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 Acquiring a small tabletop lathe in the VA/MD/PA area
LedZeppelin  [Member]
11/11/2011 10:13:20 AM EST
I'm stationed on an airforce base near DC, and I'm trying to get a small lathe (8-14" between centers) that is set up to cut threads. There are a few projects I want to tackle (non-gun related) that don't require a huge deal of precision, and in general I just want to get some more hands on experience with machining and metal working because it's what I intend to do after my enlistment is up.

Ideally, I'd like to get something like a Bolton or Grizzly mini-lathe. However, I have been unable to find anyone in the area that has what I need locally. I would even be willing to go as far as 20" between centers, although that's a stretch. I have to keep the thing in my closet when I'm not using it, and take it to where I work when I intend to use it (I could probably work a deal to keep it where I work). I don't think the Barracks manager would appreciate me turning pieces in my closet So we're looking at a 200-300lb maximum weight. I also plan to take this thing home with me when I leave this duty station.

Now I would just order the damn thing, but then I run into the issue of my work schedule (not forgiving at all), and the fact that most of these are freight shipped, so when it shows up I have to go to the base gate and get the freight truck on base etc... I'd rather not do that.

So, with all of that said, does anyone know of any places in Virginia, Maryland, DC, or Pennsylvania that sell these little hobby lathes?
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Covertness  [Team Member]
11/11/2011 10:43:54 AM EST
Grizzly has a showroom in Muncy Pennsylvania

AeroE  [Moderator]
11/12/2011 4:49:52 AM EST
Quality Machine Tools near Pittsburgh:

http://www.machinetoolonline.com/PM-1127-VF.html

LedZeppelin  [Member]
11/12/2011 7:17:34 PM EST
Well I did the haul today up to Muncy and picked up a little Grizzly 7x12" lathe. Spent the last several hours disassembling and cleaning it up and figuring out how everything works. It's surprisingly quiet. Played around with some copper pipe and other random small round things in my room. Almost had a nail threaded, but I asked too much and it self destructed.

Much to be learned, especially turning down diameter and indicating. It seems higher RPM = better turning, but I was afraid to go too fast (loud) tonight. Was hard to get stuff spinning concentrically, too.

I think next on the list is a quick change tool post. and maybe a 4-jaw chuck.
Covertness  [Team Member]
11/13/2011 2:14:26 AM EST
I don't do metal turning but I do wood turning. Higher RPM may seem like a better cut but that's not always the case. I'm sure this is the same with metal turning.
Cole2534  [Team Member]
11/13/2011 3:44:14 AM EST
This crazy concept is called 'surface feet/minute', or SFM. After you figure out your arithmetic and keeping fingers out of the sharp stuff its tje next thing to know.

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Dano523  [Team Member]
11/13/2011 6:32:24 AM EST
Originally Posted By LedZeppelin:
Well I did the haul today up to Muncy and picked up a little Grizzly 7x12" lathe. Spent the last several hours disassembling and cleaning it up and figuring out how everything works. It's surprisingly quiet. Played around with some copper pipe and other random small round things in my room. Almost had a nail threaded, but I asked too much and it self destructed.

Much to be learned, especially turning down diameter and indicating. It seems higher RPM = better turning, but I was afraid to go too fast (loud) tonight. Was hard to get stuff spinning concentrically, too.

I think next on the list is a quick change tool post. and maybe a 4-jaw chuck.


Use speed so as you are turning so you are getting chips, not long strings that can catch and take your finger clean off.

When treading, the slower the speed, the better.

HSS tools will give a cleaner surface when turning, but Carbide tools will last a lot longer (C-2 for aluminum, and C-6 for harder metals).

paulx  [Member]
11/13/2011 7:09:20 AM EST
This link has some info mini-lathe.com
LedZeppelin  [Member]
11/13/2011 11:43:10 AM EST
Originally Posted By Cole2534:
This crazy concept is called 'surface feet/minute', or SFM. After you figure out your arithmetic and keeping fingers out of the sharp stuff its tje next thing to know.

Posted Via AR15.Com Mobile


Good to know, thanks. I'm reading into it now.

I only have HSS cutters now (little 8 piece starter set). Where's a good place to get various cutting tools? Also, metal round stock to practice with?
Cole2534  [Team Member]
11/13/2011 12:22:02 PM EST
Msc for everything and if you get stocker shock try tools4cheap.

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Dano523  [Team Member]
11/13/2011 12:22:08 PM EST
Little machine shop will be more up your alley for parts and tools for the smaller machines. Grizzly tools has some smaller tools for your machine, and you may luck out at Enco for some tools as well.


Check in the yellow pages for local metal suppliers since you can save money on shipping if there price is right to start with, or you want to have metal shipped in, then On line metal store, or speedy metals ships smaller quantities.
AeroE  [Moderator]
11/14/2011 12:32:31 PM EST
Originally Posted By LedZeppelin:
Originally Posted By Cole2534:
This crazy concept is called 'surface feet/minute', or SFM. After you figure out your arithmetic and keeping fingers out of the sharp stuff its tje next thing to know.

Posted Via AR15.Com Mobile


Good to know, thanks. I'm reading into it now.

I only have HSS cutters now (little 8 piece starter set). Where's a good place to get various cutting tools? Also, metal round stock to practice with?


Speedy Metals is one source for small pieces of stock.

You'll need a grinder for sharpening tools. There's nothing wrong with HSS. I like the 5% Cobalt blanks sold by Grizzly.

mrpete222 on youtube has enough very excellent tutorials to keep you busy for weeks. Start with the first one.

You can find a copy of Southbend's "How to run a lathe" on the internet, available to down load. The Hercus "Text book of turning" primer is also available.

Check out this site: http://www.wswells.com/



Cole2534  [Team Member]
11/14/2011 1:26:13 PM EST
Onlinemetals.com has cool 'metal packs'. 3' Of various sizes of material. Great for practice and building a stash.

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LedZeppelin  [Member]
11/15/2011 4:43:02 PM EST
Originally Posted By AeroE:
Originally Posted By LedZeppelin:
Originally Posted By Cole2534:
This crazy concept is called 'surface feet/minute', or SFM. After you figure out your arithmetic and keeping fingers out of the sharp stuff its tje next thing to know.

Posted Via AR15.Com Mobile


Good to know, thanks. I'm reading into it now.

I only have HSS cutters now (little 8 piece starter set). Where's a good place to get various cutting tools? Also, metal round stock to practice with?


Speedy Metals is one source for small pieces of stock.

You'll need a grinder for sharpening tools. There's nothing wrong with HSS. I like the 5% Cobalt blanks sold by Grizzly.

mrpete222 on youtube has enough very excellent tutorials to keep you busy for weeks. Start with the first one.

You can find a copy of Southbend's "How to run a lathe" on the internet, available to down load. The Hercus "Text book of turning" primer is also available.

Check out this site: http://www.wswells.com/





I've been subscribed to his videos for almost a year now :)

I kept losing my mind trying to cut threads with this thing. I was getting what resembled buttress threads over and over again trying all different things. I had it set at "29.5" on the scale, which indeed was fairly accurate (0-29.5 is actually a 29.5 degree shift), but the "0" was 90 degrees off from where I should've been measuring from, so I actually needed 60.5 degrees.....

Anyway, once that got settled everything fell into place. This puppy screws right into the bottom of my camera (1/4"-20tpi).


I've got to pace myself... Next paycheck I'll order some aluminum and steel round stock to play with.
AeroE  [Moderator]
11/15/2011 4:59:01 PM EST
That's a common problem with the cross slides of Chinese and some Taiwan lathes. It's a pretty good idea to make sure everything is pointing the right direction no matter what the dials say.

Cole2534  [Team Member]
11/15/2011 5:18:30 PM EST
If threading is your goal you'll need some thread wires. These allow you to accurately measure a thread without a gage.

Good looking thread.

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arsw15  [Member]
11/18/2011 5:03:52 PM EST
american gunsmith institute (AGI) has a great video coarse on lathes and mills.
wilNva  [Member]
11/21/2011 7:42:28 AM EST
You might want to look into a local community college machineing course. It should be cheap to take and the AF should help pay for all or some of it. Even if you only learn a few things it's worth it to be able to play with tools you can't afford yet and decide what you might want to buy.

I bought a small lathe about 10 years ago and taught myself, but I know there's alot I don't know
LedZeppelin  [Member]
11/21/2011 7:12:42 PM EST
Originally Posted By wilNva:
You might want to look into a local community college machineing course. It should be cheap to take and the AF should help pay for all or some of it. Even if you only learn a few things it's worth it to be able to play with tools you can't afford yet and decide what you might want to buy.

I bought a small lathe about 10 years ago and taught myself, but I know there's alot I don't know


I'm actually in the Marine Corps Just stationed on an AF base. I would try that but tuition assistance has been changing a fair bit over the last couple months, I'm not even sure what's what with it at this point. Maybe some research there is in order.

I got my 4-jaw chuck, quick change tool post, and some boring bars and carbide cutters today. Loving the tool post–– should be standard (variable cutter height beats shims by a LONG shot). Everything else I'm gradually learning to use effectively. I've got turning, cutting, facing, simple boring, and outside threading down pretty well. I haven't tried internal threads yet, and I'm having issues with internal relief cuts (increasing inside diameter to make a "safe zone" to stop internal threading). Everything I try results in either nothing, or a very rough cut. I'm thinking it has to do with the angle of the cutting tool?

Here's what I'm going for.


Any tips?

Thanks all.
paulx  [Member]
11/21/2011 9:57:50 PM EST
Maybe the bar is rubbing on the entrance of the bore.
LedZeppelin  [Member]
11/21/2011 10:38:07 PM EST
Originally Posted By paulx:
Maybe the bar is rubbing on the entrance of the bore.


It's not, have a good 1/8" gap or more. the drawing is not to scale.
Cole2534  [Team Member]
11/22/2011 2:08:07 AM EST
What's the diameter of your bar, how long is it sticking out, and what material?

There's a rule of thumb for tool stick out, but its too early for me to remember it right now. Basically what it says is a given tool should not protrude from its holder so much and this is given in diameters. For instance, a 1/2" boring bar with 2.5" sticking out of the holder is 5D stickout. I try to keep my setup shorter than this rule. Naturally this all depends on your given cutting parameters.

If you have a 3/8" steel bar sticking out 4", that's certainly not helping you.

For internal threading I use an Accupro carbide internal threading bar. I bought the biggest I could because I needed some 1.5"-8 threads and it worked great. It was stiff, sharp, correctly ground, easy, and reasonably priced. You'll be hard pressed to find me internally threading with anything else, I wish I could find something similar for OD threads, but inserts have dominated that arena.

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shrikefan  [Team Member]
11/22/2011 3:49:47 AM EST
Originally Posted By Cole2534:
If threading is your goal you'll need some thread wires. These allow you to accurately measure a thread without a gage.

Good looking thread.

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Get a triangle. One works on all size threads. While maybe not as accurate at measuring pitch diameter (with wires) they work great at making parts that need a "custom" fit to only one other part.

shrikefan  [Team Member]
11/22/2011 3:52:58 AM EST
Originally Posted By LedZeppelin:
Originally Posted By wilNva:
You might want to look into a local community college machineing course. It should be cheap to take and the AF should help pay for all or some of it. Even if you only learn a few things it's worth it to be able to play with tools you can't afford yet and decide what you might want to buy.

I bought a small lathe about 10 years ago and taught myself, but I know there's alot I don't know


I'm actually in the Marine Corps Just stationed on an AF base. I would try that but tuition assistance has been changing a fair bit over the last couple months, I'm not even sure what's what with it at this point. Maybe some research there is in order.

I got my 4-jaw chuck, quick change tool post, and some boring bars and carbide cutters today. Loving the tool post–– should be standard (variable cutter height beats shims by a LONG shot). Everything else I'm gradually learning to use effectively. I've got turning, cutting, facing, simple boring, and outside threading down pretty well. I haven't tried internal threads yet, and I'm having issues with internal relief cuts (increasing inside diameter to make a "safe zone" to stop internal threading). Everything I try results in either nothing, or a very rough cut. I'm thinking it has to do with the angle of the cutting tool?

Here's what I'm going for.
http://img.photobucket.com/albums/v257/Erkorene/lathe.jpg

Any tips?

Thanks all.


Flip your bar over and cut it from the back side. You may not have enough clearance for your chips and they are pushing your bar away.

Cole2534  [Team Member]
11/22/2011 4:01:53 AM EST
Originally Posted By shrikefan:
Originally Posted By Cole2534:
If threading is your goal you'll need some thread wires. These allow you to accurately measure a thread without a gage.

Good looking thread.

Posted Via AR15.Com Mobile



Get a triangle. One works on all size threads. While maybe not as accurate at measuring pitch diameter (with wires) they work great at making parts that need a "custom" fit to only one other part.



A triangle....what?
shrikefan  [Team Member]
11/22/2011 8:22:28 AM EST
Originally Posted By Cole2534:
Originally Posted By shrikefan:
Originally Posted By Cole2534:
If threading is your goal you'll need some thread wires. These allow you to accurately measure a thread without a gage.

Good looking thread.

Posted Via AR15.Com Mobile



Get a triangle. One works on all size threads. While maybe not as accurate at measuring pitch diameter (with wires) they work great at making parts that need a "custom" fit to only one other part.



A triangle....what?


Thread triangles

ETA - It is easier to just use 1 triangle.
Cole2534  [Team Member]
11/22/2011 8:37:22 AM EST
Originally Posted By shrikefan:
Thread triangles

ETA - It is easier to just use 1 triangle.


That's slicker 'n cow shit.
shrikefan  [Team Member]
11/22/2011 11:46:46 AM EST
Originally Posted By Cole2534:
Originally Posted By shrikefan:
Thread triangles

ETA - It is easier to just use 1 triangle.


That's slicker 'n cow shit.


They can be used to chase non-standard threads but wires seem to be a little more accurate.

The triangles are convenient to use for sneaking up on the finish size of threads that you have go/nogo gages for. It seems like the cross feed dial is never 1:1 when working on threads.

Cole2534  [Team Member]
11/22/2011 1:28:45 PM EST
That's the benefit of threading with the compound- it only moves forward.

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bpm990d  [Member]
11/22/2011 3:09:08 PM EST
The Virtual Machine Shop is a great resource of information.

B
p0p0k0pf  [Team Member]
11/22/2011 5:26:54 PM EST
Pick up a Machinery's Handbook, 28th Edition. I have a 28th and my grandfather's 5th edition from 1919. If there is one book you need, that is it.

A good rule of thumb for RPM with HSS is (CS x 4)/D. CS = Cutting Speed. D= Diameter
Cutting speed is a constant- Aluminum is about 200, Mild Steel is 100, Tool steel is about 30.
If you're turning a 2" diameter Aluminum Bar, then you turn it at: (200x4)/2= 400rpm.

Invest in quality measuring instruments. Starrett used to be good stuff. Now they are a cheap knockoff of themselves. Swiss-made Brown and Sharpe is good, as well as Mitutoyo.

Long Island Indicator is a good instrument sales and repair shop.

Jason

www.accurateordnance.com
Social_Zombie  [Team Member]
11/23/2011 1:47:42 AM EST
so like, there are no cool pictures of this miniature lathe for us to look at

LedZeppelin  [Member]
11/23/2011 8:08:08 AM EST
Originally Posted By Social_Zombie:
so like, there are no cool pictures of this miniature lathe for us to look at



Of course.



I'm getting the hang of things. I tried a softer tube and messed with the cutting piece angle and was able to do things more effectively. Google and Youtube are priceless. I've been reading up on lathes/milling machines for a long time now, but the transition from paper to practice is always easier said/thought than done. I'm going to make an order today of various lengths/diameter metals to play with. My measuring tools are also lacking (1 indicator, and 1 digital caliper) Give it time. I almost think I could pull off a simple muzzle break. What I'm really interested in getting into (later on with much bigger/better machinery) is engines (radial and V block), and optics. Anyone know any good resources on cutting/grinding lenses. Would love to be able to make gears as well, but most of that requires a milling machine. I'm debating whether or not to invest in a milling attachment for this lathe. I'm also thinking about replacing the bearings. Not immediately, just on the plate. I could easily burn a hole in my wallet with this stuff

Enough rambling for now, though.
paulx  [Member]
11/23/2011 9:27:28 AM EST
I`d be thinking about a 4 jaw and a micrometre next.Thing about machining is that there is always something next.
Cole2534  [Team Member]
11/23/2011 10:11:39 AM EST
Ok, that thing is damn tiny, kinda cute.

Were I you, I'd be looking for a milling attachment.

It's a pretty crappy replacement for a mill, but it will let you drill(tap?) holes, face material, and maybe cut some slots/pockets.

Your work envelope would be pretty small, but having a small machine center in your closet for practice would be worth it. At least in my opinion.
LedZeppelin  [Member]
11/23/2011 11:21:06 AM EST
Originally Posted By paulx:
I`d be thinking about a 4 jaw and a micrometre next.Thing about machining is that there is always something next.


The picture doesn't show it very well, but that is a 4-jaw chuck. I was setting up for the eccentric radius cut on the tip of this. Then I wanted to see if I could make something like a crank shaft (my angles are not true to any spec. Just eyeballed). I've found that MS Paint is very useful for planning this stuff. It tells you how many pixels wide/tall whatever shape or line you're making is. Make 1 pixel equal .001" or .0001" and you've got fairly precise measurements for plans. For the radius cut I did it in 10 segments, and MS paint was spot on with my x^2 + y^2 = r^2 calculations to .001".

HammerSlammer  [Member]
11/29/2011 6:40:07 AM EST
Congratulations on your choice of a career field after service. The local community college is always a good choice to learn the basics. Check out the instructor, the text books, and the condition of the machinery. If the instructor does not seem interested, the program does not use text books or other published references, and the equipment is dirty and poorly maintained, GO ELSWHERE! Keep in mind this is a government supported enitity and quality of instruction will vary greatly.

Amazon.com has several used text books and reference that are inexpensive and available for the self motivated learner. I recommend the McGraw-Hill publications by Krar, Oswald and St Amand. "Machine Tool Technology", "VISUTEXT", and the workbook, if available is optional. The "VISUTEXT" is a graphically illustrated "how to" and can in effect replace the instructor. The only way to machine anything that is going to be acceptable to the public and industry is to work to a published standard. The reference guide is called variously, "The Machinist"s Handbook", or 'Machinery's Handbook', and is offered by several publishers. Get a fairly recent edition or, if you can afford it, buy a new copy from your favorite catalog house. When cutting threads you will need to have the max/min major & minor diameter and max/min pitch diameter to achieve a correct measurement over the wires and meet the criteria for "INTERCHANGEABLE MANUFACTURE". When cutting a thread on a rifle barrel you have no room for error, ($$$$$$). Make your errors while pacticing, it's cheaper.

When all else fails, read the instructions.

Enjoy the journey.

USN-RET
Machine Shop Instructor-retired
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