Wire Drive Roll - Lincoln Electric 350MP Operator's Manual

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In the case of special waveforms designed for pulsed weld-
ing aluminum, Pulse on Pulse™, the effect is similar to what
occurs with standard pulse. As the Arc Control is increased
from +1 to +10 the frequency of the Pulse on Pulse array
increases. As the frequency increases the weld bead ripples
become less distinct and the arc cone narrows. When the
Arc Control is set from -1 to -10 the Pulse on Pulse arrays
decrease in frequency, the weld bead ripples become more
distinct, and the bead width increases.
In GMAW-PP mode, arc control adjusts the modulation fre-
quency, which means the speed at which the ripples are
produced in the weld. (See Pulse-on-pulse description later
in this section.) When faster travel speeds are desired, arc
control needs to be set higher. When slower travel speeds
are desired, arc control needs to be set lower.
• The Arc-control adjustment is selected by toggling the
SELECT switch until the LED next to ARC CONTROL is
lit. The Arc-control value will be displayed. Arc-control can
be adjusted by toggling the SET switch up or down.
• The default value is "OFF."
Crater
The crater is the end of the weld, which normally solidifies
creating a concave surface. This can result in stresses that
can cause cracks in the center of the crater. The purpose of
the Crater control is to fill up the crater, so that its surface
becomes flat.
Crater control in this machine is more efficient than in other
machines. Normally, in other machines, the crater filling pro-
cedure is a step down from the welding WFS to the crater
filling WFS. In this machine instead of a step down, the tran-
sition is a ramp down, which results in a more controlled fill-
ing up of the crater and so, less stresses present in it.
The values to enter are first the desired time to stay at the
Crater settings and the desired WFS and voltage/trim to fill
the crater.
• The Crater timer is selected by toggling the SELECT
switch until the LED next to CRATER is lit and flashing. A
crater time may be set using the SET switch.
• The available values for crater control time go from "Off"
to 0.1 seconds and from there to 10.0 seconds in incre-
ments of 0.1 seconds.
• The Crater function offers the ability to set an endpoint for
WFS and Voltage that will be reached over a specified
time period. At the end of the weld when the trigger is
released, the crater timer will begin and the WFS and
Volts settings will ramp down from the Weld Mode WFS
and Voltage settings to the Crater WFS and Voltage set-
tings over the time selected. This creates a ramp down of
the WFS and Volts during the Crater time.
OPERATION
• In the GMAW, FCAW, and Power weld modes, crater
WFS and voltage are adjustable using the control knobs
on the upper case front. This in indicated by the flashing
LEDʼs next to "WFS" and "VOLTS."
• In the GMAW-P weld modes, Crater WFS and trim are
adjustable. This is indicated by the flashing LEDs next to
"WFS" and "TRIM."
Burnback
Setting the Burnback means setting the adjustable time
delay between turning off the wire feeding and turning off
the arc. Burnback helps to prevent wire sticking to the pud-
dle.
• The Burnback feature will allow current to continue to flow
for a specified time period at the end of a weld after wire
feeding has stopped.
• The Burnback timer will be selected by toggling the
SELECT switch until the LED next to BURNBACK is lit. A
burnback time may be set using the SET switch.
• The default value is "OFF" (0 seconds).
• Burnback time is adjustable from 0 to 0.25 seconds in
0.01 second increments.
Spot
The Spot Timer adjusts arc on-time for spot or tack welds.
• With the Spot feature active (Spot time selected), when
the trigger is pulled and the arc is established, the weld
will continue until the expiration of the spot timer and the
next active state will be enabled (crater or burnback). The
trigger must be released and pulled again for another Spot
cycle.
• The Spot timer is selected by toggling the SELECT switch
until the LED next to SPOT is lit. The present SPOT time
will be displayed and can be changed by toggling the SET
switch up or down.
• The default value is "OFF" (0 seconds).
• Spot can be adjusted from 0 to 10.0 seconds in 0.1 sec-
ond increments.

WIRE DRIVE ROLL

The drive rolls installed with the POWER MIG
two grooves, one groove for .035" (0.9mm) solid steel elec-
trode, and the other groove for the .045"(1.2mm) electrode.
The actual drive roll size is stenciled on the side opposite of
its groove. If feeding problems occur, a check may be
required to make sure that the wire size and the drive roll
size matches. See "Procedure for Changing Drive Rolls" in
this section.
POWER MIG 350MP
®
B-7
® 350MP have