On Wed, 10 Aug 2005 19:50:15 +0400, Gil HASH wrote:

'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?

No it cannot.

In another terms, a milling machine is more universal than a lathe or not?

While each of the two machines can be adapted in a make-shift way to
perform some of the functions of the other, they are each designed for
different purposes and should be used appropriately if optimum results
are wanted.

For example, in my case I have a 10" lathe (capable of rotating a 10"
diameter workpiece) and a small horizontal milling machine. If I needed
to turn the outside diameter ("OD") of a workpiece that was larger than
10" I *could* mount the workpiece in place of the arbor in my milling
machine and then mount a cutting bit to the table, feeding it by moving
the table. It would work but it would not give optimal results compared
to a lathe of appropriate capacity for the job.

I could also get a milling attachment for my lathe which is mounted
to the cross-slide (usually in place of the top-slide) of the lathe
and provides a means of positioning a workpiece vertically. An end mill
is inserted in the lathe's spindle (using a collet) and the workpiece,
being clamped to the milling attachment is fed into the end mill using
the carriage, etc. feeds. This arrangement is notoriously lacking in
rigidity and severely limited in workpiece size capacity compared to
even the smallest milling machines. For very simple operations this
setup can achieve satisfactory results, but most people are disappointed
by their performance.

(It's for me : buying first lathe or milling machine?)

If you study various machines you will see that they are composed
primarily of cylindrical parts. Shafts, pulleys, pins, bolts, cranks,
pistons and cylinders, etc. This is what lathes are designed to make
best, so statistically, lathes are put to use more often than other
machine tools when fabricating or repairing other machines. It depends
on what you want to make with your machine shop, but I think in general
you will find more use in a lathe than you will in a milling machine.

I know, for myself, my first machine tool purchase was a lathe, and once
I had gotten enough tooling (accessories, specialized cutters, etc.) it
kept me occupied for years before I finally bought a milling machine.
It was on the lathe that I learned about the different cutting
characteristics of different materials; speeds and feeds, tool geometry,
etc. This vital knowledge and experience was directly transferable to use
on the milling machine when I got around to buying it.