Re: [CAD_CAM_EDM_DRO] EMC Newbie

Ozzie@... wrote:

> I'd like to understand every entry in the .ini
> files,

I have used this file, which is not as much info as I'd like, but
it covers the most important stuff :
http://www.isd.mel.nist.gov/projects/emc/emcsoft.html

> how to set up a rotary axis

At the moment, you can't have real rotary axes. You can fake it as if
it were
a linear axis, or you can use some stuff that makes it work only in
manual
jog mode, but the standard kinematics routines only do 3 axes right now.

It is in the works for rotary axes to be fully supported, but it is not
ready yet.
I am waiting for the same thing.

> what "Home" really means, etc.

Home is a position that is set by detecting the closure of a switch that

references the machine position to a machine coordinate system. The
idea
is that if you set up a part at a user coordinate system of (0 , 0), and
then
turn the machine off, then back on, say, the next day and re-home the
axes, that going to user coordinate (0 ,0) will get you back to the
exact
same position. In other words, the offset from the machine to user
coordinate
systems is stored when EMC is shut down, and re-established the next
time EMC is run.

> Surely there is a document, that I can beg, borrow, steal, buy, or
> best of all, download that gives the basic operating instructions for
> EMC.

No, there is no complete, all encompassing document. This is not
commercial
software, but a work in progress.

>
> I understand creating and entering "G" code, but I don't know the
> simpler things, like turning a cylinder on the lathe using the
> buttons
> on EMC rather than turning handles.

Well, on a lathe, there is the Z axis (parallel to spindle) and the X
axis (radius).
Using buttons (which I don't really recommend) you use the <- and ->
keys
to change radius (X jog) and the page-up and page-down buttons (Z jog)
to move the carriage along the bed. The < and > keys change the jog
speed
(shown by a jog rate bar on the screen), and the 1 through 9 and 0 keys
set the jog rate at 10% through 90% and then 100% of the jog rate.

I occasionally do some things with the jog keys, but almost always
prefer
to do actual cutting with the MDI mode, entering commands like
"X5.25 F10" to make the move, so my hands are free to squirt oil,
change the feed rate, remove chips, hit E-stop or esc if necessary, etc.

The esc key cancels any move in progress, also cancels a running
program.
The P key pauses a program, the S key resumes a program or move.
The E-stop button (if you haven't set one up, I strongly recommend it,
and the bigger a machine you have, the stronger the recommendation!)
is a more severe stop, but in my setup it powers down the servo
amplifiers,
which could be required in a runaway condition.

There is a document that I don't believe is available in electronic form
which
discusses the RS-274 (G-code) interpreter that is implemented at the
heart
of EMC. We really should have an electronic copy of this, as it lists
the
G-codes (and M-codes, too) that are implemented, and how they are
expected to be used. Maybe I should do this as an extension of my
CAD-CAM... FAQ.

If you have any specific questions, you can also ask me, as I have been
using EMC since about June 1998.

Jon