Lincoln Electric 50448 Service Manual page 37

Adjusting of Pressure Roll Force
The pressure arm controls the amount of force the drive
rolls exert on the wire. Pressure force is adjusted by
turning the adjustment nut clockwise to increase force,
counterclockwise to decrease force. Proper adjustment of
pressure arm gives the best welding performance.
WARNING
If the roll pressure is too weak the roll will slide on the
wire. If the roll pressure is set too heavy the wire may be
deformed, which cause feeding problems in the welding
will gun. The pressure force should be set properly. For
this purpose decrease the pressure force slowly until the
wire just begins to slide on the drive roll and then increase
the force slightly by turning of the adjustment nut by one
turn.
Inserting Electrode Wire into Welding
Torch
Turn the welding machine off.
Depending of welding process connect proper welding
torch to the euro socket. Rated parameters of the
torch and welding machine should be matched.
Remove the nozzle from the gun and contact tip or
protection cap and contact tip. Next straighten torch
cable.
Turn the welding machine on.
Hold the Cold Feed/Gas Purge Switch [14] or use torch
trigger until wire appear over threaded end of the gun.
When the Cold Feed switch torch trigger is released spool
of wire should not unwind.
Adjust wire spool brake accordingly.
Turn the welding machine off.
Install a proper contact tip.
Depending on the welding process and the type of the
gun, install the nozzle (GMAW process) or protection
cap (FCAW process).
WARNING
Take precaution to keep eyes and hands away from the
end of the gun while the wire is being come out of the
threaded end.
Changing Driving Rolls
WARNING
Turn the input power off before installation or changing
drive rolls.
Wire Feeders LF 52D i LF 56D are equipped with drive
roll V1.0/V1.2 for steel wire. For others wires and sizes it
is required to install proper drive rolls kit (see
"Accessories" chapter) and follow instruction:
Turn the input power OFF.
Unlock 4 rolls by turning 4 Quick-Change Carrier Gear
[49].
Release the pressure roll levers [50].
Change the drive rolls [48] corresponding to the used
wire.
WARNING
Be sure that the gun liner and contact tip are also size to
match the selected wire size.
WARNING
For wires with the diameter larger than 1.6mm, the
following parts have to be changed:
The guide tube of the feeding console [46] and [47].
•
The guide tube of the Euro Socket [45].
•
Lock 4 new rolls by turning 4 Quick-Change Carrier Gear
[49].
Insert the wire through the guide tube, over the roller and
through the guide tube of Euro Socket into liner of gun.
The wire can be pushed into the liner manually for a
few centimeters, and should feed easily and without
any force.
Lock the pressure roll levers [50].
Figure 73