Lincoln Electric IM795 - Manual (Page 27)

D-3 D-3
MAINTENANCE
SP 170-I
COMPONENT
REPLACEMENT
PROCEDURES
CHANGING THE CONTACT TIP (These
instructions pertain to the Lincoln Electric® gun. The
instructions for the Magnum™ 100L gun, are similar
except that the gas nozzle is threaded.)
1. Refer to Figure D.2a or D.2b. Remove the gas noz-
zle from the gun by pulling and rotating it clockwise
off the diffuser. (Threadless slip fit).
2. Remove the existing contact tip from the gun by
gripping it with pliers and twisting counter-clock-
wise. Tip will now slip out of diffuser.
3. Insert new tip into diffuser. Grip it with pliers, push
tip into diffuser until it bottoms, then twist clockwise
to tighten.
4. Replace gas nozzle.
CHANGING DRIVE ROLL
The drive roll has two grooves; one for .023" – .025"
(0.6 mm) solid steel electrode and a larger groove for
.030" (0.8 mm) solid and .035" (0.9 mm) flux-cored
steel electrode. As shipped, the drive roll is installed in
the .030"-.035" (0.8/0.9mm) position.
If .023"/.025" (0.6mm) wire is to be used, the drive roll
must be reversed as follows:
1. Connect the machine to its rated input power per
instructions in Installation section.
2. Release the spring-loaded pressure arm and lift the
idle roll arm away from the drive roll.
3. Turn the power switch to ON (marked “I”).
4. Set the wire speed to minimum and jog the drive
unit with the trigger switch until the drive roll set
screw is facing up.
When inching the welding wire, the drive rolls,
gun connector block, and gun contact tip are
energized relative to work and ground and remain
energized for several seconds after the gun trig-
ger is released.
5. Turn the power switch to OFF (marked “O”).
6. Loosen the drive roll set screw with the 5/64" (2.0
mm) hex wrench supplied.
7. Remove the drive roll, flip over and reinstall with the
.023/.025" (0.6mm) groove (the smaller groove)
closest to the gearbox.
8. Push a length of straightened welding wire through
the wire feeder guide tubes and adjust the position
of the drive roll so that the groove is centered on
the wire. Make certain the set screw is located on
the flat portion of the shaft and tighten.
FIGURE D.1
CAUTION
3
2
1