Re: Lathes

This topic is off the main topic for this list, but in the early
days, lathes were all manual. some had one guy turning the spindle,
the other cutting. this was a wheel lathe.

smaller lathes had a foot pedal like you might see on an old sewing
machine, as you might guess, bench lathe.

later, lathes and most tools were driven by a single large main shaft
that drove belts to all the tools in the shop.

an engine lathe was a self contained unit with it's own engine.
origionally a steam engine, but now of course, electric.

bench lathe was smaller and bench mounted, and all manual, but could
be powered.

gap-bed is a lathe that can have a section of the ways removed so a
larger part can be spun. it can be an engine or bench or combinaton
of either.

Now adays, the differences blend and most lathes have feeds so are
semi-engine lathes and semi-bench lathes.

to kinda put this on topic, the terminoligy has little value but the
selection is made on what work you want to do.

Lathes are sized by how large a diameter a part can be spun and how
long a part it can hold. for the part length, remove the chuck and
insert a dead center. move the tailstock to the furtherst most point
and put in a dead center. the part can fit 'center to center' that
distance is the largest part lenght. so a 12x24 can spin a 12 inch
dia plate NOT a 12 inch tube. OR a 24 " long bar. the carrage gets
in the way so a part 12 dia and 24 in long will not fit. a third
number is the diameter over carrage and it will be much smaller than
the largest diameter part that can be swung. and a 4th number is the
gap-bed lenght and swing diameter. usually a gap is only a few
inches long.

to try to put this on topic, any lathe can be converted to CNC,
cutting forces are needed in determining the gearing of the drives
and so forth.

for more on how to cnc a lathe, check the archives, to find more on
lathes, google search 'history of lathe' or something.

Dave

--- In CAD_CAM_EDM_DRO@yahoogroups.com, JanRwl@A... wrote:
> In a message dated 1/17/2003 4:34:36 PM Central Standard Time,
> ccq@x... writes:
>
>
> > Got a question: Whats the difference between a bench lathe and
an engine
> > lathe?
> >
>
> Bill: I will take a stab at this question, but some more
experienced, REAL
> machinist can hopefully improve on my explanation:
>
> First, they can be the SAME. A "bench lathe" is simply one that
mounts on a
> bench, rather than having its own stand. The term "engine lathe"
simply
> means that you use it for making "engine parts". This is where I
need
> additional clarification, myself! Jan Rowland
>
>
> [Non-text portions of this message have been removed]