lathe decisions

[jus1975]

I want a bench top lathe and HF 9x20 on sale for $599. The Grizzly 8X19 for $825 or a used Southbend on ebay for close/ more money in simlar size. I have researched and found the grizlzy, HF and others are the same machne just different color and some come with additional tooling. I dont know anything about maching so I would think a new lathe would be better. But what do I look for when buying a used lathe. I here southbend is a great machine. Propably a lot better than the China made models. Give me some guidance.

[HarleyR]

Some of the best machines in the world are older.... The lathe and mill I learned were each over 40 years old.... So I would seriously look into a used machine alot of times you'll get way more bang for the buck people will sell all the tooling that goes with a machine simply because they have no use for it..And 90% of stuff is made in China...I dont even think you can get a new American made bridgeport anymore...

[ty1295]

Yep find a used lathe over a china new one. I would rather work on an old worn out used one, than a new china one.

Actually I had a china lathe, got it cheap $200 I think. Got so flusterated with it I sold it. I now have a Graziano that is built in mid 60's. Has some personality but cost me nothing, and is 10 times the machine.

[HarleyR]

Last shop I worked at had a Graziano lathe.... nice machine simple to operate better machine than I am machinest thats for sure

[protour70]

Buy a Hardinge, the older the better.

[Russ T Nut]

The Southbend is a good lathe but some of the older ones used leather belts to drive the spindle (to much slipage on heavy cuts). look for one with gear drive. Also make sure that you buy one that has a 110 or 220V single phase motor. Most of the used industrial lathes are 220v three phase. most home shops only have single phase power. If you do buy one with a 3 phase motor you can buy a converter but you will lose about half of the motors horse power rateing.
Good luck
Russ

[ty1295]

A variable freq. drive can be used instead of a phase convertor. Will allow you to vary speed also.

[hotrdblder]

you can cut and glue a 10 rib serpentine belt to replace the leather belt, works great, check out practical machinist.com

[rubadub]

A larger or heavier lathe as a rule will give you less vibration with your cutting tool, especially on small cuts.

I will just put out a few basic things here, like a comment or two on each section.

Heres the parts of one. You can click on one of them and it has a number.

1 Construction (http://en.wikipedia.org/wiki/Lathe_(metal)#Construction)

1.1 Headstock (http://en.wikipedia.org/wiki/Lathe_(metal)#Headstock)
H4 is the main spindle, take both hands and try and wiggle the chuck thats in it, it looks like a three jaw chuck. Your looking for side play in the spindle, if its really sloppy the spindle will need to be reworked like maybe new bearings or whatever

.
1.2 Bed (http://en.wikipedia.org/wiki/Lathe_(metal)#Bed)

1.3 Feed and lead screws (http://en.wikipedia.org/wiki/Lathe_(metal)#Feed_and_lead_screws)

1.4 Carriage (http://en.wikipedia.org/wiki/Lathe_(metal)#Carriage)

1.4.1 Cross-slide (http://en.wikipedia.org/wiki/Lathe_(metal)#Cross-slide)
3 is the cross slide it needs to be checked by turning the handle and running it back and forth, your looking for binding or running free, then binding. Also turn it close to all the way out, and take a look at the face of it, see if it looks gouged, or tore up. It will get metal shavings in it, and thats what tears them up.


1.4.2 Compound rest (http://en.wikipedia.org/wiki/Lathe_(metal)#Compound_rest)
2 is the compound rest, do the same test on this as you did on the cross slide. On smaller lathes the cross slide and the compound rest are an all together unit that you can set on the bed and it has a quick type clamp to hold it on. If you find one that runs in and out fairly smooth without binding, you hit pay dirt.


1.4.3 Toolpost (http://en.wikipedia.org/wiki/Lathe_(metal)#Toolpost)

1.5 Tailstock (http://en.wikipedia.org/wiki/Lathe_(metal)#Tailstock)
t5 holds what you call a center, its pointed on the end, the center turns, not the t5, sometimes you will get lucky and find one that goes around and around without being noisy or vibrating, but they just pop out, not a part of the lathe itself but you will use one to keep longer pieces from jumping around when there spinning.


This was very basic, I didn't mention checking all the in and out gears if its an automatic feed. I wouldn't be that concerned about finding one that has all the in and out gears working unless you want to do some threading, then you will need it.

The cross slide and compound rest and spindle I would guess are the meat and potatoes of these.

Watch out so you don't buy a lathe thats wired for 3 phase, you want single phase. I didn't put out much information here, but its a start if anybody would like to correct me, or add to it, I haven't run one for 35 years.

Rob

[rubadub]

Oops, sorry Russ allready mentioned 3 phase.:pat:

[rubadub]

Deleted it.

Rob

[Bruning Auto Design]

Most of the used industrial lathes are 220v three phase. most home shops only have single phase power. If you do buy one with a 3 phase motor you can buy a converter but you will lose about half of the motors horse power rateing.
Good luck
Russ

You will lose a 1/3 of the rated power IF you run a static phase converter. A rotary phase converter will give you 3 legs of 3-phase power.

http://www.americanrotary.com/phase-converters.html

[ty1295]

And 99% of home shops won't need that 1/3rd of lost HP anyways.

I would much rather have a older big lathe that is sturdy, stable and won't chatter than a cheap chinese that only had 20% of the rated HP of the motor to begin with, chatters, falls apart, binds up.

3 phase scare people away, but it really isn't a big deal with a phase convertor.

Or you can do what I did and bought a new 220v single phase motor, couple brackets and bam it was now single phase. (It had a 480 3 phase motor).

My mill and band saw are still 3 phase though. Isn't a big deal.

You will kick yourself when you try to make a cut on a china lathe and wonder why the chuck stopped, bit broke, etc.

[rubadub]

Heres a little more I found.

These are called collets, looks like 1/8'' up to 3/4'' size.

Some lathes have an adapter with them to use these to hold the piece of metal your going to cut or turn, there handy to have, if you find a lathe with a set of these with it, thats a good thing.

The 1/2'' collet will hold a piece of round stock (steel). A shade bigger or a shade smaller then a 1/2''.

You insert the size collet you want into the adapter, then you can turn a wheel or a slide lever to tighten it up on the piece of steel you put into it, it just squeezes it to hold it, and they will hold it tight.

Horizontal and vertical mills also use these a lot, like a bridgeport mill, you probably have heard of them.

https://static1.pt-content.com/images/noimg.gif

[hotrdblder]

you would use a 3 jaw head for round stock and a 4 jaw for square/rectangle , to hold them to head, not those collets
the collets are only used when using the tailstock to fixture the work, 95% of the time the tooling will be on the tool post or in the tailstock, plus most bigger lathes use different collets then what a bridgport would use, i have a 2hp bridgeport and a 16 inch south bend lathe 7 ft centers, 3 phase, 3 phase is critical becaue you can reverse the motor for extracting taps etc. the lathe is the single most handy tool i got in the shop

[rubadub]

you would use a 3 jaw head for round stock and a 4 jaw for square/rectangle , to hold them to head, not those collets
the collets are only used when using the tailstock to fixture the work, 95% of the time the tooling will be on the tool post or in the tailstock, plus most bigger lathes use different collets then what a bridgport would use, i have a 2hp bridgeport and a 16 inch south bend lathe 7 ft centers, 3 phase, 3 phase is critical becaue you can reverse the motor for extracting taps etc. the lathe is the single most handy tool i got in the shop

In the tool and die shop I worked in we had bridgeports and horizontal mills, we used collets in them all the time to do the machining. Having collets is not a necessity, but if they go with the machine, they are a really nice thing to have.

If your drilling a hole with a bridgeport, and you can collet that drill bit, it will be far superior to any other means for holding, especially if your after precision. The shortest distance between the spindle and the work is the key. We always used a collet for our end mills and reamers.

Its hard to remember, its been 38 years since I worked in one, but if I remember right, the only time you would use something like a drill bit chuck in the spindle of a bridgeport, would be for just roughing something in.

Anyway all good points everybody has brought up.

I found a picture of the type of lathe I used to run, these types are limited in what all you can do on them, but you can't wear them out, I run one most of the time for 11 years 9 hours a day 6 days a week, and another guy ran the same machine on the other shift, it never broke down that I can remember.



https://static1.pt-content.com/images/noimg.gif


I think we had about 12 of these, a cold header die shop in Frankfort Michigan, the shop is still going yet today.

Especially tapping, the collet keeps every thing tighter.

[68sixspeed]

yeah. Hardinge HLVH, I have one too, great lathe, split 10ths (.0001 or better accuracy) but not the typical home-owner purchase given the used value of 7-30k; new it's up to $44k last time I looked.

[rubadub]

yeah. Hardinge HLVH, I have one too, great lathe, split 10ths (.0001 or better accuracy) but not the typical home-owner purchase given the used value of 7-30k; new it's up to $44k last time I looked.

Wow, 7 to 30k, I had no idea, I guess I need to start looking at prices.

[hotrdblder]

rub, yes when using mills, etc use collets, but it also matters whats being done, and the home hobbiest will be happy to be within .003 on everything.
i mostly face,drill tap, make bushings on my lathe, want to get collet set up, however its as much as i paid for my south bend lathe.
and yes collets are all i use on my bridgeport, however i use my 3 jaw chuck and have mt3 jacobs super chuck in my tailstock.
and using phase convertor, get 20% larger convertor for what your doing

[flynbrian]

I have one of those Cheap benchtop lathes if you want it cheap! Its basically brand new...I have only cut plastic and soft metals with it. Its too small for any real work.

I also have a large floor model from ENCO....Its a fine lathe for a home shop. I am used to running VERY nice LeBlond Lathes and Warner Swasey Turrett lathes at work and the ENCO is not as nice but its waaaay better than a chinese bench top.

I recommend the ALORIS tools posts....They are the best. Collett machines are very nice too. I ran one for years and they make concentricity alot better for small parts that need machined on both ends.

[flynbrian]

I forgot to mention also, We had a Southbend lathe at the shop....I hated it.
The belt fell off or slipped all the time. Good machine because it never had enough drive power to wear anything out!! It was fine for some real small jobs we had but the second you try to set it up to do some cutting it was hell trying to keep the belt on. The belt would come off 10-15 times during a 10hr shift of rather light work. Screw that!

[beep4beep]

A home lathe is a wonderful thing, any tool is a wonderful thing.If you get yourself a lathe, go to your local comm. college inrole in machine shop class learn how to use these tools SAFTLY. I'v been tool & die maker for 35 years, still have all my fingers and eyes. Be careful most of all Randy