Thermal Dynamics CE CutMaster 50, Инструкция по эксплуатации

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Manual 0-2470 39 OPERATION
4.08 OPERATING WITH A MACHINE TORCH (continued)
Standoff Distance
Travel Speed
Piercing with a
Machine Torch
Proper tip-to-work (standoff) distance is critical to ensure accu-
racy, optimum cut quality, and maximum consumable parts life
in mechanical systems. The recommended standoff distance for
mechanized systems is 3/16 in (5 mm).
Proper travel speed is indicated by the trail of the arc which is
seen below the plate (see Figure 4-E, page 38). A straight arc is
generally recommended for the best cut using air plasma on
stainless or aluminum. For air plasma on mild steel, a five degree
leading arc is recommended.
For optimum smooth surface quality, the travel speed should be
adjusted so that only the leading edge of the arc column produces
the cut. If the travel speed is too slow, a rough cut will be pro-
duced as the arc moves from side to side in search of metal for
transfer.
Travel speed also affects the bevel angle of a cut. When cutting in
a circle or around a corner, slowing down the travel speed will
result in a squarer cut. The power supply has a corner slowdown
feature which reduces output for this purpose (see Corner Slow-
down Operation, page 37).
To pierce with a machine torch, the arc should be started with the
torch positioned as high as possible above the plate while allow-
ing the arc to transfer and pierce. This standoff helps avoid
having molten metal blow back onto the front end of the torch.
When operating with a cutting machine, a pierce or dwell time is
required. Torch travel should not be enabled until the arc pen-
etrates the bottom of the plate. As motion begins, torch standoff
should be reduced to the recommended 1/8 - 3/8 inch (3 - 9 mm)
distance for optimum speed and cut quality. Clean spatter and
scale from the shield cup and the tip as soon as possible. Spraying
or dipping the shield cup in anti-spatter compound will minimize
the amount of scale which adheres to it.