Seiko CH-2B User manual
Operating
Instructions
For
CH
Series
CH-2B
CH-2B/DF
CH-6B
CH-7B
CH-8B
CH-2-RF
<f
h
SEIKO
SEWING
MACHINE
CO.,
LTD.
TOKYO
•
JAPAN
From the library of: Superior Sewing Machine & Supply LLC
Specifications
of
CH
Types
Sewing
speed;
Needle
type:
Number
of
needle:
Sewing
type:
Hook:
Bobbin:
Thread:
Feed
system:
Stitch
length:
Presser
foot:
Presser
lift:
Thread
take-up:
Thread
take-up
stroke:
Needle
bar
stroke:
Bed
shape:
Bed
size:
Working
space:
Net
weight
(head
only)
JIS
classifications:
Motor:
Motor
pulley:
V
Belt:
Applications:
Max. 800
s.p.m.
(Max.
sewing
speed
will
be
changed
by
the
models
and
applications.)
DD X 1
#24-25,
standard
#24
(Needle
type
may
differ
from
the
above
types
according
to
the
threads
to
be
used
and
the
materials
being
sewn.)
Single
needle
Lockstitch
Oscillating
large
hook
CH
Type
(240 x30.3
width)
Cotton
or
synthetic
fiber
(SB) Needle,
upper
&
lower
feed,
reverse
feed
(7B)
Needle,
Lower
feed,
reverse
feed
(6B)
Lower
feed,
reverse
feed
(2B)
Upper
&
lower
feed,
reverse
feed
(2B/DF)
Upper
&
lower
feed,
reverse
feed
(Capable
of
intermediate
shirring)
Max.
10mm
(SB) Alternating
foot
(walking
foot
&
presser
foot)
(7B)
Flat
foot
(6B)
Roller
foot
or
flat
foot
(2B) Alternating
foot
(walking
foot
&
presser
foot)
(2B/DF)
-
ditto
-
20mm
by
knee
lifter
(10mm
by
lever)
Cam
type
90.5mm
51mm
Cylinder
bed
(tubular
type
820)
820
X
600mm
200mm
x
400mm
65Kg
LS3
400W.
4P
clutch
motor
6O0(5OHZ)
5O0(6OHZ)
M62
Suitable for
sewing
of
shoes,
bags, satchels, sport-goods,
luggages,
ultra
heavy
materials.
From the library of: Superior Sewing Machine & Supply LLC
Contents
1Lubrication 1
2Needle 1
3Thread 1
4Insertion
and
Removal 2
5 Winding the Bobbin Thread 3
6Upper Threading 3
7Tension of Bobbin Thread and Needle Thread 4
Adjusting Needle Thread Tension 4
Adjusting Bobbin Thread Tension 4
8Pressure of Presser Foot 5
9Adjustmentof Stitch Length 5
10 Timing of Thread Tension Releasing Mechanism 6
11
Removal of Shuttle Race Body 6
12 Adjusting on
the
Each Points 7
(A)
Adjusting Needle Position Against Needle Hole of 7
the
Feed
Dog
{7B & 8B
Types)
(B)
Adjusting of Feed Dog Height 7
(C)
Adjusting theForward and Backward Position of q
Needle
BarFrame
(D)
Timing of Needle and Hook 8
Positioning of
needle
and
tip of
the
hook 9
Adjusting
the
height of needle bar 9
Adjusting
the
position of
the
tip of hook 9
Clearance between needle
and
tip of hook 9
Each timing for up/down strokes of
presser
10
foot
(2B & SB
Types
only)
13
CH-2B/DF
11
a. Use of
the
Differential Feed Mechanism 10
b. Adjusting Upper Feed Length Against Lower Feed 11
Length
14
CH-2-DF
Adfusting
Upper
Feed
Length
11
Adfudting
Lower
Feed
Length 12
Positioning
Upper
Feed
Dog 13
Adjustment
14
Adjusting
Up/Down
Amount
of
Upper
Feed
14
Positioning
presser
Bar
15
From the library of: Superior Sewing Machine & Supply LLC
1
Lubrication
Lubricate all points indicated by arrows in figure.
2
Needle
Turnthe balance wheel over toward you untilthe needle bar reaches its highest point. Loosen
the
needle
clamp
screw
(1).
Hold
and
insert
the
needle
(2)
into
the
needle
bar
hole
up
as
deeply
asit
will
go,
keeping
the
long
groove
ofthe
needle
tothe
left
and
eye
of
the
needle
in
line
with
machine arm directly. Securely tighten it with needle clamp screw
(1).
3
Thread
For
needle
(Upper
thread)
use
left-twisted
thread
only,
and
for
bobbin
(Lower
thread)
use
either
left
or
right
twisted
thread.
To
find
out
thread
twist,
hold
the
thread
as
shown
by
illustgation,
andturnthe thread overtowardyou betweenthe thumb andforefinger of
right
hand,andthen
left-twistedthread
will
wind tighter strands, and right-twistedthread
will
unwind.
1 -
From the library of: Superior Sewing Machine & Supply LLC
4
Insertion
and
Removal
of
Bobbin
§
Removal
of
Bobbin
Open the hook cover and drop-down the needle bar at lowest point, then insert the opener (3)
between the snap spring
(1)
and bobbin case
(2)
and depress the snap spring and pull up the
bobbin
case
outward,
then
take
the
bobbin
out
of
the
bobbin
case.
§
Insertion
of
Bobbin
When inserting, pull
out
the
thread
and
depress
it,
then
insert
the
bobbin (4) in
the
bobbin
case
(5).
Pull
the thread upward passing through the thread slit
(7)
of the bobbin case. Youcan pull
out the thread through the thread passing hole through underneath the tension spring (6).
Make sure
that
the snap spring in the shuttle is clicked after pressing bobbin case into the
shuttle.
2 -
From the library of: Superior Sewing Machine & Supply LLC
5
Winding
the
Bobbin
Thread
Bobbin winding should be made by the following order.
(l)Spool pin—
(2)
Thread guide
(arm)
—
(3)
Needle
thread tension thread guide — passing
through the clearance betweentwo tension discs —(4)
Needle
thread tension thread guide
(5)Bobbin (winding several times) — (6)Move
the
bobbin winding lever.
A
Winding
volume
should
be
adjusted
bythe
screw
(7)
and
positioning
ofthe
moving
lever
(6).
6
Upper
Threading
Upper threading should be made by the following order.
(I)
Spool
pin
—(2)
Thread
guide
ofthread
tension
—(3)
Clearance
of
two
tension
discs
—(4)
thread guideofthreadtension
—(5)
Thread
controller-*^disc
wind
a time—
(6)
Thread
guide
(7)
Tensionspring —
(8)
Thread take-up —(9) Thread guide, face plat —(10) Needlecramp
(II)
Needle
\|1^(1)
- 3 -
From the library of: Superior Sewing Machine & Supply LLC
7
Tension
of
Bobbin
Thread
and
Needle
Thread
(A)
Balanced
tension
(A)
When stitch tension is well balanced, the bobbin thread is engaged with the needle thread
at
the
center of given material thickness, as
shown
by Fig.
(A)
12^
(B)
Tight
needle
of
loose
bobbin
thread
tension
(B) Fig. (B)
shows
unbalanced
tension,
tight
needle
thread
or loose
bobbin
thread.
(C) Loose
needle
or
tight
bobbin
thread
tension
(C)
Fig.
(C)
shows unbalanced tension, loose needle thread or tight bobbin thread.
§Adjusting Needle Thread Tension
nTo adjust tension of needle thread, turn Tension Regulating
Thumb.
By
turning
the
knurling
nut
clockwise,
needle
thread
tension
increases'-^.
By
turning
the
knurling
nut
counter-clockwise,
needle
thread
tension
decreases-*^.
§Adjusting Bobbin Thread Tension
To
adjust
tension
of
the
bobbin
thread,
turn
Tension
Regulating
Screw.
By
loosen
set
screw
(1)
and
adjusting
tension
regulating
screw
(2).
The
set
screw
(1)
should
exactly
be
tightened
after
tension
of
the
bobbin
thread
was
adjusted.
By
turning
the
set
screw
clockwise—^,
bobbin
thread
tension
increases,
and
turning
the
set
screw
counter
clockwise'^,
bobbin
thread
tension
decreases.
- 4
From the library of: Superior Sewing Machine & Supply LLC
8
Pressure
of
Presser
Foot
By
turning
the
pressure
regulating
thumb
screw
clockwise'-^,
pressure
increase,
and
turning
pressure
regulating
thumb
screw
counter-clockwise^^,
pressure
decreases.
Tension
regulating
nut
should
be
tightened
after
pressure
was
adjusted.
Adjustment
should
be
made
to
suit
for
the
materials
being
sewn.
9
Adjustment
of
Stitch
Length
By pull-up t feed regulating lever (1), reverse stitch is performed, and push-down feed I
regulating
lever
(1),
forward
stitch
is
performed.
By
turning
knurling
nut
(2) & (3)
clockwise'^,feed
length
decreases,
and
turning
knurling
nut
(2) & (3)
counter-clockwise<«^,
feed
length
increases.
Knurling
nut
(2) & (3)
should
be
tightened
each
other
after
desired
stitch length
was
determined.
(Note)
When
upward
&
downward
moving
of
the
feed
regulating
lever
is
loosened,
feed
adjustin
screw
(4)
should
be
tightened.
- 5
From the library of: Superior Sewing Machine & Supply LLC
10 Timing of Thread Tension Releasing Mechanism
(a)When moving the lifting lever (1)for knee
lifter,
upper
thread
is adjusted to loosen.
(b)
Adjustment
Pull-up
the
presser
bar
lifter (3),
clearance
should be made over 1 mm between tip of
the
tension releasing plate
and
tension disc,
and
then
tighten
the
screws
(2)
on
the
tension
releasing
plate.
11 Removal of
Shuttle
Race Body
Tighten the shuttle race back spring screw
(1),
then loosen and take offthe two shuttle race
screws (2)and remove
the
shuttle race body and shuttle hook.
(Note)
In
case
of
the
removal of
shuttle
race body,
without tightening of shuttle race back spring
screw
(1),
shuttle
race
back
and
shuttle
race
back
spring
may
run
out
and/or
may
difficult to
set
the
shuttle
race body.
The shuttle race back spring screw (1) is surely
loosened, while the materials are being sewn.
U
From the library of: Superior Sewing Machine & Supply LLC
12
Adjusting
on
the
Each
Points
(A)
Adjusting
Needle
Position
Against
Needle
Hole of
the
Feed
Dog. {7B & 8B
Types)
Needle
should
be
positioned
at
the
center
of
needle
hole
of
feed
dog
and
moved
together
with
the
feed
dog.
(a)
Loosen
feed
(upper)
shaft
connecting
screw
(2),
upper
feed
length
will
differ
by
the
moving
(push-in
or
pull
out)
of
feed
(upper)
shaft
connector
(B) (1).
(b)
Loosen
feed
(upper)
shaft
connector
(A)
screw
(3),
and
needle
set
at
the
center
of
needle
hole
of
feed
dog,
then
tighten
the
screw
(3).
(Needle
dropping
point
is
to
be
set
at
the
center
of
needle
hole
of
the
feed
dog.)
n
(Note)
Feed
(upper)
shaft
connector
(A) (4) is fixed
and
the
screw
(3)
is
tightened
for
the
prevention
of
the
moving
of
leftward
and
rightward.
(B)
Adjusting
of
Feed
Dog
Height
Taking
off
the
needle
in 7B
and
8B.
The
height
of
feed
dog
is
adjusted
1.3mm
-
1.5mm
above
the
surface
of
the
throat
plate,
at
the
lowest
point
of
needle
bar
by
feed
dog
height
adjustable
screw
(1).
In 6B. 2B
types;
The
height
of
feed
dog
is
adjusted
1.3mm
-1.5mm
above
the
surface
of
the
troat
plate
at
the
lowest
point
of
needle
bar.
Refer
to
Removal
of
Shuttle
Race
Body
m
l.Smm
-
1.5nim
- 7
From the library of: Superior Sewing Machine & Supply LLC
(C) Adjusting
the
Forward
and
Backward Position of Needle Bar Frame
Correct position
between
needle
bar
frame
and
presser
bar
is
determined
by
the
distance
between
presser
bar
and
needle
bar
being
16mm
under
the
stitch length being "0"
mm.
(D)
Timing
of
Needle
and
Hook
Adjustment
of
the
clearance
between
presser
bar
and
needle
bar
is
to
be
made
by
the
screws
(1).
Positioning
of
needle
and
tip
of
the
hook
When
the
needle
bar
has
risen
4.5mm
-
5.5mm
from
its
lowest
position,
the
tip
of
the
hook
should
meet
the
center
Line
of
the
needle.
2.5imD~3nn
U
4.5inD~5.5min
Distance
between
the
upper
tip
of
the
needle-eye
and
the
tip
of
the
hook
shall
be
2.5mm
-
3mm.
Adjusting
the
height
of
needle
bar
Loosen
the
screw
of
bar
connecting
stud
(2) by
wrench
which inserts to
the
hole (1) of
arm
and
adjust
the
needle
bar
(3)
(
upward
and
downward.
Adjusting
the
position
of
the
tip
of
hook
Loosen
the
screw
(5) of
the
shaft
crank
by
the
spanner
which
inserts
to
the
hole
(4) of
the
head,
then
determine
the
forwardness
or
backwardness
(high
speed
or
low
speed)
of
the
tip
of
hook.
Tighten
the
screw
(5)
after
adjustment.
- 8
From the library of: Superior Sewing Machine & Supply LLC
©
T
Clearance
between
needle
and
tip
of hook;
0.05mm
-
0.3mm
In 7B & 8B
types;
Determination
of
the
position
of
needle
bar
rock
frame.
Loosen
the
set
screw
(1)
of
the
needle
bar
rock
frame
hinge
stud,
and
the
set
screw
(5)
of
the
needle
bar
rock
frame
hinge
stud
(small) (4)
positioned
lower
part
of
needle
bar
rock
frame
(2),
and
also
the
set
screw
(7)
of
the
needle
bar
rock
frame
hinge
stud
(large) (6).
Then,
moving
the
needle
bar
rock
frame
hinge
stud
(large)
(6)
to
rightward
and
also
moving
the
needle
bar
rock
frame
leftward
&rightward-**,
and
turn
the
balance
wheel,
determines
smooth
position
of
the
needle
bar
and
adjust
the
clearance
between
needle
and
tip
of
the
hook.
After
determination
of
the
clearance,
tighten
the
set
screw
(2) of
the
needle
bar
rock
frame
hinge
stud,
and
then
put
the
needle
bar
rock
frame
hinge
stud
(small)
(4)
to
slightly
the
needle
bar
rock
frame
position
bracket
(8).
And,
put
the
needle
bar
rock
frame
hinge
stud
(large)
(6)
to
the
side
face
of
the
needle
bar
rock
frame
(2),
and
then
turn
the
balance
wheel
and
tighten
the
each
screws
exactly.
If
the
looseness
of
the
leftward
&
rightward-*-^of
the
needle
bar
should
happen,
it will
be
resulted
in
the
breaking
of
needle,
stitch
skipping.
0.05mm
0.3mm
From the library of: Superior Sewing Machine & Supply LLC
Each
timing
for
up/down
strokes
of
presser
foot
(2B & 8B
types
only)
a.
Timing
of walking
foot
is
adjuted
walking
foot
reach
to
feed
dog
before
needle-eye
reaches
to
feed
dog,
after
downing
the
lever
of
presser
bar
lifter,
turning
the
balance
wheel
toward
you.
Adjsutment
is
made
by
the
two
stopper
screws
of
cam
(1) {upward &
downward).
Byup &down the presser cam (upward &downward) fI , walkingfoot against needle is
touching
to
feed
dog
speedily
and
slowly.
As for 2B
type,
adjusting feed
dog
and
presser
foot to
set
equivalent
point on
the
upper
face
of
the
throat
plate.
b.
For
the
setting
walking
foot
and
presser
foot
equivalent,
the
lifting
eccentric
connection
crank
pinch
screw
(2) is to
be
adjusted.
Adjustment
is
to
be
made
by
the
materials
being
sewn.
c. Up/down strokes of walking foot and
presser
foot is loosened by the screw (3)and up f
the
screw
(3),
the
stroke increases,
down
I
the
screw
(3),
the
stroke
decreases.
s
a.
Use
of
the
Differential
Feed
Mechanism
Pull-down
the
chain
(1),
upper
feed
volume
increases
by
maximum
80%
against
lower
feed
volume
Pull-down
the
chain
(1),
upper
feed
length
increases
by
maximum
80%
against
lower
feed
length.
(e.g..
Lower
feed:
10mm,
Upper
feed:
18mm)
Adjusting
Upper
Feed
Length
Turn
the
dial (2) clockwise'-^.,
upper
feed
length
decreases.
Turn
the
dial (2)
counter-clockwise-^,
upper
feed
length
increases.
Fixed
position
of
feed
length
is
adjusted
by
stopper
(3)
and
stopper
nut
(4)
10
From the library of: Superior Sewing Machine & Supply LLC
b. Adjusting Upper Feed Length Against Lower Feed Length
For adjusting equivalent
the
upper feed length against lowerfeed length.
Adjustment
is to be
made
by
the
stopper
screw
(3)
and
stopper
nut
(4).
Turn
the
stopper
screw
(3) clockwise^-'^,
upper
feed length increases.
Turn
the
stopper
screw (3)
counter-clockwiseupper
feed length decreases.
(Note)
Over
turning
of
stopper
screw
(3) &
stopper
nut
(4)
counter-clockwise
will
cause
the
troubles
that
the
top
of
feed
adjusting
lever
touch
with
the
feed
upper
shaft
connector.
CH-2-DF
©Adjusting Upper Feed Length
1.
Coarse
stitch
of
upper
feed
length
can
be
performed
by pull
down
the
lifting
lever
(A),
regardless
of
lower
feed.
r
(A)
nB
11
From the library of: Superior Sewing Machine & Supply LLC
2.
Upper
feed
position
can
be fixed by (B) & (C).
*{C)
position
should
be
set
equivalently
with
lower
feed
length
on
the
condition
that
pin
(D)
comes
in
contact
with
(C).
*The
position
of shirring
amount
for
the
materials
being
sewn
can
be
set
by (B). (Fig. a & b)
Fig. a
large
\
^1
3
1
II
0
Fig.b
small/ Irr
Fig. d
3. Incase of unifying of shirring amount and/or general sewing (equivalent with lower feed),
pin (D)
should
be fixed by
pinching
(B) & (C). (Fig. d)
©Adjusting Lower Feed Length
Loosen
the
feed adjusting nuts
(A)
&
(B)
and
turn them clockwise, feed length decrease and
turn
them
counter-clockwise,
feed
length
increase.
After
adjustment,
the
lever
should
be
pulled
down
exactly,
then
operate
the
machine
on
the
condition
that
nut
(A)
touches
with
plate
(C).
-
12
0
«
Pull
down
Lever
From the library of: Superior Sewing Machine & Supply LLC
©
Adjustment
Loosen
the
set
screw,
adjustment
can
be
made by
change
(turn)
the
screw driver
groove
position (B).
Set
screw
(A)
should
be
tightened
without
any rattle or the leftward & rightward of
the
upper
feed
arm
(C).
©
Adjusting
Up/Down
Amount
of
Upper
Feed
Loosen
nut
(A),
turn
the
adjusting
screw
(8)
^ a
clockwise,
up/down
amount
decrease, turn
it^b
counter-clockwise,
up/down
amount
increase.
After
adjustment,
nut
(A)
should
be
tightened
exactly.
-
14
-
@
Wrong
(K)
More
than
(A)
(B)
From the library of: Superior Sewing Machine & Supply LLC
1,
5mm
u
1.
5inni
15
©Positioning of
Presser
Bar
Clearance
between
upper
feed
arm
(C)
and
presser
bar
guide
should
be
1.5mm.
Lay
<E)
& (F)
on
arm,
clearance
between
(F)
and
(G)
should
be
2mm.
Clearance
(H)
should
be
more
than
3mm.
From the library of: Superior Sewing Machine & Supply LLC
SEIKO
SEWING
MACHINE
CO.,
LTD.
Head Office : 11-3,
Imado
1-chome,
Talto-ku, Tokyo 111,
Japan
Telex:
2657148
SEIKO
J
Cable:
SEIKOSEWMCO
TOKYO
Show
Room
: 21-7,
Asakusa
1-chome,
Taito-ku, Tokyo 111,
Japan
Osaka
Branch
: 5-10,
Terada-cho
2-chome,
Tennoji-ku,
Osaka
543,
Japan
Show
Room
: 5-10,
Terada-cho
2-chome,
TennojI-ku, Osaka 543,
Japan
Tel:
03-3872-6173-4
(Export
Dept.)
Telefax:
03-3873-6596
Tel:
03-3872-6493
Tel:
06-779-7578
Tel:
06-779-7578
96033000
<E)
From the library of: Superior Sewing Machine & Supply LLC
This manual suits for next models
5
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