Tweco 281 Thermal Arc Fabricator - Manual (Page 46)

FABRICATOR 281
4-8 April 10, 2006
SPOT:
This mode of welding is used to weld two plates
together at a desired location by melting the top &
bottom plates together to form a nugget between
them. The spot time period is set by the Weld (Spot/
Stitch) control knob located in the electrode wire
compartment.
WELD MODE WELD MODE
2T 2T
SPOT SPOT STITCH STITCH
4T 4T
A
rt # A-07427
Figure 4-6: Spot Weld
NOTE
A spot nozzle should be used on the MIG gun
to obtain consistent spot welds.
STITCH:
This mode of welding is used to weld two or more
components together with a stitch weld. The WELD
(Spot/Stitch) shaft controls the welding or ‘ON’ time
and the "DWELL (Stitch)" shaft controls the interval
or ‘OFF’ time for stitch welding.
Art # A-07428
Figure 4-7: Stitch Welding
4T (Latch):
This mode of welding is mainly used for long weld
runs, as the operator need only press the trigger to
activate the weld, then press the trigger again to stop.
This replaces the need for the operator to depress
and hold the trigger for the complete length of the
weld run.
WELD (Spot/Stitch)
MIN MIN 4
1 3
2
WELD WELD
(SPOT / STITCH) (SPOT / STITCH)
t A
rt # A-07429
Figure 4-8: Weld (Spot/Stitch) Control
WELD MODE - SPOT
When the Weld Mode control is in the Spot position,
the Weld (Spot/Stitch) knob controls the duration of
a single spot weld.
WELD MODE - STITCH
When the Weld Mode control is in the Stitch position,
the Weld (Spot/Stitch) knob controls the length of
the stitch weld.
Dwell Stitch
4
(STITCH)
(STITCH)
1 3
2
t
MIN MIN
DWELL DWELL
A
rt # A-07430
Figure 4-9: Dwell (Stitch) Control
DWELL (STITCH) CONTROL KNOB
When the Weld Mode control is in the Stitch position, the
Dwell (Stitch) knob controls the length of the non-weld
portion of stitch welding.
Burnback Control
BURNBACK BURNBACK
A
rt # A-07431
Figure 4-10: Burnback Control
Burnback time is the difference between the wirefeed
motor stopping and the welding current ceasing. The
Burnback time allows the electrode wire to burn out
of the molten metal weld pool. The Burnback time is
factory set for optimum performance. Burnback time
is adjusted by the knob of the potentiometer.
Clockwise adjustment increases Burnback time.