HIGHLEAD GM747-3 Instruction Manual

Customer Service
Copy
HIGH LEAD
GM747series
HIGH-SPEED OVERLOCK SEWING
MACHING
Instruction Manual
Parts Catalog
SHANGHAI HUIGONG N0.3 SEWING MACHINE FACTORY

Contents
To the Operators··················································································································································· I
Ho\v to install the machine································································································································ 1
Ho\v to operate tl1e ne\v machine···················································································································· I
l
.. ubrication and drainage······················································································································· ........... I
I. Lubrication .................................................................................................................................................... I
2. Drainage ........................................................................................................................................................ I
3. Needle ('ooling Lubrication-Silicon oil··································································································· I
Tltreading the machine······································································································································· I
Thread tension
....................................................................................................................................................... 2
I. ·rension Nuts Adjusttnent ............................................................................................................................. 2
2. Needle Thread Control·································· .. ······•·•········•·············••·········· ... ························..··•····•·•·······•··•· 2
3. Looper l~hread Control ................................................................................................................................. 2
4. Chain Looper Thread Can1 Control········································..................................................................... 3
Stitch Length Adjustment ............................................................................................................................... 3
Needle replacement
.............................................................................................................................................. 3
Differential feed ratio adjustment···············
.. ································································································· 4
Parts relation and timing ................................................................................................................................... 4
I. Needle and Needle Plate .............................................................................................................................. 4
2. Upper Looper and Needle···························································································································· 4
3. Lo\ver Looper and Needle·······················································································································..... 5
4. Upper Looper and Lo\ver Lopper................................................................................................................ 5
5. Needle and Needle Guard ............................................................................................................................ 5
6. Chain Looper and Needle··················································································································..·•······· 5
Problem settlement·············································: ................................................................................................. 5
Parts catalog······················· ..................................................................................................................................... 8
Specifications
Stitch Presser foot Decibel Overedging
Sewing speed Torque
Models Thread length
(r/min) lift(mm) (dB) (N·m) width(mm)
(mm)
GM747-3 3
5500--6000
0--5
6 ~84 ~0.4 1.5--6
GM747-4 4
5500--6000
0--5 6 ~84 ~0.4
1.5--6
GM747-5 5
5500--6000
0--5
6 ~84 ~0.4 L5--6

To the operator
Thank you very much for using our High speed, Straight Needle, Overlock Safety Stitch 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 high speed machine. Do not run
it before filling oil and making sure the
correct direction
of motor.
How to install the machine
1. Install the machine according to the table cut-out diagram, Cushion Rubber and Rest Board as
enclosed. In case
of semi-submerged, the distance between Needle plate top surface and Table Top is about
1
OOmm,and for fully-submerged is about Smm.
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 cJockwise. And the belt can be pressed inward about 10mm.
NOTE: The dimensions
of motor pulley and sewing speed are shown in Table 1.
How to operate the new machine
Please run the new machine in the first four at 20%less speed than maximum. Then replace the new oil and
thereafter the machine may be operated up to maximum speed.
Lubrication and drainage
1. Lubrication Fig.l
. Remove Screw A and fill in enclose high speed lubricate oil(or similar to Mobii#IO, Esso#32) until the
top
of Oil Level indicator between two lines of Oil Level SighfWindow, Then replace Screw A.
When the machine is operated for the first time
is 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 ScrewA and drain out the oil then replace 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 necessary.
3. Needle Cooling Lubrication-Silicon oil.
Fig. 1 Fig.2
-1-

Threading the machine
Refer to the sewing type you need for correct threading. Any incorrect threading may cause thread break,
uneven stitches or skip stitches etc.
For seamtype 516 only
For four thread only
Fig.3 Fig.4
Thread tension
Fig.5
The thread tension be adjusted according to sewing fabric, thickness, sewing thread, seam width, stitch .
length etc. Therefore the pressure of the Tension Nuts or Thread Guides must be adjusted in each individual
case.
1. Tension Nuts Adjustment Fig.S
The tension Nut( I)controls the double chain needle thread
or left side overlock needle thread.
The tension Nut(5)controls the double chain looper thread.
The tension Nut(2)controls the overlock needle thread.
The tension Nut(3)controls the upper looper thread.
The tension Nut( 4)controls the 1 Ower looper thread.
2. Needle Thread Control Fig.6
Fig.6
In case of sewing type 504,512,&514. push Thread guide CD and®to lowest point, and up to highest point to
sewing type 503,505.
Note: The(+)direction is for more needle thread tension, and the(-)direction is for less needle thread tension.
3. Looper thread Control Fig.7
For sewing type 512, when Upper Looper is extremely left, push take up CDand ®at the position as the chain;. ·
line ( ----- ).
In case of sewing type 503. &505. When Upper Looper moves to lowest, set Take up CD and® at th~· · J · .·
.. ::. '.
position as the continuous line ( -- ).
Adjust thread guide @ as follow. Point A: for stretchy lhread is used.
-~-

Point 8: for seaming and blind stitch hemming. Point C: for seaming type 512.
Adjust Thread
guide® as follows.
Point 0: for stretchy thread is used. PointE: for seaming and blind stitch hemming.
NOTE: The direction is for more thread in sewing seam. and the direction is for less thread in sewing seam.
4. Chain LooperThread Cam Control Fig.8
When the needle moves to its highest position, the right corner of the Thread Cam ® matchs with the upper
surface ofThread Guide Bracket CD.
Loosen screw® and adjust the thread cam® as clockwise is late for timing of looper thread cam.
Fig. 7
Stitch length adjustment
The stitch length adjustment is made according to the sewing fabric, differential feed ratio etc.
Keep pushing the Push Button enter deep inside.
Keep pressing the Push Button and match the desired stitch length which is shown on the pulley with the
indicating point of Belt Cover.
Maxi diff Machine
ratio
type 1 2
1:2 Seaming 1
1.5
1:3
Shirring 0.7 1
I: 1.3
Serge
1.6 2.3
I :4 Special 0.6 0.9
~
JuL
~·
/"
Fig.9
/
Needle replacement
Please use DCX27 or equivalent needle size.
Loosen Screw CD and remove the old needle.
Pulley scale
3 4 5 6 7
2 2.5
3
3.5
3.8
1.4 1.7 2
2.3 2.5
3.1 3.9 4.7 5.4 5.9
1.2 1.5 1.8 2.1 I
L.-
:T)
Fig. 10
-3-

Insert the needle which long groove faces you and push it up deep into the needle hole until it stops and
tighten Screw (i).
Differential feed ratio adjustment
The ditlerential teed ratio is the ratio of movements between Main Feed Dog and Differential feed dog,
when the movement of Main feed dog is bigger than differential feed dog. the fabric be stretched in sewing,
Uthcrcise the fabric be shrinked.
Loosen Nut
Q) then turn screw ® in clock\vise for stretching the fabric, and in reverse direction for
shrinking the fabric then tighten Nut CD.
Note: ~·hen the surface of adjusting level® be set at the scale® the differential feed ratio is 1: I, and if it
be ~et over the scale its ratio can be adjustable up to I:0.7.
r
I
I
I
Scale 1 2 3 4 5
1:1.3
-1:0.7 1:0.9
1:1.1
1:1.3
Differe-
ntial
1:2 I:0.7
1:1
I: 1.4
I: 1.7
1:2
Feed
1:3 1:1 I:1.5 1:2
1:2.5
1:3
ratio
1:4
1:1.1
1:1.6 1:2.3
1:2.8
1:3.3
Fig . 11
Parts relation and timing
1. Needle and Needle Plate Fig.12
When the Needle moves to the highest position, the distance between needle point (left needle iftwo needle)
and needle plate is 9.5-9.7mm for standard lift machine or
I0.8-II.Omm for high lift machine. Each needle must centers in each
needle slot
of Needle plate. The right needle must ahead about
0.~-0.Jmm than left needle. And the distance between the needle
point (right needle if two needle)
to needle slot of Needle Plate or
presser
foot is 1.2mm.
Slightly loosen Screw Q)ofNeedle Drive Crank.
Rotate
the pulley to check if needle center in each needle slot of
needle plate. or you may loosen screw®and adjust needle holder.
1\ ~.5-'1.7
High Lifl lfU~-11
Fig. 12
Rotate the pulley for removing the needle to the highest position, tap the Needle Holder guide until the
~orrcct needle height is obtained. Tighten screw(i).
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.
-4-

A: 4.5-5.0
8: 6.5-8.0
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 n~edle if2 needle)is 3.4-3.6mm for high
lift machine. When the lower looper moves to the
center line of needle (Ieft needle if 2 needle) the gap
between needle and looper is 0-0.0Smm.
4. Upper Looper and Lower LooperFig.16
When the Upper and Lower Looper is crossed, the
upper looper is as near as possible to the lower looper,
the gap A is O.Smm, the gap B is 0.2mm. When Needle
moves to the lowest position, the gap between Needle
and front Needle guard B if0.1-0.2mm.
5. Needle and needle Guard Fig.17
When the Lower Looper point is opposite the
center line of Needle{ left needle if2 needle). The gap
between Needle and rear Needle Guard A is Oram,
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 needle Fig.18
The Chain Looper must be fixed into the lowest
position of the holder and when the Chain Looper
Fig. 14
8
0
I
0
~
- t
Fig. 15
0
moves the extremely left, the distance between the looper point and center line of needle is 2.5mm.
0.0
\ r 0.1-0.20
~I
ccdlc Yl//ZZ '\--:'
.~a
Fig. 16
,.~
A Fig. 17
2.5 Fig.
18
-5-
Fig. 13

Problem settlement:
Needle break
REASON
1. Needle installed wrong.
2. Wrong needle size.
3. Needle is bended.
4.
Wrong relation with Needle Guard.
5. Wrong relation with looper.
6. Needle does not center the needle.
Slot ofNeedle Plate or Presser Foot.
Thread break
REASON
I. Inferior quality of thread.
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 ofNeedle Guard
8. Thread Disc or Guide is burred.
9. Wrong relation of Needle and Looper.
10. Needle, Looper needle Plate and guide
is burred.
Skip stitches
REASON
1. Wrong relation ofNeedle 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.
Loosen stitches
REASON
1. Wrong threading
2. Thread is thicker than Needle
hole.
3. Tension Disc do not press thread
properly.
4. Needle thread is not 1ubricated.
S. Wrong setting of Needle and
Loopers.
CORRECT
1. Reset needle correctly.
2.
Use properly needle for fabric and thread.
3. Replace new needle.
4. Readjust Needle guard.
5. Readjust looper.
6. Readjust the Needle Plate and Presser Foot.
CORRECT
I. Use good quality thread.
2.
Use proper Needle for fabric and thread.
3. Rethreading correctly.
4. Readjust thread tension nut.
5. Reset needle correctly.
6. Reset thread stand for threading smoothly.
7. (1)Fill in Silicone oil.
(2)Readjust Needle Guard.
8. Gring offpolish or replace new one.
9. Readjust Needle and Looper.
10. Grind.off, polish or replace new one.
CORRECT
l. Readjust Needle and Looper.
2. Rethreading correctly.
3. Reset Needle correctly.
4. Readjust Thread Tension Nut.
5. Replace new one.
6. Replace new one.
7. Readjust Needle guard.
CORRECT
l . Rethreading correctly.
2. Use proper Needle.
3. Reset Tension Disc properly.
4. Fill silicon oil.
5. Readjust needle and loopers.
__:_(:)-

Uneven stitches
REASON
I. Wrong threading.
2. Thread stand installed wrong.
3.
Lower Knife installed wrong.
4.
Khives do not trim neatly.
(I )Knives installed wrong.
(2)Dulllower knife.
5. Thread
Disc or Guide in burred.
6. Needle point
is damaged.
7. Inadequate height
of feed dogs.
8. Inadequate thread tension.
Wrinkled stitches
REASON
I. Thread tension is too strong.
2. Inadequate pressure
of presser foot.
3. Inadequate height
of feed 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 chain of finger ofNeedle plate.
CORRECT
I. Rdhreading correctly.
2.
Reset Thread for threading smoothly.
3. Readjust 1
Ower knife.
4. Correct
as follow:
(I )Readjust Knives.
(2)Sharpen or replace new knives.
5. Gring
off, Polish or replace new one.
6. Replace
new Needle.
7. Readjust feed dogs.
8. Readjust Thread tension nut.
CORRECT
I. Readjust thread tension nut.
2. Readjust Presser
foot pressure.
3. Readjust
feed dogs.
4. Readiust knives
or sharpen knives.
5. Readjust differential
feed ratio.
6.
Use proper Needle for fabric and thread.
7. Readiust
seam width or replace the chain or
finger.
Thread chain does not come out smoothly
REASON CORRECT
1.
Presser foot installed wrong.
I.
Reset presser foot correctly
2.
Inadequate timing of looper thread cam.
2. Readjust Looper thread Cam.
3. Double chain looper installed wrong. 3.
Reset Double chain looper correctly.
4. Wrong threading. 4. Rethreading correctly.
5. Inadequate or too strong thread tension. 5. Readjust Thread tension
nut.
6. Wrong relation of Needle and looper.
6.
Readjust Needle and looper.
7. Needle Plate Thread Disc or Presser foot
7.
Gring off, polish or replace new one.
is burred.
8.
Thread tension disk is rough.
8.
Polish thread tension disk.
-7-

A~ Frame assemblies
. ', ......
~: ..
•'
-8-

A~ Frame assemblies
Ref.NC
Part
NO.
Name
Amt. Req.
3t&
4~
5~
1 MI-lA
machine frame
1 1 1
2 MI-2
needle thread cover plate
1 1 1
3
M1-3A
upper knot cover 1 1 1
4 M1-4A
upper knot cover pad
1 I 1
5'
M1-5A
lather shell upper knot 1 1 1
6
Ml-6
needle plate
1 1 1
7 MI-7
upper washer 1 1 1
8 M1-8
oil tube 1 1 I
9 MI-9
rear oil
adhesive case 1 I I
10
Ml-10
oil seal
1 1 1
11 M1-11 rear cover 1 1 1
12
Ml-12
rear cover oil
seal
1 1 I
13
MI-13
oil seal
1 1 1
14
Ml-14
cover 1 1 1
15
Ml-15
oil sear washer 1 1 1
16
MI-16
cove~ washer 1 1 I
17
MI-17
rivet
4 4 4
18
M1-18A
machine modle plate
1 1 1
19
Ml-19
model tube 1 1 1
20
Ml-20
pin 2 2 2
21
Ml-21
oil screen 1 1 1
22
M1-22
snap ring
1 1 1
23
Ml-23
oil seal
I 1 1 1
24
M1-24
oil seal II
1 1 1
25
M1-25
begin pin 4 4 4
26
Ml-26
trade mark plate
1 1 I
27 MI-28
mard plate
1 1 I
28 Ml-29
oil amount adjusting pin 1 1 I
1 S064
screw 4 4 4
2 •
S065
screw 3 3 3
3
S0 54
needle bar bushing screw 2 2 2
4
S061
needle
lind set serew 1 1 1
5 S009
needle thread cover
plate
top silk
1 1 1
6
S071
needle thread cover plate set screw 1 I 1
7
S041
main cover bearing regulate screw 1 1 1
8 N03
main cover bearing regulate nut 1 1 I
9
S032
rear cover plate
11
11
11
10
S036
lower cover plate
2 2 2
11
SOB!
oil pan join screw 4 4 4
12
W14
washer 4 4 4
13 W03
elasticity washer 4 4 4
14 SOBO
nexagon socker screw 4 4 4
15
S044
screw 1 I I
16
S065
screw 1 1 I
-9-

B, Cloth plate assemblies
®--'
-10-

B, Cloth plate assemblies
Ref. NO
Part NO.
Name
Amt. Req.
3~
4~
5~
1 M2-1
cloth plate
1 1 1
5M2-I
cloth plate
0 0 0
2 M2-2
washer 1 1 1
3
~-3
colloid cose 4 4 4
4
M2-4
colloid cose 1 1 1
5
M2-5
cloth plate spring screw 1 1 1
6
M2-6
spring
1 1 1
7
M2-7
cloth plate spring 1 1 1
8
M2-8
cloth plate slider cover 1 1 1
9
M2-9
cloth plate cover spring 1 1 1
10
M2-10
cloth plate lower plate
1 1 1
5M2-10
cloth plate lower· plate
0 0 0
11 M2-11
washer 1 1 1
12
M2-12
upper looper sealing plate
1 1 1
13
M2-13
upper looper sealing plate washer 1 1 1
1 5037
upper looper sealing plate screw 3 3 3
2 5049
set screw 1 1 1
3
SOlO
serew 2 2 2
4
N03
set nut big cover stable screw 2 2 2
5 5083
screw 1 1 1
6
Wll
s.crew washer 1 1 1
7
NOI
screw nut 1 1 I
8
W08
washer 2 2 2
9
5012
big cover spring screw 2 2 2
10 5099
big cover join screw 3 3 3
11 W07
big cover join screw washer 3 3 3
-11-

emblies
C, Cover ass
-12 -_

C, Cover assemblies
Ref. NO
Part NO.
Name
Amt. Req.
3~
4~ 5~
1 M3-1
upper cover 1 l l
2 M3-2
upper cover washer 1 1 l
3 M3-3
thread guide supporter 1 1 1
4
fM3-4A belt cover 1 1 l
5
M3-5
thread cover spring 1 1 1
6
M3-6
cloth guide plate
1 l 1
7
M3-7
oi 1 guide II
1 1 1
8 M3-8
pin 1 l l
9 M3-9
front spring
1 1 1
10 M3-10
frong cover 1 1 1
11
M3-ll
front cover guard 1 1 0
5M3-11
front cover guard 0 0 l
12
M3-12
front cover hinge 1 1 1
13
M3-13
hinge pin 1 1 1
14
M3-14
front cover hinge spring
1 I I
15 M3-15
front cover hinge washer 1 1 1
16 M3-16A
trade mark plate
1 1 1
17 M3-17
oil flow window
2 2 2
18 M3-18
front cover snap guard 1 1 1
19
M3-19
oil guard I 1 1 1
20
M3-20
oil sight gauge washer 1 1 1
21
M3-21 pin 1 l l
22
M3-22A
oil cover gauge cover I 1 I
23
M3-23A
oil sight
1 1 1
24 M3-24
washer 1 1 1
25
M3-25
trade mark plate
I l I
26 M3-26A
upper cover 1 1 l
1
S098
upper cover screw 4 4 4
2
~091
thread guard screw 2 2 2
3 S017
upper cover spring screw 3 3 3
4 WI7
washer 2 2 2
5
S032
cloth guide plate screw 5 5 5
6 S020
oil guard screw I 2 2 2
7 S090
snap plate
4 4 4
8
S082
screw 3 3 3
9
S027
front cover plate block spring screw 2 2 2
10 S024
front cover hinge screw 3 3 3
ll
Wll
front cover hinge washer 3 3 3
12 E02
snap uing 1 1 1
-13-

D, Main shaft
assemblies
- 14-

D, Main shaft assemblies
~ef.NC
•'
..
..
·\, ~: · ~ -~ ~
.•. -- :' .
- '.
1
2
3
4
5
6
1
8
9
10
11
12
13
14
15
16
17
1
2
3
4
5
6
1
8
9
Part NO.
M4-l
M4-2
M4-3
M4-4
M4-5
M4-6
M4-7
M4-8
M4-9
M4-10
M4-ll
M4-12
M4-13.
M4-14
5M4-14
M4-15
M4-16
5M4-17
S073
W03
S070
S085
S032
S043
S078
S019
S022
Name
main shaft
wheel
rear shaft bearing cover
rear shaft bearing cover washer
main shaft spring washer
main shaft busing
Seal ring
main shaft queen shaft bearing
oi1
pump worm
main shaft bearing
shaft end bushing washer
main shaft light bushing
bearing
80200
bearing cover
beari.ng cover
bearing cover washer
pulley
bulgy pulley bearing
pulley screw
pulley screw washer
pulley
set screw
pulley
set screw
rear shafting bearing cover screw
oil pump worm screw
screw
screw
bearing cover screw
-15-
Amt. Req.
3~
4~
5~
1 1 1
1 I I
1 1 1
1 1 1
1 1 1
1 1 1
1 I 1
1 1 I
I I 1
1 I l
1 I 1
1 1 I
1 1 1
1 1 0
0 0 1
1 I 1
1 I 1
0 0 0
1 1 I
1 I I
1 1 1
1 1 1
3 3 3
1 1 1
2 2 2
1 1 1
3 3 3

E, Needle b
ar asseml·
1es
-16-

E~ Needle bar assemlies
Ref. NO
Part NO.
Name
Awt .. Req.
3f'&
4~
5~
1 M5-l
needle bur driving frame roek shaft
1 1 1
2
&15-2
eccentric shaft
1 1 1
3
M5-3
needle bar shaft bushing back
1 1 1
4 M5-4
snap ring
1 1 1
5 M5-5
throat driving crank 1 1 1
6 M5-6
oil wick
1 1 1
7 M5-7
needle bearing 1 1 1
8
M5-8
washer ring
1 1 1
9
M5-9
throat clip guide pin 1 1 1
10
M5-10
oil wick
1 1 1
11 M5-ll
throat bar rock crank 1 1 1
12 M5-12
needle driving shaft bearing 1 1 1
13
M5-13
seal ring
2 2 2
14
M5-14
needle bar rear driving copper bearing 1 1 1
15 M5-15
snap ring
2 2 2
16
M5-16
balance block 1 1 1
17 M5-17
needle bar flame rock shaft crank 0 1 0
5M5-17
throa~ bar shaft crank 1 0 1
18
M5-18
needle bar connecting rod 1 1 1
19
M5-19
connecting link pin 1 1 1
20 M5-20
washer 1 1 1
21 M5-21
throat clip guide bushing 1 1 1
22 M5-22
needle bar
1 1 1
23
M5-23
oil felt
1 1 1
24
M5-24
oil wick
1 1 1
25 M5-25
plasties tube 1 1 1
26
M5-26
oil wick
2 2 2
27 4M5-27
needle clamp
0 1 0
3M5-27
needle clamp
1 0 0
5M5-27
needle clamp
0 0 1
28
M5-58
needle 1 1 1
29 M5-59
oil seal
1 2 2
1
S0 57
snap ring screw 4 4 4
2
S102
hexagon socket screw 1 1 1
3
S055
balance block position screw 2 2 2
4 S043
frame rock shaft set screw 3 3 3
5 S074
shaft position screw 2 2 2
6
S0 53
screw 1 1 1
7
SOOl
screw 1 1 1
8
S006
screw 1 1 1
9
S012
screw 1 1 1
10 5009
screw 5 5 5
11
E01
snap ring
1 1 1
-17-

"de assemblies F, Thread gul
- lH-