Knife
forked
base
Moving
knife
Fig. BCD
Knife
forked
base
Knife h!nged_
screw
/
Moving
knife-
Fig. B(D
Knife
forked
base
Moving
knife
Fig. B(D
18. Adjusting
the
bobbin
thread
presser
If the bobbin thread
presser
(Fig.C
(D ) is penetrating too deep toward the bobbin case at the
trimming time, the bobbin will not rotate and the bobbin thread will be trimmed too short,
causing thread slippage at the start of sewing.
On
the
contrary,
if it is not
inserted
deep
enough,
the
needle
thread
will
slip
out
from
the tip of
the
bobbin
thread
presser
at the
trimming
time,
shortening
the
thread
remaining
amount
at the
tip of the needleeye after the trimmingand invitesthread slippingout.
1) The correct position of the bobbin thread presser
When
the thread trimming lever is pressed hard against the stopper side, the bobbin thread
should
be pulledout
easily.
At this
position,
the
clearance
between
the tip
(Bobbin
presser)
of
the bobbin thread
pre.sser
and the upper carved part of the bobbin should be 1.5~2mm as
shown in Fig,D.
2) How to adjust the bobbin tliread presser
Loosen
the
.screws
(Fig.C
® ), and
adjust
by
moving
the
bobbin
thread
presser
inandout or
up ond down. At this instant, adjust the fore and aft position of the bobbin thread presserand
adjust the positionof the thread
trimming
stopperarmas shownin the
figure.
After
adjusting,
tighten
the set
screw
of thestopper. Besure to
verify
that the tip of the
roller
shaft is not contacting the bottom of the cam
groove
when the stopperisdeeplyinserted. If
it's contacting, refer to the chapter on"Adjustingthe slideshaft" and re-adjust the positionof
the
slide
shaft
collar.
1.5
~2mm
Ea
T
OLO-432-4
-18-
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