Shielding Gas - Lincoln Electric HANDY MIG IM756-A Operator's Manual

B-3
FIGURE B.3 – WIRE THREADING DETAILS
Spring Loaded Thumb Screw
Ingoing Guide Tube
Wire
Wire Feed
Lower Drive Roll
Refer to Figure B.3.
4. Release the spring loaded thumbscrew and lift up
the idle roll arm away from the wire feed drive roll.
Ensure that the visible, stenciled size on the drive
roll side facing you matches the wire size being
used.
5. Carefully detach the end of the wire from the spool
maintain tension on the wire. To prevent the spool
from unwinding and do not release the wire until
after step 8.
6. Cut the bent portion of wire off and straighten the
first 4" (100 mm).
7. Thread the wire through the ingoing guide tube,
over the drive roll, and into the gun liner.
8. Close the idle roll arm and turn down the thumb-
screw until the idle roller presses down firmly on the
wire. (Now you may release the welding wire).
Make sure the wire is positioned in the groove of
the lower drive roll.
9. The spring loaded thumbscrew on the idle roll arm
adjusts the pressure on the wire. Adjust pressure
by turning the thumbscrew to prevent spool over-
run, but still allow smooth and easy wire feeding.
Start with the pressure set to an intermediate value.
Readjust, if necessary. Slightly less pressure may
be required when using 0.023 - 0.025" (0.6 mm)
wire. If the drive roll slips while feeding wire, the
pressure should be increased until the wire feeds
properly.
WARNING
• When feeding the welding wire
through the gun, the drive roll, the
gun connector block and the gun
contact tip are always energized rela-
tive to work and ground.
OPERATION
FIGURE B.4 – WIRE STICKOUT
Upper
Idler Roll Arm
CONTACT
TIP
WIRE
ELECTRODE
10. Remove the gas nozzle and contact tip from the
gun.
11. Turn the machine ON ("I").
12. Straighten the gun cable assembly.
13. Depress the gun trigger switch and feed welding
wire through the gun and cable. (Point the gun
away from yourself and others while feeding wire.)
Release the gun trigger after wire appears at the
end of the gun.
14. Turn off the machine.
15. Replace the contact tip. Refer to Figure B-4. Cut
the wire off so that 3/8" to 5/8" (10 - 15 mm) pro-
trudes from the end of the tip.
16. Turn on the machine. The machine is now ready
to weld.

SHIELDING GAS

When using the MIG process, you will need a cylinder
of carbon dioxide (CO
mixed shielding gas.
The preset regulator supplied with the machine is
designed for use with argon blend gas. An adapter
and plastic washer are needed for using 100% CO
gas. This adapter is available from your local gas sup-
plier.
1. Open the cylinder valve slowly a fraction of a turn.
When the cylinder pressure gauge pointer stops
moving, open the valve fully.
2. Keep the cylinder valve closed, except when weld-
ing. When finished welding:
• Close the cylinder valve to stop gas flow.
• Depress the gun trigger briefly to release the
pressure in the gas hose.
• Turn off the machine.
HANDY MIG
3/8"
Contact Tip To Work
Distance (CTWD)
) or argon-carbon dioxide
2
B-3
2