Thermal Arc 281 FABRICATOR, Service Manual

Page: 33 / 108

FABRICATOR 281
Manual No. 0-4880B -1 INSTALLATION
Spool Hub Brake Hex Head Bolt
Spool Hub Nut
Wire Drive
Pressure Adjusting Device
Art # A-07461
Figure 3-13: Wire Installed
3.14 Wirefeeder Feedroll Pressure
Adjustment
The idler roll on the swing arm applies pressure to the
drive roll via adjustable tension devise. The Pressure
Adjuster should be set to a minimum pressure that
will provide satisfactory wire feed without slippage.
If slipping occurs, and inspection of the wire out of
the MIG gun reveals no deformation or wear, the
conduit liner should be checked for kinks or clogging
from metal flakes. If this is not the cause of slipping,
the feedroll pressure can be increased by rotating
the Pressure Adjusting device clockwise. The use of
excessive pressure may cause rapid wear of the feed
roller, motor shaft and motor bearings.
NOTE
Genuine TWECO contact tips and liners
should be used. Many non-genuine liners
use inferior materials which can cause wire
feed problems.
3.15 Wire Spool Hub Brake
The wire spool hub incorporates a friction brake which
is adjusted during manufacture for optimum braking.
If it is considered necessary, adjustment can be made
by turning the hex head bolt inside the open end of
the wire spool hub. Clockwise rotation will tighten the
brake. Refer to Figure 3-13 above.
CAUTION
Excessive tension on the brake will cause
rapid wear of mechanical wire feed parts,
over heating of electrical componentry and
possibly an increased incidence of wire
Burnback into the contact tip.
NOTE
Correct adjustment will result in the wire
spool circumference continuing no further
than3/4-inch (20mm) after release of the
Gun trigger switch. The wire should be slack
without becoming dislodged from the spool
.