Tweco A40-A60 CutMaster - Manual (Page 37)

CUTMASTER A40, A60
Manual 0-5120 OPERATION 4T-3
4T.03 Automation Torch Parts Selection
Check the torch for proper consumable parts. The
parts supplied in the torch may not be correct for
the operator’s chosen amperage level. The torch
parts must correspond with the type of operation.
Torch parts:
Shield Cup, Cutting Tip, Electrode and Starter
Cartridge
NOTE
Refer to Sections 4T.08 and following for ad-
ditional information on torch parts.
Change the torch parts for a different operation as
follows:
4T.04 Cut Quality
NOTES
Cut quality depends heavily on setup and pa-
rameters 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.
Kerf Width
The width of the cut (or the width of material
removed during the cut).
Top Spatter (Dross)
Top spatter or dross on the top of the cut caused by
slow travel speed, excess cutting height, or cutting
tip whose orifice has become elongated.
4T.05 General Cutting Information
!
WARNING
Disconnect primary power at the source before
disassembling the power supply, torch, or torch
leads.
Frequently review the Important Safety Pre-
cautions at the front of this manual. Be sure
the operator is equipped with proper gloves,
clothing, eye and ear protection. Make sure no
part of the operator’s body comes into contact
with the workpiece while the torch is activated.
CAUTION
Sparks from the cutting process can cause dam-
age to coated, painted, and other surfaces such
as glass, plastic and metal.
NOTE
Handle torch leads with care and protect them
from damage.
Piloting
Piloting is harder on parts life than actual cutting
because the pilot arc is directed from the electrode
to the tip rather than to a workpiece. Whenever
possible, avoid excessive pilot arc time to improve
parts life.