Tweco 251 Thermal Arc Fabricator - Manual (Page 51)

FABRICATOR 251
Manual No. 0-4847 4-13 OPERATION
4.08 Stitch Welding Operation
Welding consumable costs can be reduced by replacing a continuous weld bead with the Stitch weld bead. It will
also reduce heat distortion in thin plate.
Coarse & Fine Voltage Selector Switches and Wire Speed Control
Set these controls to obtain the desired welding conditions for the wire and material being welded.
Mode Selector Switch
Set the WELD MODE switch to STITCH.
WELD (Spot/Stitch) Time
Adjust the WELD (Spot/Stitch)control knob for the desired weld or ‘ON’ time while stitch welding.
Dwell Time
Adjust the DWELL (Stitch) control knob for the desired interval or ‘OFF’ time while stitch welding.
SPOT WELDING NOZZLES
TYPE NO.4 400 AMP
24A-62-FAS
1240-1520 (5/8"
Bore)
24A-75-FAS
1240-1530 (3/4"
Bore) Flat Arc Spot
24A-100-FAS
1240-1550
(1" Bore)
Inside Corner Arc Spot 24A-75-IAS
1240-1531
(3/4” Bore)
Outside Corner Arc Spot 24A-75-IAS
1240-1532
(3/4” Bore)
Automotive Stud Nozzle N/A
4.09 Spot Welding Operation
Fit an optional spot welding nozzle to the MIG gun
for consistent spot welding operations. Refer to the
Spot Welding Nozzle table. The Fabricator 251 will
operate effectively using .030” (0.8mm) electrode
wire when spot welding. Penetration depth is limited
when using .024”(0.6mm) electrode wire for spot
welding. Set the controls as follows for spot welding:
Coarse & Fine Voltage Selector Switches and
Wirespeed Control
Select higher Voltage Selector switch positions and
set the Wirespeed Control between 354 to 590 ipm
(9 to 15 m/min) for maximum penetration.
Mode Selector Switch
Set the WELD MODE switch to SPOT.
Spot Time
Adjust the WELD (Spot/Stitch) control knob for the
desired weld or ‘ON’ time for spot welding.
Dwell Time
The DWELL (Stitch) control knob has no affect in
this mode of operation.