PDA

View Full Version : Please tell me about Lathes/Mills


mr fixit
February 02, 2009, 12:33
I'm not a machinist by any stretch of the imagination. I have worked in a machine shop, and done some light machine work though. Lathes and mills are not completely new to me.

I've been trying to save for while to buy a lathe and or mill. I've been watching the ads, sales, auctions etc..

I'm not going to be doing production work. What I will be doing is just an occasional hobby task that you just can't do without a lathe or mill as the case may be.

I've heard time and time again not to buy a combo machine (lathe/mill). but what I am asking now is "why not?". For a hobby guy, that only does a few 'jobs' occasionally and is not to worried about speed of set up, how bad is a combo?

honestly, I don't mind if I have to check table level or runout every time I set up. If I have one, it will be a one time set up, do the job and then everything sets until the next time which may be days or weeks.

Are the combo's accurate? Will they do the work?

Other than telling me I don't want one, tell me why? Or why not.

Mr Fixit

ggiilliiee
February 02, 2009, 13:32
really depends on what ya want to do with it ..

a big NO on the combos ...useless ...unless your machining marshmallows and using a tape measure ...hehe

you can get a tool post mill attachment and do alot there with an end mill chucked up ...
big no on babbit type headstocks .they are junk .tapered roller bearings are the best bet ...

IF YOUR AFTER A BENCH LATHE have a look at "LATHEMASTER " one of the best rated chineese units ..or if ya got bucks ..just get a used HARDIGE .....

your best bet (not in your case) is to take a class ..so your not just a guy with a lathe ...(see GP post ...why is my cut down barrel shooting 8 feet off at 50 yds )...hehe..
anyone can own a lathe ....making GOOD parts that "pass inspection" is another thing ..ehh

Ron Walker
February 02, 2009, 13:36
The diehard machinists will tell you no way on the combos and looking at it from their perspective, they are right. A combo cannot have the accuracy or versatility of a heavy frame industrial lathe or mill. But , for the hobbyist, it is difficult to justify the $10-40k plus cost (times two) for the higher grade lathes and mills. The 36" bed Smithy or Grizzly combo machines are rated to .0005" accuracy, and if you get an extra 4 jaw chuck with them , you can do most every thing a hobbyist or even a small shop gunsmith would need. There are a number of benchrest shooters who use them with excellent results. Ron

ggiilliiee
February 02, 2009, 13:45
might look at the SEIG ..if your pockets are full .heheh...kinda sad the best machines are not from here ....

mountainman
February 02, 2009, 16:28
look at how high that headstock on the lathe in the combo machines is. Thats one reason the rigidity is poor. Anyways, you'll regret it. Hey Giglie I'll tell you why the Chinese tools are better than teh made in teh USA in terms of low budget folks and hobbyists. Look up Sherline ( curse the day I wasted my money on it)

Hellion Productions
February 02, 2009, 18:19
Check craigslist in your area. Many machine shops are going out of business.

I've seen Bridgeports and South Bends going for great prices, with tooling. If you've got 220 single phase in your garage, phase converters can be bought for good prices as well.

Only hitch is: you usually gotta move 'em yourself. Engine Hoist and Pallet Jacks help. Renting a Liftgate truck, too.

Best,
JBR

cavegeo
February 02, 2009, 19:26
I am no machinist either but you might be interested in my experience, I too have worked in a large industrial machine shop.

I have used these combo machines when I was a Harley Mechanic and if you just need to make relief cuts for valves on a piston or similar work these machine will do just fine just do not expect them to hold the tolerance very well say like .002 inch.

shlomo
February 02, 2009, 20:42
It would help if we had some idea of the type of work you envision.

If you plan to barrel, turn and chamber benchrest rifles, that is a different class of machine than for futzing around making odd bolts and small parts for tinkering.

One of the best machines for the money (lathe, that is) that straddles the zones above is a South Bend Heavy 10. You can usually find one that is in decent shape and decently tooled for 1500 bucks; sometimes half that, if you're vigilant and quick. It is a fairly compact machine, and has a large, 1 3/8" spindle bore, which makes it ideal for gun work. Some of the later ones have hardened ways, and will not show a great deal of wear, even when heavily used.

The small mill category also has a machine that is fairly rigid and yet compact. The Clausing 8520. It takes morse taper tooling, as opposed to the more common (these days) R-8 collets. It also averages in the 1500 buck range.

I have never used a multi-tool, nor a round-column mill, but every single person I've ever met that had used one disliked it and regretted buying it. Same problems: lack of rigidity, and time-consuming setup and changeover with the multi-tool, and constant re-tramming of the head on the mill, every time it is moved.

mr fixit
February 02, 2009, 21:30
Originally posted by shlomo
It would help if we had some idea of the type of work you envision.


Ok, in no particular order things I would have done on a lathe if I had one when I worked on that project:

Cut a rifle barrel, and crown
thread a rifle barrel
make an XM-177 slip over flash hider clone for a heavy barrel AR
make a set of delrin bushings for a washing machine to stop tub from spinning off
make a hollow threaded extension for light fixture

Just general light machine work that only requires light tolerances. I don't envision making aircraft parts.

mr Fixit

L Haney
February 02, 2009, 21:49
I've been reading like crazy over at [URL=http://www.practicalmachinist.com/[/URL] for about a week now. Those guys know machining like people here know FAL's. I'm attempting something like you are, but I'm not willing to trade off that last half thousandths. LOTS of used machines out there, if you're lucky you may not have to have a flat bed to move it. Looks like I'm not that lucky. I'm also not competent (yet) to tell if a machine is gently used or a clapped out cow. But I'm gettin' there. I'm also smack dab in the middle of bribing some people on here to give me a hand learning this new field. :rofl:

Lowell

shlomo
February 02, 2009, 21:51
Originally posted by mr fixit


Ok, in no particular order things I would have done on a lathe if I had one when I worked on that project:

Cut a rifle barrel, and crown
thread a rifle barrel
make an XM-177 slip over flash hider clone for a heavy barrel AR
make a set of delrin bushings for a washing machine to stop tub from spinning off
make a hollow threaded extension for light fixture

Just general light machine work that only requires light tolerances. I don't envision making aircraft parts.

mr Fixit

It's the barrel work that generally knocks out the smaller lathes in the 9" class, and the multi-machines. Most of them have spindle bores in the 3/4" range. This is not a problem if you are working on sporter taper barrels, but if you are doing bull barrels, blanks, or varmint tapers, you will not be able to put the barrel thru the headstock spindle bore and dial in each end to concentric (which is the preferred way to get them true). Your only option with a small spindle bore is to turn with a steadyrest, and you will need something like 30-34" between centers to make this work. This generally translates to a minimum of a 4' bed, and 4 1/2' would be better.

Again, something like a South Bend Heavy Ten might be ideal for you. There might be others as good or better, but that's the one I know a little about, and it has long had a reputation as an excellent general gunsmith's lathe. It is a level of magnitude more rigid than the smaller 9" lathes of the same make, as well as the Chinese 9x20s. Stimpy here on the board had one of the latter as a starter machine, and soon became frustrated with its shortcomings and replaced it with a larger SB. Perhaps he will spot this and expand on it.

The Chinese gear-head lathes from Enco, MSC, and Grizzly (mostly the same machines, badged differently) in the size range larger than 9" may be okay machines, but cost new about two or three times what the SB H10 can be had for. I've read some encouraging reports on them, and also some disturbing stuff about QC, like finding sand from the casting process in the headstocks, and such.

Maybe somebody here can give a report based on actual experience...

SteveW
February 09, 2009, 13:16
> I'm also not competent (yet) to tell if a machine is gently used
> or a clapped out cow.

That's my problem too. I have been to a lot of auctions where machine tools like mills and lathes are selling, but they are not usually hooked up and running. You can't tell much about the tool like that, except the really blindingly obvious, like taking a close look at the bed ways close to the head, wear on the lead screw etc..etc.. In general the people at such auctions pay a lot for the stuff I thought was crap, and vise-versa. That tells me that I haven't a clue.

Has anyone looked at a ShopTask ? It's a combo machine, but seems well suited for a home/hobbiest gunsmith. It can be set up for CNC as well, but one step at a time. (Joke. Boom, Boom !).

http://www.shoptask.com/

Clark
February 09, 2009, 14:50
For gunsmithing, a lathe + mill + tooling is $5k ~ $10k.
That is the easy part.
The wife seeing the big stuff roll in is the hard part.

stimpsonjcat
February 12, 2009, 17:20
I would not recommend the little 9" import stuff unless you can get it with just plain gobs of tooling for cheap. I had a good time with mine and learned a lot, but you gotta take small cuts cause they have no power.

I upgraded to a big 13" Southbend which I love, but it may be a bit on the big side for bbl work on the chamber side. I haven't gotten to chambering on it, but I have several plans on how to do this properly.

Still, working with ANY lathe is more fun than not working with one.

Find a friend who will let you tinker, once you do that the money will seem insignificant anyway. All you will be able to see is all the stuff you can make or make better. I have Shlomo to blame, one simple threading operation and the synapses in my head lit up like a Christmas tree.

I have an ENCO mill, big 10x54 manual I got that came with a noisy head with a bird nest inside. I have had to fix several things on it, but it gets the job done for me and was cheap at $800.

One thing I have discovered is that you can find inexpensive, but usually time-consuming, methods of doing complicated things without the ideal tooling. As a bonus, doing this gives you a keen insight on the features you want in the right tooling when you do buy it. So don't be in too big a rush to buy all the fancy tooling. Heck a lot of it you can make yourself.

idsubgun
February 14, 2009, 07:17
Originally posted by stimpsonjcat
I upgraded to a big 13" Southbend.......

Right there is your answer. Everyone I've talked to, heard about or read about has eventually sold their combo and bought a better machine. Why spend the money on the combo?

You only buy quality once...you buy crap several times.

yovinny
February 14, 2009, 09:52
All good advice here, you'd do well to heed it.
I just have one thought to add.

Dont believe the sales hype that they use to promote those combo machines.
At the very least, their way less than ideal for just about any task you can think of.

As with most mechanical things, a top notch, very experienced person with no time constraints can produce some incredible results with less than ideal machinery, where a novice will not only produce junk and frustration, but will gain no true experience.

YV

Tankdriver
February 14, 2009, 13:43
A big no on combos. If nothing ekse the amount of time it takes to change between lathe, and mill, and get everything setup, is just not worth it. I have a HF end mill and lathe..... I know it is not the best on the market, but like my instructor told me a LONG time ago....

It's a bad machinist who blames his tools.....

Just allow for what it's able to do.

Clark
March 23, 2009, 11:19
I have a Precision Mathews 12x36 on order.

It is a Chinese import with most parts interchangeable with Grizzly and Harbor Freight 12x36 lathes.

The 12x36 size is about the minimum for my work. Many other gunsmiths pay the extra and get a Jet 13x40.

ggiilliiee
March 23, 2009, 11:28
if ya think about what youll be able to do with the crambo unit ....they are a joke ...hand drill over the chuck will do the same thing ...and youll actually have some travel ...


youd be miles better off with just a lathe and a milling attachment on the tool post .

Tankdriver
March 25, 2009, 09:04
I have an inexpensive 9X20 lathe, and a small end mil. Do not get a combo. You'll spend more time swapping them around for one set up to the other, than you will running them. Both of mine are Harbor Freight "Junk" but, they have done everything I have asked of them.

As I was told in my classes years ago....."It's a poor machinist who blames his tools for his bad work"......:smile: