milling machine question

[sungod]

I have been looking at the home workshop series of books and they claim that a milling machine is pretty important. I am assuming that you dont need a machine that vacuums the floor, does the dishes, and smokes a cigarette afterwards.
The one thing the books do not mention is the actual specifications that the machine needs (its capabilities I guess).
Can somebody WHO KNOWS please tell me the actuall technical stuff I should be looking for in one of these machines? There are several extremely well priced (i am not made of money unfortunately) combination vertical mill/drill presses and I was wondering if these would do the job. Here are some links to show these units so you know what I mean.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=58254&item=3844167445&rd=1
http://www.mini-lathe.com/Mini_mill/Main/mini-mill.htm

[nbk2000]

If you're making gun parts at home, then look at the specs on the blueprints (I'm assuming you're using these) and it'll give the tolerances there.

Use a machine that has a max of half of the lowest required tolerance.

IE: If the tolerance for the most precise part is .002", then you need a tool with a max run-out tolerance of .001"

[sungod]

thank you
could you please advise me as to wether mods/admins have received my communications regarding the difficulties i am having using the forums and just in case you havent received them this will probably be of onterest to you.
http://www.johntaylorgatto.com/chapters/3b.htm

[Magas]

Hi Sungod

The Milling machines u are looking at do not have the tolerances to produce fine gun parts they are typically for rough model buiders. My mill is a nc mill but then again it also cost $32K. However having said that finer tolerances are possible on the mills u are looking at as u can fit both of these with a vernier on the x & y axis for about $300 in kit form. They are quite capable to mill dovetails and other components if you take the time. You might also like to consider the type of steel u wish to mill as this influences the type of tooling u need and this is quite expensive. So u will have to factor this also in your purchase costs :cool:

[nbk2000]

The letter U is NOT a substitute for the word YOU.

Correct your grammatical error or be erased as per the Rules.

[tom haggen]

Running a vertical mill is not something you can just do automatically. You really should take a basic manufacturing class sungod, and buy a machinists handbook. There are many formulas you need to know for maching. (4*cutting speed) / diameter. Not to mention formulas for cnc maching some of which I have forgotten.

[meselfs]

Actually, you can. I've never taken such a course, yet nowadays I mill all the time, and do it well. I rarely use a formula, those are mostly for high-production stuff.
Just try to remember that if the tool is chattering or squealing, something is wrong :D.
A book can help alot, though.

Do not find yourself fascinated by "mill/drill" machines; that's just a name meant to sell more. I find that machines designated that way just so happen to be kinda low quality...
The real fact is that any vertical mill will function as a drill press as well ;->

Make sure your machine has a GOOD vise. The vise quality is crucial. Made in china vises will work fine, but make sure it's a good one. Look for those that have "positive holddown" or "positive lockdown". Such vises have an internal wedge which causes much of the holding force to be used to secure the jaw downward.


Finally, I recommend you get a lathe too. Lathe + Mill = basic shop.



Whatever you pick, happy trails with it. You won't regret it :D.

[sungod]

Thank you for all your responses. You have been extremely helpful. At the moment I am leaning towards getting a decent lathe, teaching myself how it all works and then I have heard you can get kits for lathes that allow you to do the rudimentary milling that I would require.
If anyone knows about/or has done milling work with a lathe can they please let me know as I would dearly like to pick your brains.

[JV44]

If you are looking for a small, high-quality manual milling machine for most homeshop work one can think of, I can only recommend a used Deckel FP1. They are very rigid for their size and allow some very accurate work, if they have not been abused.

[Magas]

Sorry NBK

Hi Sungod

The Milling machines you are looking at do not have the tolerances to produce fine gun parts they are typically for rough model buiders. My mill is a nc mill but then again it also cost $32K. However having said that finer tolerances are possible on the mills you are looking at as you can fit both of these with a vernier on the x & y axis for about $300 in kit form. They are quite capable to mill dovetails and other components if you take the time. You might also like to consider the type of steel you wish to mill as this influences the type of tooling you need and this is quite expensive. So you will have to factor this also in your purchase costs

[sungod]

Thanks for your response Magas. I haven't had internet access for a fair while and so I apologise if I appeared to just drop this thread. Life's been a little 'confused' lately(to be polite).

[Skean Dhu]

If you're up to a challenge, you could try your hand at building lathe/milling machines. There is a book series printed by lindsay books written by David Gingery(http://www.lindsaybks.com/dgjp/djgbk/series/index.html) that can be bought which detail the construction of the machines.

I have the series, however they are unavailable to me at this time, and when I will have access to them again, I won't have the means to upload them(ain't life a bitch).

I'm sure there are pdf copies of them floating around the web somewhere(perhaps our FTP? ). Or if you can't find them online and can't wait theres always the option of buying them.

edit:
I found a torrent, http://thepiratebay.org/search.php?q=gingery this should contain all of the books on the previous link I posted.

Gingery milling machine rapid share curtosy of NBK:
http://rapidshare.de/files/13347437/_Gingery_-_4._The_Milling_Machine__1982__OCR_7.0-2.6_LotB.pdf.html

[stupid939]

Even if you do find a decent-priced mill, as with most machines, you will probably spend more on the accessories than you will on the mill.

I have Sherline equipment (mill and lathe), and I have spent about $6,000 on the machines and accessories. If you have a lathe, you could probably cut that in half, and maybe less if you get imported accessories and tools for your mill. If you do this, you have to challenge yourself to get the accessories to be adaptable to your milling machine.

I love my Sherline machines, and if you take your time, you can get your parts within a tolerance of less than 0.001. With these machines, you can also upgrade to DRO (Digital Read Out) packages or CNC packages. Sherline offers just about every accessory that you would need, and if you break/lose one of the pieces to you machine, you can get any replacement part from them.

Heres the link

sherline.com

-copy and paste-

[blackberrygoose]

A Sherline machine may not be what you are looking for, especially if your are on a budget, from what I can see of their website they only sell small hobby type lathes and vertical milling machines. For gunsmithing work this may not be the best option especially if you want to work on some of Bill's bigger jobs (.50BMG rifle, Auto shotgun, M83 9mm, home conversion 9mm AR-15).

Try a lathe with a maximum length between centres of 36" (about 1000mm) + (or the largest diameter barrel you wish to accomadate) with a minimum swing over of about 24" or about 600mm. As for power go for anything above 5.75 hp, in the size you are looking for. If all you want to use it for is "sub guns" then try a Myford ML7 or Super 7 (an old engineer reckons this is o.k.), but then even Bill Holmes writes that a Taiwanese import would suffice.

As for vertical machining tools, same as above, look for a machine tool that has a minimum traverse travel of 6"+ or about 145mm and a longditudinal travel of 16" or about 400mm, with a minimum power rating of 1 kw or 1.34hp

Sure these might sound like hobby type machines but this is the minimum that I would recomend. Like NBK said,
"Use a machine that has a max of half of the lowest required tolerance.

IE: If the tolerance for the most precise part is .002", then you need a tool with a max run-out tolerance of .001" "

If it is a gunsmiths machine that you desire, and you are broke or have kids, then there are only a few options left.

Option 1: Use the Gingery method of lathe and mill construction, Dave claimed that he could get .001" accuracy from his lathe. This method would be dilatory and fraught with peril.

Option 2: Commandeer a lathe/vertical machine tool. Nothing is as cheap as something that has already been paid for (paraphrased from "He died with a falafel in his hand"). While your at it comandeer two, of each. Of course being caught and paying the penalty may leave you wondering why you didnt go to the trouble of making one.

Another part to this option (comandeer) would be to befriend an existing lathe/machine tool owner and get the tutorial that goes with a bribe (box/slab/unit of their favorite beer/whiskey/rum/softdrink).

Option 3: Thouroghly scour: auctions, sale yards, garage/carboot/white elephant sales, clearance sales (highly lucrative), tool distributors, machine tool distributors, importers, tips, rubbish dumps, industrial sites, empty wharehouses, neighbors sheds, engineering firms/workshops/jobsites, and "take what you can, give nothing back!". and soon you shall find yourself the proud owner of monstrous piles of crap.

If you get a job as an engineer, or work somewhere you can get your hands on some lathe/mill time you may not need to buy one at all, as you may be able to work on a piece of work one at a time, of course you would need to make sure the work did not arouse suspicion (see Gerad Metral's D.I.Y. 9mm Submachine gun).

[209]

If you are making pieces on a mill or lathe DON'T make the gingery machines. They are just no good for super exact tolerances that are standard in gunsmithing.

Go to Princess Auto or something similar and pick up a decent quality mill and lathe (and dish out that months wages :rolleyes: ) Its much better knowing you have a quality piece of machinery that will turn out good parts ever time rather than a half ass attempt at casting your own lathe and mill.

Here is a ok design for a mill if you want to make your own anyway - http://www.gizmology.net/vertmill.htm

[nbk2000]

If a person was interested in beginning small scale production of a particular part, proper investment is required.

http://www.cinmac.com/Used/index.htm

Cincinatti Milacron machines, used.

Prepare to part with the K's, but well worth it, as the money you invest into quality machines and tooling translates into faster production with less downtime due to production errors and breakage.

[hydra]

Sungod,

Mill-Drills: If you have no other machine, and can afford no other, these machines will do a helluva lot of work for very little money.

However, be aware that they are typically JUNK; in terms of being a 'precision' machine tool. I have an "R-12" model....fairly typical, about a grand new, 2hp. The table was not cut/ground square between X and Y !!

Hopefully you already know enough about machining to understand how serious a problem that is.

And in a practical sense, there is nothing easy that's going to fix it.

Probably it's just a fluke...but it is very typical of the kinds of flaws in these chinese junk machine tools. I've seen other mill-drills where the column wasn't square to the table-surface. Again, this is something which would be VERY difficult for someone who doesn't already have a full shop to correct.

Also, the leadscrew nuts are terrible; and wear very quickly. You can indeed still make precision parts with loose leadscrews, but you have to know what you're doing.

Another issue that nobody mentioned yet is shop-space. If you have the space, then in my opinion you are FAR better off getting old, used, full-size, US machine tools. They will be far more accurate, smooth, and stable over time....and if you're sharp, you can find them for not much more money than chinese-junk machines like the mill-drill.

Nevertheless, if you don't have the space or money, then in regards to the mill-drill, Sherline, small lathe, etc.....GO FOR IT ! You will NOT regret it; because ANY machine tool is far far better than no machine tool at all !

If you decide it's something you're going to stick with, then you can sink more money into better machines later. In the meantime, you'll have a machine, and you'll be learning and making useful parts. After you get a 'real' mill, you can always just use the mill-drill as a 'precision drill press'.

Tooling: tooling is like the 'software' for the machine. You spend a few hundred bucks on a PC...and then spend thousands on software over the next decade...lol... That's what it'll be like with tooling (i.e., chucks, cutters, work-holding and fixturing, measuring instruments, etc. etc).

Best of luck

[lemons]

If you're strapped for cash but want something with tighter tolerances than the Gingery machines, consider building a MultiMachine: http://opensourcemachine.org/mm2html2/How_to_build_a_multimachine.html

[6The6Beast6]

Building your own milling machine can be an interesting learning experience, or a severely laborious task depending on the person, but there are still options open to the "poor man" of the improvised weapons community. Thousands of universities exist in the united states that have on-campus milling machines that are available for student use. This introduces various possibilities with obvious disadvantages depending on the how much the faculty and staff know about what you are doing, but there are various ways to avoid this as long as you are not blatantly obvious about what you are doing.

[Jacks Complete]

I'm begining to think this topic is bipolar. On the one hand we are talking about cheap machine tools and how to knock out a barrel and a few parts, and on the other we are talking about micron accuracy CNC tools and production runs.

As ever, if you just want a gun, you are better off keeping that grand and buying a gun on the black market. True, it's a sellers market in the UK, but you could probably get three pistols for £1k. If you have to kit out the whole 'hood, then if you are making pistols, you will be fine with a cheap mill and lathe combo. Tolerances that are high won't be needed, since you will be at close quarters.

If your plan is to arm your underground bunker's army of super soliders, then yes, those battle rifles would be better turned out on a full CNC system, if only because the parts will likely be interchangable. However, for most people, unless they are becoming a gunsmith who wants to make lots of custom gear, and even then, are going to be doing runs of stuff rather than neat one-off jobs, it is overkill. The only parts that really need insane accuracy are the barrels, the rest can be hand finished and fitted.

If you can't freely buy barrels, then unless you can recoup your investment before going to jail for a long time, be careful.

[reddog_2711]

A friend of mine recently bought a mill/drill machine from Harbor Freight for not too much cash. I work in a machine shop and have 25 CNC mills at my disposal, so I would think that something from Harbor Freight would be junk, but he claims that it was far better than he thought it would be considering the price.

I wouldn't do anything with a tighter tolerance of ±.003 on it, and I'd think that you'd have to re-set it up for every cut and not "trust" the machine at all, but with a little patience, he's getting his moneys worth from it.

I think I'll stick with my CNC's ;-)