yourname wrote:

Pete C. wrote:
Boris Beizer wrote:

"Gil HASH" wrote in message
.. .

'lo
Xcuze me for the newbie's strange question of the day :
Can a lathe be replaced by a milling machine for quite all metalworking?
In another terms, a milling machine is more universal than a lathe or not?
(It's for me : buying first lathe or milling machine?)

The primary limitation of using a mill for turning (i.e., lathe work) is the
size of piece you could handle. On a small vertical mill you might be able
to handle a piece about 7" diameter and 12" long. On a small horizontal
mill you might be able to do 20" diameter x 3" long. A typical home shop
lathe (e.g., a 9" South Bend) can handle 9" diameter by 30" long.
Conversely, a similar lathe used in milling could handle about a 6" x 5"
work piece without moving the work between cuts. While turning on a mill
is doable, it is a pain to set-up .. I only do it on those rare occassions
when I have to turn something big diameter and relatively thin.
As for which to get first .. I strongly disagree with the idea of
getting a mill first if you expect to do mostly milling. The lathe is
inherently more versatile. Also, milling attachments and fixtures for
lathes abound. The reverse for mills doesn't hold. Another serious
limitation of using a mill is the difficulty of mounting the work .. indeed,
if a chuck can be mounted on the mill spindle at all. Most likely, you'd
have to machine some adapters for face plates or chucks.. for which you
would need a lathe. I've yet to find chuck commercially available adapters
for small mills -- beyond a wimpy 3 jaw chuck like you'd find on a drill
press. that is, wimpy compared to the typical chuck you find on a lathe.
By the time you've tooled up the adapters you need to mount a chuck, you've
already heavy into lathe work .. tapers, threads, boring, turning, etc.

Boris

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I think you're approaching it all wrong.

To do limited lathe type work on a mill, you would not place a lathe
type chuck on the mills spindle to turn the work piece. What you do is
use a rotary table or dividing head to hold and turn the work piece and
use conventional milling cutters to do the work. This is why a lathe
type chuck to go in a mill spindle does not exist and numerous rotary
tables and dividing heads do exist.

Although I have done just that on a cnc mill, with great success, but on
a manual mill you are correct, it is silly

I've used my Bridgeport and a rotary table to "turn" the outside of a
30" diameter x 1/2" think piece. Also drilled a bolt circle and a few
other features. I rough cut the piece to about 31" dia with a jig saw
first.



Milling on a lathe is at least as awkward as lathing on a mill, and the
mill is still the more versatile machine to have. There are certainly
parts that you can make on a lathe that you can't make on a mill, and
vice versa, however for typical home shop projects the mill will be able
to accomplish more of the tasks.

Much of what you can't do on the mill is shafts and bushings that can be
readily purchased, and in fact with a boring head you can make most of
those bushings on the mill as well.

Either way, a proper shop should have both a mill and a lathe along with
the proper tooling for both, which will cost more than the base
machines. But start with the mill.

Pete C.

I bought a lathe first, and while your argument is persuasive, I think
that most 'hobbyist' mill operations can be done to some extent with a
angle grinder or a file, the same is not true for turning operations.

Never chucked a shaft in your electric drill and gone at it with a file?
Sucks, but is comparable to milling with a grinder and file.

The stuff even an amateur needs [boring a bushing] is more easily done
correctly, with less tooling cost, on a lathe.

Boring head and a pair of disposable soft jaws for the milling vice.
close the vice and drill/bore the jaws to fit the bushing OD and then
use the vice to hold the bushing while you bore the ID. Not ideal
certainly, but quick and workable.


In the end I say : Neither

Buy one of those old Bridgeport BOSS stepper machines and put a pc
control on it

If you can find one. I keep hearing how they're everywhere and cheap,
but I haven't seen one cheap. If you know of one let me know since I'd
like to buy one. I have a 1J right now.

Pete C.