HIGHLEAD GC0618-1-SC Instruction Manual

GC0618-1/-SC/-D2/GC0518-1
Heavy Duty Compound Feed
Lockstitch Sewing Machine
Instruction Manual Parts Catalog

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 o when the machine is not in use, or when the operator leaves the seat
3 ) Power must be turned o 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
1 ) 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 GC0618-1 GC0618-1 SC GC0618-1 D2 GC0518-1
Max. Sewing Speed 2000rpm
Stitch Length 0-10mm
Take-up Lever Stroke 71.5mm
Needle Bar Stroke 35mm
Height of Between Main and
Sub Presser Foot
25mm
Presser foot lift by Hand 8mm
Presser foot lift by Knee 14mm
Needle DPX 17 22# 24#
Rotating Hook Double Capacity Hook Large Hook for
Trimmer
Double Capaci-
ty Hook
Lubrication Manual
Motor 370W Clutch Motor Speed adj.
Motor
370W Clutch
Motor

3 PREPARATION AND LUBRICATION
1 ) Cleaning the machine
Before leaving the factory, the machine parts are coated with rust-preventive grease, which
may be hardened and contaminated by dust during storage and shipment This grease must be
removed with gasoline.
2 ) Examination
Though every machine is confirmed by strict inspection and test before leaving the factory,
the machine parts may be loose or deformed after long distance transportation with jolt. A
thorough examination must be performed after cleaning the machine. Turn the balance wheel
to see if there is running obstruction, parts collision, uneven resistance or abnormal noise. If
these exist, adjustment niust be made accordingly before nm-in operation.
3 ) Oiling (Figs 1, 2, 3, 4)
Please do not operate the machine before lubricating well. The points with arrow in the figure
are oil positions. Caution: Please use white spindle oil.
Lubrication of rotating hook (Fig 4)
Add the oil from the oil hole 1 until to the position 2.
Adjusting the lubrication (Fig 4)
Oil adjusting screw 3 can adjust the lubrication of the rotating hook: Turn oil-adjusting screw 3
clockwise to increase oil and turn oil-adjusting screw 3 counter-clockwise to decrease oil.
ABE
Fig 1
GD
Fig 2
C
H
J
Fig 3
F
12
5
4
3
Adjusting
screw
Decreases Increases
Fig 4
ABE
Fig 1
GD
Fig 2
C
H
J
Fig 3
F
12
5
4
3
Adjusting
screw
Decreases Increases
Fig 4
ABE
Fig 1
GD
Fig 2
C
H
J
Fig 3
F
12
5
4
3
Adjusting
screw
Decreases Increases
Fig 4
ABE
Fig 1
GD
Fig 2
C
H
J
Fig 3
F
12
5
4
3
Adjusting
screw
Decreases Increases
Fig 4

4 REPLACE NEEDLES (Fig 5)
1 ) Turn the balance wheel to lift needle bar 1 to the
upper end of its stroke.
2 ) Loosen needle clamp screw 2. While keeping the
long groove of the needle leftward fully insert
the needle shank up to the bottom of the needle
socket.
Caution: The direction of the long groove should
be left.
3 ) Then tighten needle clamp screw 2.
5 WINDING (Fig 6)
1 ) Put the bobbin 3 on the bobbin winder shaft as far
as it will go.
2 ) Bring the thread forward toward the boobin and
wind from below in clockwise direction several
times around the bobbin.
3 ) Push the lever 4 toward other side so that the
winding wheel and “V” belt will engage and then
start the machine.
4 ) The winding wheel will automatically be free from
“V’’ belt and stop after the bobbin is filled with
thread.
6 WINDING ADJUSTMENT
(Fig 6)
1 ) When the wound thread layer does not present
a cylindrical shape, loosen set screw 5 of bobbin
winder tension bracket and slide bracket leftward or
rightward. After adequately positioning the bracket,
tighten set screw 5.
2 ) Do not overfill the bobbin. The optimum length of
thread will fill about 80% of bobbin capacity. This
can be adjusted by adjusting screw 6 of bobbin
winder stop latch.
3 ) Adjusting of the winding tension: The winding
tension can be adjusted by tension screw 7.
Fig 5
AB
12
3
Fig 6
712
5
3
6
4
2
1
Fig 7
Fig 5
AB
12
3
Fig 6
712
5
3
6
4
2
1
Fig 7

7 REMOVING AND
INSERTING THE BOBBIN
1 ) Turn the balance wheel to lift needle bar
1 to the upper end of its stroke. Place the
feed dog at this side in its travel turning the
balance wheel, and open the slide plate A.
(Fig 7)
2 ) Open on the drip pan, and then open the
hinged latch with left thumb and index finger. And pull bobbin case and bobbin from rotary
hook. While the latch is held open, the bobbin will be retained in the bobbin case. Release of
the latch and turning of the open side of the bobbin case downward will cause the bobbin to
drop out.
3 ) Hold the bobbin between the thumb and forefinger of your right hand and pull out a length
of about 5cm of thread. Holding the bobbin case in your left hand turn the open side up and
place the threaded bobbin into it. (Fig 7)
4 ) With the right hand guide the thread into the slot in the edge of the bobbin case. Then pull the
thread to the left, under tension spring 1 (Fig 7) and into the delivery eye. In order to keep the
bobbin from dropping out of the case when it is turned with the open side down, always keep
the hinged latch at the front of the bobbin case open.
5 ) Take the threaded bobbin case by the latch and place it on the center stud of the bobbin
case holder. Release latch and press bobbin case on to center stud until the latch catches the
undercut thereon with a click that can be heard. Permit about 5cm of bobbin thread to hand
down freely. Be sure to push the slide plate to the right before starting to sew.
8 THREADING (Fig 8)
1 ) Raise the needle bar to its highest point and
lead the thread from the thread stand the
following order. From the thread stand lead the
thread from back to front through the lower
guide hole in pin 1 on top of the machine arm,
then again from right to left through the upper
guide hole in this pin. Pass thread in weaving
fashion through the three holes in guide 2,
and from right to left over and between the
tension disc 3. Now pull thread downward and
from right to left beneath and around thread
controller 4, continue to pull thread upward
against the pressure of the wire spring into
the fork 5, in the thread controller. Guide upward through the point of controller discs 6, and
thread guide 7, and from right to left through the eye in take-up lever 8, down through thread
guide 7, again and then through 9, 10, 11 and from left to right through the eye of the needle 12.
2 ) After the above threading, hold the end of thread with your left hand, and turn the balance
wheel with your right hand so that bobbin thread may be picked up by needle thread. And put
their ends of thread back through under the presser foot for starting operation.
Fig 5
AB
12
3
Fig 6
712
5
3
6
4
2
1
Fig 7
Fig 8
A
1
2
34
5
6
7
8
9
10
11 12

9 REGULATING THE THREAD TENSIONS
For ordinary stitching, the tension of the upper and the lower threads should be equal so as to lock
both threads in the center of the material. (1 Fig 9) If the tension on either thread is stronger than on
the other, imperfect stitching will be the result. If the tension on the upper thread is greater than that
on the lower thread, it will lie straight along the upper surface of the material. (2 Fig 9) If the tension
on the lower thread is greater than that on the upper thread, the lower thread will lie straight along
the underside of the material. (3 Fig 9)
1 ) Tension of the upper (needle) thread:
Before adjusting the tension of the upper (needle) thread, be certain that the presser foot is let
down but not in lifted position. To adjust tension, turn serrated nut (A Fig 8) on tension device
to clockwise to increase tension, while turning it to counter-clockwise to decrease it.
2 ) Tension of the lower (bobbin) thread: (Fig 7)
The lower (bobbin) thread tension is controlled by the larger screw (2 Fig 7) near the end of the
spring at the outside of the bobbin case. Turning this screw to clockwise to increase the thread
tension, while turning it to counter-clockwise to decrease it.
10 ADJUSTMENT OF THE PRESSURE
ON THE MATERIAL
The pressure of the presser feet is adjusted by the screw D (Fig 2) with screwdriver. To increase the
pressure, turn the screw to clockwise and to counter-clockwise to decrease it.
1 Well balanced 2 Upper thread strong
or lower thread weak
3 Upper thread weak
or lower thread strong
Fig 9

11 ADJUSTING THE LIFT
OF THE ALTERNATING
PRESSER FEET (Fig 10)
The thickness of the material should control
the height of the lift of the alternating presser
feet. The lift should be just enough for
clearance of the material.
1 ) With normal adjustment both feed lift to equal height: To later lift, loosen the wing nut A and
move the link and stud assembly along the slot-move up to raise the feeding presser foot and
push down to lower this foot. Tighten wing nut upon completion of adjustment. However, some
materials may require unequal height of lift.
2 ) When altering the lift of the lifting presser foot (A Fig 5) unequally against that of the vibrating
presser foot (B Fig 5) or vice versa, see the instructions “19 ADJUSTING THE HEIGHT OF THE
PRESSER FEET”
12 STITCH LENGTH
ADJUSTMENTS AND
REVERSING LEVER (Fig 11)
Stitch length can be set by turning the detail 2. Numeric
figures on the dial show the stitch length in mm. The
desired numeric figure on the dial should be set at just
above, while depressing the reversing lever 1 slightly.
13 ADJUSTING THE HEIGHT
OF THE FEED DOG (Fig 12)
The maximum height of the feed dog (1 Fig 12)
from the surface of the needle plate (2 Fig 12) is
normally 1mm.
1 ) Lay down the machine head toward the
other side, and turn the balance wheel so as
to raise the feed dog to it highest point.
2 ) Loosen bell crank screw F (Fig 4) and adjust
the height of the feed dog by raising or
lowering it.
3 ) Securely tighten the screw upon completion
of adjustment.
Fig 10
Fig 11
Fig 12
A
1
2
1 Feed dog
1mm2 Needle plate
Fig 10
Fig 11
Fig 12
A
1
2
1 Feed dog
1mm2 Needle plate
Fig 10
Fig 11
Fig 12
A
1
2
1 Feed dog
1mm2 Needle plate

14 RELATIVE POSITION
OF THE FEED DOG
TO NEEDLE PLATE (Fig 13)
1 ) Set the stitch length at minimum.
2 ) Turn the balance wheel so as to raise the feed
dog to its highest point.
3 ) Lay down the machine head toward the other
side and loosen the screw 5 (Fig 4).
4 ) Adjust to be 32.1mm from the edge of the
needle plate to the center of the needle hole on
the feed dog. (Fig 13)
5 ) Securely tighten the screw.
15 THE POSITION OF THE
NEEDLE AND
THE NEEDLE HOLE OF THE
FEED DOG
Turning the balance wheel to lower slowly the needle
bar, check whether the needle descends to the center of
the needle hole of the feeder or not. (Please check again
the needle is perfect one.)
1 ) Remove the cover G (Fig 2) and loosen the screw 1
(Fig 14) slightly.
2 ) Holding the bottom of the needle bar rock frame H
(Fig 3), move it as may be required to get the correct
position to the feed dog.
3 ) Tighten the screw and close the cover.
16 TIMING THE NEEDLE
WITH FEED DOG
(Figs 15, 16)
It is important that the timing relationship between
the needle on its downward stroke and the feed dog
movement is maintained at all times. When the scarf of
the needle on the downward stroke reaches the top
surface of the feed dog, the feed dog movement must
start. When adjustment is required, use the following
procedure to change the position of cam.
Fig 13
Fig 14
Fig 15
Fig 16
32.1mm
1
1
2
910 6
11 8 7 5
Fig 13
Fig 14
Fig 15
Fig 16
32.1mm
1
1
2
910 6
11 8 7 5
Fig 13
Fig 14
Fig 15
Fig 16
32.1mm
1
1
2
910 6
11 8 7 5

1 ) Loosen the screw 1 for cover plate 2 and then
remove the cover plate 2.
2 ) Normally put the arrow mark 7 of the cam 6 on
the “V” ditch 5 of arm shaft. Then tighten the
cam screw.
3 ) Turn the balance wheel to the needle at 1mm up
from its lowest point.
4 ) Pushing the stitch length regulating lever up
and down, turn the cam 6 and set this at the
point both the needle and the feed dog rest.
After positioning completed, tighten each screw
securely.
17 ADJUSTING THE HEIGHT OF
THE NEEDLE BAR (Fig 17)
When the needle bar is at its highest point, normally the
measurement between the surface of the needle plate and
the upper end of the needle eye is 22.3mm.
You can also adjust this at its lowest point. In this case,
normally the measurement between the surface of the
needle plate and the upper end of the needle eye is 11mm.
To adjust this, loosen the screw J (Fig.3) and raise or lower
the needle bar as may be required. Then, tighten the screw upon completion of adjustment.
NOTE: These measurements are approximate standard, accordingly, following final adjustments “18
TIMING BETWEEN THE HOOK AND THE NEEDLE” are recommended.
Fig 13
Fig 14
Fig 15
Fig 16
32.1mm
1
1
2
910 6
11 8 7 5
Fig 17
Fig 18
22.3mm
2.4mm
Fig 19
Fig 20
0.05mm-0.1mm
1
2
345
Fig 17
Fig 18
22.3mm
2.4mm
Fig 19
Fig 20
0.05mm-0.1mm
1
2
345
Fig 17 Fig 18
22.3mm
2.4mm
Fig 19
Fig 20
0.05mm-0.1mm
1
2
345

18 TIMING BETWEEN
THE HOOK AND
THE NEEDLE
(Figs 18, 19)
After setting the needle bar height, set stitch
length to minimum, turn the balance wheel
toward you until the needle bar reaches its
lowest point. Continue turning and allow
the needle bar to raise about 2mm while
on its upward stroke. With needle bar in
this position, the point of the sewing hook
should be at the center of the needle, and normally, the measurement between the hook point and
the upper end of the needle eye should be 2.4mm, further the clearance between the hook point
and the needle hollow should be about 0.05mm to 0.1mm.
1 ) If the sewing hook should not be timed correctly, loosen the three set screws. Tum the hook
shaft to align the hook point with the center of the needle. Re-tighten the three set screws and
re-check the timing of the sewing hook.
2 ) To adjust the clearance between the hook point and the needle hollow, loosen the two screws
and move the hook to the right or to the left as may require. Please note one of the two
screws is placed on the “V” ditch of hook shaft. Therefore, keep the screw on “V” ditch during
adjustment. Re-tighten the screws.
19 ADJUSTING THE HEIGHT OF
THE PRESSER FEET (Fig 20)
1 ) Adjustment by the presser bar lifter
Loosen the screw 1 suciently raise the presser bar lifter and loosen the set screw 2. Move the
lifting presser foot up or down as may be required so as to get the correct height and tighten
the screws.
2 ) Adjusting the lift of alternating presser feet
If the height or the lifting presser foot changes, the momentums of the lifting and vibrating
presser foot vary thus the height of the vibrating presser foot must be adjusted. To adjust this,
lower the presser bar lifter, holding the vibrating presser foot B (Fig.6) and loosen the hexagon
screw 3 and move the presser foot up or down as may be required. After setting the position
tighten the screw.
Fig 17 Fig 18
22.3mm
2.4mm
Fig 19
Fig 20
0.05mm-0.1mm
1
2
345

20 TIMING OF THE VIBRATING PRESSER FOOT
This is the normal liming when turn the balance wheel toward you, after lowering the presser bar
lifter, the vibrating presser foot should reach the feed dog earlier than the needle eye comes to,
and when the needle raises, the vibrating presser foot should leave the feed dog after the needle
eye has left the feeder. This is due the reason that the vibrating presser foot must lightly hold the
goods while the needle is passing the goods for avoiding irregular stitches. To adjust this, set the
lift of the alternating presser feet to equal, loosen the two screws 4 (Fig 20) and adjust the rotating
position of the cam 5 (Fig 20) faster or slower as may be desired, and tighten the screws.
21 ADJUSTMENT OF THE CLEARANCE BETWEEN
FEED FORKED CONNECTION A D FEED FORK
COLLAR (Figs 15, 16)
Incorrect clearance between the fork 8 of feed forked connection and feed fork collar 9 will bring
irregular stitch length or overheating etc. To adjust this, open the cover plate. Remove the cover
plate and the oil reservoir. To increase the clearance, loosen the screw and turn the screw to left or
counter-clockwise. This adjustment should be done with turning the balance wheel toward you to
get correct clearance. Upon completion of adjustment, tighten the screw which is loosened to touch
the feed fork.
22 ADJUSTING THE THREAD
CONTROLLER
SPRING (Fig 21)
Normally, the thread controller spring 1 should hold
slack of the upper thread until the needle reaches to the
goods, and it should pause while raising of the needle
and passing of the upper thread through the bobbin
case.
1 ) For more controller action on the thread: Loosen
the stop screw 2, move the stop to the right (For
less action, move to the left). Tighten the screw.
2 ) To adjust the tension spring: Loosen the serrated
nut 4 and the screw 5. Turn the tension stud 6
slightly to the left to strengthen the tension (to lighten the tension, turn to the right) with a
screwdriver. Tighten the screw and nut upon completion of adjustment.
Fig 21
Fig 22
4
5
1
6
3 2
Adjusting tool
Before
After
Pully
B

23 ADJUSTMENT
OF NEEDLE BAR
STOP POSITION
(Figs 22, 23)
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 3mm adjust as follows:
Disconnect the plug (12 pins) of
cable from the machine head.
Run the machine and stop at “UP”
position.
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 heel the machine stops as “DOWN” position. If the
marks deviate larger than 3mm adjust as follows:
Disconnect the plug (12 pins) of cable from the machine head.
Run the machine and stop at “DOWN’’ position.
While holding the balance wheel insert the “adjusting tool” in the hole B, then remove the tool.
3 ) Confirm the stop operation then the plug (12 pins) coming from the machine head into the
receptacle.
Fig 21
Fig 22
4
5
1
6
3 2
Adjusting tool
Before
After
Pully
B
Fig 23
3rd mark
1st mark
Rotating
direction
Timing
mark arm
1st mark “UP” position
3rd mark “DOWN” position

24 ADJUSTMENT OF
KNIFE ENGAGEMENT
(Fig 24)
1 ) Position of movable knife (left) and
fixed blade:
See the illustration. The standard
distances from the needle center are
7.5mm and 7mm 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
1.5mm to 2.0mm.
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 this way: Loosen lock nut B and adjust
it by using adjusting screw A.
Fig 24
Fixed blade
B A
Knife driving crank
7mm7.5mm
Moveable
knife (left)
1.5mm-2mm
Fixed blade
Moveable knife (left)
Moveable knife (left)
3mm
Fixed blade