Tweco 181i Thermal Arc Fabricator - Manual (Page 65)

Fabricator 181i
Manual 0-5191 4-7 BASIC WELDING GUIDE
Solving Problems Beyond the Welding Terminals - Inconsistent Wire Feed
Wire feeding problems can be reduced by checking the following points.
FAULT CAUSE
1 Feed roller driven by motor in the
cabinet slipped.
Wire spool brake is too tight.
2 Wire spool unwinds and tangles. Wire spool brake is too loose.
3 Worn or incorrect feed roller size A Use a feed roller matched to the size you are welding.
B Replace feed roller if worn.
4 Wire rubbed against the misaligned
guides and reduced wire feed-ability.
Misalignment of inlet/outlet guides.
5 Liner blocked with swarf A Increased amounts of swarf are produced by the wire
passing through the feed roller when excessive pres-
sure is applied to the pressure roller adjuster.
B Swarf can also be produced by the wire passing
through an incorrect feed roller groove shape or size.
C Swarf is fed into the conduit liner where it accumu-
lates thus reducing wire feed-ability.
6 Incorrect or worn contact tip A The Velocity contact tip transfers the weld current
to the electrode wire. If the hole in the contact tip is
too large then arcing may occur inside the contact tip
resulting in the wire jamming in the contact tip
B When using soft wire such as aluminum it may be-
come jammed in the contact tip due to expansion of
the wire when heated. A Velocity contact tip designed
for soft wires should be used.
7 Poor work lead contact to work piece If the work lead has a poor electrical contact to the
work piece then the connection point will heat up and
result in a reduction of power at the arc.
8 Bent liner This will cause friction between the wire and the liner
thus reducing wire feed-ability.
Table 4-3: Wire Feeding Problems