Tweco 38 CutMaster - Manual (Page 31)

Manual 0-2964 4-7 OPERATION
J. Cutting Technique
Hold the torch with one or two hands, with the torch tip close to the workpiece. Do not cut or handle the
workpiece without welding gloves and protective clothing. Always wear protective eye shielding when cutting
or gouging. Move the torch along the cut line so the arc penetrates the workpiece and sparks emerge from the
bottom of the cut. Good cutting speeds create a slight trailing arc.
K. Typical Cutting Speeds
Cutting speeds vary according to torch output, the type of material being cut, and operator skill. Speeds shown
are typical for this cutting system using air plasma to cut mild steel, with output current at 30 amps and torch
held at 0 - 1/16" (0 - 1.6 mm) standoff.
5
9.5 0.375
0.2
0.1
6
18
Inches/ Meters per Minute
CUTTING SPEED
Gage
MM
MA
TERIAL
THICKNESS
0.25
0.3
0.15
0.35
0.05
20
12
8
6
7
2
4
1
3
Inch
Inches
Meters
20
0.5
40
1.00
60
1.5
80
2.0
100
2.5 120
3.05
140
3.5
160
4.06
180
4.57
200
5.08
220
5.56
240
6.1 400
10.1
Typical Cutting Speeds
Air Plasma on Mild Steel
24
10
0.25
0.5 12.7
0.4
A-03381
Output current setting or cutting speeds may be reduced to allow slower cutting when following a line, using a
template or cutting guide while still producing cuts of excellent quality.
L. Postflow
Release the trigger to stop the cutting arc. Gas continues to flow for approximately 10 seconds. During post -
flow, if the user moves the trigger release to the rear and presses the trigger, the pilot arc starts. The main arc
transfers to the workpiece if the torch tip is within transfer distance to the workpiece.
M. Shutdown
Turn the ON / OFF switch to OFF (down). All Power Supply indicators shut off. Unplug the input power cord
or disconnect input power. Power is removed from the system.