Tweco CutMaster 12mm - Manual (Page 38)

CUTMASTER 12mm
4T-6 OPERATION Manual 0-5076
CAUTION
Touching the torch tip or shield cup to the work
surface will cause excessive parts wear.
Torch Travel Speed
NOTE
Refer to Appendix Pages for additional information
as related to the Power Supply used.
Optimum torch travel speed is dependent on current set-
ting, lead angle, and mode of operation (hand or machine
torch).
Current Setting
Current settings depend on torch travel speed, mode of
operation (hand or machine torch), and the amount of
material to be removed.
Lead Angle
The angle between the torch and workpiece depends on
the output current setting and torch travel speed. The
recommended lead angle is 35°. At a lead angle greater
than 45° the molten metal will not be blown out of the
gouge and may be blown back onto the torch. If the lead
angle is too small (less than 35°), less material may be
removed, requiring more passes. In some applications,
such as removing welds or working with light metal, this
may be desirable.
35°
Workpiece
Torch Head
Standoff Height
A-00941_AB
Gouging Angle and Standoff Distance
Standoff Distance
The tip to work distance affects gouge quality and depth.
Standoff distance of 1/8 - 1/4 inch (3 - 6 mm) allows for
smooth, consistent metal removal. Smaller standoff dis-
tances may result in a severance cut rather than a gouge.
Standoff distances greater than 1/4 inch (6 mm) may result
in minimal metal removal or loss of transferred main arc.
Slag Buildup
Slag generated by gouging on materials such as carbon and
stainless steels, nickels, and alloyed steels, can be removed
easily in most cases. Slag does not obstruct the gouging
process if it accumulates to the side of the gouge path.
However, slag build - up can cause inconsistencies and
irregular metal removal if large amounts of material build
up in front of the arc. The build - up is most often a result
of improper travel speed, lead angle, or standoff height.
4T.06 Mechanized Torch Operation
Cutting With Mechanized Torch
The mechanized torch can be activated by remote control
pendant or by a remote interface device such as CNC.
1. To start a cut at the plate edge, position the center of
the torch along the edge of the plate.
Travel Speed
Proper travel speed is indicated by the trail of the arc which
is seen below the plate. The arc can be one of the following:
1. Straight Arc
A straight arc is perpendicular to the workpiece surface.
This arc is generally recommended for the best cut using
air plasma on stainless or aluminum.
2. Leading Arc
The leading arc is directed in the same direction as torch
travel. A five degree leading arc is generally recommended
for air plasma on mild steel.
3. Trailing Arc
The trailing arc is directed in the opposite direction as
torch travel.