Thermal Arc 281 FABRICATOR, Service Manual

Page: 44 / 108

FABRICATOR 281
OPERATION 4-8 Manual No. 0-4880B
SPOT:
his 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) timer control located in the electrode wire
compartment.
WELD MODE
2T
SPOT STITCH
4T
Art # A-07427_AB
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) timer 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)
Art # A-07429_AB
WELD
(SPOT / STITCH)
t
MIN
1
5
7
9
3
2
4
6
8
Figure 4-8: Weld (Spot/Stitch) Control
WELD MODE - SPOT
When the Weld Mode control is in the Spot
position, the Weld (Spot/Stitch) timer 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
Art # A-07430_AB
(STITCH)
DWELL
t
MIN
5
7
12
3
2
4
6
8
9
10
11
Figure 4-9: Dwell (Stitch) Timer Control
DWELL (STITCH) TIMER CONTROL
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
Art # A-07431_AB
t
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.