Tweco 39 CutMaster - Manual (Page 44)

cutmaster 39
OPERATION 4T-8 Manual 0-4975
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).
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.
At 80 amps, 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, re-
quiring more passes. In some applications, such as
removing welds or working with light metal, this
may be desirable.
35˚
Workpiece
Torch Head
Standoff Height
1/16"
A-08068
Gouging Angle and Standoff Distance
Standoff Distance
The tip to work distance affects gouge quality and
depth. Standoff distance of 1/16 inch (1.6 mm) al-
lows for smooth, consistent metal removal. Smaller
standoff distances may result in a severance cut
rather than a gouge. Standoff distances greater than
1/16 inch (1.6 mm) may result in minimal metal
removal or loss of transferred main arc.
Slag Buildup
Slag generated by gouging on materials such as car-
bon 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.