65
Basic Theory and Function
Section 3
NOTE: Over time, pressure on the drive rolls causes metal fragments from the filler wire
’
s surface to find its
way to the gun cable liner. If the wire guide is not cleaned, it can gradually clog up and causes wire feed mal-
functions. If feeding difficulty is observed, clean the liner in the following manner
：
1) Remove the welding gun
’
s gas nozzle, contact tip and contact tip adapter.
2) With an air nozzle blow compressed air through the wire guide. Wear eye protection!
3) Blow out the wire feed mechanism and reel housing with dry compressed air.
4) Reassemble components. Tighten the contact tip and contact tip
’
s adapter with the spanner included to en-
sure tightness. Do not overtighten any fittings or stripping of the threads may result.
The MIG torch liner may eventually become worn and will need to be replaced. When welding aluminum with
the main gun, a Teflon liner must be used, necessitating a liner change. A spool gun is the preferred method to
weld Aluminum. To change the liner:
1) Remove the securing nut of the liner (#15 in previous page) which exposes the end of the wire guide.
2) Straighten the gun cable and withdraw the liner from the gun.
3) Carefully push a new wire guide in to the gun. Make sure that the wire guide travels all the way to the contact
tip.
4) Make sure the O
-
ring at the machine
-
end of the gun is installed
5) Tighten the wire guide in place.
6) Cut the liner 2mm from the mounting nut and file the sharp edge of the liner.
7) Reattach the gun and tighten all parts.
8) Re
-
thread wire through gun as normal.
