Cebora Plasma PROF 166 HQC, Instruction Manual

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Fig. 22
4.4 CUT QUALITY
Many are the parameters and their combinations which
affect cut quality: the Cut Table manual shows the per-
fect adjustments for cutting a specific material. Never -
theless, because of the inevitable difference caused by
installation on different pantographs and variations in
the characteristics of the cut materials, the most perfect
parameters can undergo small variations with respect to
those indicated on the above tables. The following points
can help the user to make those small alterations needed
to obtain a good-quality cut.
As is shown on the cutting tables, there are various sets
of expendable parts depending on the cutting current
and gas used.
If high output requirements prevail, and therefore the
need for high cutting speeds, set the maximum allowed
current and the nozzle with the largest diameter. If on the
other hand, focus is on cutting quality (greater squaring
and narrower kerf) set the minimum current allowed for
the material and the thickness being worked.
Before making any adjustment, make sure:
The torch is perpendicular to the cutting surface.
The electrode, nozzle, H2O nozzle carrier and nozzle
protection are not too worn and that their combination
corresponds to the chosen job.
The cutting direction, depending on the figure to be ob -
tained, is correct. Remember that the best side of a cut
is always the right side with respect to the direction of
movement of the torch (the plasma diffuser used has the
holes in clockwise direction).
If large thicknesses have to be cut, special attention
must be given during the break-through phase: in par-
ticular, try and remove any build-up of melted material
around the hole where cutting starts to avoid double
arc phenomena when the torch passes over the start-
ing point again. Also always keep the nozzle protection
clean of any melted metal slag.
Table 7 indicates some of the most frequent problems
and relative solutions.