USING THE MACHINE TORCH
You will need to refer to the manufacturer’s instructions for specifics on operating the
machine torch in your configuration. However, the information in the following sections
will help you optimize cut quality and maximize consumable life.
Ensure the torch and table are set up correctly
Use a square to align the torch at right angles to the work piece in two dimensions.
The torch may travel more smoothly if you clean, check and “tune” the cutting table’s rails
and drive system.
Unsteady machine motion can cause an irregular, wavy pattern on the cut surface.
Ensure that the torch does not touch the work piece during cutting. Contact with the work
piece can damage the shield and nozzle and affect the cut surface.
Understand and optimize cut quality
There are several factors to consider in cut quality. The following sections explain how these
factors can affect cut quality.
Cut Angle
A positive cut angle results when more material is removed from the top of the cut than from
the bottom.
A negative cut angle results when more material is removed from the bottom of the cut.
Dross
Some amount of dross will always be present when cutting with air plasma. However, you can
minimize the amount and type of dross by adjusting your system correctly for your application.
Excess dross appears on the top edge of both pieces of the plate when the torch is too low (or
voltage is too low when using a torch height control). Adjust the torch or adjust the voltage of
your torch height controller in small increments (5 volts or less) until the dross is reduced.
Low-speed dross forms when the torch’s cutting speed is too slow and the arc angles
ahead. It forms as a heavy, bubbly deposit at the bottom of the cut and can be removed
easily.
Increase the speed to reduce this type of dross.
High-speed dross forms when the cutting speed is too fast and the arc angles behind. It
forms as a thin, linear bead of solid metal attached very close to the cut. It is more firmly
attached to the bottom of the cut than at low speed and is difficult to remove. To reduce
high
‑
speed dross:
Decrease the cutting speed.
Decrease the torch-to-work distance.
