Tweco 251 Thermal Arc Fabricator - Manual (Page 31)

FABRICATOR 251
Manual No. 0-4847 3-9 INSTALLATION
3.09 Input And Output Wire Guide
Installation
Refer to Figure 3-7.
Install the input wire guide (the longer one) by loosening
the input guide lockscrew and inserting the guide into
the hole in the feedhead assembly. The recessed end of
the guide should be toward the wire spool. Adjust the
guide so that it is clear of the feed rolls and tighten the
input guide lockscrew.
Install the output wire guide in the same manner, with
the conical end toward the feed rolls. The tip of the coni-
cal end should be as close to the feed rolls as practical.
Tighten the output guide lockscrew.
NOTE
Before tightening the input and output guide
lockscrews, install the drive roll to help in the
alignment of the wire guides.
Output Wire Guide
Input Guide Lockscrew
Input Wire Guide
Output Guide Lockscrew
Art # A-07445
Figure 3-7: Wire Guide Installation
3.10 Selection and Installation of
Feedrolls
A Feedroll consists of two different sized grooves. As
delivered from the factory the drive roll is installed for
.035” / .045” .
The stamped marking on the feedroll refers to the groove
furthest from the stamped marking. When mounted, that
will be the groove closest to the motor and the one to
thread.
To ensure proper wire feed, the groove closest to the
motor must match the electrode wire size being used.
.045” (1.2mm) Groove
Art: A-07150
The size that is visible when
fitting the feedroll is the groove
size in use.
.045
1.2
.045” (1.2mm) Stamping
Figure 3-8: Feedroll Example
NOTE
All grooved feed rolls have their wire size or
range stamped on the side of the roll. On rolls
with different size grooves, the outer (visible
when installed) stamped wire size indicates
the groove in use.
Refer to feed roll kit #375980 in the Appendix for the
proper selection and ordering of feed roll kits. Kit includes
drive rolls, an input wire guide and an output wire guide
for a specific wire type and size.
Feed rolls are removed by twisting the feed roll retainer
cap and aligning the retaining knob splines/tabs with the
drive gear splines. Feedrolls are installed by putting the
feedroll onto the drive gear splines and twisting the
feedroll retainer cap so that the splines/tabs rest against
the face of the feedroll where they will click into place.
NOTE
Installation of all styles of feed rolls for the
Fabricator 251 are identical.
WARNING
The welding wire is electrically Hot if it is fed
by depressing gun switch. Electrode contact
to work piece will cause an arc with gun switch
depressed.