Re: Newbie trying to help others make sense of it all

Start with the idea in your head. That idea then needs to
go into a CAD program
so that it is captured electronically. A CAM program takes
the idea and generates
toolpath information about the idea. A machine control
program then takes the toolpath information and issues
commands to the machine motors which then move the cutters
into the metal to make the idea become a reality.

There are a variety of CAD programs out there. Each has
it's plusses and minuses and there are devotees of all on
this list.

There are a variety of CAM programs out there and as before
- different strokes for different folks.

Windows based control programs do not seem to get much
approval as Windows does not allow the real time control
that is needed to machine metal. Due to this limitation,
DOS or an operating system based on Unix ideas - called
Linux - is used.

Linux is available at low or no cost and is gaining a strong
following among the computer literate who tend to dislike
and even distrust Microsoft. It behaves very much like Unix
so a smattering of knowledge there can be a good thing. It
can run most Windows based programs in a really real time
environment. There are still a few programs that do not run
well so some of us have two machines - one Windows and one
Linux. Two partitions on a big Hard drive so we can choose
which we want to run today also works. There are many books
to help get you up to speed on Linux if you need them.

The programs that run on DOS to control the machines are
fewer in number, but there are devotees of each here on the
list.

EMC is a US Government developed, free program for machine
tool control written and adapted to run under a real time
flavor of the Linux operating system. The BDI porject is an
attempt to put together a CD-ROM that will install a working
version of Linux and EMC onto a computer without the need
for operator intervention or understanding. Whole books
have been written on how to install a working Linux machine
- so this is an ambitious project indeed. Well worth the
$10 or all night download and burn your own. This is
designed to bring Linux and EMC to the unwashed masses - a
good thing. Sooner or later they will want to learn more
and will learn about Linux and EMC as their need and
interest dictates.

I am working towards a X-Y-Z-Rotary table CNC 3 in one
Mill/Lathe using a CAD/CAM solution in my house tied via
sneakernet to an EMC controller in the shop using steppers
with encoder controls. I have the Box for the Linux/EMC to
run in, am getting the BDI CDRom downloaded tonight. I have
a slew of weak Steppers, four 5A controllers from
CAMTRONICS, and the DRO board.

I am stymied on the encoders. I have seen pictures about
home built ones with Parts from US Digital, but they don't
make sense to me. I cannot visualize how they attach to the
table and provide position data and cannot see how to put
them on my little hunk of iron.

Getting encoders on and achieving a DRO function is my first
step at the machine end. Maybe a stepper to give me X power
feed as well.

Hope this helps some of the newer list people figure it out
a bit and hope that some help with the encoders for the DRO
board will come my way.

Karl Peterson, High School Chemistry Teacher, amatuer
putterer and inventor.
Currently trying to make a home made protype injection
molding machine that will accept production molds.