Overall costs for 80% builds

[IdaD]

It hasn't ever seemed worth the hassle to me, especially for an aluminum AR receiver. One of the Glock lowers would be pretty easy to do, but then you've got to think about what ultimately happens to that gun. It could subsequently become illegal, or after you're gone somebody's going to have to think about how to legally transfer it (if they even are aware that it could be an issue). I just don't really see the point.

 

[12Bravo20]

Using a drill press as a milling machine is a wonderful way to destroy a drill press and whatever you are working on. Quit being so cheap and just get a milling machine. You can get a light duty machine for under $1000. For $3000 to $6000 you can get one that will do some real work. Here is a crazy idea. When your $50,000 pickup truck gets to be 3 three years old, don't go get a new one. A really nice milling machine and lathe with full set of tooling costs less than a fishing boat and takes up less space.

I couldn't agree more!!!!!!!

A drill press, especially the cheap big box store brands are designed to drill into wood. A drill press is not the correct tool to do any type of milling in any material. The spindle, spindle bearings, and chucks are not designed for the lateral (sideways) thrust of milling. You will wear out the spindle and bearing prematurely by using a drill press as a milling machine. This is the facts. You will get way better results using a jig and router since a router IS designed for the lateral thrust on the spindle and bearings.

But don't let my decades of experience as a machinist/tool and die maker, and mill wright change your mind that a cheap wood working drill press is a suitable substitute for an actual milling machine.

 

[James Fonteneaux]

I've done a couple of aluminum AR lowers and a couple of glock kits. I didn't save a dime over what I would have paid just buying the factory stuff with a warranty. That being said, I enjoyed the process of the completion projects, and learned a lot along the way. I also like the feel of the P80 "glock" kit in my hand a little better than the factory version, but that's just me. The glock kits are much less time consuming than the rifle kits, but I wasn't going for speed either. I used a jig and router, and while it was slow, the end result is pretty good for not having professional grade tooling. For me, I get a sense of satisfaction from shooting a gun I assembled with ammunition I loaded. With the handguns, I got upgraded sights right away too. I don't know if I'll do any more, I've looked into the 1911 builds, but yikes!

 

[WestKentucky]

I couldn't agree more!!!!!!!

A drill press, especially the cheap big box store brands are designed to drill into wood. A drill press is not the correct tool to do any type of milling in any material. The spindle, spindle bearings, and chucks are not designed for the lateral (sideways) thrust of milling. You will wear out the spindle and bearing prematurely by using a drill press as a milling machine. This is the facts. You will get way better results using a jig and router since a router IS designed for the lateral thrust on the spindle and bearings.

But don't let my decades of experience as a machinist/tool and die maker, and mill wright change your mind that a cheap wood working drill press is a suitable substitute for an actual milling machine.

I agree for the most part, but there is plenty that a drill press can do without much risk. Working with plastics and aluminum doesn’t produce the significant side load that steels do, so with an industrial grade machine you are probably OK. Not always, but usually. My Clausing from the 60s has been rebuilt and hold tight enough tolerances for now. I already have a set of bushings and bearings for when I kill it though. Cutting steel (I have, and will again) has to be done with extreme caution and I’m only taking off a few thousandths per pass. I rough in the shape with drills and grinders then finish with slow and deliberate motions stopping every few minutes to put pressure on the chuck to make sure it has t come loose. So far so good. An actual mill is a far better tool but it’s much more complex and takes more training to run it because a drill press is basically an on/off switch with an up/down lever. Brass is also drill press machinable but it also takes great care to not mess it up. It can be done with care, but it has to be a great deal of care and a whole lot of attention while you work.

 

[12Bravo20]

I agree for the most part, but there is plenty that a drill press can do without much risk. Working with plastics and aluminum doesn’t produce the significant side load that steels do, so with an industrial grade machine you are probably OK. Not always, but usually. My Clausing from the 60s has been rebuilt and hold tight enough tolerances for now. I already have a set of bushings and bearings for when I kill it though. Cutting steel (I have, and will again) has to be done with extreme caution and I’m only taking off a few thousandths per pass. I rough in the shape with drills and grinders then finish with slow and deliberate motions stopping every few minutes to put pressure on the chuck to make sure it has t come loose. So far so good. An actual mill is a far better tool but it’s much more complex and takes more training to run it because a drill press is basically an on/off switch with an up/down lever. Brass is also drill press machinable but it also takes great care to not mess it up. It can be done with care, but it has to be a great deal of care and a whole lot of attention while you work.

A drill press no matter how careful you are is still not intended to be used as a milling machine. I will stick with my decades of experience in building and maintaining and repairing precision machines along with all of the invest cast molds and stamping dies that I have made over the years. I also have quite a bit of experience in building firearms and weapon systems while in the Army and as a civilian. We always used the proper tool/machine for the job.

And yes I am a retired journeyman machinist, tool and die maker, and mill wright. I had to go through the apprenticeship program for each of those separately.

 

[mokin]

the answer is "it depends"

on your knowledge/skill level
whether or not you have access to a milling machine
how much value you place on your time

I've never done one... but think most who do... do it for the fun of it.

I think SSN Vet nails it here. I could buy a stock Glock for less than what I have in my 80% build but it wouldn't be the gun I want. By the time I swapped out the parts to make it the gun "I want", I'd be in for a lot more money and have a bunch of spare parts. Since this is in the Rifle subforum, I've come to a similar conclusion regarding the 10/22 I'm thinking about.

 

[ColoradoMinuteMan]

For a poly 80% frame, a milling machine is completely unnecessary. Sure there is added control and durabilty that comes with a mill, but unless you're planning on making a serious hobby out of 80%, it really makes no sense at all. There is almost no load on even a hobby drill press when using the tiny end mill bit needed to cut the soft, small poly tabs on an 80% handgun frame. Even taking your time and making shallow passes it's about 10 minutes of actual cutting in total.

Using a drill press as a milling machine is a wonderful way to destroy a drill press and whatever you are working on. Quit being so cheap and just get a milling machine. You can get a light duty machine for under $1000. For $3000 to $6000 you can get one that will do some real work. Here is a crazy idea. When your $50,000 pickup truck gets to be 3 three years old, don't go get a new one. A really nice milling machine and lathe with full set of tooling costs less than a fishing boat and takes up less space.

 

[12Bravo20]

For a poly 80% frame, a milling machine is completely unnecessary. Sure there is added control and durabilty that comes with a mill, but unless you're planning on making a serious hobby out of 80%, it really makes no sense at all. There is almost no load on even a hobby drill press when using the tiny end mill bit needed to cut the soft, small poly tabs on an 80% handgun frame. Even taking your time and making shallow passes it's about 10 minutes of actual cutting in total.

I have seen enough Big Box Store made in China drill presses with questionable spindle bearings out of the box get ruined by people trying to use them as a milling machine. Again I rely on my decades of experience as a journeyman tool and die maker. Use the correct tool/machine for the job. I definitely recommend using a jig and router to finish a 80% AR lower over trying to use a cheap drill press.

 

[ColoradoMinuteMan]

I completely respect your skills and experience, and OF COURSE you're going to error on the side of using dedicated machine shop tools, you have access to them and you've used them to make a living. With all due respect though, just because I have a vehicle lift I use to repair farm equipment or restore trucks and use it to do a break job on my Polaris doesn't mean it's required. For the average person who wants to do a one off break job I'm not going to recommend they go out and buy a lift. Though it's not ideal, a hydraulic jack and a couple of jack stands will get it done safely.

A drill press no matter how careful you are is still not intended to be used as a milling machine. I will stick with my decades of experience in building and maintaining and repairing precision machines along with all of the invest cast molds and stamping dies that I have made over the years. I also have quite a bit of experience in building firearms and weapon systems while in the Army and as a civilian. We always used the proper tool/machine for the job.

And yes I am a retired journeyman machinist, tool and die maker, and mill wright. I had to go through the apprenticeship program for each of those separately.

 

[ColoradoMinuteMan]

With all due respect, I can throw away 3 cheap Chinese hobby drill presses for what I can buy 1 Chinese hobby mills for. In addition, I'm referencing 80 polymer handgun frames. If a drill can't take the load of cutting off a couple MM of soft polymer, it won't survive drilling through a piece of metal of any sort.

I have seen enough Big Box Store made in China drill presses with questionable spindle bearings out of the box get ruined by people trying to use them as a milling machine. Again I rely on my decades of experience as a journeyman tool and die maker. Use the correct tool/machine for the job. I definitely recommend using a jig and router to finish a 80% AR lower over trying to use a cheap drill press.

 

[12Bravo20]

With all due respect, I can throw away 3 cheap Chinese hobby drill presses for what I can buy 1 Chinese hobby mills for. In addition, I'm referencing 80 polymer handgun frames. If a drill can't take the load of cutting off a couple MM of soft polymer, it won't survive drilling through a piece of metal of any sort.

And this thread is actually about building 80% AR lowers not P80 pistol frames. There is quite a bit of a difference between the two when it comes to machining them.

And yes I have built enough P80 frames to know about them. The only thing I use a Dremel for on P80 frames is drilling the holes (with a Dremel Workstation) and polishing thing. I use fret cutters, files and sand paper to remove all the tabs and finish smooth. And I still wouldn't use a cheap box store drill press for drilling holes in a P80 frame either. Most of those cheap presses have way too much spindle run out (wobble)

 

[Elkins45]

And I still wouldn't use a cheap box store drill press for drilling holes in a P80 frame either. Most of those cheap presses have way too much spindle run out (wobble)

I handheld mine with a cordless drill. It worked 100% from the first round. I even used the cheap supplied bits. I did the frame rails with a pocket knife. The only thing I used a Dremel for was the recoil spring slot.

 

[SSN Vet]

I would never recommend that someone buy a milling machine (China benchtop or otherwise) just to finish a couple (Aluminum) 80% lowers.

But if you're interested in learning about machining and want to get into a fun hobby... setting up your own hobby mill is a ton of fun and you'll learn a lot. You'll also spend more on tooling than you do the mill, but then you learn even more.

Once you get into hobby machining, finishing an (Aluminum) 80% lower is an fun, gun related project that will be both doable and rewarding.

As I said previously, I've yet to do an 80% lower, but what I have done is design and fab several custom gun smith tools and fixtures. Hobby gun smithing and machining is (imo) a match made in heaven.

 

[Bcwitt]

80's aren't really meant to be price busters. It's a hobby all it's own. If your only interest is a small savings, you aren't likely to achieve that w a single build without some machine shop experience & equipment. It's kinda like hand loading. Sometimes you achieve a SMALL " savings" , but till tooling & time, not likely. Actually, if you figure the time, it will likely be the most expensive & least reliable firearm you own, unless you are exceptionally proficient in your shop practices. That dosent detract from the Joy's of it, however

 

[castile]

I have built a couple of AR lowers using a drill press from Harbor freight. I only use it to drill not end mill. I use a porter cable router to finish. Works fine. On the poly 80 Glocks one only needs a dremel flat file and a round file. I would use the drill press to do the holes for the pins no issue.