Distance from the MIG Torch Nozzle
to the Work Piece
The electrode wire stick out from the MIG Torch
nozzle should be between 10mm to 20mm. This
distance may vary depending on the type of joint
that is being welded.
Travel Speed
The speed at which the molten pool travels
of the welding run.
MIG Welding (GMAW) Variables
Most of the welding done by all processes is on
carbon steel. The items below describe the welding
variables in short-arc welding of 24gauge (0.024”,
0.6mm) to ¼” (6.4mm) mild sheet or plate. The
applied techniques and end results in the GMAW
process are controlled by these variables.
Preselected Variables
Preselected variables depend upon the type
of material being welded, the thickness of the
material, the welding position, the deposition rate
and the mechanical properties.
These variables are:
• Type of electrode wire
• Size of electrode wire
• Type of gas
•
Primary Adjustable Variables
These control the process after preselected
variables have been found. They control the
penetration, bead width, bead height, arc stability,
deposition rate and weld soundness.
These variables are:
• Arc Voltage
• Welding current (wire feed speed)
• Travel speed
Secondary Adjustable Variables
These variables cause changes in primary
adjustable variables which in turn cause the
desired change in the bead formation. They are:
1. Stick-Out (distance between the end of the
contact tube (tip) and the end of the electrode
wire). Maintain at about 10mm stick-out
2. Wire Feed Speed. Increase in wire feed speed
increases weld current. Decrease in wire feed
speed decreases weld current.
3. Nozzle Angle. This refers to the position of the
welding gun in relation to the joint. The transverse
angle is usually one half the included angle
between plates forming the joint. The longitudinal
angle is the angle between the centre line of the
welding gun and a line perpendicular to the axis
of the weld. The longitudinal angle is generally
called the Nozzle Angle and can be either trailing
(pulling) or leading (pushing).
Vertical Fillet Welds (Fig 1-6)
10
o
Longitudinal Angle
Direction of Travel
10
o
to 20
o
Longitudinal Angle
30
o
to 60
o
Transverse
Angle
30
o
to 60
o
Transverse
Angle
Direction of Travel
(Fig 1-7)
5
o
to15
o
Longitudinal
Angle
30
o
to 60
o
Transverse
Angle
Electrode Stick-Out
(Fig 1-8)
Gas Nozzle
Tip to
Work Distance
Contact Tip (Tube)
Electrode Wire
Actual
Stick-Out
Transverse & Longitudinal
Nozzle Axes (Fig 1-9)
Longitudinal Angle
Transverse Angle
Axis of Weld
14
Summary of Contents for WT180MP
Page 1: ...OPERATING INSTRUCTIONS WT180MP INVERTER MULTI PROCESS WELDER www weldtech net nz...
Page 24: ...MMA Stick Troubleshooting 24...
Page 27: ...TIG Welding Troubleshooting WT180MP Welding Machine 27 www weldtech net nz...
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