If you’re maintaining the proper travel
speed, the sparks will exit the workpiece at
a 15- to 20-degree angle.
CFIGURE 1 An air filter and dryer
help maintain the air quality needed for
plasma cutting quality
Get more life; fast, clean cuts > > >
By Don Keddell
Perform a Preflight Check
Plasma cutting is easy to
learn, and cutters are simple
to use. In fact, it’s so easy
that many users go right to
work as soon as they remove the unit
from its packaging. However, that
approach may not optimize your plasma cutter’s capabilities. Here are some
tips and suggestions for best practices
that will increase your efficiency and
precision and prolong the life of your
plasma cutter and consumables.
Read the Manual
The first and most important step is
one that many users fail to do: Take
the time to read the manual thoroughly and familiarize yourself with
your particular plasma cutter. It pays
to do so because the manual contains
important information on getting the
most from your plasma cutter.
Note that plasma cutting produces
fumes and gases that may be hazardous
to your health. Proper ventilation and
attire are required. Please review your
owner’s manual for important safety
information on the proper practices
used and attire worn for plasma cutting.
Develop a “preflight routine” for
using your plasma cutter, starting from
the back of the machine and working
1. Check the power cord to make
sure it is in good condition and that it
is plugged into the correct type of primary power supply. Some units allow
you to plug them into any power supply
from 208 to 575 V. Other units require
a specific voltage, so it is up to you to
make sure the unit is plugged into the
correct power supply and any power
selection switches are correctly set.
2. Check your air supply to make
sure you have the correct airflow and
pressure entering the machine. Your
owner’s manual should list the air
3. Dry air is important for plasma
cutting because it maximizes cutting
capacity. Install an air filter and/or
dryer on the machine, if it does not
come equipped with one (see Figure
1). Check, clean, and replace the filter
and dryer in accordance with the
manufacturer’s recommendations. It is
important to have some type of
sealant on the connection to decrease
the risk of an air pressure leak.
4. Connect the torch, if it is not
5. Make sure all of your consumables are in place and correct for the
job and that they are snug and secure.
Overtightening the cup can result in
6. If applicable, select the proper
process. On some high-output
machines, a switch allows the user to
choose between cutting and gouging.
7. Turn on the machine.
8. Check the air setting (see
Figure 2). The pounds per square inch
(PSI) setting may be different for cutting and gouging. On some plasma cutters, you can turn the amperage down
to zero, which turns on the airflow and
allows you to set the correct pressure.
9. Set the output to the correct
10. Check the ground connection
to the workpiece. Although plasma
can cut through painted metal, it does
require a solid connection on a clean
part of the workpiece as close to the
work area as it is practical to do so.
11. Make sure you have all of your
safety gear in place. Your owner’s manual will have more details, but generally you want the same type of protec-
CFIGURE 6 Angle the torch forward
to cut the last section of the metal at the
end of a cut.
tive gear as you wear when welding. If
the table is wet and you lay your bare
arm on it, you can become part of the
circuit and receive a shock, so make
sure you are wearing welding leathers,
along with proper gloves and eye protection. Usually a No. 5 shade is the
minimal eye protection required, but
darker shades may be needed,
depending on amperage. See your
owner’s manual for the manufacturer’s
recommendation. A face shield also is
12. Make a sample cut on the same
type of material as your workpiece to
check your settings and travel speed.
The FABRICATOR | An FMA Publication
www.thefabricator.com | March 2007