JUKI MEB-3200 Engineer's Manual page 47

Adjustment Procedures
1) Initial position of the lower knife
1. When stopper screw B 2 is slightly loosened, it can be slided
to the left or right since there is nut 4 in the slot on the rear of
the presser plate and stopper screw B 2 is screwed in the nut.
2. Loosen stopper screw B 2 and move stopper screw B 2 to
the left or right so that the knife comes in contact with stopper
screw B 2 when the blade section of lower knife 1 aligns with
the edge of holding plate, right 3. Then tighten the screw.
2) Adjusting the stroke of the upper knife
1. At this time, loosen clamping screw 8 in looper thread trimming
driving arm 6 and adjust so that looper thread trimming driving
arm 6 comes in contact with stopper screw 7.
2. Move looper thread trimming driving arm 6 on the rear of the
presser plate in the direction of arrow mark A so that the length
of engagement at the top end of the knife is 1 to 2 mm.
(Caution) When tightening clamping screw 8, perform the
work while slightly pressing driving link 9 so that the
vertical (thrust) play does not occur at looper thread
trimming driving arm 6.
Results of Improper Adjustment
™ If the lower knife comes out from
holding plate, right, the throat
plate interferes with the lower
knife during sewing and the
blade section of the knife is
damaged. As a result, thread
trimming failure or defrective
feed will occur.
In addition, the presser pressure
is excessively applied to the
lower knife when the presser
comes down. As a result, knife
breakage will occur.
™ If the lower knife is put back from
the holding plate, right, the
pressing range of the material
w i t h t h e p r e s s e r f o o t i s
d e c r e a s e d . A s a r e s u l t ,
defective pressing will occur.
™ If the length of engagement is
excessive, knife return failure
will occur. In addition, when
setting the presser plate, the
roller of lower thread trimming
arm cannot be entered in the
click section of the lower thread
trimming cylinder.
™ If the length of engagement is
insufficient, thread trimming
failure will occur.
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