I'd love if you ever have the time to explore the concept of buying a hobby-level machine capable of turning out a functional 1911 or AR - even if it taxes the CNC and takes a week to mill the frame. When Miller started III Arms he entered with a Tormach - an "Entry level" machine in the world of real CNC - but I'd love to know if you think there is an answer out there for the Patriot who wants the ability to load some pre-constructed code, add steel blocks, and end up with a defensive tool.The answer is that they probably are all capable. It's not falling off a log easy, and some operations might be a bit scary, but I think there are tons of people using CNC-modified Grizzly and Harbor Freight mills and lathes to do this. I would love to have a nice Tormach machine, but they are serious money for a hobbyist. As a runner up, the Chinese company Sieg produces the majority of the cheaper imported machine tools, with differing capabilities, sizes and costs. I've mentioned this one before and with the exception of not having the room in my garage, I probably would have bought one of these by now. Seig makes this one, as well as the machines you see sold by various tool companies like Grizzly, Harbor Freight, and others. My machines are currently all Sherline, with options by A2Z CNC. Both the Sherline parts and the A2Z CNC add-ons are made in the US. While the Sherline's standard work envelope is small, they are more accurate out of the box than pretty much anything else you can buy until you hit that Tormach, to the best of my knowledge. A2Z has made their own versions of the Sherline machines which are capable of machining bigger things. See their website.
As you say, with a smaller or less rigid machine, you can make more shallow cuts than on a bigger machine, and you take longer. CNC is ideal for this; it never gets tired, never miscounts turns on the hand wheels.
Of course, I've got a permanent post on how I built an AR-15 from an 80% lower (my rifle and the machine I made it on, below). I haven't mentioned it, but thanks to The Redneck Engineer, I have some "0%" lowers (forgings) that I intend to machine all the way. With the personal issues that have complicated life this year, I haven't been able to get to it, but I always thought of it as a "round tuit" project. Judging by "The Book", I think this task is possible with my Sherline tools, but would be easier with a bigger capacity lathe. This guy has a pretty thorough look at the process - on big machines.
Of course, the AR platform, while a fine rifle, isn't the be all and end all of guns. You might want a 1911. There are 80% 1911 forgings to complete on your mill. KT Ordnance of Dillon, Montana, is a prominent source. This gets around the potentially nasty problem of cutting out the magazine well, which is a long reach for an unsupported cutting tool. KT says the BATFE has ruled what constitutes an 80% lower, and you'll need some special cutters, which they'll sell you. This guy has a decent write up. KT sells an 80% Ruger Mark 1, .22LR pistol!
You will need information and places to hang out and just read. Of course, AR15.com is a go to site for all things AR. But don't miss The Weapons Guild or CNC Guns. There are many forums devoted to particular machine tools where you can learn the ins and outs of your particular machines Yahoo! Groups has several. YouTube has many videos of small milling machines converted to CNC, and there are commercial options, too. The advantage of going with one that was sold as a complete system, like the Little Machine Shop tools mentioned above, is you have one seller to go to for support. When you put it all together yourself, you can have problems isolating problems and getting it all running; with one of these, you may need to clean it up to remove protective grease, but it should work when you power it up.
Hope that answers it. If not, let me know!
There are a few machines that are a combination Lathe and milling machine. Manual machines are of course cheaper and have some pro's over CNC machines. Take some classes at a community college if you have no practical experience on metal working machines.
ReplyDeleteThere is the diylilcnc at http://diylilcnc.org/
ReplyDeleteThere is the DIY Iron Glock at http://www.thefirearmblog.com/blog/2013/07/18/diy-iron-glock/
I've never tried a 1911. I'm a Glock girl myself.
I just learned how to run a vertical mill. I think it's a very perishable skill though. I have already forgotten some of how, there's a lot to know about bits, for example, and speeds.
Last comment: Barrels and barrel rifling will likely be the main issue in building a gun from scratch. Best to just obtain a barrel as a part rather than try to machine one, if you are going for a design that already is tried and true. Or, you can make a REALLY thick barrel instead of a hard one, but you still have the rifling to consider. You could print a plastic one with the rifling in the pattern, and just plan to keep replacing it as it wears down.
Milling an 80% can be done entirely with a drill press. Milling a 0% with a drill press can be a bit complicated, but can be done using an X-Y vise. Your tolerances need to be good, but not perfect. Having the right tools to do it 24/7 just cost more money than once a year stuff.
ReplyDeleteHad it not been for cashing out a retirement plan that I'll never be allowed to retire and use, I'd still be making aluminum chips with a file and drill press.
I just converted my Rong Fu mill to CNC. I spent a whopping 800 bucks. It would have been under 500 had I not used ballscrews. I guess I'll post up some info on it later.....
ReplyDeleteRifling is not the impossible task that many think it is. I know of a fellow builder that makes his own barrels on a lathe similar to mine; a hong kong fooey special 13x40. Barring that, buy barrel blanks now while they are still cheap. I use a ton of Green Mountain blanks and they are worth every penny.
Good comments, everyone.
ReplyDeleteI'm with Penny Pincher on the idea of getting some barrels when they're available. Barrels are consumable items after all, and it does make sense to have some spares for fast change out. Replacement barrels for any handguns you have would be easier than machining one from steel. Ever seen the barrel in an LCP or Taurus TCP? There's so little metal left you wonder how you could hold it to machine.
But I've been doing some thinking similar to what Theredneckengineer says about rifling not being too hard. Another way of thinking about rifling is internal threading, like the threads on a pipe cap or something, only with a really long pitch. Either way, you push a cutter through lengthwise while either turning the barrel slowly with a fixed cutter or turning the cutter in a fixed barrel. Or maybe turning them both at different rates. A couple of years ago, I saw a video of guys making historically accurate Kentucky Long Rifles and they were rifling the barrels completely under human power. It seems like a fixture could be built, or a gear ratio found that could get you the right twist rate...
BTW, Penny Pincher, thanks for the link on the iron Glock. Not enough details to see what's in it, but I suppose I'm the one gun nut left on Earth who hasn't stripped a bunch of Glocks. Maybe everyone else knows what they look like inside.
Look up button rifling...you would have to build a hydraulic "press". You are actually pulling not pressing.
DeleteThis link to the Iron Glock will have more detail:
ReplyDeletehttp://www.northeastshooters.com/vbulletin/build-yourself/214022-iron-glock.html
Excellent! Thanks.
DeleteBrownells has a couple of good articles on fabricating an AR barrel from a blank.
ReplyDeletehttp://www.brownells.com/.aspx/lid=16209/GunTechdetail/AR-15-Barrel-Fabrication-101-Part-1
http://www.brownells.com/.aspx/lid=16219/GunTechdetail/Brownells-Gunsmith-Corner-July-2013
A good guide to machining a 0% forging is here:
ReplyDeletehttp://www.ray-vin.com/frtech.htm
There are also 80% 10/22 receivers, too:
ReplyDeletehttp://www.ruger1022receiver.com/
Oh, that's cool! Bookmarked for future use, for sure.
DeleteThanks!
Just some food for thought here. You can buy a used bridgeport mill for under $2k if you look a bit. Then you wouldn't have to worry about light cuts, and they do make kits to turn it into a CNC machine. On the flip side, then you do need to have some idea as to what you're doing. Also, then you do need a little bit of area to work in.
ReplyDeleteA guy I used to work with (mechanical engineer) had one he picked up used, and they show up every year or so around here, where there are a lot of little machine shops.
DeleteLike you say, they need room around them, and once they're in place don't ever expect to move them again, but they are the name in the business. Virtually indestructible. You may have to run a separate power into your house just for it. And it will be worth it.
I could be convinced to do that in a nanosecond. If I had the room.
I have used one of these in the past... Makes doing impossible cuts (special pockets, spherical surfaces, etc.) as easy as filling in a few questions on the conversational menu.
ReplyDeletehttp://www.centroidcnc.com/bridgeportkneemill.htm