JUKI LK-1900B series Engineer's Manual

– 51 –
Adjustment procedures Results of Improper adjustment
1. Attain the check program 07.
2. Tread on the pedal for needle thread clamp
❸
origin retrieval.
3. Press EDIT key
❽
to set the needle thread clamp
❸
in the
standby position.
4. Drive the needle thread clamp
❸
on a pulse-by-pulse step with
DATA CHANGE key
❼
from its standby position to the
position where A becomes zero (0) (when needle thread clamp
release plate
❹
closes). Then, keep READY key
❷
held
pressed for two seconds.
Numeric value that is displayed on the screen will be "27".
[LK-1900BB, 1903BB, 1900BNB, 1903BNB]
Drive the needle thread clamp
❸
on a pulse-by-pulse step with
DATA CHANGE key
❼
from its standby position to the
position where A becomes zero (0) (when needle thread clamp
release plate
❹
closes). Then, press the "+" key of the data
change key two times. After that, keep READY key
❷
held pressed for two seconds.
Numeric value that is displayed on the screen will be "27". When
numeric value is "25", clearance A between the needle thread
clamp release plate
❹
and the needle thread clamp
❸
becomes
zero (0).
5. Tread on the pedal for needle thread clamp
❸
origin retrieval and
dene it to the most advanced position by pressing EDIT key
❽
once.
6. Conrm that the distances between the needle thread clamp
release plate
❹
and the needle
❺
is 2 ± 0.2mm both A and B.
7. If the distance is found to be inadequate, adjust the position
toward the needle
❺
according to "3.-(35) Needle thread clamp
device connection/disconnection". Since then, perform the above
adjustments again.
(Caution) If the reference position is established at a wrong
position, "E929 Needle thread clamp motor
displacement error" can occur.
In the case a loss-of-synchronism occurs, correctly
adjust the position of the origin not by retrieving
the origin with the check program 07 but setting the
position of the origin of the thread clamp at a position
where out-of-synchronism will not occur by moving
the thread clamp back or forth by several pulses.
[LK-1900BB, 1900BNB]
o
If a clearance A between the
needle thread clamp release
plate
❹
and the needle thread
clamp
❸
is too large, nee-
dle thread at the sewing start
can not be held by the needle
thread clamp
❸
. As a result,
needle thread remaining on
the rear side of the material will
be longer. If that is too small,
needle thread is held in while
pulling up needle thread by the
thread take-up lever. As a result,
a stitch failure at 1st stitch will
occur.
[LK-1903BB, 1903BNB]
o
If a clearance A between the
needle thread clamp release
plate
❹
and the needle thread
clamp
❸
is too large, needle
thread at the sewing start can
not be held by the needle thread
clamp
❸
. As a result, needle
thread of wrong side of material
is entangled. If that is too small,
needle thread is held in while
pulling up needle thread by the
thread take-up lever. As a result,
a stitch failure at the stitch will
occur.

JUKI LK-1900B series Specifications

General

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