JUKI LH-4128-7 Engineer's Manual page 29

1) Lubrication system
Prior to operating the sewing machine, insert a circulation tube in the
circulation filter of the bottom cover (Asm.).
1. Remove oil hole cap
No. 1 using the oiler supplied with the machine.
2. Feed the lubricant so that the tip of the oil amount indicating rod
comes in between the upper and lower engraved marker lines of the
oil amount indicating window
In this case, note that excessive oil supplement will result in oil leak-
age from the air hole of the oil tank or failure in normal lubrication.
3. When you operate the sewing machine, refill oil if the top end of oil
amount indicating rod
line of oil amount indicating window
(Caution) 1. When you use anew sewing machine or a sewing
machine after an extended period of disuse, use the
sewing machine after performing break-in at 3,000 rpm
or less.
2. For the oil for hook lubrication, purchase JUKI New
Defrix Oil No. 1 (Part No. : MDFRX1600C0).
3. Remove the drain screw
the oil collected in the bottom cover.
4. When tightening the drain screw
more after the rubber washer begins to collapse. Too
much tightening may result in breakage of the rubber
washer.
2) How to clean the filter section
Plunger filter 1 and Plunger filter 2
1. Loosen the setscrew
from the bed.
2. Loosen the pipe stopper
3. Recover the initial state after the removal of dust attached to the net
area of the joint .
4. For the urethane filter
chips, cloth, and dust from these filters.
(Caution) Periodically (approximately once every three months),
clean the filter sections
Exercise due care not to clog the plunger filter 2
ure to observe this may impair the lubricating function
resulting in burning the hook.
3) Hook oil amount
The amount of oil can be adjusted with the oil amount adjusting screw
that is mounted on the hook shaft base. The amount of oil is increased
when the oil amount adjusting screw
decreased when it is turned counterclockwise. The amount of oil is
measured in five seconds.
(Caution) 1. Height of the oil amount adjusting screw
adjusted to a standard of approximately 22mm.
2. Be careful not to let the oil trace removal paper en-
tangled around the hook.
Adjustment Procedure
and fill the oil tank with JUKI New Defrix Oil
.
comes down to the lower engraved marker
.
and periodically discard
of the lubrication tube holder
to take out the tube
and the circulation filter
, ,
is turned clockwise, and is
, turn it by 0.5 turns
for removal
and the joint .
, remove thread
and (four places).
. Fail-
shall be
– 25 –
Results of Improper Adjustment
o If the amount of oil in the hook is
insufficient, poorly-tensed seam
will result.
Furthermore, the hook will
become hot causing seizure.
o If the amount of oil in the hook is
excessive, the thread will be
stained with oil. The material will
also be stained with oil.