JUKI LK-1900B series Engineer's Manual

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Adjustment procedures Results of Improper adjustment
After thread cutting, the wiper spring
❶
is used to hold the needle
thread with the aid of the wiper
❷
.Adjustthewiperspring
❶
and
xitwiththesetscrew
❸
sothattheintensityofthespringforcebe-
comes 20 to 30g (somewhat stronger than that of the bobbin thread
that is protruded from the bobbin case).
1. Remove the setscrew
❸
and take out the wiper spring
❶
from
the wiper
❷
.
2.Adjustthewiperspring
❶
and mount it on the wiper
❷
againby
means of the screw
❸
.
(Caution) 1. If the holding force is too strong, the thread may
be protruded above the button.
2. If the holding force is insufcient, needle thread
castoff may occur.
3. If the wiper spring
❶
position is inadequate, the
needle thread cannot be held correctly and this
can be a cause of needle breakage.
Adjustment procedures Results of Improper adjustment
1. Loosen the two setscrews
❷
and four setscrews
❹
oftheYfeed
motor
❶
and the two setscrews
❹
oftheXfeedmotormounting
plate
❺
.
2. Pressing it in the direction of the arrow
C
, tighten the two upper
setscrews
❷
intherstplace.Then,tightenthetworemaining
setscrews
❹
and another two setscrews
❹
,Xfeedmotormount-
ing plate
❺
.
3. Loosen the four setscrews
❼
oftheXfeedmotor
❻
. Pressing it
in the direction of the arrow
B
, tighten the setscrew
❼
.
o
If the pressing force is insuf-
cient,feedgearbacklash
becomes too much and nee-
dlelocationaccuracymaybe
decreased.Thiscanalsobe
a cause of feed error, needle
breakage, etc.

JUKI LK-1900B series Specifications

General

Brand	JUKI
Model	LK-1900B series
Category	Sewing Machine
Language	English