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DETERMINING MACHINE SETTINGS
AMPERAGE - For metals thicker than 0.0625" [1.59mm], 40A output on the optional Eastwood Versa-Cut 40 CNC Plasma Cutter is optimal for max speed and is
required for thicker materials. Thinner gauge steels may be cut with lower amperage.
Lower amperage will allow you to reduce heat into the workpiece, therefore minimizing warp. It will also require lower speeds which can make for a smoother
cut; the computer may struggle to keep up with high speeds (eg. 3000mm/min) on a complicated file may result in jumpy motion.
CUT SPEED - To get a cut speed, first start with a suitable speed for your material thickness from the CUT SPEED REFERENCE TABLE. Depending on a multitude
of factors, such as condition of consumables, amperage, and material quality, the speed should then be fine-tuned.
The best speed is the fastest possible with minimal dross on the finished piece. Large, chunky dross means speed is too low and a small, hard dross bead means
speed is too fast. When cutting in the optimal speed range, it is typical for a narrow spray of sparks to shoot out over top the sheet and for the plasma spray exit-
ing the bottom to slightly lag behind the torch position. It will leave a shallowly curved line on cut edges.
RADIUS SPEED - Using Small Arc Limit (mm/min) and Limited Speed Below Radius (mm) to reduce tight radius speed does not have a drastic effect, but
generally a slight reduction is optimal for good quality, especially at high cut speeds.
PIERCE TIME - Improper pierce time can cause two things: failure to penetrate, resulting in a spark and slag shower with poor initial cut; or arc failure and
sputtering at the beginning of a cut. Thick metal may require nearly a second of pierce time or more, while thin gauge may not require any. See the CUT SPEED
REFERENCE TABLE for a start point based on material thickness.
Pierce time being too short will mean the plasma arc has not fully penetrated the material before movement starts. This results in slag and sparks being showered
across the table, increased consumable wear, and an incomplete cut. Optimal pierce time will allow for full penetration of the material before movement occurs.
When the pierce time is too long the plasma arc will have fully penetrated the material, resulting in a hole beneath the torch. The plasma cutter will have trouble
maintaining the arc because there is no material to conduct it. This results in sputtering as it switches between the pilot arc and cutting arc or simply an arc
break alarm that pauses the cut.
THC LOCK TIME - Time to lock THC (S) is the time the THC will be locked after starting the cut. On thick material this setting can improve initial stability of the
arc, where extreme variations in arc voltage cause unstable automatic torch height control.
ACCELERATION - The jumpiness of the movement is predominately controlled by Acceleration (S) time setting. At high speeds increasing it may make move-
ment smoother.
ARC VOLTS - Arc volts is the measured voltage drop across the arc, which is useful for controlling height. The Torch Height Controller (THC) will attempt to
keep the arc volts at Set Arc; the optimal range will vary slightly depending on the plasma cutter used. For the Eastwood Versa-Cut 40 CNC Plasma Cutter it is
between 98-115.
IHS TIME - The Initial Height Setting is defined by seconds of motor run time upwards. Ideally, the initial height is slightly higher than the cutting height. With
thick material, good initial height is critical because damage to the consumables can occur from slag being shot back into the Plasma Torch.
KERF - The kerf varies depending on numerous factors, and even varies slightly as the table cuts. However, it is typically close to your Plasma Torch nozzle
orifice diameter. To get the most accurate kerf width, measure a cut piece with zero kerf compensation applied and subtract the actual size from the set size. If
both sides being measured have been cut, divide by two. Due to the nature of plasma cutting there will almost always be a positive bevel that is most evident on
thicker materials. This means, from top to bottom, inside features will slope smaller and outside features will slope larger.
CUT SPEED REFERENCE TABLE
This table provides a starting point when CNC Plasma Cutting. It is directly applicable when using the Eastwood Versa-Cut 40 CNC Plasma Cutter with Machine
Torch, but you may find it suitable for other plasma cutters of similar capability. Note that depending on amperage being used, consumable condition, material,
and a multitude of other factors you may need to fine tune these parameters for the best cut possible.
Thickness
(inch) – [mm]
0.0375 (20 gauge) [0.952]
0.050 (18 gauge) [1.27]
0.0625 (16 gauge) [1.59]
0.109 (12 gauge) [2.77]
0.125 [3.18]
0.25 [6.35]
40
Amperage
Cut Speed
(ipm) - [mm/min]
(A)
3500
2500
1700
40
1300
1200
1000
Pierce Time
Acc Time
(sec)
(sec)
0.1
0.2
0.3
0.2
0.5
0.2
0.8
0.3
0.9
0.3
1.2
0.3
Eastwood Technical Assistance: 800.343.9353 >> tech@eastwood.com
Arc Volts
IHS Time
(V)
(sec)
102
0.3
102
0.3
103
0.3
103
0.4
103
0.4
105
0.4
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