JUKI MF-7800D Series Engineer's Manual page 13

Adjustment Procedure
1. Length of the rocking thread take-up
(1) Loosen screws and move rocking thread take-up
or left to adjust the length.
2. Position of the rocking thread take-up
(1) Loosen screw and move rocking thread take-up
to adjust the position.
(Caution) When adjusting the position of rocking thread take-up
, fix the rocking thread take-up with setscrew
the rocking thread take-up so that spreader thread take-
up and spreader thread guide
contact with each other.
3. To adjust the timing of the rocking thread take-up
top cover, loosen setscrew
and move the position of rocking thread take-up ball arm
fro.
(1) Standard adjustment figure is the position where the rear end (anti-
operator's side) of rocking thread take-up ball arm
engraved marker line
standard at this time, note that the clearance provided between the
rear end of rocking thread take-up ball arm
4 mm.)
(Caution) 1. When loosening screw
ball arm
up rotates by its weight. After the adjustment, be
sure to check the rocking position (flush at the lowest
position) of rocking thread take-up
2. When moving rocking thread take-up ball arm
the operator's side, adjust rocking thread take-up ball
arm within the range where it does not come in
contact with rocking thread take-up bushing
(operator's side).
4. Relation between timing of rocking thread take-up and needle thread loop
When needle bar thread take-up is used
When needle bar thread take-up is not used
Adjusting procedure is the same as step 3. Loosen setscrew
adjust the position of rocking thread take-up ball arm
(Caution) Adjust the timing of rocking thread take-up
or conditions.
in the rocking thread take-up ball arm
on rocking thread take-up shaft
in rocking thread take-up
, there is a case where rocking thread take-
(Move to operator's side.)
to the right
up or down
in
do not come in
, remove the
to and
aligns with
. (As the
and thrust collar is
.
to
Delay timing
Loop becomes small.
Loop becomes large.
in rocking thread take-up ball arm
.
each time in accordance with thread used
– 9 –
Results of Improper Adjustment
o When length of rocking thread
take-up is lengthened, needle
thread is tightened.
(Caution) W h e n l e n g t h e n i n g
rocking thread take-up
, check whether it
comes in contact with
t h e t h r e a d t a k e - u p
cover.
o When length of rocking thread
take-up is shortened, needle
thread is loosened.
o When installing position of
rocking thread take-up
raised, needle thread is loosened
when the needle bar thread take-
up is used, and needle thread is
tightened when the needle bar
thread take-up is not used.
Advance timing
(Move to anti-operator's side.)
Loop becomes large.
Loop becomes small.
is
and