HIGHLEAD GC188-MC User manual

®
HIGH LEAD
Purchasing Dept
Copy
GC188-MC/GC188-MC-D
High Speed Lockstitch Machine With Edge Cutter And
Automatic Thread
Trimmer
Instruction Manual
Parts Catalog
SHANGHAI HUIGONG N0.3 SEWING MACHINE FACTORY
From the library of: Superior Sewing Machine & Supply LLC

From the library of: Superior Sewing Machine & Supply LLC

CONTENTS
1. PRECAUTIONS BEFORE STARTING OPERATION ............................................................... 2
2. MAIN SPECIFICATIONS ................................................................................................. 2
3. INSTALLING THE BELT. ............................................................................................... 3
4. ADJUSTMENT OF NEEDLE BAR STOP POSITION ............................................................... 3
5. LUBRICATION ............................................................................................................. 4
6. CONDITION OF OIL LUBRICATION ................................................................................ .4
7. LUBRICATION ADJUSTMENT ....................................................................................... 4
8. ADJUSTMENT OF OIL PUMP .......................................................................................... 4
9. REGULAR CLEANING..... .. ... .... .. .. ... .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .... .. . .. .................... 5
10. WINDING ADJUSTMENT ............................................................................................. 5
11. REPLACE NEEDLES ................................................................................................... 5
12. THREADING
............................................................................................................... 6
13. SET STITCH LENGTH AND REVERSE FEEDING ............................................................... 6
14. ADJUSTING THE THREAD TENSION .............................................................................. 6
15. UPPER THREAD TENSION ............................................................................................ 7
16 LOWER THREAD TENSION ......................................................................................... 7
17. ADJUSTMENT OF FEED DOG INCLINATION ..................................................................... 7
18. ADJUSTMENT OF THREAD TRIMMER MECHANISM ......................................................... 8
19. INSTALLING OF
THE NEDDLE PLATE ........................................................................... 9
20. CLOTH CUTTING KNIFE ............................................................................................. 9
21. THROAT PLATE COVER. .............................................................................................. 9
22. OTHER REPLACEMENT PARTS
................................................................................ 10
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From the library of: Superior Sewing Machine & Supply LLC

1. PRECAUTIONS BEFORE STARTING OPERATION
1) Safety Precautions:
(1) When turning the power on, keep your hands and fingers away from the area around/under the needle
and the area around the balance wheel.
(2) Power must be turned off when the machine is not in use, or when the operator leaves the seat.
(3) Power must be turned off when tilting the machine head, installing or removing the "V" belt, adjusting
the machine, or when replacing.
(4) Avoid placing fingers, hairs, bars etc., near the balance wheel, "V" belt, bobbin winder balance wheel,
or motor when the machine is in operation.
(5) Do not insert fingers into the thread take-up cover, under/around the needle, or balance wheel when the
machine is in operation.
(6) If a belt cover, finger guard, eye guard are installed, do not operate the machine without these safety
devices.
2) Precautions before Starting Operation:
(1) If the machine's oil pan has an oil sump, never operate the machine before filling it.
(2) If the machine is lubricated by a drop oiler, never operate the machine before lubricating.
(3) When a new sewing machine is first turned on, verify the rotational direction of the balance wheel with
the power on. (The balance wheel should rotate counter-clockwise when viewed from the balance
wheel)
( 4) Verify the voltage and (single or three) phase with those. given on the machine nameplate.
3) Precautions for Operating Conditions:
(I) Avoid using the machine at abnormally high temperature (35 'C or higher) or low temperature (5 'C or
lower)
(2) Avoid using the machine in dusty conditions.
2. MAIN SPECIFICATIONS
Item GCI88-MC-D
GCI88-MC
Material Light-Medium heavy
Max.sewing speed 4500 rpm
Stitch length 0-5mm
Needle bar stroke 31.8nnn
By hand
4nm1
Presser By knee
lOnm1
Needle
DBX I #9~#14
Lubrication Auto lubricated
Auto trinnner 0 -
Auto backtracking 0 -
Rotating hook Auto lubrication hook
(Thread trinnning) Auto lubrication hook
Motor Speed adj. Motor 370W clutch motor
-2-
From the library of: Superior Sewing Machine & Supply LLC

3. INSTALLING THE BELT (Fig.l)
1) Use a V-belt for sewing machine use, type M
2) To adjust the belt tension, change the motor
height by turning the tension adjust nuts so that the
belt sinks about 15 mrn when depressed by hand at
the center of the belt span. If the tension is too low,
the speed may not be consistent in the low or
medium range, or the needle may not stop in the
proper position.
If the tension is too high, the motor
bearings will deteriorate more rapidly.
4. ADJUSTMENT OF NEEDLE
BAR STOP POSITION (Fig. 2, 3)
1) Adjusting of "Up" position
When the pedal is kicked down by heel, the
machine stops at "UP" position.
If the marks
deviate larger than 3 mm adjust as follows:
(
1) Disconnect the plug ( 12 pins) of cable
from the machine head.
(2) Run the machine and stop at "UP"
position.
(3) While holding the balance wheel insert
the "adjusting tool" in the hole A, then
remove the
tool.
2) Adjusting of "DOWN" position
Set the machine stops at "DOWN" position.
When the pedal is kicked down by hell, the
machine stops
as "DOWN" position. If the marks
deviate larger than 3
nrrn adjust as follows:
(I) Disconnect the plug (12 pins) of cable
from the machine head.
(2) Run the machine and stop at "DOWN"
position.
(3) While holding the balance wheel insert
the "adjusting tool" in the hole B, then remove the tool.
Timing mark arm
Adjusting tool
3rd mark
\ Rotating
\ \ direction
1st mark
1st mark "Up" position
2
3
3) Confirm the stop operation then the plug (12 pins) coming from the machine head into
the receptacle.
-3-
From the library of: Superior Sewing Machine & Supply LLC

5. LUBRICATION (Fig.4)
Pour oil up to position A of the oil tank.
During operation, check the oil level periodically,
and
in cases where the oil level is below position B
replenish the
oil supply up to position A.
Use white spindle oil.
6. CONDITION OF OIL LUBRICATION (Fig.S)
While operating the machine, check the
condition
of oil lubrication through the oil check
window.
7. LUBRICATION ADJUSTMENT
(Fig.6)
Adjusting the lubrication of rotating hook
Oil adjusting screw (A) can adjust the
_]ubrication of the rotating hook as follows:
(1)
Tum oil adjusting screw (A) clockwise to
increase oil
and turn oil adjusting screw (A)
counter-clockwise
to decrease oil.
(2) Oil adjusting screw (A) adjusts oil amount
within 5 turns. When oil adjusting screw (A) is fully
tightened, oil amount is maximum.
(3) Readjustment depends
on temperature,
sewing speed and the like. In practice, oil amount
can be
judged as follows: remove the throat plate and
place a piece
of paper on instead, run the machine for
about 20 seconds, then check the oil splashed
on the
paper.
8. ADJUSTMENT OF OIL PUMP
(Fig.7)
The standard adjustment is as follows: The
adjusting plate keeps the bypass hole fully closed.
To
decrease splashing, open the bypass hole
appropriately
-4-
A 6
7
From the library of: Superior Sewing Machine & Supply LLC

9. REGULAR CLEANING (Fig.8)
1) Cleaning feed dog
Remove the throat plate and clear
off the dust and lint between feed dog tooth slots.
2) Cleaning rotating hook
Swing out the machine
head and clean the hook. Wipe the bobbin case with soft cloth.
3) Cleaning oil pump, screen
Swing out the machine head and clear
off the dust and dirt on oil pmnp screen.
Feed dog
10. WINDINGADJUSTMENT (Fig.9)
I) The wound bobbin thread should be neat and tight, if not, adjust the winding tension by turning tension
stud nut (A)
ofbobbin winder tension bracket.
Note: nylon or polyester thread should
be wound with little tension; otherwise, bobbin (D) might break or
defonn
2) When the wound thread layer does not present a cylindrical shape as shown in Fig.9 (a), lo,osen set screw
(B)
of bobbin winder tension bracket and slide bracket (C) leftward or rightward. If thread is wound as shown in
Fig.9 (b), move the bracket rightward, but if thread is
wound
as shown in Fig.9 (c), move the bracket leftward.
After adequately positioning the bracket, tighten set
screw (B).
3) Do not overfill the bobbin. The optimum length of
thread will fill about 80% of bobbin capacity. This can be
adjusted by adjusting screw (E) of bobbin winder stop
latch.
11. REPLACE NEEDLES (Fig.lO)
Turn the balance wheel to lift needle bar to the upper
-5-
10
A
b c
Lo:cg groove
From the library of: Superior Sewing Machine & Supply LLC

end of its stroke. Loosen needle clamp screw (A). While keeping the long groove of the needle leftward fully
insert the needle shank up to the bottom of the needle socket. Then tighten needle clamp screw (A).
Note: Fig. (b): insufficient insertion.
Fig (c): \\'Tong direction of long groove.
12. THREADING (Fig.ll)
To thread the needle thread, raise needle bar to the upper end of its stroke, lead the thread from spool and
perform threading as sho\\n in Fig.3. To draw the bobbin thread, hold the end of the needle thread and turn the
balance wheel to lower the needle bar and then to lift it to its highest position. Pull the needle thread and the
bobbin thread is drawn up. Put the ends of needle thread and bobbin thread frontward under presser foot.
12
Pu~
-~~-----·~Reverse lever
Stitch len~~---;-
adj ust i ng Jit:( I
13. SET STITCH LENGTH AND REVERSE FEEDING (Fig.12)
l) To change the stitch length, rotate the stitch length adjusting dial while pressing the push lever.
2) Pressing the reverse lever to reverse stitching.
3) The button switch can be pressed to perform reverse stitching.
4) Normally, set the button switch as illustrated by the solid lines. To reverse stitching, press the button
switch.
14. ADJUSTING THE THREAD TENSION (Fig.13)
0 X X 13
~ d:==?ii*? ~~
Wei I balanced The upper thread is The upper thread is
stitch too tight or lower too loose or lower
thread is too loose thread is too tight
-6-
From the library of: Superior Sewing Machine & Supply LLC

15. UPPER THREAD TENSION (Fig.14)
1) The upper thread can be adjusted based on the
lower thread tension.
2) Adjustment can be done by rotating the thread
tension
nut. For special fabric sewing with special thread,
the desired tension can
be obtained by adjusting the
strength and operating range
of thread take-up spring.
16. LOWER THREAD TENSION (Fig.15)
1) The lower thread tension can be adjusted by
rotating screw A
•
17. ADJUSTMENT OF FEED DOG INCLINATION (Fig.16)
The feed dog has been set to standard
(horizontally).
If necessary, adjust the inclination
according
to the material to be sewn as follows:
1) Slightly loosen screw A located in the feed
rock shaft crank.
2) Using a screwdriver. While pressing the
groove located in the eccentric shaft
by using
a screwdriver, rotate the eccentric shaft
clockwise (to lift the front end)
or
counter-clockwise (to lower the rear end).
3) When adjustment is completed, tighten screw
A
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Position of mark on the
eccentric shaft
~-
Horizontal
8)'
Up
ffi\
Down
Eccentric shaft
14
ead tension nut
Feed dog
~
Standard
~
Front up
(MAX.)
~
Front down
(MAX.)
From the library of: Superior Sewing Machine & Supply LLC

18. ADJUSTMENT OF THREAD TRIMMER MECHANISM
1) Thread trimmer mechanism as shown Fig.l7
Operation stroke
of the thread trimmer solenoid
(1) Standard operation stroke is 6.0
mm.
(2) This stroke can be adjusted by using nut A.
I F1xed blade bracket untt I
~
Thread gUide~~ @
F1xed blade , '
Movable kn1fe (left) Knife dr~ving Knife dnvmg
cr<.mk shaft
Tw1st spr~ng
Collar '\
'
-----·-----·-----·----- --,
I Thread tnmmer solencud urut :
A
\\
Fle.,ble w~re
· Tw1st spnng
' Stopper
Cam
follower
crank (1 I Cam
follower Drive lever Stopper plate
crank(2}
2) Adjustment of knife engagement (Fig.l8)
(1) Position of movable knife (left) and fixed blade.
See the illustration. The standard distances from
the needle center are 6.5 nun and 3.3 mm from
the movable knife (left) and fixed blade
respectively.
(2) Adjustment
of knife engagement. With the
solenoid activated,
tum on the machine. This
rotates the thread trimming cam which rotates the
movable knife (left). When the movable knife
(left) has moved to its farthest distance, the
standard engagement
of the blade is 1.5-2.0 tmn.
(3) Adjustment of knife engaging pressure. If a
thread is poorly cut, particularly when it is thick,
slightly increase the engaging pressure. This
should solve the problem. The engaging pressure
can be adjusted in tllis way: Loosen lock nut
B,
and adjust it by using adjusting screw A
-8-
Fixed blade
Movab Ie kn ife6. 5mm :3. 3mm/ B A
(left) \ V /
Knife driving crank
1. 5-2. Omm
Movable knife (left)
Movable knife (left)
3mm
Fixed blade
Fixed blade
From the library of: Superior Sewing Machine & Supply LLC