JUKI DDL-9000C-S Series Engineer's Manual page 73

Adjustment Procedure
4) Adjusting the knife unit
1. For checking the knife unit
1. Check to make sure that the power switch is in the OFF state.
Remove the gauge (presser foot, throat plate and feed dog) from
around the needle.
2. In the standby state of loop spreading knife ❶, the distance from
center of needle A to the tip of loop spreading knife ❶ is 5.5 to 6.5
mm. (H type: 5.0 to 6.0 mm)(Refer to Fig.1)
3. The purpose of adjustment of the aligning position of loop spread-
ing knife ❶ and thread trimming knife ❷ (far end of the hole in
loop spreading knife ❶ and the tip of thread trimming knife ❷) is
to align the aforementioned aligning position with center of needle
A. (Refer to Fig.2)
4. The amount of engagement between loop spreading knife ❶ and
thread trimming knife ❷ is 2.5 to 3 mm as measured from center
of needle A. (Refer to Fig.3)
Results of Improper Adjustment
◦ Be aware that, if the distance be-
tween loop spreading knife ❶ and
center of needle A is reduced,
thread loop is likely to interfere with
loop spreading knife ❶.
* Refer to "3.-(9)-4)-2. Adjustment of
the knife unit" for how to adjust it.
◦ Be aware that, if the aligning posi-
tion of the loop spreading knife and
the thread trimming knife does not
align with center of needle A, the
length of thread remaining on the
material after thread trimming will
be longer.
◦ Be aware that, if the amount of
engagement between them is insuf-
ficient, faulty thread trimming can
occur.
Refer to "3.-(9)-4)-2. Adjustment of
the knife unit" for how to adjust it.
◦ The needle thread may be trimmed
excessively short in the case thread
such as filament thread which is
likely to cause unstable thread
loop formation is used or thread
trimming is carried out at a posi-
tion where there is no material. If
the aforementioned phenomenon
occurs, it should be corrected by
carrying out the below-stated pro-
cedure.
1. Make the thread take-up spring
2. Make the pitch for thread trim-
3. Turn OFF the condensation
– 57 –
stroke larger than the standard
value.
ming during condensation stitch
larger than the standard pitch.
stitch operation when carrying
out thread trimming at a position
where there is no material.