MSK-8900M/H high speed straight lockstitch
sewing machine adopts single needle, needle bearing
link to take up thread, small hook to catch loop
which forms lockstitch seam. It features high precise
bevelgear for driving upper and lower shafts, dial
stitch length regulator, lever type forward and reverse
feed mechanism, full automatic lubricating system
assures reliable lubrication.
With the features of reasonable design, beautiful
apperance, precisely manufacture, little vibration
and lower noise, it s a good machine for the makers
of garments, suitcase, leather goods, shoes and caps,
etc.
3. Main parts name (Fig. 1)
Needle bar
Thread take-up lever cover
Oil window
Hand wheel
Stitch dial
Feed lever
Pressure adjusting screw
Bobbin winder
Belt guard
ModelModel
Applications
Max. Sewing speed
Max. Stitch length
Needle bar stroke
Presser foot lift
height
Height of feed dog
Needle
Hook
Lubrication
Motor power
23
7
1
MSK-8900MMSK-8900MMSK-8900HMSK-8900H
Medium - and
heavy - weight
materials
4200.s.p.m.
4.2mm 5mm
31mm
6mm by hand
13mm by knee
0.8mm 1.2mm
DB 1 14#
Small auto - lubricating hook
Automatic lubrication
370W
3
4
2
1
Heavy - weight
materials
3500.s.p.m.
35mm
DB 1 21#
4
5
6
1
11
4. The method of installation
1. Installing the oil pan (Fig. 2)
(1) Put the vibration-proof pad (black) and
(double color) under the four corners of oil pan ;
8
9
2a2a
Page 5
2b2b
(2) Put the oil pan into the cutouts of table
fix it by nails ;
(3) put the machine casting hinge cushion into
the cutouts of table and fix it by nails .
and
33
2. Installing the machine head (Fig. 3)
(1) Insert the knee lifting rod ;
(2) Insert the casting hinge to the hole in the
bed;
(3) Put the hinge in the cushion and put the
head on the pad ;
(4) Inset the machine head supporter in the table.
Notice:
Be sure to full inset the supporter in the table
Otherwise it may cause danger while put the
machine head down.
Page 6
3. Installing the knee lifter (Fig. 4)
Install the knee lifter on the knee lifter hinge
shaft and fix it by screw .
44
4. Adjusting the knee lifter mechanism (Fig. 5)
(1) Lay down the presser foot lifting bar to
lower the presser foot ;
(2) Loosen the nut ;
(3) Press the knee lifter plate cover to make
movement amount of the knee lifter positioning
bracket about 2mm, then adjust the screw ;
(4) After adjustment, tighten the nut .
(5) Loosen the nut ;
(6) Adjust screw to make its length above the
bracket 8mm;
(7) Adjust screw , the clearance between presser
foot and needle plate should be less than 13mm when
the knee lifter is pressed to its maximum position;
(8) After adjustment, tighten the nut .
5. Installing the V-belt (Fig. 6)
(1) Lower the machine head and install the belt
on the hand wheel and motor pulley;
(2) Press the belt by forefinger with the power
of 4.9N (500gf), adjust the nut to make the belt
a slack of 10~14mm.
55
66
Page 7
77
(1) The optimum tilt angle of pedal A against floor
is approx.20 ~30.
(2) Adjust the clutch of motor E to make the rod B
6. Connecting pedal with lever of clutch motor (Fig.7)
G
F
E
D
C
B
A
10~1210~12
¡«¡«
and the clutch lever C run in one line.
(3) When runing, the machine balance wheel G
should rotate counter - clockwise observed form
opposite side of the balance wheel, the motor D
rotates in the same direction. The rotation of motor
can be reversed by reversing the plug of power ( turn
over 180)
(4) Adjust the tension of V-belt F by moving the
motor upward or downward. The proper tension of
V-belt is a slack of 10~12mm when the V-belt is
depressed by forefinger.
88
9a9a
7. Installing the bobbin winder (Fig.8)
(1) Press the winding controlling lever to its
utmost position;
(2) Install the winder parallel with the belt hole in
the table, be sure that the belt
can be pressed to
5mm by winder pulley ;
(3) Fix the winder by two wooden screw ;
(4) When the lever
restores its original position,
be sure that the clearance between winder pulley
and belt is 8mm.
8. Installing the belt guard (Fig.9)
(1) Install the three screws on the machine
casting, please don't tighten the screws too tight.
-b
-a
-c
Page 8
(2) Lay down the machine head and install the belt
guard in the screw bar and screw , tighen the
e
scr w -a.
(3) Raise the machine head and tighten the screw .
(4) Aim the gib of upper belt guard to the screw
-b, and cover the hand wheel by upper belt guard .
(5) Fix the upper belt guard by screw -b, -c
and .
(6) Install the lower belt guard and there should be
a overlap of 23mm with belt guard , tighten the two
screw .
(7) Insert the plate between belt guard and .
(8) Move the plate along the groove of belt guard
as far possible.
(9) Be sure that there should be not any clearance
between belt guard and plate .
(10) Tighten the two screws (refer to step ).
9b9b
-b
-c
9. Oiling
(1) Please pull out the power plug to avoid hurting;
(2) lay down the machine head and fill the oil in the
oil pan till to the mark of HIGH
Notice:
Please use sewing oil 18#
Please replenish the oil when the level of oil
approaches to the mark of LOW
5. Preparation before sewing
1. Installing the needle (Fig. 11)
(1) Turn the hand wheel to lift the needle bar to
its highest position;
(2) Loosen the needle set screw ;
(3) Make the needle groove to the left side of the
operator, then fully insert the needle shank until to
the bottom of the needle bar socket, tighten the set
screw .
1010
1111
FrontalFrontal
Long grooveLong groove
Page 9
1212
2. Uninstalling the bobbin case (Fig. 12)
(1) Turn the hand wheel to lift the needle above
the needl plate;
(2) Open the opener and uninstall the bobbin
case;
(3) Release the opener and uninstall the bobbin
1313
1414
3. Winding the bobbin thread (Fig. 13)
(1) Turn the power on;
(2) Install bobbin to bobbin winder shaft ,
push the lever down to the utmost position;
(3) Wind the thread several circles on the bobbin
(4) When the machine running, the bobbin will
be wound;
(5) After winding, the lever will be released
automatically, then uninstall the bobbin.
If the thread is wound unevenly. Loosen the
screw and move the bracket to the side which
the thread is little wound.
The winding amount can be adjusted by
screw
Increase the amount tighten
Decrease the amount loosen
Please be sure the optimum capacity of thread is
filled about 80% of bobbin outside diameter
4. Install the bobbin case (Fig. 14)
(1) Put the bobbin into the bobbin case as Fig 14
shown;
(2) Draw the bobbin thread through the slit and
pass it under the lace spring plate l
(3) Draw the bobbin thread out of the slit at the
top of lace spring plate;
(4) Draw the thread and confirm if the bobbin can
turn;
(5) Hold the opener and put the bobbin case in
the hook.
Page 10
5. Threading the needle thread (Fig. 15)
Turn the hand wheel to lift the thread take-up lever to its highest position.
1515
About 50mm
6. Adjusting the stitch length (Fig. 16)
(1) Turn the stitch dial to make the pin aim
at the number on the stitch dial.
The more big the number becomes, the more
long the stitch length is.
Please put the feed lever at the medium
position, then the dial can been turned easily.
55
1616
6. Sewing
1. Sewing method
(1) Turn the switch on;
(2) The sewing begins after step the pedal
Page 11
1717
2. Reverse sewing (Fig.17)
When sewing, press down the feed lever to
perform reverse sewing, release the lever, the
forward sewing is resumed.
Weaken
strengthen
Bobbin thread
Strengthen
WeakenWeaken
1818
7. Adjusting the tension of thread
1. Adjust the tension of thread (Fig. 18)
(1) Adjust the tension of needle thread
Lower the presser foot and adjust the nut as
shown in the Fig 18 (left)
(2) Adjust the tension of bobbin thread
Hold the tip of bobbin thread, the proper tension is
that the bobbin case can drops slowly, Adjust the
screw as shown in the Fig.
Weakenstrengthen
1919
2. Adjust the pressure of presser foot (Fig. 19)
(1) Loosen the nut
(2) Turn the screw to adjust the pressure
Under the condition of without slippage, the
more small the pressure of presser foot, the more
good it is.
(3) Tighten the nut .
.
Page 12
8. Maintenance (Fig. 20~25)
For protect the sewing machine and keep its good
performance, the machine must be maintained every
day, if the machine is left unused for a long time,
please maintain it as following sequence
1. Lift the presser foot;
2. Loosen the screw and uninstall the needle
plate ;
3. Clean the dust on the feed dog with a tooth
brush;
4. Fix the needle plate by screw .
5. Turn the hand wheel slowly to make the needle
enter into the center of the hole of needle plate
exactly;
If the needle cannot enter into the center of the
hole of needle plate,
Confirm if the needle bends
Loosen the screw and adjust the needle plate
again.
6. Turn the hand wheel to lift the needle up to the
needle plate and confirm if the pinpoint has been
damaged, if yes, please change a new one.
2020
2121
2222
7. Lay down the sewing machine
8. Uninstall the bobbin case ;
9. Clean the dust on the hook and check if it has
been damaged;
10. Pull the bobbin out of the bobbin case and
clean the bobbin case with cloth;
11. Put the bobbin in the bobbin case and put
the bobbin case in the hook.
12. Open the face plate periodically
13. Clean the fiber deposits on the needle bar
and needle bar bushing with a brush or cloth;
14. Fix the face plate and tighten the screw
If dont t clean periodically, it may cause the
possibility of oil exudation or oil leakage or polluting
the fabric.
,
2323
Page 13
2424
15. Clean the oil dust with cloth
16. While the oil level is lower than the mark of
LOW, please supplement the oil.
Please use sewing oil 18#
If the oil is dirty, uninstall the screw and
replace the fresh sewing oil, also please clean the
dust on the magnet and oil pan .
2525
2626
17. Lift the machine head
18. Confirm the threading sequence of needle
thread;
19. Trial sewing
9. Correct adjustment
1. Adjust the thread take-up spring
(1) Adjust the tension of spring (Fig. 26)
The tension standard of thread take-up spring:
model MSK-8900M is 0.245~0.343 N ( 25~35gf ) and
model MSK-8900H is 0.29~0.49 N ( 30~50gf )
a. Press the needle thread and tighten the nut
slightly;
b. Test the tension when the bottoms of spring
and thread guide are at the same height.
c. Turn the screw by a screwdriver to adjust
the tension of thread take-up spring
<-3>
<-3>
0.25~0.34N
0.25~0.34N
(25~35gf)(25~35gf)
<-5>
<-5>
0.29~0.49N
0.29~0.49N
(30~50gf)(30~50gf)
Page 14
(2) The position of thread take-up spring (Fig. 27)
lower the presser foot , the clearance between
thread take-up spring
is 6~8 (for MSK-8900M) and 4~6mm (for MSK-8900H)
a. Lower the presser foot ;
b. Loosen the screw ;
c. Turn the thread tension base to adjust it;
d. Tighten the screw .
and the top of thread guide
2727
~~
~~
2. Adjust the casting thread guide (Fig. 28)
The proper position of casting thread guide
that the screw locates at the center of adjusting
range of thread guide
When adjustment, Loosen the screw and
move the thread guide
1. For sewing heavy weight materials, please move
the thread guide leftward;
2. For sewing light weight materials, please move
the thread guide rightward;
3. Adjust the height of presser foot
Lift the presser foot by presser foot lifting bar
, the standard height of presser foot is 6mm
(1) Loosen the nut and screw
Note: The height A of screw cannot exceed
49mm, otherwise the presser spring and spring rod
will be out.
(2) Lift the presser foot by presser foot lifting
bar ;
(3) Pull out the rubber plug ;
(4) Loosen the screw and move the presser bar
upward or downward to make the height of presser
foot 6mm
(5) Tighten the screw ;
(6) Inset the rubber plug;
(7) Adjust the pressere of presser foot with screw
, then tighten the nut .
is
MoreMore
2828
LessLess
2929
Page 15
<-3>0.8mm<-3>0.8mm
<-5>1.2mm<-5>1.2mm
3030
4. Adjust the height of feed dog (Fig. 30)
The highest height of feed dog against needle
plate is 0.8mm. ( For MSK-8900M ) or 1.2 mm ( for
MSK-8900H)
(1) Turn the hand wheel to lift the feed dog to its
highest position;
(2) Loosen the screw ;
(3) Turn the crank and adjust the feed dog
supporter ;
(4) Tighten the screw .
Standarel
Front decline
Front raise
3131
5. Adjust the angle of feed dog (Fig. 31)
While the feed dog is at its highest position,
the standard angle is that the mark on the shaft
inosculates the ones on the feed dog supporter
(1) Turn the hand wheel to lift the feed dog to its
highest position;
(2) Loosen the screw ;
(3) Loosen the shaft and adjust it within the
range of 90shown in the Fig.31 upon the standard
position
If the materials puckering, adjust the feed dog
as Fig A shown;
If the materials slippery, adjust the feed dog
as Fig B shown;
(4) Tighten the screw .
After adjustment, the height of feed dog will
change, so please adjust the height of feed dog again.
3232
6. Adjust the height of needle bar (Fig. 32)
When the needle bar
the second mark a on the needle bar should align
with the bottom of needle bar bushing
(1) Locate the needle bar at its lowest position
(2) Pull out the rubber plug
(3) Loosen the screw and adjust the needle bar
upward or down ward
(4) Tighten the screw
(5) Inset the rubber plug
is at its lowest position,
Page 16
7. Adjust the position between needle bar and feed
dog (Fig.33)
When the feed dog moves down to the position
which is same with the surface of needle plate from its
highest position,the standard position of needle should
be as follows:
For light and medium weight materials
The surface of feed dog and needle plate
should be same and the pinpoint of needle is 1mm
lower than the needle plate
For heavy weight materials
The surface of feed dog and needle plate
shousd be same and there is a clearance of 3mm
between the pinpoint and needle plate
(1) Uninstall the back cover;
(2) Loosen the screw on the cam and screw
on the feed cam , slightly turn and adjust the
cam and feed cam ( these two cams are connect
-ed by pin and should turn alternative side)
If the timing of needle is fast, turn as shown in
the Fig. A ; if the timing of needle is slow, turn as shown
in the Fig. B For avoiding materials misplacing, please make
the timing of needle slowly (Fig. B )
For avoiding stitch puckering, please make the
timing of needle fast (Fig. A )
Notice: If turn the cam and feed cam overlar
-ge as Fig. A Shown , it will make needle broken
(3) After adjustment, tighten the screw and
8. Adjust the position between needle and hook
(Fig.34)
Lift the needle bar from its lowest position ,
while the lowest mark on the needle bar aligns with
the bottom of needle bar bushing , the tip of hook
should aim at the center of needle .
(1) Turn the hand wheel and lift the needle bar
to make the mark b align with the bottom of needle
bar bushing When the needle is lifted 1.8mm (for MSK-8900M)
or 2.2mm (for MSK-8900H), the clearance between the
hole of needle and the tip of hook should be 0~0.5mm
(2) Loosen the screw and make the tip of hoodk
aim at the center of needle .
the lateral clearance between the tip of hook
and needle . should be 0.05mm
(3) tighten the screw
9. Adjust the oil amount of upper shaft and hook
(Fig.35)
(1) Upper shaft
Uninstall the face plate, turn the screw to adjust
the oil amount of upper shaft
(2) Hook
Lay down the machine head, turn the screw to
adjust the oil amount of hook.
After adjustment, let the machine be run for 2~3
mim. and confirm the oil amount again
Washer
Screw
Stitch length regulator
Hinge shaft
Stop ring
Screw
Pin
Screw
Stitch length regulating link crank
Screw
Positioning plate
Screw
Spring
Feed lever
Screw
Feed lever shaft
Stop disc
Washer
Stop ring
O-seal
Screw
Reset spring