machine ways was Re: Motor vs. Servo

Hello,

We'll try to clear it up :-)

Ways are a surface that something else slides upon. The term can
refer to both the "slider" and the "slid-upon". Not all "ways" are
in machine tools. For example, when old ships (and even new ships)
were launched they slid down greased wooden "tracks" (planks, logs,
etc.) which were called ways. The ship was said to be sliding down
the ways into the water.

The part of our tools corresponding to the "ship" is a way also. The
two parts together are called "ways".

In the ship description the "way" supports the ship that is sliding
upon it. Often one of the two "ways"(sliding surfaces) of a given
axis will be shorter than the other(just as the ship is shorter than
its track). The short one may slide on the long one (as in the ship
example), or the other way (pun intended).

In machine tools we have two general types of way, the dovetail and
box. Here is a link to the box style:
http://www.mfg.mtu.edu/marc/primers/machtool/gif/mt3.gif

Any decent picture of a Sherline mill or lathe will show you its
dovetail ways. Also bridgeports, machinist vises, etc. Even better,
at the Sherline website there is an instruction sheet which describes
adjusting the gibs of these tools. The description there should lead
you out of any remaining confusion.

Now the fact is that the two parts of the dovetail ways and box ways
both intermesh so it's sometimes hard to tell which is "in", and
which is "out". We usually just say something slides "ON" the ways...

A final thought to confuse things<G>: The term way was created before
we had roller and linear bearings for our machine tools. So a modern
tool may have parts referred to as ways, that DON'T SLIDE. They roll.
And they might not be "boxlike" or "dovetail" at all. Since they
function the same as the sliding type we still call them ways.

The term "rails" is sometimes used (in place of "ways") for some
types of modern linear bearings, and I've heard an old-timer or two
refer to even the old-style sliding ways as rails.

Hope we're a ways from where we started, :-)

Ballendo

P.S. To answer your exact question, I would say that the table slides
on the saddle(x axis), and not even mention the ways... (The ways are
a PART of the table and saddle.) The Table/saddle assy. then slides
on the Machine Base(if a bedmill), or knee(for a knee mill) to make
up the Y axis.

> > Bill Vance wrote:
> >
> > Now I'm getting confused again, (don't worry it isn't hard to

do). :-)

> >
> > So a table would slide _on_ ways, or _in_ ways? <snip>