Liebersew 737 User manual

SUPER HIGH SPEED
OVERLOCK SEWING MAGHINE
Operation Manual
Parts Book
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Contents
TO THE OPERATERS ......
HOW TO INSTALL THE MACHINE ...
HOW TO OPERATE THE NEW MACHINE
LUBRICATION AND DRAINAGE ""''"" I
l.Lubrication """""' """"""" I
2.Drainage
3. Needle Cooling Lubrication-silicon oil """"":""""""" " j""""""""""' I
THREADING THE MACHINE ""'"'' 2
THREAD TENSION .",...", 2
l.TensionNutsAdjustment """ """"""2
2. Needle Thread Control
3. LooperThreadControl """""""'3
..',....3
4. Chain Looper Thread Cam Contol """"""
ST]TCH LENGTH ADJUSTMENT ... """ 3
NEEDLE REPLACEMENT :...".".''
DIFFERENTIAL FEED RATIO ADJUSTMENT ." """ 4
PARTS RELATION AND TIMING ...." '""""'" 4
l. Needle and Needle Plate "' """ 4
2. Upper Looper andNeedle
3. LowerlooperandNeedle """""""""'5
4. Upper Looper aird Lower LoPPer
5. Needle and Needle Guard """"""""" 5
6. Chain Looper and Needle " " " 5
Clear a stoppage """"""' 6
MAIN SPECIF ATIONS
Models Thread Sewing speed
(volv/min) Stitch length
(mm) Presser foot
lift (mm) Decibel
(dB) Torque
(N'm) Overedge width (mm)
35500 - 6000 0-5 6=84 =0.4 1.5-6
747 45500 - 6000 0-5 6=84 =0.4 1.5-6
7s7 55500 - 6000 0-5 6s84 >_o.4 1.5-6

Machine. Before operating this machine, please study this book thoroughly, understand the functions
and features of the machine. Then it will help you to increase your sewing efficiency and quality.
ATTENTION: Because this is an ultra high speed machine. Do not run it before filling oil and
i::king sure the correct turection of motor.
ffi
1. Install the machine according to the table cut-out diagram, Cushion Rubber and Rest Board as enc-
losed. In case of semi-submerged, the distance between Needle plate top surface and Table Top is
about 100mm, and for fully-submerged is about 5mm.
2. Setting the pedal of clutch motor to the left side and the pedal of presser foot lift at right ride.
3. Install the cloth waste chute, thread stand as parts list.
4. Be sure the motor turning direction is clockwise. And the belt can be pressed inward about 10mm.
NOTE: The dimensions of motor pulley and sewing speed are shown in Table 1.
Please run the new machine in the first four at20Vo less speed than maximum. Then replace the
new oil and threafter the machine may be operated up to maxim um speed.
Lubricatdn.And' age
1. Lubrication Fig.l
Remove Screw A and fill in enclosec ultra high speed lubricate oil (or similar to Mobil#lO, Esso#32)
until the top of Oil level indicator between two lines of Oil Level Sight Window, Then replace Screw A.
When the machine is operated for the first time is was idle for a long time, please be sure to oil the
top of the needle holder, guide, upper looper guide etc . before operating the machine.
2. Drainage Fig.2
Remove Screrv A and drain out the oil then eplace Screw A.
For keeping the good lubrication and machine life. please replace the new oil when the new machine
has been operating over four weeks, And after that, change oil every four months.
This machine has been fixed with oil filer, Please clean it every month or replace a new one if nec-
essary.
3. Needle Cooling Lubrication Silicon oil.
_,:- .: : : . i
. '.: " ' .:
S, l, :,.,. 1'11'11:::11r:r,,:L:;1
-1-

Refer to the sewing type you neecl for correct threading. Any incorrect threading may cause thread break'
uneven stitches or skip stitches etc.
For seamtypc 516 onlY
Fig.3
Thre€ftI&n's'ion
tubG@@ Fig.5
The threaci tension be adjusted according to sewing fabric, thickness, sewing thread, seam width,
stitch length etc. Therfore the pressure of the Tension Nuts or Thread Guides must be adjusted in each
individual case.
l.Tension Nuts Adjustment. Fig.S
. The tension Nut Ocontrols the double chain needle thread
or left side overlock needle thread.
' The tension Nut Ocontrols the double chain looper thread'
' The tension Nut @controls the overlock needle thread'
' The tension Nut O controls the upper looper thread'
' The tension Nut @ controls the lower looper thread'
2. Needle Thread Control Fig.6
In case of sewing type 504,512,&5l4,push Thread guideOand Oto lor*'est point. and up to
highest point fo sewing type 503,505.
Note: The (+) direction is for more needle thread tension, antl the (-) direction is for less needle thread
tension. -2-
i
ffi3 [i
:PN
Ttr' .,,U
For four thread onlY

3. Looper thread Control l'ig.7
For sewing type 512, when Upper Looper is extremely left, push takeup O and (D at the position
as the chain line(-----).
In case of sewing tupe 503, &505, When Upper Looper moves to lowest, set Take up O and O
at the position as the continuous line (-----).
Adjust thread guide G) as follow. Point A-for stretchy thread is used.
Point B--for seaming and blindstitch hemming. Point C--for seaming tupe 512.
Adjust Thread guide @ as follows.
Point D--for stretchy thead is used.
NOTE: The direction is for more thread in
sewing seam.
4. Chain Looper Thread Cam Control Fig.8
When the needle moves to its highest position, the right corner of the Thread Cam Omatchs with
the upper surface of Thread Guide BracketO.
oosen scrwe @ and adjust the thread cam O as clockwise is late for timing of looper thread cam.
Point E--for seaming and blindstitch hemming.
sewing seam, and the direction is for less thead in
\b
@
2Fig.7
The stitch length adjustment is made accoring to the sewing fabric, differential feed ratio etc.
Keep pushing the Push Botton enter deep inside.
Keep pressing the Push Botton and match the desired stitch length which is shown on the pulley
with the indicating point of Belt Cover.
Maxidiff
ratio Machine
type Pulley scale
I2J4567
l:2 Seaming I1.5 22.5 J3.5 3.8
l:3 Shirring 0.7 I1.4 1.7 2 2.3 2.5
1:1.3 Sergin 1.6 2.3 3.1 3.9 4.7 5.4 5.9
l:4 Special 0.6 0.9 r.2 1.5 1.8 2.1 I
Fig.9 Fig. lO
-3-

Please use DCX27 or equivalent needle size'
Loosen ScrewOand remove the old needle'
Insert the needle which long groove faces you and pusl it up deep into the needle hole until it
The differential feed ratio is the ratio of movements between Main Feed Dog and Differential feed
dog, when the movement of ain feed dog is biffer than differential feed dog, the fabric be stretched
in sewing . Othereise the fabric be shrinked.
Loosen Nut Othen rum screwq)in clockwise for stretching the fabric, and in reverse direction for
shrinking the fabric then tighten NutO '
Note: When the furface of adjusting level@be set at the scale @the defferential feed ratio is 1:1, and
if it be set over the scale its ratio can be adjustable up to 1:07'
Scale I2345
Differen-
tial Feed
ratio
1:13 l:0.7 l:0.9 1:1.1 l:1.3
I:2 1:0.7 1:1 l:I.4 l:1.7 l:2
l:3 l:l 1:1.5 I:2 l:2.5 1:3
1:4 l:1.1 l:1.6 l:2.3 l:2.8 1:3.3 Fig.l I
stops and tighten ScrewO.
1. Needle and Needle Plate Fig.12
When the Needle moves to the highest position, the distance between needle point (left needle if
two needle) and needle plate is 9.5-9.7mm for standard lift machine or 10'8-ll.Omm for high lift ma-
chine, Each needle must centers in each needle slot of Nedle plate. The right needle musted ahead ab-
out 0.2-0.3mm rhan left needle. And the distance between the needle point (right needle if nvo needle)
to needle slot of Needle Plate or presser foot is 1'2mm'
Slightly loosen ScrewOof Needle Drive Crank. Rotate the pulley to check if needle center in
each needle slot of needle plate. or you may lossen screw @and adjust needle holder.
Rotate the pulley foiremoving the needle to the highest position, tap the Needle Holder guide
until the correct needle height is obtained. Tighten screwO '
\
+E--<-r
.reJ
A9.5-9.7
High Lift rO.8-11 Fig. l2
-4-

2. Upper Looper (Spreader) and Needle Fig.13
When the Upper (spreader) moves to the extremely left, the distance between the point of looper
(spreader) and center line of needle is 4.5-5.0, for I needle (spreader) to center line of left needle is
5.5-6.0mm for 2 needle machine.
A: 4.5-5.0
B: 5.S.0
Fig.l3
3. Lower Looper and Needle Fig.14 15
When the lower looper moves to the extremely left,
the distance between looper point and center line of
needle (left needle if 2 needle) is 3.4-3..6mm for
high lift machine. When the lower looper moves to
the center line of needle (eft needle if 2 needle) the gap
beween needle and looper is 04.05mm.
4. Upper Looper and Lower Lopper Fig.16
When the Upper and l,ower l-ooper is crossed.
5. Needle and eedle Guard Fig.17
When the Lower Looper point is opposite the center line of Needle (left needle if 2 needle), the
gap between Needle and rcar Needle Guard A is Omm. When Needle moves to the lowest position, the
gap between Needle and front Needle guard B if 0.15-0.2mm.
6. Chain Looper and eedle Fig.18
The Chain Looper must be fixed into the lowest pgsition of is holder and when the Chain Looper
moves the the extremely left, the distance between the looper point and center line of needle is 2.5mm.
d
do
g
o
I
o
I
----- |
F;;-T
-5-

\i7
K-y
2.5
Fig. 18
Fig.l6 Fig. 17
Problem settlement,
REASON
l. Needle installed wrong
2. Wrong needle size
3. Needle is bended.
4. Wrong relation with Needle Guard.
5.Wrong relation with looer.
6. Needle does not center the needle
slot of Needle Plate or Presser Foot.
REASON
1. Inferior quality ofthread.
2. Thread thicker than Needle hole.
3. Wrong threading.
4. Thread tension is too strong.
5. Needle installed wrong.
6. Thread Stand installed wrong.
7. Over heat of Needle 1.No silicon oil
2 Wrong setting of Needle Guard.
8. Thread Disc or Guide is burred.
9. Wrong relation of Needle and Looper.
10. Needle, Looper needle Plate and guide
is burred.
REASON
l.Wrong relation of Needle and Looper.
2. Wrong threading.
3. Needle installed wrong.
4. Inadequate thread tension or tension
too strong.
5. Looper point is damaged.
6. Needle is bended.
7. Wrong installed Needle Guard"
CORRECT
1. Readjust Needle and Looper.
2. Rethreading correctly.
3. reset Needle corrcetly.
4. Readjust Thread Tension Nut.
5. Replace new one.
6. Replace new one.
7. Readjust Needle guard.
-6-
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CORRECT
l. Reset needle correctly.
2. Use properly needle for fabric and thread.
3. Replace new needle.
4. Readjust Needle gr.rard.
5. Readjust looper.
6. Readjust the Needle Plate and Presser Foot.
CORRECT
l. Use good quality thread.
2. Use proper Needle for fabric and thread.
3. Rethreading correctly.
4. Readjust thread tension nut.
5. Reset needle correcly.
6. Reset thread stand for threading smoothly.
7. (1) Fill in Silicone oil.
(2) Readjust Needle Guard.
8. Grind off polish or replace new one.
9. Readjust Needle and Looper.
10. grind off, polish or replace new one.

REASON
1. Wrong threading
2. Thread is thicker than Needle
hole.
3. Tension Disc do not press thread
properly.
4. Needle thread is not lubricated.
5. Wrong setting of Needle and
Loopers.
CORRECT
1. Rethreading correctly.
2. Use proper Needle.
3. Reset Tension Disc properly.
4. Fill silicon oil.
5. Readjust needle and loopers.
REASON
l. Wrong threading.
2. Thread stand installed wrong.
3. Lower Knife installed rvrong.
4. Knives do not trim neatly.
(1) Knives installed wrong.
(2) Dull lower knife.
5. Thread Disc or Guide in burred.
6. Needle point is damaged.
7. Inadequate heigh of feed dogs.
8. Inadequate thread tension.
REASON
l. ThreaC tension is too strong.
2. Inadequate pressure ofpresse foot.
3. Inadequate height of feeC dogs.
4. Knives do not trim neatly.
5. Differential feed is not matched.
6. Needle is too thick.
7. Seam width is too narrow against
the chainoff finger of Needle plate.
REASON
l. Presser foot installed wrong.
2. Inadequate timing of looper thread cam.
3. Double chain looper installed wrong.
4. Wrong threading.
5. Inadequate or t,, ' strong thread tension.
6. Wrong relation of Needle and looper.
7. Needle Plate Thread Disc or Presser foot
is burred.
8. Thread tension disk is rough.
CORRECT
l. Rethreading correctly.
2. Resei Threadt for threading smoothly.
ii. readjust ,.rwer knife.
,1. Correct -r" follow:
(l) Readjust Knives.
(2) Sharpen or replace new knives.
5. Grind off, Polish or replace irew one.
6. Replace new Needle.
7. readjust feed dogs.
8. Readjust Thread tension nut.
CORRECT
R.eadjust thread tension nut.
Readjust Presser foot pressure
Readjrist feed dogs.
Readjust knives or sharpen knives.
Readjust differential feed ratio.
Use proper Needle for fabric and thread.
Rendjust seam width or replace chain off
finger.
l.
2.
4.
5.
6.
"7.
+irffi$iffi
CORRECT
l. Reset presser foot correctly.
2. Readjust Looper thread Cam.
3. Reset Double chain looper correctly.
4. Rethreading correcty.
5. Readjust Thread tension nut.
6. Readjust Needle and looper .
7. Grind off, polish or replace new one.
8. Polish thread tension disk.
-7 -

-. Frame assemblies
t-
I
Ref.No Part No- Name Amt. Req.
3
IMI-IA machine fmmc
2Ml-2 needle thread cover Dlate I
3MI.3A uDFr oncde cover I
4MI-4A oncde cover oad I
5M5A lathcr shell uDrer knol t
6M-6 needle plate I
7M7 uDEr washer I
8M-8 oil tube I
9M-9 ret oil adhesive cxe I
l0 Ml0 oil seal I
ll Mll rcil cover
L2 M t2 lw cover oil seal
l3 Ml3 oil seal
t4 Mt4 cover
t5 Ml5 oil rcar washer
t6 Ml6 cover washer
t7 Mt7 rivet 4
t8 Ml8A machine modle plate
l9 Mt9 model tube
20 M-20 pin 2
2l M 2t oil $rcen
22 M22 snap fing
Ref.No Part No. Name Amt. Req
345
23 M23 oil seal II
24 M24 oil seal II I
25 M25 4 4 4
26 M-26 trade m{k plste I
2'1 M-28 mard Dlate I
28 M-29 oil amount adiustins Din I
SOGI scrcw 444
)so65 $rew 333
3so54 Edle bu6m *Fw 22
4so6l needle lind st rcrc* I
5s{xx) o@dk thEad cover Dlate toD silk I
6s0?r tEdlc thrcad over Dl& *t screw I
7s04r Ein @vs beainq rcrulate rcrew
6NO3 min owbcrins rcolab nut
9so32 tw cover plaG t1l
l0 so36 lower cova oldc 22
il s08l oil De ioin ffiw 44
t2 wl4 washer 44
t3 wo3 elasticity washer 44
t4 so80 nexagon scker scrcw 4 4
l5 s0.14 screw I
l6 so65 I