AR15.Com Archives
 What Mill for 80% Lowers?
Woodys556  [Team Member]
5/31/2011 3:40:43 PM
I have busted a couple of drill bits off while using a drill press for machining the final 20% of my lowers.

I am looking at getting a bench top mill.

Who uses what and WHY?

More importantly WHY would you NOT have bought it if you had known.

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b_rogers  [Team Member]
5/31/2011 3:47:59 PM
Originally Posted By Woodys556:
I have busted a couple of drill bits off while using a drill press for machining the final 20% of my lowers.

I am looking at getting a bench top mill.

Who uses what and WHY?

More importantly WHY would you NOT have bought it if you had known.



Great question, I am curious as well. Been thinking about buying one for a while.
jaqufrost  [Team Member]
5/31/2011 4:05:22 PM
This is a tag, I've got a 0% lower that I'd like to finish someday.
Woodys556  [Team Member]
5/31/2011 4:11:15 PM
WOW i don't feel so alone now.

PLEASE chime in on Mills and the Pluses and Minuses.
joe___223  [Member]
5/31/2011 4:13:37 PM
Originally Posted By Woodys556:
I have busted a couple of drill bits off while using a drill press for machining the final 20% of my lowers.

I am looking at getting a bench top mill.

Who uses what and WHY?

More importantly WHY would you NOT have bought it if you had known.




how do you break a drill in aluminum?
JustKeepSwimming  [Member]
5/31/2011 4:37:22 PM
Originally Posted By joe___223:

how do you break a drill in aluminum?


I know! I know! Ooooh pick me! Pick me! I know this one!
Russ4777  [Team Member]
5/31/2011 6:24:24 PM
I have finished 3 of them now using my Chinese drill press and a Chinese 2-axis slide vise. Normal drill bits and endmills have worked just fine.
mn_mike  [Member]
5/31/2011 6:42:28 PM
Being in the machining trade, I myself have looked into some bench top mills and such just to have at home.

I would suggest if you have the room, watch some local industrial auctions in your area and just pick up a manual Bridgeport or something similar. You can end up paying the same price for a benchtop unit as you could for a full blown rigid manual mill. (Keep in mind then you have to deal with a 3-phase power system to power it up).

Or throw it all out and just by a full CNC Machining Center........ Used ones on the market can be pretty reasonable.

Mike in MN
b_rogers  [Team Member]
5/31/2011 7:02:59 PM
Originally Posted By mn_mike:
Being in the machining trade, I myself have looked into some bench top mills and such just to have at home.

I would suggest if you have the room, watch some local industrial auctions in your area and just pick up a manual Bridgeport or something similar. You can end up paying the same price for a benchtop unit as you could for a full blown rigid manual mill. (Keep in mind then you have to deal with a 3-phase power system to power it up).

Or throw it all out and just by a full CNC Machining Center........ Used ones on the market can be pretty reasonable.

Mike in MN


The problem with people like us buying a used machine is we don't know what to look for. We cant tell if its working correctly or has problems. It seems more appealing to buy a new smaller unit..

Any used mills i have found locally have been WAY over 1,000 bucks and that about all i got to spend.
Woodys556  [Team Member]
5/31/2011 7:03:28 PM
Originally Posted By JustKeepSwimming:
Originally Posted By joe___223:

how do you break a drill in aluminum?


I know! I know! Ooooh pick me! Pick me! I know this one!


If I knew I would not have broken 3 of them. It might have something to do with them being DeWalt bits (Cheapest fuckers on the fucking planet) but I still broke them. I used tapping/cutting oil with them to. I wish I knew.
Woodys556  [Team Member]
5/31/2011 7:06:37 PM
Originally Posted By b_rogers:
Originally Posted By mn_mike:
Being in the machining trade, I myself have looked into some bench top mills and such just to have at home.

I would suggest if you have the room, watch some local industrial auctions in your area and just pick up a manual Bridgeport or something similar. You can end up paying the same price for a benchtop unit as you could for a full blown rigid manual mill. (Keep in mind then you have to deal with a 3-phase power system to power it up).

Or throw it all out and just by a full CNC Machining Center........ Used ones on the market can be pretty reasonable.

Mike in MN


The problem with people like us buying a used machine is we don't know what to look for. We cant tell if its working correctly or has problems. It seems more appealing to buy a new smaller unit..

Any used mills i have found locally have been WAY over 1,000 bucks and that about all i got to spend.


I am not allowed to have 3 phase in my neighborhood. I don't want a 1 ton unit in my basement and I agree with the above statement, I have no idea what to look for in a USED unit. I am building 80-90 dollar lowers, I don't want to spend a grand on a mill do do it. I am not afraid to drop 500.00 maybe more, but somebody tell me what is out there and what to look for, PLEASE!

I love how these posts asks a SIMPLE question and the answers are all over but to the point.

Can somebody answer my question?

Sorry I had a REAL bad day.
Bretshooter  [Member]
5/31/2011 7:17:31 PM
Originally Posted By Woodys556:
Originally Posted By JustKeepSwimming:
Originally Posted By joe___223:

how do you break a drill in aluminum?


I know! I know! Ooooh pick me! Pick me! I know this one!


If I knew I would not have broken 3 of them. It might have something to do with them being DeWalt bits (Cheapest fuckers on the fucking planet) but I still broke them. I used tapping/cutting oil with them to. I wish I knew.


What were you trying to do with them? A mill won't do anything with a drill bit that a drill press won't do.
Woodys556  [Team Member]
5/31/2011 7:32:47 PM
Originally Posted By Bretshooter:
Originally Posted By Woodys556:
Originally Posted By JustKeepSwimming:
Originally Posted By joe___223:

how do you break a drill in aluminum?


I know! I know! Ooooh pick me! Pick me! I know this one!


If I knew I would not have broken 3 of them. It might have something to do with them being DeWalt bits (Cheapest fuckers on the fucking planet) but I still broke them. I used tapping/cutting oil with them to. I wish I knew.


What were you trying to do with them? A mill won't do anything with a drill bit that a drill press won't do.


If you read the post on doing 80%ers with a drill press, you need to drill out the bulk of the material before milling. Drill presses can handle the lateral load like mils can so the bulk of the material needs to be removed via drilling first. I was drilling the 1/8" holes before I went to the larger drills before i go to the end mills.



Look people I am not trying to be a jerk, But enough of the comments and questions, can somebody PLEASE give me/us some useful information?

I know I used cheap bits, that is what I get for using DeWalt crap. Point is on the OP is WHAT bench-top Mills do people use and why? Or why would they not recomend the ones they decided on. Simple question.

Bench top typically means 110v single phase, not a 3 ton unit. BUT WHICH ONE???
motoguy  [Team Member]
5/31/2011 7:37:52 PM
X3 sized mill, or equivalent, seems to be a good way to go for finishing 80% lowers. X2 sized might be too small. Both have aftermarket cnc kits available. Rong Fu RU-45 (iirc) seems to be a good, larger, desktop style mill.

www.practicalmachinist.com
www.diyguns.com
www.cncguns.com
http://www.homegunsmith.com
www.cnczone.com
http://www.chaski.com/homemachinist/

http://www.homegunsmith.com/cgi-bin/ib3/ikonboard.cgi

etc etc etc

Oh, and I agree...you can get MUCH more machine, used, for the same money as one of these new ones. If you're looking for a new machine under $1k...you won't be getting much. I think the X3 will be at the top of that (very short) list.
VLODPG  [Team Member]
5/31/2011 7:43:04 PM
If I had the money & space, I would get something like this:

http://www.northerntool.com/shop/tools/product_200423983_200423983

As it is now, I have to visit my friend machine shop to use his old Bridgeport.
mn_mike  [Member]
5/31/2011 7:46:01 PM
Well I wasn't trying to be a smarta**, sorry.

Anyways, troll ebay or craigslist for little benchtops for used ones.

Honestly, if you are looking for something a step up from a drill press, just about anything should work for you.

Also, a neat site is http://www.machinetoolhelp.com/

Also the above links are all pretty core sites that I follow.

Mike in MN

JustKeepSwimming  [Member]
5/31/2011 7:47:03 PM
OK, now I feel bad because I was goofing in your thread, so I'll offer a little help. I would offer more, but the machine I'm using is old, rare and is old chicom stuff anyway. It's the ancestor of this which is more than you want to pay.

People are always drawn to the lower-end machines like Harbor Freight sells. As I understand it, the same machine is sold as Harbor Freight, Sieg and Grizzly. I don't know if that's true, I'm not familiar with the brands or what they offer.

But here's a good review, and on a useful site, because it's all about machining and gunsmithing at home, so you can glean a lot of good info.

http://www.homegunsmith.com/cgi-bin/ib3/ikonboard.cgi?s=87659047e4888da4aefd9b1922135db5;act=ST;f=8;t=16735

There are plenty of photos and a lot of attention to detail. Note that the thread author spends a lot of time showing modifications he made. The areas he thought needed improvement are all areas that can and will cause you headaches if you don't compensate for the weaknesses somehow, maybe not by modification, but maybe learning to work slower. Having said that, an 80% AR lower isn't brain surgery and the smallest of this family of mills would, I expect, be capable of the job. I doubt if it would work well enough to turn out a good lower out from a 0% forging without a LOT of headaches.

Yet another good review of this same family of machinery:

http://www.mini-lathe.com/X3_mill/X3rvw/X3.htm

One problem with asking about a suitable mill here is we use so many different machines. A lot of folks are using some antique that you won't find, and some are using industrial grade equipment that they got a good deal on. I now return you and the thread to the users who aren't smartasses.
Woodys556  [Team Member]
5/31/2011 8:19:40 PM
Thank you for the useful info.

I know there are LOTS of types of machines being used here. Many guys have access to high end expensive machines AND the expertise to use them. I now this is not brain surgery but I am frustrated enough by my screw ups. I asked the questions and came back with my angry comments because of that frustration and the lack of support and info. I asked the question, which I will admit has finally started to get answers, because I KNEW there were answers here.

I appreciate all of the recent comments that ate positive and helpful. I didn't say anybody was being a smart ass, it is just frustrating when you ask a sincere question and get off the point and obviously BAD answers.

Thank you to the on point responses.
JustKeepSwimming  [Member]
5/31/2011 8:28:46 PM
Originally Posted By Woodys556:

If you read the post on doing 80%ers with a drill press, you need to drill out the bulk of the material before milling. Drill presses can handle the lateral load like mils can so the bulk of the material needs to be removed via drilling first. I was drilling the 1/8" holes before I went to the larger drills before i go to the end mills.



First, assuming you meant "can't" handle. If you're breaking the 1/8 pilot drills you're most likely putting too much pressure on the drill, not backing the bit out to clean it and/or have a dull bit. Pilot hole, hog it out with large drills and then mill it is typical technique for a mill too, so you might to see what works on the drill press first, lest you get a mill and find out you are having the same problem. Just sayin'.

(And I know you didn't call me a smartass, I'm just owning up to what I am)
Woodys556  [Team Member]
5/31/2011 8:44:16 PM
Originally Posted By JustKeepSwimming:
Originally Posted By Woodys556:

If you read the post on doing 80%ers with a drill press, you need to drill out the bulk of the material before milling. Drill presses can handle the lateral load like mils can so the bulk of the material needs to be removed via drilling first. I was drilling the 1/8" holes before I went to the larger drills before i go to the end mills.



First, assuming you meant "can't" handle. If you're breaking the 1/8 pilot drills you're most likely putting too much pressure on the drill, not backing the bit out to clean it and/or have a dull bit. Pilot hole, hog it out with large drills and then mill it is typical technique for a mill too, so you might to see what works on the drill press first, lest you get a mill and find out you are having the same problem. Just sayin'.

(And I know you didn't call me a smartass, I'm just owning up to what I am)


I did all that. I use light pressure and backed it out repeatedly to clean the bit off. I used GREAT tapping/cutting oil to keep it all cool. I have completed One lower successfully with this method. I know I did it right, I just went cheap on the DeWalt shit. I WILL get better bits. The problem I have is I have two lowers with busted bits in them and I need to mill out around them to get the bits out and finish the lowers. I know I can save these but I am going to get a bench top mill so I can do this better.

Home Depot Dewalt Bit SUCK, FYI

Bretshooter  [Member]
5/31/2011 9:19:15 PM
Originally Posted By JustKeepSwimming:
Originally Posted By Woodys556:

If you read the post on doing 80%ers with a drill press, you need to drill out the bulk of the material before milling. Drill presses can handle the lateral load like mils can so the bulk of the material needs to be removed via drilling first. I was drilling the 1/8" holes before I went to the larger drills before i go to the end mills.


First, assuming you meant "can't" handle. If you're breaking the 1/8 pilot drills you're most likely putting too much pressure on the drill, not backing the bit out to clean it and/or have a dull bit. Pilot hole, hog it out with large drills and then mill it is typical technique for a mill too, so you might to see what works on the drill press first, lest you get a mill and find out you are having the same problem.


And I wanted to make sure you were not using a drill bit to make lateral cuts. Do these DeWalt bits have hex shanks? Does your drill press have obvious runout? This process should work fine following Swimmin's directions above. You can get 1/8" and 1/4" bits in bulk relatively cheaply, iirc.

Edited to add: 1/4" bits would be less likely to break off.
mn_mike  [Member]
5/31/2011 9:45:14 PM
I know this might be a little bit off the topic,

but for those that aren't used to drilling deep holes in aluminum especially with a drill press. Don't get too aggressive in with your pecks. Pecks in machining is the depth by which you engage the drill with each up and down movement.

There is a great deal of argument in machining on how big a depth of a "Peck" is with a standard high speed drill. I typically use 1/2 the diameter to be safe, even on a good $100k CNC machine. It sux scraping a part because of a broken drill.

So using a drill press, I typically take many many light pecks. So in this example with an 1/8" drill, I would easily go less than .060" depth per depth, which when you think about it isn't much. It never is a matter of how fast you can get it done, it's a matter that you can get it done!

So yes, there is something to be said for higher end drills, but for one offs, a little bit of time and a gentile feel for it is better than dealing with a broken tool.

By the way Woody, it is frustrating, I know. But don't get too excited about breaking a drill, we all wreck stuff. When I started out machining, I wrecked tons of stuff in the first couple years of the trade. Being that you already made an 80% lower, you should be proud of your accomplishment.

I know tons of guys that have been in the trade for years that couldn't finish one of those things off by hand....

Mike in MN
b_rogers  [Team Member]
5/31/2011 9:49:14 PM
Originally Posted By motoguy:
X3 sized mill, or equivalent, seems to be a good way to go for finishing 80% lowers. X2 sized might be too small. Both have aftermarket cnc kits available. Rong Fu RU-45 (iirc) seems to be a good, larger, desktop style mill.

www.practicalmachinist.com
www.diyguns.com
www.cncguns.com
http://www.homegunsmith.com
www.cnczone.com
http://www.chaski.com/homemachinist/

http://www.homegunsmith.com/cgi-bin/ib3/ikonboard.cgi

etc etc etc

Oh, and I agree...you can get MUCH more machine, used, for the same money as one of these new ones. If you're looking for a new machine under $1k...you won't be getting much. I think the X3 will be at the top of that (very short) list.


Thank you for all the links! More shit to read and learn...
MMcfpd  [Life Member]
5/31/2011 11:09:38 PM
Taggage
jduke  [Member]
6/1/2011 9:19:08 AM
I have a sieg x3 sold by grizzly as G0463 they are about $1k

I bought it for non gun products and with plans to cnc
Now I have given up on cnc plans for a while.

It works well for an 80% lower.

Best add on after buying the mill is a digital read out of some sort.
I just have 3 cheap scales working independently and it improves my ability to use the machine immensely

Duke
jduke  [Member]
6/1/2011 9:34:25 AM
One more thing.
3 phase is a plus rather than a minus.
Better motors and with a VFD you can dial speed up or down without changing a belt
Also easy to add external controls.

I replaced the single phase motor on my 9x20 lathe with 3 phase and VFD and it is the best improvement I could have made.

Single phase power in and 3 phase out with a multitude of programmable options

Duke
Woodys556  [Team Member]
6/1/2011 9:41:52 AM
Originally Posted By jduke:
One more thing.
3 phase is a plus rather than a minus.
Better motors and with a VFD you can dial speed up or down without changing a belt
Also easy to add external controls.

I replaced the single phase motor on my 9x20 lathe with 3 phase and VFD and it is the best improvement I could have made.

Single phase power in and 3 phase out with a multitude of programmable options

Duke


I am well aware of the benefits of 3 phase power. The unfortunate point is it requires commercial zoning in order to get it here. I can't even put up an 8 ft fence without getting a blessing from the pope. Much less ANY kind of 3 phase power. So until i get really good at this gun smithing shop, I am stuck with single phase power
RCC1  [Team Member]
6/1/2011 11:03:02 AM
If you happen to find a mill that requires 3 phase power, its very easy to fix with out involving the power company. You can use a small phase converter to make your sinngle phase into 3 phase.

Link to a phase converter-

Phase Converter

Woodys556  [Team Member]
6/1/2011 11:07:43 AM
Originally Posted By RCC1:
If you happen to find a mill that requires 3 phase power, its very easy to fix with out involving the power company. You can use a small phase converter to make your sinngle phase into 3 phase.

Link to a phase converter-

Phase Converter



That is an interesting option. MORE money, but interesting.
jduke  [Member]
6/1/2011 2:04:22 PM
You had better tell my variable freq drive that it has to leave since my property is zoned residintial

I am using a VFD that uses 110v ac common single phase household current on the input side and putting out clean well regulated 3 ph on the other side.

Sure this one is only rated for 1hp

Look up TECO vfd. They have some rated up in the 3 to 5 hp range that you can plug into your household single phase and get 3 phase.

No rezoning required.

Duke
motoguy  [Team Member]
6/1/2011 2:45:21 PM

Originally Posted By Woodys556:


I am well aware of the benefits of 3 phase power. The unfortunate point is it requires commercial zoning in order to get it here. I can't even put up an 8 ft fence without getting a blessing from the pope. Much less ANY kind of 3 phase power. So until i get really good at this gun smithing shop, I am stuck with single phase power

I think there's some confusion going on. When the previous poster was referring to 3-ph, he was referring to a machine with a 3-phase motor. As mentioned above, you can run a 3-phase motor on single phase, via a VFD. This allows control of RPM and such, as mentioned above. He's not saying you need a 3-phase line to your house...he's saying a machine (with a 3-phase motor, meant for 3-phase power) running off of a VFD (single phase input, 3-phase output) can be more useful than a machine that is meant to run off of single phase. Ie, don't take a machine off of the "potential purchase" list just because it's a 3-phase...there are ways to get the machine running, even if you only have single phase power running to your place.
Woodys556  [Team Member]
6/1/2011 6:08:26 PM
Originally Posted By motoguy:

Originally Posted By Woodys556:


I am well aware of the benefits of 3 phase power. The unfortunate point is it requires commercial zoning in order to get it here. I can't even put up an 8 ft fence without getting a blessing from the pope. Much less ANY kind of 3 phase power. So until i get really good at this gun smithing shop, I am stuck with single phase power

I think there's some confusion going on. When the previous poster was referring to 3-ph, he was referring to a machine with a 3-phase motor. As mentioned above, you can run a 3-phase motor on single phase, via a VFD. This allows control of RPM and such, as mentioned above. He's not saying you need a 3-phase line to your house...he's saying a machine (with a 3-phase motor, meant for 3-phase power) running off of a VFD (single phase input, 3-phase output) can be more useful than a machine that is meant to run off of single phase. Ie, don't take a machine off of the "potential purchase" list just because it's a 3-phase...there are ways to get the machine running, even if you only have single phase power running to your place.


I know the difference between single and 3 phase power. I just didn't know I could turn one into the other so easily. This does change things a bit.

Thanks


pipewelder74  [Member]
6/1/2011 7:01:18 PM
A bit of advice on the milling..(I'm assuming that we are all using Ray-Vin's guide) I just built two receivers and used the guide religiously, BUT I do disagree
with the guide regarding the use of drill bits at all in the fire control group.

I did my first one doing all the drilling, and ran into a lot of bit "chatter" while milling, especially near the bottom where the drills taper makes a cone shape...

On my second one, I just milled .200 cuts to the X/Y travel limits (.005 short initially, of course) and finished it in WAYYY less time, with better results.
This does not answer the "Where to get a mill from?" question, but will save you guys some time when you do get one.

As far as I can tell, the mill that harbor freight sells should be just fine for milling out the receiver, but I PROMISE YOU...If you can afford or access a mill
with DRO (Digital Read Out), you will save TONS of time and drastically reduce human error events...

This is where I got my 7/16 bit.. http://www.mcmaster.com/#end-mills/=ckb7pe

Part # 8949A47

[img]http://www.ar15.com/images/smilies/anim_beer.gif
Doernuth  [Team Member]
6/2/2011 9:34:12 AM
I have the mill that Harbor Freight sells and have done several lowers with it. It works well is easy to operate and doesn't cost an arm and a leg.

That being said there are a few drawbacks. Getting hold down clamps that work well in it has caused me some problems.

I am having trouble finding a vise that is not so big that it makes the mill non-functional.

I alleviated the drill bit problem by using a ball end mill to plunge cut instead of a drill. Just make sure your stop is set a little short.

Also get a collet set as the drill chuck is huge.
JustKeepSwimming  [Member]
6/2/2011 11:04:58 AM
How about sharing some of the details? A lot of people look at the HF machines expressly because they want to finish up an 80%, so your experience would be helpful not only to the OP but future searchers

Originally Posted By Doernuth:
I have the mill that Harbor Freight sells and have done several lowers with it. It works well is easy to operate and doesn't cost an arm and a leg.
So, you're talking about this machine in particular? http://www.harborfreight.com/two-speed-variable-bench-mill-drill-machine-44991.html

That being said there are a few drawbacks. Getting hold down clamps that work well in it has caused me some problems.
Details on what clamps to avoid? I would have assumed the HF Bridgeport clamp copies would work? Not true?


I am having trouble finding a vise that is not so big that it makes the mill non-functional.
Just a comment for this one, I would use an angle plate to get the work down on the table instead of a vise. http://www.wttool.com/index/page/product/product_id/20881/ With smaller angle plates like the one shown, you can run out of real estate for your clamps, so a size larger is easier to manage.

I alleviated the drill bit problem by using a ball end mill to plunge cut instead of a drill. Just make sure your stop is set a little short.

Also get a collet set as the drill chuck is huge.

Wise advice on the collets. Good practice and provides more effective vertical workspace.

Another item that makes setups easier are the two plates shown in the Ray-Vin manual appendix: http://arlower.ray-vin.com/ar15/chapter14drawings.pdf if the builder didn't buy a similar jig with his 80% piece.

One last comment for those trying to stay in a budget to turn out your first lower. The tooling; clamps, cutters, collets, all these things eat into your budget pretty hard. If you're going to buy your first mill, you have to consider those costs for a realistic estimate of what it will cost you to make the first one.

ETA fix linkage


Woodys556  [Team Member]
6/2/2011 11:53:24 AM
Originally Posted By JustKeepSwimming:
How about sharing some of the details? A lot of people look at the HF machines expressly because they want to finish up an 80%, so your experience would be helpful not only to the OP but future searchers

Originally Posted By Doernuth:
I have the mill that Harbor Freight sells and have done several lowers with it. It works well is easy to operate and doesn't cost an arm and a leg.
So, you're talking about this machine in particular? http://www.harborfreight.com/two-speed-variable-bench-mill-drill-machine-44991.html

That being said there are a few drawbacks. Getting hold down clamps that work well in it has caused me some problems.
Details on what clamps to avoid? I would have assumed the HF Bridgeport clamp copies would work? Not true?


I am having trouble finding a vise that is not so big that it makes the mill non-functional.
Just a comment for this one, I would use an angle plate to get the work down on the table instead of a vise. http://www.wttool.com/index/page/product/product_id/20881/ With smaller angle plates like the one shown, you can run out of real estate for your clamps, so a size larger is easier to manage.

I alleviated the drill bit problem by using a ball end mill to plunge cut instead of a drill. Just make sure your stop is set a little short.

Also get a collet set as the drill chuck is huge.

Wise advice on the collets. Good practice and provides more effective vertical workspace.

Another item that makes setups easier are the two plates shown in the Ray-Vin manual appendix: http://arlower.ray-vin.com/ar15/chapter14drawings.pdf if the builder didn't buy a similar jig with his 80% piece.

One last comment for those trying to stay in a budget to turn out your first lower. The tooling; clamps, cutters, collets, all these things eat into your budget pretty hard. If you're going to buy your first mill, you have to consider those costs for a realistic estimate of what it will cost you to make the first one.

ETA fix linkage





All Great comments and questions from both posters.
CFCNC  [Team Member]
6/2/2011 9:34:54 PM
I'm looking for a mill as well for lowers. I've been researching them for about a year now to use for other purposes so I do have a rough idea of what is out there. I really have only been looking at the Sieg family (Harbor Freight, Grizzly, etc.) due to limited space for it.

My main concern was if the X2 was large enough, but via previous posts, it seems that people have gotten buy with it... To help others out who are looking for one, I highly suggest these two over the Harbor Freight one: LMS or Micro-Mark These are called SX2 (S for Super), and are simply enhanced versions of the X2 found at HF.

I would lean towards the Little Machine Shop one as it has a little more travel and larger table. They are about $100 more than the HF, but it is well worth the extra cost as these use DC brushless motors, meaning more power and no belts to change.

I highly suggest reading thru this entire site if anyone is interested in the Sieg products: Mini-Lathe.com He gives very good reviews and covers a majority of the variations out there, although most of the site is centered around lathes, there is quite a bit of good mill info there.
b_rogers  [Team Member]
6/3/2011 12:00:30 AM
FWIW, i just left John Norrell's shop (suppressor/machine gun guru) and he had a 1200 dollar harbor freight mill and a enco good size lathe. Pretty simple stuff.
error404  [Member]
6/3/2011 12:14:05 AM
I have a X2 mini mill, that I just finished converting it into a CNC machine

I'm still working out some bugs and increasing the Y axis travel so I haven't tried any lowers yet... but you can see it in action cutting wood:

http://www.youtube.com/watch?v=YN4Xu2GYLm4
Woodys556  [Team Member]
6/3/2011 7:45:45 AM
I have been looking at the Little Machine Shops mini mill. caught my eye. will that seriously do the job?

So what is involved with turning this into a cnc machine? tat is cool, but is it necessary?
JustKeepSwimming  [Member]
6/3/2011 8:44:13 AM
Originally Posted By Woodys556:
I have been looking at the Little Machine Shops mini mill. caught my eye. will that seriously do the job?

So what is involved with turning this into a cnc machine? tat is cool, but is it necessary?


It's not necessary for an 80% AR, but it will let you perform some operations you might not be able to do otherwise when you use the machine for other home projects. (or if you want to build from 0% on your next lower) Somebody has already mentioned that DRO will also make life easier, and that's considerably cheaper than CNC, especialy now that DRO component prices are coming down.

One disadvantage to a CNC conversion is that now you have learn a lot of new software and commands and add those to your skill set before you can go on with your lower.

If you search the OKHTF forum in the years past, I have a couple of posts about converting my machine to CNC, but you wouldn't be missing much if you skipped the search because I didn't go into it very deep.
Woodys556  [Team Member]
6/3/2011 8:51:47 AM
Originally Posted By JustKeepSwimming:
Originally Posted By Woodys556:
I have been looking at the Little Machine Shops mini mill. caught my eye. will that seriously do the job?

So what is involved with turning this into a cnc machine? tat is cool, but is it necessary?


It's not necessary for an 80% AR, but it will let you perform some operations you might not be able to do otherwise when you use the machine for other home projects. (or if you want to build from 0% on your next lower) Somebody has already mentioned that DRO will also make life easier, and that's considerably cheaper than CNC, especialy now that DRO component prices are coming down.

One disadvantage to a CNC conversion is that now you have learn a lot of new software and commands and add those to your skill set before you can go on with your lower.

If you search the OKHTF forum in the years past, I have a couple of posts about converting my machine to CNC, but you wouldn't be missing much if you skipped the search because I didn't go into it very deep.



I give. Maybe the coffee hasn't kicked in yet. What the hell is "DRO" PLEASE expalin. I think I am narrowing my search. Big bummer is the additional 180.00 in shipping the LMS machine to me from Commiefornia to the home of the Kentucky Wildcats!! Gotta do what ya gotta do, I guess.
motoguy  [Team Member]
6/3/2011 8:58:33 AM

Originally Posted By Woodys556:


I give. Maybe the coffee hasn't kicked in yet. What the hell is "DRO" PLEASE expalin.

Digital Read Out. When you're doing your machine work, you simply watch these numbers on the display:



Instead of watching these turn and counting the number of turns:


Woodys556  [Team Member]
6/3/2011 8:59:59 AM
Originally Posted By motoguy:

Originally Posted By Woodys556:


I give. Maybe the coffee hasn't kicked in yet. What the hell is "DRO" PLEASE expalin.

Digital Read Out. When you're doing your machine work, you simply watch these numbers on the display:

http://www.chesteruk.net/store/product_detail_pages/images/dro_3axis_front_mill.jpg

Instead of watching these turn and counting the number of turns:

http://www.ihcnc.com/images/clip_image016.jpg


Okay COOL, How much more does that cost ya?

error404  [Member]
6/3/2011 9:06:40 AM
Originally Posted By Woodys556:
I have been looking at the Little Machine Shops mini mill. caught my eye. will that seriously do the job?


The Little Machine Shop's X2 mini mill has a slightly bigger table (or at least more x and y travel). However, they wanted $200 for shipping and handling. Harbor Freight was $28 for S&H (Both were coming from California when I order).


So what is involved with turning this into a cnc machine? tat is cool, but is it necessary?

Lets put it this way, the pieces to convert a X2 mini mill into a CNC machine will cost more than the machine itself. (Unless you have access to another CNC machine to make parts and you know what you are doing... expect to spend more than $1,000 for already made kits)

Then you need all the supporting stuff to cut things like
http://littlemachineshop.com/products/product_view.php?ProductID=4212&category=
and also calibrating tools like:
http://littlemachineshop.com/products/product_view.php?ProductID=1260&category=
http://www.shars.com/products/view/1927/Precision_Magnetic_Z_Axis_Setter_2quot_Height_x_0001quot

After all that, you need CAD software (you know how to use CAD right?) $$$

Then, you will need a CAM software (you know CAM right?) $$$

Then you will need a PC for you CNC machine and a software that will tell the CNC machine what to do (Mach3) $

all that so you can make a $60 lower receiver



Woodys556  [Team Member]
6/3/2011 9:21:56 AM
Originally Posted By error404:
Originally Posted By Woodys556:
I have been looking at the Little Machine Shops mini mill. caught my eye. will that seriously do the job?


The Little Machine Shop's X2 mini mill has a slightly bigger table (or at least more x and y travel). However, they wanted $200 for shipping and handling. Harbor Freight was $28 for S&H (Both were coming from California when I order).


So what is involved with turning this into a cnc machine? tat is cool, but is it necessary?

Lets put it this way, the pieces to convert a X2 mini mill into a CNC machine will cost more than the machine itself. (Unless you have access to another CNC machine to make parts and you know what you are doing... expect to spend more than $1,000 for already made kits)

Then you need all the supporting stuff to cut things like
http://littlemachineshop.com/products/product_view.php?ProductID=4212&category=
and also calibrating tools like:
http://littlemachineshop.com/products/product_view.php?ProductID=1260&category=
http://www.shars.com/products/view/1927/Precision_Magnetic_Z_Axis_Setter_2quot_Height_x_0001quot

After all that, you need CAD software (you know how to use CAD right?) $$$

Then, you will need a CAM software (you know CAM right?) $$$

Then you will need a PC for you CNC machine and a software that will tell the CNC machine what to do (Mach3) $

all that so you can make a $60 lower receiver





OH you are preachy to the choir here, i am just curious about it. Besdies I do everything on a MAC so scratch the cnc stuff.
Doernuth  [Team Member]
6/3/2011 10:28:21 AM
Originally Posted By JustKeepSwimming:
How about sharing some of the details? A lot of people look at the HF machines expressly because they want to finish up an 80%, so your experience would be helpful not only to the OP but future searchers

Originally Posted By Doernuth:
I have the mill that Harbor Freight sells and have done several lowers with it. It works well is easy to operate and doesn't cost an arm and a leg.
So, you're talking about this machine in particular? http://www.harborfreight.com/two-speed-variable-bench-mill-drill-machine-44991.html
Yes that is the one

That being said there are a few drawbacks. Getting hold down clamps that work well in it has caused me some problems.
Details on what clamps to avoid? I would have assumed the HF Bridgeport clamp copies would work? Not true?

To be clear the T-nuts are the problem Ive had, I think I should have bought the 7/16 ones. Also for lowers, with a jig the standard triangle bases in the set are too short to hold it down.

I am having trouble finding a vise that is not so big that it makes the mill non-functional.
Just a comment for this one, I would use an angle plate to get the work down on the table instead of a vise. http://www.wttool.com/index/page/product/product_id/20881/ With smaller angle plates like the one shown, you can run out of real estate for your clamps, so a size larger is easier to manage.
Thanks Ill check that out!!

I alleviated the drill bit problem by using a ball end mill to plunge cut instead of a drill. Just make sure your stop is set a little short.

Also get a collet set as the drill chuck is huge.

Wise advice on the collets. Good practice and provides more effective vertical workspace.
I bought a complete set of R-8 Colletts from Enco has the sizes I needed and then some.

Another item that makes setups easier are the two plates shown in the Ray-Vin manual appendix: http://arlower.ray-vin.com/ar15/chapter14drawings.pdf if the builder didn't buy a similar jig with his 80% piece.
I use the jig from Tactical Machining but Ray-Vins look good too.

One last comment for those trying to stay in a budget to turn out your first lower. The tooling; clamps, cutters, collets, all these things eat into your budget pretty hard. If you're going to buy your first mill, you have to consider those costs for a realistic estimate of what it will cost you to make the first one.

ETA fix linkage




JustKeepSwimming  [Member]
6/3/2011 11:18:25 AM
Originally Posted By Doernuth:

To be clear the T-nuts are the problem Ive had, I think I should have bought the 7/16 ones.



About that, I recall a comparison of several benchtop mills that said the HF mill T-slots are advertised as 1/2" but they were really smaller. Maybe HF had trouble with metric conversion! (I got no link)

ETA (I knew I had seen this somewhere) Replacing the rack on this same HF mill gets another 1.75" of vertical travel for $26 http://www.littlemachineshop.com/products/product_view.php?ProductID=1486&category=6 and this page shows how one guy did it http://www.homegunsmith.com/cgi-bin/ib3/ikonboard.cgi?s=28aadaa253998f9aba7c828ed66a9874;act=ST;f=8;t=16735;st=150
JoshAston  [Life Member]
6/3/2011 6:20:16 PM
My research on various machining forums points to Taig. I have no experience with them, but unless someone here as an overwhelming reason not to, it's what I intend to try out sometime in the near future.
Woodys556  [Team Member]
6/3/2011 9:17:29 PM
I saw that mill and liked it also. the price is what swayed me away from it. My research has shown i can get as much machine with the LMS machine above, or comparable. like you i am looking for definitive info on anything.
CFCNC  [Team Member]
6/4/2011 3:35:40 AM
Originally Posted By error404:
Lets put it this way, the pieces to convert a X2 mini mill into a CNC machine will cost more than the machine itself. (Unless you have access to another CNC machine to make parts and you know what you are doing... expect to spend more than $1,000 for already made kits)

Then you need all the supporting stuff to cut things like
http://littlemachineshop.com/products/product_view.php?ProductID=4212&category=
and also calibrating tools like:
http://littlemachineshop.com/products/product_view.php?ProductID=1260&category=
http://www.shars.com/products/view/1927/Precision_Magnetic_Z_Axis_Setter_2quot_Height_x_0001quot

After all that, you need CAD software (you know how to use CAD right?) $$$

Then, you will need a CAM software (you know CAM right?) $$$

Then you will need a PC for you CNC machine and a software that will tell the CNC machine what to do (Mach3) $

all that so you can make a $60 lower receiver





Just as a rough idea of cost, when I built my CNC router it was almost $3,000 for the software and computer hardware. Not including the stepper motors, drivers, power supply, the machine itself, etc... I went above and beyond what was needed, but I think the cheapest decent option is still around $1,000 for software and a junk computer. The last option is EMC2 (linux) and free CAD/CAM, but in my opinion they are all worthless. Mach3 is only $150 and its a hell of a better program. I use Vectric Aspire and love it, I started with Cut2d and it was nice, but 2.5d is pretty limiting. Overall, I've been happy with all Vectric has offered (I've tried most all their programs.) Thankfully I have AutoCAD, or it would be several more thousand for that... and as a word of warning, avoid BobCAD-CAM. Worst piece of software I have ever used, the free stuff was nicer and about $600 less. After you use stuff like Autodesk, all else pretty much sucks lol.

BUT! CNC is just as fun and addictive as AR's if you are into tools, so be careful :)
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