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PlasmaCAM is Unlike Conventional CNC Cutting
Notice that for conventional CNC, many more steps are required
to get from the original design to the actual cut part. The additional
required software means more time, money and confusion.
Conventional CNC Programming and Cutting
| Cutting artistic parts |
Cutting geometric parts |
- Scan a drawing of the part and save it to a bitmap file.
- Import the bitmap file, convert it and save it as a vector
file using an expensive raster-to-vector conversion program.
- Import the vector file into an expensive CAD program.
Manually clean up the shape of the part to remove defects
(this can take up to 4 hours). Also scale and position the
part appropriately.
- Complete steps 2 through 6 shown at left.
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- Draw up a new design using a CAD program, or import an
existing design from another CAD program.
- Still using the expensive CAD program, manually add pierce
points and other features to the design to ready it for
cutting (this can take up to 4 hours). Then export the drawing
again as a vector file.
- Import the vector file into a program that is able to
sort the entities and build a machine code program file
- Load the code file into a text editing program and manually
edit it to cut multiple copies of parts, control kerf compensation,
etc.
- Load the code file into a program that is able to transfer
it by serial port to the machine.
- The machine can now run the program that it has stored
in its memory (as many times as necessary).
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Designing and Cutting with PlasmaCAM
| Cutting artistic parts |
Cutting geometric parts |
- Scan a drawing of the part and save it to a bitmap file.
- Import the bitmap file into our software (it is converted to
vectors in the same step). The software automatically cleans up
the shape and helps you remove defects in less than five
minutes. Also scale and position the part.
- Complete steps 2 and 3 shown at left.
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- Draw up a new design using the CAD features of our program,
or import an existing design from another CAD program.
- Automatically convert the design to cut paths in one step
(this compensates for kerf width, handles indexing of large
shapes, and adds pierce points).
- Select all the shapes that you want to cut and choose
Cut from our program's menu.
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To further contrast between the two methods of making computerized
parts, consider the following questions:
Can I adjust settings (such as cut speed, rapid travel speed,
how high the torch raises between cutting, etc.) while the machine
is cutting?
| PlasmaCAM: |
Yes. You can adjust the cut speed to any value
on the fly. You can also pause the machine and adjust any other
setting from the computer. |
| Other CNC: |
No. Some machines give you limited control over
cut speed during cutting, but most adjustments require reprogramming
of the machine. |
Suppose I am cutting a large number of parts and the machine
has problems in a couple of places because of hard spots in material,
speed settings, height maladjustment, etc. Can I easily stop the
machine and recut a few holes or a section of a perimeter
| PlasmaCAM: |
Yes. You can stop the machine and select the areas
to recut. You can even pause the machine and dial it back over
an area that you want to recut before resuming. |
| Other CNC: |
No. You should let the entire program finish and
just hand-cut the areas that need repair. If you stop the program,
you will have to start it over at the beginning and you may
potentially have to wait for hours while it catches up to where
it left off. |
If I have a small or irregular piece of material, can I have
the machine cut a part out of it? Can I cut accurately placed holes
in an existing part?
| PlasmaCAM: |
Yes. You can easily move the computer drawing
or the material so that the two are in alignment. Jog and Moveto
commands allow the drawing program to monitor and control the
exact position of the cutter. |
| Other CNC: |
No. Your best bet is to guess the positioning
on a small piece of material and run through the whole program
without cutting to see if it will work. You must completely
reprogram the machine if an adjustment is needed. Do not attempt
to accurately place holes on an existing part, this job is better
done by a machinist. |
Can I easily change the order in which a group of parts is cut?
| PlasmaCAM: |
Yes. Select the parts to reorder and choose one
of the Reorder commands. You can preview the new cutting order
using the Cut Preview command. |
| Other CNC: |
No. Cut order is often random or dependent upon
the order in which entities are listed in a CAD file. Reordering
is virtually impossible. |
Can I see what progress the machine is making during cutting,
and what is left to cut?
| PlasmaCAM: |
Yes. The computer screen shows an animation of
the cutter in real-time as it moves around the selected drawings
being cut. |
| Other CNC: |
No. Your best bet is to watch the material being
cut and compare it to a printout of the original drawing. Although
the machine shows the program code being stepped through. |
Will I ever have problems with running out of memory?
| PlasmaCAM: |
No. Modern PCs are equipped with large amounts
of RAM as well as virtual memory swapping capability. This means
that regardless of the number and complexity of the shapes you
cut, you will probably never experience memory problems. If
you are using PlasmaCAM to program other CNC machines with limited
memory, the Smooth command can automatically trim down the resolution
of a drawing as needed in one simple step. |
| Other CNC: |
Yes. Most high-dollar machines use proprietary
computer controllers that are extremely outdated in performance.
For example, one popular $500,000 laser cutter has only 32K
of memory, and the only option to increasing this is to pay
another $5,000 to have the memory doubled. (64K of memory is
about 1/2000th the RAM found in an ordinary modern PC, not to
mention the virtual memory capabilities of PCs!) Because of
their limitations, most CNC machines simply are not capable
of cutting complex or artistic type shapes. |
Does my drawing have to be absolutely perfect in order for me
to cut it?
| PlasmaCAM: |
No. Although we recommend that you clean up messy
images before trying to cut them, our software will import,
convert and cut virtually anything, regardless of the defects
present. Furthermore, automatic functions are provided for finding
and removing defects in very little time. Also, our program
exports DXF files that are simplified acceptable to most other
software packages. |
| Other CNC: |
Yes. Most software packages are very particular
when importing DXF files and will not accept most. This means
you will need to experiment until you find another program that
makes acceptable DXF files. Also, you may be limited on the
types of entities that you can import (eg. "polylines" are not
acceptable in most cases). Furthermore, most CNC software requires
that every adjacent line and arc be exactly coincident. For
example, one software package simply would not accept a drawing
file because it contained several gaps of about 0.000001 inch
between adjacent entities (even though the shapes had been drawn
as coincident in the CAD package used). Finally, any small defects
like tiny intersecting pieces or a profile that cannot be offset
without intersections will cause most software to terminate
conversion. In many cases, you won't even be able to find the
defect that caused the problem. Because of these limitations,
most CNC software simply cannot handle complex or artistic type
shapes. |
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