Tweco 15XC CE Merlin PAK - Manual (Page 53)

Manual 0-2529 3 - 19 OPERATION
Cutting with a
Machine Torch
(continued)
5. Cut with a standoff of 1/8 - 3/8 in (3 - 10 mm) from the
work. The torch should be held perpendicular to the
workpiece while cutting. Start cutting slowly and
adjust cutting speed for optimum cutting performance.
Cutting Speeds (page 3-26) contains typical cutting
speeds for various materials and material thicknesses.
A standard shield cup is recommended for most machine
cutting applications. The touch cup (short shield cup) is
designed for light gage cutting where arc voltage measure-
ment is needed for a standoff control. Do not allow an
exposed torch tip to contact the workpiece.
The arc characteristics vary with gases used, cutting speed,
material, and thickness. Air plasma normally produces a
straight arc (on stainless or aluminum), while nitrogen
plasma generally creates a 5° trailing arc (see Figure 3-J).
Figure 3-J Machine Torch Operation