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Posted: 7/12/2014 9:30:15 AM EDT
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I am thinking about trying out 80% lowers and was wondering what you guys and girls use for drill presses. $500 and less would be great, and Pictures of your presses in action or not thank you. |
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A lot depends on the drill press. I have an old (1954) Rockwell Delta drill press, and the chuck has a JT holding the chuck, but it is also retained by a nut that pulls the chuck onto the taper. I have done 3 80%'ers now, and no issues with the chuck coming loose/off. But- I can imagine the disastrous results if it was to come off.
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You do not want to try and do any milling with a Drill Press, if you side load the chuck it can come off with disastrous results. |
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(I know many people have done 80’s on drill presses)
Having built all kinda hot rods and stuff over the years and having been around and done quite a bit of machining I wouldn’t machine a lower on a drill press …. but that’s easy for me to say having access to mills and lathes. As common as these machines are I’ve got to believe someone you know has one or knows someone that knows someone. Hell it wouldn’t cost that much to walk in the front door of a machine shop and have it done … im sure there’s plenty of hungry small shops out there |
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(I know many people have done 80’s on drill presses) Having built all kinda hot rods and stuff over the years and having been around and done quite a bit of machining I wouldn’t machine a lower on a drill press …. but that’s easy for me to say having access to mills and lathes. As common as these machines are I’ve got to believe someone you know has one or knows someone that knows someone. Hell it wouldn’t cost that much to walk in the front door of a machine shop and have it done … im sure there’s plenty of hungry small shops out there Then the machine shop would be committing a Felony, the OWNER of the receiver must do the machine work. |
| 550 for a milling machine from harbor freight, tones of worthwhile upgrades around the net, instructional videos, the only reason I haven't done it, is because I don't need to start cranking out ARs. I would need to do 4 lowers to make it worth while in my mind and I just don't need 4 more AR's |
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550 for a milling machine from harbor freight, tones of worthwhile upgrades around the net, instructional videos, the only reason I haven't done it, is because I don't need to start cranking out ARs. I would need to do 4 lowers to make it worth while in my mind and I just don't need 4 more AR's The way to look at it is if you needed four ar15's you could buy a mill use it then sell it. That would bring your investment back down. If they werent so hrd to ship I bet they would be for sale in EE like the jigs. |
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I think the router method is a better option than the drill press. Even $500 drill presses leave much to be desired these days. I have a 40 year old monster that is the real deal but the new stuff is shaky. This member nailed it. LINK 
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Getting the depth of milling correct with a drill press or router is always going to be the hardest part to pull off.
They’re just not designed for precision in that axis / lots of time will be spent creeping up on the number and going to deep is likely to result. But on the other hand exact isn’t that important for this job unless you’re anal |
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A drill press is just the wrong tool for this job - but you can make it work, if you try.
Drill presses are meant to drill - so do 99% of your cutting as plunge cuts - moving the bit and removing material the way a drill/drill press is meant to remove it, by drilling. Lots and lots of holes side by side until most of the material is removed, then you try carefully smoothing the sides and bottom of the fire control well with a mill bit chucked into your drill press, but be super careful on the amount of side load you put onto the chuck - it's just mounted on a taper, and not designed to take any side stress at all. If you're going to use a drill press, get a good, heavy-duty one, and an xy table with enough travel to let you move the work piece around while keeping it clamped. Save any use of the mill bit for the very end, finishing the sides and bottom of the fire control well. Drill your trigger and hammer pin holes a bit undersized and finish them with a reamer, unless you're just too cheap to buy a finish reamer, then proceed with the correct size drill bit, and good luck to you. |
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Drill your trigger and hammer pin holes a bit undersized and finish them with a reamer, unless you're just too cheap to buy a finish reamer, then proceed with the correct size drill bit, and good luck to you. What I'm having a hard time understanding is how you can exactly center an undersized bit in your jig. I have no issue with additional steps to have better results but this seems to be almost impossible unless someone offers side plates with undersized holes or bushings for the undersized bits. |
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What I'm having a hard time understanding is how you can exactly center an undersized bit in your jig. I have no issue with additional steps to have better results but this seems to be almost impossible unless someone offers side plates with undersized holes or bushings for the undersized bits. If you're using a jig instead of locating your holes by measuring, you've got a point. Though you can still precisely locate undersize bits in a jig hole by measuring offsets from the sides of the hole in the jig. Me? I measure, scribe, center punch and then drill - no need for jigs if you know how to measure. |
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I did my first lower back around 2001-2002 when ARs4ever was selling "50%" lowers and there were no jigs. But then I had access to a Bridgeport Mill.
Basically all he did was EDM the mag well in on an AR forging. This was back during the heyday of Tannery Shop 80% castings. |
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If you're using a jig instead of locating your holes by measuring, you've got a point. Though you can still precisely locate undersize bits in a jig hole by measuring offsets from the sides of the hole in the jig. Me? I measure, scribe, center punch and then drill - no need for jigs if you know how to measure. Quoted:
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What I'm having a hard time understanding is how you can exactly center an undersized bit in your jig. I have no issue with additional steps to have better results but this seems to be almost impossible unless someone offers side plates with undersized holes or bushings for the undersized bits. If you're using a jig instead of locating your holes by measuring, you've got a point. Though you can still precisely locate undersize bits in a jig hole by measuring offsets from the sides of the hole in the jig. Me? I measure, scribe, center punch and then drill - no need for jigs if you know how to measure. I suppose I could turn a center punch down to .154 and use the jig to center punch the forging. Thoughts on that idea? |
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If your particular milling jig set doesn’t have the plate to drill a series of small holes
Get a set of these …. I think mine were six bucks a Harbor Freight Transfer punches http://pic90.picturetrail.com/VOL2204/2603122/7239997/409778441.jpg |
| If you want to use a drill press, check flea markets, pawn shops and garage sales for the most robust oldest drill presses you can find. Typically presses made before 1970 are pretty reliable, durable machines. I had my grandfather's which was made in the 1920's and it was bulletproof. When I moved, I gave it to my Brother in law under the condition it's to be handed down and never sold. |
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I got the $400 floor model Porter Cable at Lowes and bolted a X-Y axis Harbor Freight milling vise that was relatively inexpensive.
Worked ok. I ended up green Loctiting the chuck to the arbor and the arbor to the spindle. It is also important to frequently check the tightness of your drill chuck and re-checking your depth. Don't ask me how I know. 
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I got the $400 floor model Porter Cable at Lowes and bolted a X-Y axis Harbor Freight milling vise that was relatively inexpensive. Worked ok. I ended up green Loctiting the chuck to the arbor and the arbor to the spindle. It is also important to frequently check the tightness of your drill chuck and re-checking your depth. Don't ask me how I know. <a href="http://s1357.photobucket.com/user/D_A_Lutz/media/first95_zpsac6d3141.jpg.html" target="_blank">http://i1357.photobucket.com/albums/q759/D_A_Lutz/first95_zpsac6d3141.jpg</a> Which HF XY vise did you get? 5 or 6" model? I have seen the reviews in several places that said the 5" one is much better than the 6. I am thinking to get one for my next (few?) 80%'ers. I also see a few divots in the sides, besides the extra drain hole by the trigger hole. Were they also related to the chuck losing it's grip on the end mill? Or are they from before you loctited the chuck to the arbor? |
| Is this the milling vice you guys are using: http://www.harborfreight.com/5-in-rugged-cast-iron-drill-press-milling-vise-69159.html |
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Is this the milling vice you guys are using: http://www.harborfreight.com/5-in-rugged-cast-iron-drill-press-milling-vise-69159.html Sure is. |
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I found an older Delta drill press on Craig's list for $75. I just did my first lower this weekend and it worked pretty well. The chuck did loosen up and caused one hole to go a little deeper than spec, but it never went all the way through. It took right at three hours to do the entire thing. Using an end mill bit in the drill press was a little exciting but we got it done. The biggest pain was cleaning up all the metal shavings. Next one I know not to use 80 psi when blowing out the chips. |
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My Rockwell Delta has a spanner nut that retains the chuck. (Jacobs 633C). Does yours have threads right above the chuck? Some of those use a morse taper spindle, rather than a JT spindle. I did blow the chips out at first, but after seeing what a mess it was, I started using a big shop vac to suck them up. Sooo much neater, lol.
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I found an older Delta drill press on Craig's list for $75. I just did my first lower this weekend and it worked pretty well. The chuck did loosen up and caused one hole to go a little deeper than spec, but it never went all the way through. It took right at three hours to do the entire thing. Using an end mill bit in the drill press was a little exciting but we got it done. The biggest pain was cleaning up all the metal shavings. Next one I know not to use 80 psi when blowing out the chips. |
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Mine is also a tapered (jacobs taper) spindle, but right above the taper is a threaded portion, maybe a half inch long, about 1" diameter, on mine anyway. Mine is I believe from 1954 or 58, cant remember. Check yours, it is possible someone replaced the chuck with a regular JT style chuck, instead of the correct one with the threaded collar.
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Yes it is a tapered spindle. Once we figured out it was a problem we would have to check the depth before drilling each hole. |
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