JUKI MB-1373 Engineer's Manual page 11

Adjustment Procedure
1. Amount of lift of the button clamp
(1) The knife moves in accordance with the lifting of the button
clamp. Therefore, the length of the remaining thread on the
wrong side of a fabric depends upon the height of the button
clamp at which the thread is trimmed.
(2) When the machine is in stop-motion status and when the stop-
motion hook comes in contact with the stop-motion disc,
standard clearance
face of button clamp jaw lever
is 8.5 to 9.5 mm.
(3) To adjust the height of the button clamp unit, loosen screw
in the button clamp lifting hook and move button clamp lifting
hook up or down.
2. Button clamp pressure
(1) The standard work pressure force is obtained when a clearance
of 28.5 to 29.5 mm is provided between the top end of nut
and the bottom end of pressure adjusting bar
adjust the clearance to the aforementioned value.
Adjustment Procedure
1. Adjust so that tension disc
motion by moving thread tension releasing lever
2. If thread tension releasing lever
disc may remain floating during sewing.
between the back side of the bottom
A
and the top face feed plate
floats by 1 mm at the time of stop-
is not correctly positioned, the
– 7 –
Results of Improper Adjustment
o Increasing the lifting amount of the
button clamp will increase the
length of the remaining thread.
o If the height of the button clamp is
too low, the remaining length of the
thread will be shorter.
o If the pressure of the button clamp
is too low, the thread end at the
start of sewing will come out on
. Turn nut to
the wrong side of the fabric
unevenly by 10 to 20 mm.
Results of Improper Adjustment
o If the floating amount is too high,
laterally. the thread tension disc keeps
floating during sewing operation,
resulting in insufficient button
stitching.
o If the floating amount is too low,
the thread length at the start of
s e w i n g w i l l b e c o m e s h o r t ,
resulting in thread slip-off.