Tweco A80-A120 CutMaster - Manual (Page 35)

CUTMASTER A80, A120
Manual 0-5119 OPERATION
4T-3
A-03510_AB
Electrode
Start Cartridge
Tip
Shield Cup
Torch Head
Torch Parts
(Drag Shield Cap & Shield Cup Body Shown)
3. Install the replacement Electrode by pushing
it straight into the torch head until it clicks.
4. Install the starter cartridge and desired tip for
the operation into the torch head.
5. Hand tighten the shield cup assembly until
it is seated on the torch head. If resistance is
felt when installing the cup, check the threads
before proceeding.
4T.04 Cut Quality
NOTES
Cut quality depends heavily on setup and param-
eters such as torch standoff, alignment with the
workpiece, cutting speed, gas pressures, and
operator ability.
Cut quality requirements differ depending on applica-
tion. For instance, nitride build - up and bevel angle
may be major factors when the surface will be welded
after cutting. Dross - free cutting is important when
finish cut quality is desired to avoid a secondary clean-
ing operation. The following cut quality characteristics
are illustrated in the following figure:
Kerf Width
Cut Surface
Bevel Angle
Top Edge
Rounding
Cut Surface
Drag Lines
Dross
Build-Up
Top
Spatter
A-00007
Cut Quality Characteristics
Cut Surface
The desired or specified condition (smooth or
rough) of the face of the cut.
Nitride Build - Up
Nitride deposits can be left on the surface of the cut
when nitrogen is present in the plasma gas stream.
These buildups may create difficulties if the mate-
rial is to be welded after the cutting process.
Bevel Angle
The angle between the surface of the cut edge and
a plane perpendicular to the surface of the plate.
A perfectly perpendicular cut would result in a
0° bevel angle.
Top - Edge Rounding
Rounding on the top edge of a cut due to wearing
from the initial contact of the plasma arc on the
workpiece.
Bottom Dross Buildup
Molten material which is not blown out of the
cut area and resolidifies on the plate. Excessive
dross may require secondary cleanup operations
after cutting.