Brother rh-918a Sewing Machine User Manual


 
9. STANDARD ADJUSTMENTS
RH-981A
55
9. STANDARD ADJUSTMENTS
CAUTION
Maintenance and inspection of the sewing
machine should only be carried out by a
qualified technician.
Ask your Brother dealer or a qualified electrician
to carry out any maintenance and inspection of
the electrical system.
Turn off the power switch and disconnect the
power cord from the wall outlet at the following
times, otherwise the machine may operate if the
start switch is pressed by mistake, which could
result in injury.
When carrying out inspection, adjustment
and maintenance.
When replacing consumable parts such as
the loopers and knife.
Disconnect the air hoses from the air supply and
wait for the needle on the pressure gauge to
drop to "0" before carrying out inspection,
adjustment and repair of any parts which use
the pneumatic equipment.
If the power switch and air need to be left on
when carrying out some adjustment, be
extremely careful to observe all safety
precautions.
If any safety devices have been removed, be
absolutely sure to re-install them to their original
positions and check that they operate correctly
before using the machine.
9-1. Adjusting the height of the spreader and looper
Spreader height
The clearance between the left spreader (forked spreader) and the eye looper must be set to match the thickness of
the lower thread. The clearance between the right spreader and the right looper should be as small as possible while
still letting the parts slide.
1. The right spreader (1) and left spreader (2) move by means of springs (3). Adjust so that the spreaders move
smoothly between the right spreader stopper (4), the left spreader stopper (5) and the LS-holder bracket (6), with
no looseness.
2. If adjustment is necessary, loosen the screw (7) and then move the right spreader stopper (4) or left spreader
stopper (5) up or down.
Looper height
1. Set the clearance between the eye looper (8) and the left spreader (2) to the same distance as the thickness of
the lower (looper) thread.
2. The clearance between the right looper (9) and the right spreader (1) should be as small as possible.
3. If adjustment is necessary, loosen the screw (10) and then move the eye looper (8) and right looper (9) up or down.
3072Q
3071Q
3073Q
3074Q