11. THREAD TENSION ADJUSTMENT(Fig. 12, 13, 14)
Normal
stitch
form
~-+Needle
thread
""~""""""'"'"""'""""'""""'*Bobbin
thread
13
12 Thread tension should
be
determined
in
accordance with the stitches obtained by adjusting
the tension of the bobbin thread
and
needle tension
(Fig.
12).
The tension of the bobbin thread: to
be
adjusted
by turning the tension spring regulating screw of the
bobbin
case.
After adjusting, insert the bobbin into
the bobbin
case
and
hold
the end of the thread from
the bobbin case to
hang
the bobbin
case,
if the
bobbin
case
falls slowly
and
evenly, the proper
tension
of
the
bo
-
bbin
thread is obtained.
14
The tension
of
the needle thread:
to
be
adjusted by turning the thumb nut.
The stroke
of
the thread take
-up
spring runs from 6mm to 1Omm. When sewing very thin fabrics, reduce the thread take -
up
spring tension
and
increase the thread take
-up
spring stroke, whereas increase the thread take
-up
spring tension
and
reduce
the thread take
-up
stroke when sewing very thick fabrics.
Adjusting the thread take
-up
spring tension: (Fig.13)First loosen the set screw
(A),
turn the tension stud(B)counter -clockwise
to decrease the tension
of
the thread take
-up
spring (C)to
zero,
then turn the tension stud (B)clockwise till the spring (C)comes
to the notch
of
the tension regulating bushing,
and
again
turn the tension stud
(B)
halfway back (counter -clockwise) .After the
adjustment, tighten the set screw
(A).
Adjusting the thread take
-up
spring stroke: (Fig.14) 'oosen the set
screw(B),
turn the stud(C) clockwise to increase the
stroke or turn the stud(C) counter
-clockwise
to decrease the stroke. After the adjustment, tighten the set screw
(B).
j12.ADJUST
THE
SYNCHRONILATION
OF
THE
NEEDLE
WITH
ROTATING
HOOK(Fig.15,
16)1
15 16
When lifting the needle
bar
from its lowest position of the stroke to the distance
A,
the hook point D
of
the bobbin should
align with the center line of the needle
and
be
1. 0
-1.
5 mm above the upper end
of
the needle
eye.
(Fig. 15)
The clearence between the bottom
of
the needle notch
and
the hook point should
be
0. 05 mm(Fig. 16).
. Modle 6160 6160H 61608
A
2.2
mm
2.2mm
2.4mm
5
From the library of: Superior Sewing Machine & Supply LLC
