Re: CNC PLASMA

>
> DeskCNC does this for him automatically. No extra cost CAM needed.
>
>

It appears that DeskCNC is closer to a CAM program. It does allow
CAD creation. It looks to incorporate the CAM and Controller pieces.

>
> DeskCNC takes care of some of this too, by creating only closed
> shapes. Vector Cad-only would be a good tool to use for optimizing
> and precisely controlling location, direction, and order of cuts,

arc

> fitting, etc.

The problem lies in the fact that you end up with hundreds if not
thousands of little closed vectors in a lot of busy bitmaps. The
vectors are not always what you want. After many attempts at using
various bitmap to vector conversion files I now import all bitmaps in
on a separate layer and hand trace what I want. In doing plasma you
have to stop and think about what you want to cut out and what you
want to leave. Making detail cuts in the middle of a waste piece
that falls out from a wider contour cut is a waste of time. You have
to fix all of those things before you cut. Then there is the issue
of the centers of letters falling out if you cut the
font "negative". You have to manually go in and place "stems" in the
a's e's o's p's l's and other looping letters. A powerful weld
command in the vector edit section is a must.

>
> > 5. Your controller software needs to support continuous

contouring

> > (Constant Velocity = CV) so the moves are smooth and constant.
> Jerky
> > moves cause the floppy flame to "color outside the lines" The
> > controller software is one of the pieces you need in the CNC
> > equation. It takes g-code and puts out signals to the motor
> control
> > modules. Hobby versions of controller software are available

that

> > support CV.
>
> DeskCNC handles this better than most because of the smooth pulse
> rates available even when using dumpster class Windows computers
> running Windows 98.

It does require a special external card and that locks you in on the
controller software and hardware combination.

The bigger factor is that plasma really needs a THC to control the
piercing cycle, material warpage and other nasty occurances. While
external stand alone THC's are available, you will find they are
rather expensive. For the guy that wants to do some hobby cutting
for himself and friends and can afford to ruin some metal, tips, and
waste time a THC is not needed, but if you expect your machine to run
hours each day and you would like for the machine to pay for itself,
then a THC is mandatory. While MACH2 is not a CAM program it is a
good Controller Program and runs my machine smooth as butter. The
integral THC logic makes it something the plasma inclined person
should take a look at.

These perspective are from a user that cuts a lot of "decorative"
steel designs and signs. It's a lot different than the CNC milling I
do to make precision parts and an illustration program rather than a
CAD program works much better and faster for me

There are a myrid of choices for CAD, CAM and Controller Software.
There is 2D, 3D and everything in between. If push comes to shove a
cheap program like Corel 5 - 9 with a HPGL file export and import
into MACH2 gets you 90% there for shape cutting. There are a lot of
good features in DeskCNC and for control of a mill it looks to be a
contender.

regards

Tom C