and take a little off at a time. I wish that I had a Mill in my shop.
I'm interested in this topic as well.
Have you seen one of the many you tube videos on the process?
Looks like it works, although I'm not clear on the quality level of the finished lower.
I've seen guys drill away most of the material and then finish the cavity with files.
Not sure what quality this would turn out though.
If you do it right, you can have enough clearance for the trigger, and just leave the slight "wave" left from the holes over lapping.
sent from mah gun,using my sights
MOVED SINCE THIS ISN'T A CUSTOM BUILD TOPIC.
Plunge cuts with an end mill would work to smooth out pocket.
It would take a lot of them, and a file would likely still be needed for the sides on the FCG cavity.
I agree with polymorpheous on this one. Can it be done on a drill press? Maybe, assuming you are ONLY drilling and not milling. You will have to have a really good mill vice, use center drills, stub drills, cutting fluid, etc. You could try to plunge cut with a 4 flute endmill, but anyone that knows the first thing about machining is going to cringe at the idea. The tooling alone would more than cover the cost difference between an 80% and a title 1 receiver.
DO NOT try to side-load a drill press with an endmill. Bad bad things will happen. Especially if you are using some cheesy Dewalt or whatever drill press from Home Depot/Lowes/Harbor Freight.
Personally I wouldn't try a 80% receiver on anything less than a Bridgeport or similar mill with the proper tools, prints, and a DRO. YMMV.
Some of us metal heads don't need no stinking DRO!
Sure is nice to have one though.
Lol, as was shown in another thread, you don't need an optic on your rifle to make hits at 1000 yards. But it sure helps! :D
I've done my fair share of manual machining using the indicators on the hand wheels, but man, unless it's a newer (ie less worn) high quality mill the amount of backlash in the hand wheels is so great doing anything where you're holding .005 in. or less is a damn trick.
Ah yes.
I'd want the forging as well.
Ares gets them from Tactical Machining.
Doesn't help though, because they are also OOS.
I can help you with billet 80% lowers, but not forged. We are also running AR308 80's.
A drill press is far less than ideal but I have seen them done with a drill press and dremel. Wasn't pretty at all, but the rifle is still running lol
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I understand the political appeal to "manufacturing" your "own" lower, but from a cost analysis, I don't see how you would save a penny without doing 10+ lowers due to the tooling cost of doing it right. Obviously folks who have a respectable hobby mill or better at home with the proper tooling are in a different boat, and I can see how it would appeal to them more as a fun machining project with tangible results. But to the guys trying to machine these on a $200 drill press, with little or most likely no machining experience, and a drill index as you only tooling, I think you're setting yourself up for disaster. I'm not even mentioning the measurement tools you would need to properly inspect your work and ensure you are adhering to the prints. If I were you, I really wouldn't trust an 80% done on a drill press for much more than a plinker.
Evil thought: Give me a small CNC mill like a Tormach or whatever, a copy of EdgeCAM or Master CAM and I could crank out 3-5 of these a day once I got a good fixture setup. :D
It has absolutely nothing to do with economics but I do agree about not doing it on a drill press. I have no plans on using anything but a mill, however, I have personally seen a few that did use a drill press. Aside from looking like complete ass, they functioned just fine.
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I get it, and I like the idea of 80% receivers a lot. I'm curious to hear some 1st hand feedback on folks who have done these successfully.
I guess the OCD machinist/engineer in me has a hard time with half-assed drill-press/dremel jobs, but if it works for you then cheers!
I have built one with a 2/3 hp drill press and carbide end mills. final sanding with a dremel tool and sanding drums. I also used a cross slide vice on the press. It can be done. I have twice the cash in it than buying a stripped lower but the challenge was what pulled me in.
I sold all the end mills and jigs to recover 1/3 of what they cost me.
If I were to do another one, I would want a hobby mill machine to make it easier.
Has anyone done one of the plastic 80% lowers? YouTube videos make it look easy enough.
To some, like me, who live in commie states, it's not about economics, it's about not having to file paperwork with the state agencies or feds. The climate in MD right now, like a handful of other leftist led states is just too risky for me to tell them what I have, so...
Fortunately for me, I have access to a machine shop with non cnc setups (mills and lathes) and my work leads me to use some local cnc shops to make parts that we need in quantity or of high quality. The allure of 'doing it yourself' is what got me into black guns and I started out with a forged 80% lower conversion, have done a few raw forgings on the Bridgeport and finally just succumbed to having a local shop cnc the 80's and then I finished them from there. It's not hard, plenty of resources out there for doing the AR-15 lowers. They don't have to be pretty inside, but the holes have to be done properly and the pocketing has to be adequate to allow clearance for all the parts to move and also enough left on the sides to give it the structural strength required (which isn't that much on a lower receiver).
AR-15s are about to be banned in MD, including finishing lowers, if the law withstands all the challenges. The only real option left if that happens for us is AR-10s or 308 variants as they are not affected presently. I'm done with AR-15 lowers, have what I want, now on to the 308 variants for a couple builds.. :)
It may sound off the wall but you could practice on a bunch of 2x4's until you perfected the process.
I'm sure it would work fine. In fact, I'd rather use the attachment before a drill press any day. Realistically though, unless it's a small garage hobbyist, chances are if someone has access to a lathe, an actual mill would probably be parked nearby.
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