Tweco 75XL Plus PAK Master - Manuel (Page 39)

Manual 0-2807 5-3 SERVICE
ure 5-2). To make a square-edged cut along an inside di-
ameter of a circle, the torch should move counterclock-
wise around the circle. To keep the square edge along an
outside diameter cut, the torch should travel in a clock-
wise direction.
Right Side
Cut Angle
Left Side
Cut Angle
A-00512
Figure 5-2 Side Characteristics Of Cut
E. Dross
Generally when dross is present on carbon steel, it is re-
ferred to as either "high speed or slow speed dross".
"High speed dross" usually forms a narrow bead along
the bottom of the cut edge and is very difficult to remove.
"Slow speed dross" will be in larger quantities but does
not adhere tightly to the cut edge and can be easily re-
moved.
When cutting a troublesome steel, it is suggested that the
torch travel speed be reduced to produce "slow speed
dross". Any required cleanup can then be done by scrap-
ping, not grinding.
Dross present on top of the plate (top spatter), is normally
caused by a slow torch travel speed or too high of a torch
standoff distance.
F. Common Cutting Faults
1. Insufficient Penetration
a. Cutting speed too fast
b. Torch tilted too much
c. Metal too thick
d. Worn torch parts
e. Cutting current too low
f. Non-Genuine Thermal Dynamics parts
2. Main Arc Extinguishes
a. Cutting speed too slow
b. Torch standoff too high from workpiece
c. Cutting current too high
d. Work cable disconnected
e. Worn torch parts
f. Non-Genuine Thermal Dynamics parts
3. Excessive Dross Formation
a. Cutting speed too slow
b. Torch standoff too high from workpiece
c. Worn torch parts
d. Improper cutting current
e. Non-Genuine Thermal Dynamics parts
4. Short Torch Parts Life
a. Oil or moisture in air source
b. Exceeding system capability (material too thick)
c. Excessive pilot arc time
d. Air flow too low (incorrect pressure)
e. Improperly assembled torch
f. Non-Genuine Thermal Dynamics parts