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Powermax125
Service Manual 808070
7 – Mechanized Cutting
Cut or bevel angle
A positive cut angle results when more material is removed from the top of the cut than from the bottom.
A negative cut angle results when more material is removed from the bottom of the cut.
Figure 4 – Cut angles
The squarest cut angle will be on the
right
side with respect to the forward motion of the
torch. The left side will always have some degree of cut angle.
To determine whether a cut-angle problem is being caused by the plasma
system or the drive system, make a test cut and measure the angle of
each side. Next, turn the torch 90° in its holder and repeat the process. If
the angles are the same in both tests, the problem is in the drive system.
If a cut-angle problem persists after mechanical causes have been
eliminated (see
Setting up the torch and table
on page 105), check the
torch-to-work distance, especially if the cut angles are all positive or all
negative. Also consider the material being cut: if the metal is magnetized
or hardened, you are more likely to experience cut angle problems.
Dross
Some amount of dross will always be present when cutting with air plasma. However, you can minimize the amount and
type of dross by adjusting your system correctly for your application.
Excess dross appears on the top edge of both pieces of the plate when the torch is too low (or voltage is too low when
using a torch height control). Adjust the torch or adjust the voltage in small increments (5 volts or less) until the dross is
reduced.
Low-speed dross forms when the torch’s cutting speed is too slow and the arc angles ahead. It forms as a heavy, bubbly
deposit at the bottom of the cut and can be removed easily. Increase the speed to reduce this type of dross.
Negative cut angle
Square cut
Positive cut angle
Problem
Cause
The torch is too low.
The torch is too high.
Solution
Raise the torch; or if you are using a torch height
control, increase the arc voltage.
Lower the torch; or if you are using a torch height
control, decrease the arc voltage.
90°
