Tweco PCM - 102 Machine Torch - Manual (Page 31)

Manual 0-2818 4-7 OPERATION
C. Piercing With Machine Torch
To pierce with a machine torch, the arc should be started
with the torch positioned as high as possible above the
plate while allowing the arc to transfer and pierce. This
standoff helps avoid having molten metal blow back onto
the front end of the torch.
When operating with a cutting machine, a pierce or dwell
time is required. Torch travel should not be enabled until
the arc penetrates the bottom of the plate. As motion be-
gins, torch standoff should be reduced to the recommended
1/8 - 1/4 inch (3-6 mm) distance for optimum speed and cut
quality. Clean spatter and scale from the shield cup and
the tip as soon as possible. Spraying or dipping the shield
cup in anti-spatter compound will minimize the amount of
scale which adheres to it.
4.09 Recommended Cutting
Speeds
Cutting speed depends on material, thickness, and the operator’s
ability to accurately follow the desired cut line. The following
factors may have an impact on system performance:
• Torch parts wear
• Air quality
• Line voltage fluctuations
• Torch standoff height
• Proper work cable connection
NOTES
This information represents realistic expectations
using recommended practices and well-maintained
systems. Actual speeds may vary up to 50% from
those shown.
Refer to Appendix Pages for cutting speed chart
information as related to the Power Supply used.
4.10 Gouging
WARNINGS
Be sure the operator is equipped with proper
gloves, clothing, eye and ear protection and that
all safety precautions at the front of this manual
have been followed. Make sure no part of the
operator’s body comes in contact with the work-
piece when the torch is activated.
Disconnect primary power to the system before
disassembling the torch, leads, or power supply.
CAUTIONS
Sparks from plasma gouging can cause damage to
coated, painted or other surfaces such as glass, plas-
tic, and metal.
Check torch parts. The torch parts must correspond
with the type of operation. Refer to Section 4.04,
Torch Parts Selection.
A. Gouging Parameters
Gouging performance depends on parameters such
as torch travel speed, current level, lead angle (the
angle between the torch and workpiece), and the dis-
tance between the torch tip and workpiece (stand-
off).
B. Torch Travel Speed
NOTE
Refer to Appendix Pages for additional informa-
tion as related to the Power Supply used.
Optimum torch travel speed is dependent on current
setting, lead angle, and mode of operation (hand or
machine torch).
C. Current Setting
Current settings depend on torch travel speed, mode
of operation (hand or machine torch), and the amount
of material to be removed.