80% lowers

[ram1009]

Anyone into machining 80% lowers for AR15s?

[Euph0ny]

Anyone into machining 80% lowers for AR15s?

Apparently lots.

[ram1009]

Apparently lots.

I meant on this board but thanks for the link.

[Seastar]

Yep -- I have.
Question?
Bill

[CalM]

Is it worth the effort?

I'm considering a .308

[ram1009]

Yep -- I have.
Question?
Bill

I don't have a mill or a drill press with spindle control (stop/depth) sufficient to do the job. Do you have any advice? You can send a private message if you like.

[danlb]

I don't have a mill or a drill press with spindle control (stop/depth) sufficient to do the job. Do you have any advice? You can send a private message if you like.

Advice; If you can afford the AR15 and the ammo, you can afford to buy a drill press and the files needed to do the job. You can always sell the drill press when you are done. You will have a much better appreciation of the work that goes into it when you are done.

Dan

[ram1009]

Advice; If you can afford the AR15 and the ammo, you can afford to buy a drill press and the files needed to do the job. You can always sell the drill press when you are done. You will have a much better appreciation of the work that goes into it when you are done.

Dan

I do have a drill press but the spindle (like all but the most expensive) doesn't have an accurate calibration of depth nor a method of locking the spindle to the desired depth. I don't think it's reasonable to think I can hold the spindle (with end mill) absolutely still with one hand while I move the part/fixture with the other. Please tell me if I'm missing something. BTW, I can afford to buy a mill, I just can't justify it for this project alone.

[danlb]

I do have a drill press but the spindle (like all but the most expensive) doesn't have an accurate calibration of depth nor a method of locking the spindle to the desired depth. I don't think it's reasonable to think I can hold the spindle (with end mill) absolutely still with one hand while I move the part/fixture with the other. Please tell me if I'm missing something. BTW, I can afford to buy a mill, I just can't justify it for this project alone.

You are thinking of a drill press as a mill. That gets dangerous quickly. I'm thinking of it as a quick way to rough out the dimensions that you need by drilling. The files will allow you to make nicely finished surfaces.

Most drill presses have a depth stop on them. They are really nothing more than a threaded rod with a couple of nuts and a flange attached to the spindle that hits the nut. If you do need accurate depth calibration, make test holes in scrap, adjusting the nut until you reach the desired depth. Then tighten the lock nut to hold it in place.

It's not quite as easy as using tools meant for milling pockets in metal, but it does work.

Dan

[ram1009]

You are thinking of a drill press as a mill. That gets dangerous quickly. I'm thinking of it as a quick way to rough out the dimensions that you need by drilling. The files will allow you to make nicely finished surfaces.

Most drill presses have a depth stop on them. They are really nothing more than a threaded rod with a couple of nuts and a flange attached to the spindle that hits the nut. If you do need accurate depth calibration, make test holes in scrap, adjusting the nut until you reach the desired depth. Then tighten the lock nut to hold it in place.

It's not quite as easy as using tools meant for milling pockets in metal, but it does work.

Dan

The videos I've watched all imply that the drill press can serve as a mill by just adding an X/Y table however they gloss over the part about spindle depth control. I've done searches for probably 100+ drill presses and the only ones with spindle stops are bench tops that are too small for this job. Twice now you've mentioned "files" a means of witling away excess material to a finished dimension. I just don't see how that's practical. It's not mentioned in any videos or text I've seen. I've been thinking about buying this http://www.80percentarms.com/products/80-ar-15-easy-jig setup and using a router. Do you know anybody who has done this?

[Highpower]

BTW, I can afford to buy a mill, I just can't justify it for this project alone.

Well, there is always plan "B". http://www.80percentarms.com/collect...ar-15-easy-jig
I think there are a few different makers of those types of jigs now.

Disclaimer: I have never used one of those jigs personally, nor completed the machining on an "80%" receiver.
Raw forgings, well.... that's a different kettle of fish.

Oooops... never mind. Posted at the same time.

[ironmonger]

If you can tig weld see this:http://www.theflatspot.net/ar-15-receiver-flat.html

[ram1009]

If you can tig weld see this:http://www.theflatspot.net/ar-15-receiver-flat.html

There's also some precision drilling & tapping to do in steel and when you get all done it weighs 3 times as much as aluminum.

[Boostinjdm]

What exactly is your goal?

[ironmonger]

Yeah, but odds are you'll be the only guy at the range with a blued lower instead of one that's anodized or painted.

Don’t think the precision drilling or tapping is any more of a problem in steel than ally. Besides, if you screw up, just TIG on some more metal. The only interesting hole location seems to be the bolt hold open pivot.

I cheated and built a block with locating pins to check the alignment prior to welding.

Thinking of using the same process for a Frank DeHass single shot build.