JUKI MF-7900 Series Engineer's Manual page 29

Adjustment procedures
Loosen setscrews ❹ in spreader thread guide ❷ and adjust
1.
the position of spreader thread guide ❷ . (Spreader thread
take-up ❶ is fixed to rocking thread take-up ❺ and can not be
adjusted in the height direction.)
2. After the adjustment, turn the sewing machine by hand and
check whether spreader thread take-up ❶ comes in contact
with spreader thread guide ❷ , or section A of clearance is too
small.
3. Adjusting procedure of the clearance
(1) Loosen setscrews ❹ in spreader thread guide ❷ and adjust
in the lateral direction, or loosen setscrews ❸ in the rocking
thread take-up and move spreader thread take-up ❶ to the
right or left to adjust the clearance.
(Caution) When loosening setscrews ❸ in the rocking thread
take-up and adjusting the position of spreader thread
take-up ❶ , adjust so that length of rocking thread
take-up ❺ (83 mm) does not change.
Results of Improper adjustment
◦ When the relation of position
between spreader thread take-
up ❶ and the spreader thread
guide ❷ is not proper, sewing
troubles such as stitch skipping
and the like will be caused.
◦ If thread is less stretched and
slackness of thread occurs at
the thread take-up section when
spreader thread take-up ❶ is in
its highest position, the spreader
fails to pick up thread and stitch
skipping occurs.
◦ If stretch or feeding of thread is
excessive when spreader thread
take-up ❶ is in its highest posi-
tion, not only thread on the seam
side is drawn and needle thread
can not be tightened, but also
needle bend or needle breakage
will be caused.
◦ If stretch or feeding of thread is
excessive when spreader thread
take-up ❶ is in its lowest po-
sition, thread slacks when the
spreader moves from left to right
and stitch skipping occurs.
– 15 –