Troubles And Corrective Measures - JUKI MB-1373 Instruction Manual

5. trouBLES aND corrEctIVE MEaSurES

TROUBLES
1. Thread breakage 1 The yoke slde does not move n the correct
2 The tenson lever has been mproperly
3 The thread tenson post No. 2 fals to release
4 Lftng amount of the button clamp jaw unt s
5 The thread npper catches the thread.
6 The needle does not enter the center of the
7 The needle s too thck for the dameter of the
2. The machne forms a 1 The thread pull-off lever has been mproperly
seam after t has run for a
whle nstead of formng t
2 Tenson of the thread tenson gude on the
from the start of sewng.
3. Buttons are not sewn 1 The yoke slde does not move n the correct
tghtly
2 The thread tenson post No. 2 fals to release
3 The thread tenson post No. 2 does not gve
4 The needle does not enter the center of the
5 The work pressng force s too hgh or too low. ™ Adjust the work pressng force properly.
4. The last back-tack sttch 1 The tenson lever has been mproperly
s poorly tensed.
2 Tmng of the knot-tyng plate s ncorrect.
3 The npper has been mproperly adjusted.
5. The first stitch trails The thread pull-off lever does not work properly.
relatvely long thread
from the rght sde of the
button.
6. Thread trmmng falure 1 The thread tenson post No. 2 fals to release
n the state of stop-
moton
2 The needle hts the edge of the holes n the
3 The thread npper fals to press the thread.
4 The work pressng force s too hgh.
7. Thread trmmng falure 1 The movng knfe does not separate the
2 The needle does not enter the center of the
3 The last sttch skps.
4 The movng knfe thread separaton nal s too
8. The needle thread s 1 The movng knfe s set n wrong place.
cut n two places on the
wrong sde of the fabrc.
2 The movng knfe thread separaton nal s too
9. Button trals too long 1 Tmng of the movng knfe moton s wrong.
thread after thread
trmmng.
2 Lftng amount of the button clamp jaw unt s
10. Length of thread 1 Poston of the movng knfe s not correct.
remanng, after thread
trmmng, on the wrong
2 Lftng amount of the button clamp jaw unt s
sde of the materal
vares.
CAUSES
way.
adjusted.
the thread at correct tmng.
excessve.
The npper has been mproperly adjusted.
(The clearance s too small.)
holes n the button.
hole n the button.
adjusted.
face plate s excessve.
way.
the thread at correct tmng.
sufficient tension.
holes n the button.
adjusted.
(The clearance s too large.)
the thread at correct tmng.
button.
thread on the fabrc wth ts separaton nal.
holes n the button.
hgh or too low.
hgh or too low.
excessve.
excessve.
– 16 –
CORRECTIVE MEASURES
™ Adjust the tmng of forward, backward and
sdeways of the yoke slde.
™ Properly adjust the tenson lever.
™ Make the thread release tmng slghtly earler.
™ Adjust the lftng amount of the button clamp jaw
lever to 8 mm.
™ Adjust the poston of the npper bar block.
™ Adjust the button clamp jaw lever holder.
™ Replace the needle by a thnner one.
™ Adjust the thread tenson gude on the face plate
so that t provdes a lower tenson.
™ Properly adjust the tenson lever.
™ Adjust the tmng of the moton of the yoke slde at
each end.
™ Make the thread release tmng slghtly later.
™ Tghten the tenson nut of tenson post No. 2.
™ Adjust the button clamp jaw lever holder.
™ Properly adjust the tenson lever.
™ Advance the tmng of the knot-tyng plate.
(Adjustment of the knot-tyng notch)
™ Adjust the npper wth the npper bar block.
™ Adjust the thread pull-off lever by the npper bar
block (rear).
™ Make the thread release tmng slghtly later to
gve more tenson to the sttches.
™ Adjust the button clamp jaw lever holder.
™ Adjust the npper bar block.
™ Adjust the work pressng force by the pressure
adjustng nut.
™ Adjust the poston of the movng knfe.
™ Adjust the button clamp jaw lever holders.
™ Adjust the looper.
™ Adjust the heght of the movng knfe thread
separaton nal.
™ Adjust the poston of the movng knfe when the
machne s n the stop-moton state.
™ Adjust the heght of the thread separaton nal.
™ Adjust the poston of the movng knfe.
when the machne s n the stop-moton state.
™ Adjust the lftng amount of the button clamp jaw
lever to 8 mm.
™ Adjust the poston of the movng knfe when the
machne completes stop-moton. (10 to 11 mm)
™ Adjust the lftng amount of the button clamp jaw
lever to 8 mm.