HIGHLEAD GC1998-MCDZ User manual

GC1998-MCDZ
High Speed Semi-Dry Direct Drive Lockstitcher With Edge
Cutter And Thread Trimmer
Instruction Manual
Parts Catalog
S
HANGHAI BIAOZHUN HAILING SEWING MACHINERY CO., LTD
.

----- CONTENTS -----
1. PRECAUTIONS BEFORE STARTING OPERATION······································································1
1) Safety precautions····························································································································1
2) Precaution before Starting Operation····························································································1
3) Precaution for Operating Conditions ····························································································1
2. PREPARETION BEFORE START TO OPERATE ···········································································1
Adjustment of needle bar stop position ·························································································1
3. PRECAUTIONS FOR STARTING TO OPERATE············································································2
1) Lubrication ·····································································································································2
2) Adjustment of the amount of oil for hook ·····················································································2
3) Periodical cleaning···························································································································2
4) Precaution for detector····················································································································3
4. HOW TO USE THE MACHINE ··········································································································3
1) How to attach needle·······················································································································3
2) Threading·········································································································································3
3) Adjusting of stitch length & reverse lever··················································································· 4
4) Adjustment of the thread guide······································································································4
5) Adjusting of pressure of presser foot·····························································································5
6) Adjusting the thread tension···········································································································5
7) Adjustment of upper thread tension······························································································5
8) Adjustment of lower thread tension·······························································································5
9) Thread wiper (for machine equipped with thread wiper)·························································· 6
10) How to wind the lower thread on the bobbin················································································6
11) Adjustment of feed dog height and inclination·············································································6
12) Adjustment of remaining needle thread length after thread trimming······································7
13) Adjustment of feed timing ··············································································································7
14) Adjustment of forward/backward stitch length············································································7
15) Adjustment of knife engagement····································································································8
16) Installing of the neddle plate···········································································································9
17) Cloth cutting knife···························································································································9
18) Other replacement parts···············································································································10
5. SPECIFICATIONS······························································································································10
6. PARTS CATALOG·······························································································································11
A) Arm bed & Its accessories·············································································································11
B) Needle bar and thread take-up mechanism·················································································14
C) Feeding and feed lifting mechanism·····························································································16
D) Stitch regulator mechanism··········································································································18
E) Knife mechanism···························································································································22
F) Presser foot mechanism·················································································································24
G) Thread trimmer mechanism·········································································································27
H) Touch back mechanism & Detector mechanism·········································································30
I) Motor mechanism··························································································································32
J) Oil lubrication mechanism············································································································34
K) Accessories······································································································································36

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1
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 pulley.
(2) Power must be turned off when the machine is not used,.
(3) The power must be turned off before tilting the machine head, installing or adjusting the machine, or
when replacing.
(4) Avoid placing fingers, hairs bars etc. nears the pulley, bobbin winder pulley, when the machine is op-
eration. Injury could result.
(5) Do not insert fingers into the thread take-up cover, under/round the needle, or pulley when the ma-
chine is in operation.
(6) If a mini motor cover, finger guard, and/or eye guard are installed, do not operate the machine with-
out these safety devices.
2) Precaution 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 pulley with the
power on.
(The pulley should rotate counterclockwise when viewed from the pulley.)
(4) Verify the voltage and (single or three) phase with those given on the machine nameplate.
3) Precaution for Operating Conditions
(1) Avoid using the machine at abnormally high temperature (35℃or higher) or low temperatures (5℃
or lower). Otherwise, machine failure may result.
(2) Avoid using the machine in dusty conditions.
2. PREPARETION BEFORE START TO
OPERATE
Adjustment of needle bar stop position
1)Adjust 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.
(1)Loosen the screw1 and 2，

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2
(2)Run the machine and stop at "UP" position. Then turn the magnet base counter clockwise until the
screws 4 on the upside and then tight the screws.
(3) When the 1st mark of pulley is align with the timing mark arm, tighten the screw 2, then tight the screw
1.
3. PRECAUTIONS FOR STARTINGTO OPERATE
1)Lubrication
Before starting sewing machine operation, fill oil for hook
lubrication into the oil tank.
(1)Remove the rubber plug from the oil port, and fill the oil
from the oil port.
(2)Fill in oil until the tip of the oil level indicator matches
the line in the oil check window.
(3)When done filling the oil, set the rubber plug into the oil
port.
(4)If the tip of the oil level indicator drops below the line in
he oil check window during operation, replenish the oil .
2)Adjustment of the amount of oil for hook
turn the oil level adjustment screw, and adjust amount of oil
for hook..
3) Periodical cleaning
a. Machine
(1) Remove the throat plate and clean the feed dog.

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3
(2)Assembling is to be made by screwing in the screw by 2
to 3rotations by hand at first, then tightening them evenly
by use of a long size screw driver.
3)Lay down the machine head and clean the hook and inner
bobbin case.
b. Maintenance of motor
Remove dust from the motor filter every one or two month.
(If operation is continued with the filter clogged with lint
or dust, the motor might overheat.)
c.Control box
Remove dust from the connector (If the connector covered
with dust, machine might misoperation.)
4) Precaution for detector
The lights type detection element is used in the mini motor. Thus, take care not to adhere dust or oil on the
detector plate sewing machine pulley is removed for adjustments, etc. If dust or oil does adhere, wipe off
with a soft cloth.
4. HOW TO USE THE MACHINE
1) How to attach needle
Note: Before making the following adjustment, be sure to
switch off the power source.
Insert the needle up to the bottom of needle clamp and tigh-
ten the screw keeping the long groove side of needle forward
the left．
Note: if snapping of thread occurs during back Sewing with
polyester threads，it may be avoided by fitting the
needle with the long groove Shifted to the front side．
Use DB×1 or DA×1 needle.According to fabric & thread ,please choose the size of needle as follows.
Size of Needle No. of thread Fabric
#9 #100 to #80 Extra thin fabric such as de Chin, Georgette, Organdy.etc
#11 #80 to #60 Thin fabric such as Silk, Calico, Poplin. etc.
#14 #60 to #50 General fabrics such as Cotton,Wooden fabric ,etc.
#16 #50 to #30 Thick Cablico,Thick wooden fabric, Water proof cloth, thin leather,ect.
#18 #40 to #20 Thick fabric such as Suiting and Coat material, thin Pouches, Denim ,
ect.

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4
2) Threading
Raise the thread take-up lever to its highest position and thread the upper thread in the following order.
3)Adjusting of stitch length & reverse lever
(1)Rotate the drop feed dial while depressing the reverse
lever and then, pressing the push lever, when making the
stitch length shorter.
(2)If the reverse lever is depressed, reverse sewing (back-
ward sewing) will take place.
(3)Touchback switch
a. With the push-button (touchback switch) pressed lightly
during sewing, reverse sewing can be done.
Reverse sewing will take place while the push-button is
pressed.
When the push-button is released, reverse sewing turns into
forward sewing.
b. When the push-button is turned 180 degrees in the direc-
tion of the arrow, the switch will be locked, and backward
sewing will not take place even if the button is pressed.
4) Adjusting of the thread guide
1 2 3
Thread guide position
Left Middle Light

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5
Materials Heavy Medium Light
Thread(Ref.)
Polyester
Cotton
Vinylon #30 or more
Polyester #50 to #60
Polyester
#50 to #60
Cotton
Vinylon #50 to #80
Refer to the table above, and adjust according to the stitching conditions, the material and thread
5) Adjusting of pressure of presser foot
Pressure of the presser foot can be adjusted by
turning the pressure regulating thumb screw
6) Adjusting of thread tension
7)Adjusting of upper thread tension
(1) Upper thread tension can be adjusted by thread
tension nut.
(2)Upper thread is to be adjusted according to the lower
thread tension.
(3)For special fabric sewing with special thread, the de-
sired tension can be obtained by adjusting the strength
and operating range of thread take-up spring.
8) Adjusting of lower thread tension
(1) Lower thread tension can be adjusted by screw (A).
(2) In the case of cotton thread #60, the thread ten-
sion can be checked as the following. Hold the
end of pulled out thread and if the bobbin case
fall slowly, the tension is proper.

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6
9) Thread wiper(for machine equipped with thread wiper)
(1) When the thread wiper is operated, in next sewing at starting point the end of upper thread does not remain
on the surface of fabric.
(2) Turn the switch OFF when not required. The switch is located in the wiper solenoid cover behind the arm.
10) How to wind the lower thread on the
bobbin
(1) Press the bobbin onto the thread winding shaft.
(2) Pass the thread for winding thread as shown in
the figure, and wind the end of the thread clock-
wise around the bobbin several times, then wind
the thread on the thread adjuster side coun-
ter-clock wise several times.
(3) Press lever ①in the direction of the arrow, and
start the sewing machine.
(4) The operation will automatically stop when
winding is completed.
(5) Adjustment of thread winding strength
Adjust with the thread adjuster nut ②.
(6) Adjustment of thread winding amount
Adjust by loosening screw ③and moving the
adjustment plate ④
a. The thread winding amount will decrease when
moved in the direction of a.
b. The thread winding amount will increase when
moved in the direction of b.

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7
11) Adjustment of feed dog height and inclination
(1) As a standard, the eccentric shaft ①mark on the left of the horizontal feed arm is set to the direct
left side, and the feed dog height is set to 0.8mm (maximum) as shown in the figure.
(2) To adjust the feed dog height and inclination,
loosen the screw ③, and turn the eccentric
shaft ④, loosen the screw ②at the left of the
horizontal feed arm, and turn the eccentric shaft
①.
(3) When the eccentric shafts are set to "DOWN"
position, puckering may be avoided and free
loop is less likely to occur.
(4) When the eccentric shafts are set to "UP" posi-
tion, misalignment of fabrics is less likely to oc-
cur and yarn severance may be avoided.
12) Adjustment of remaining needle thread
length after thread trimming
(1) Turn the pretension nut ①and adjust.
(2) When turned clockwise, the length of thread left
in the needle will be short.
When turned counterclockwise, the length of the
thread left in the needle will be long.
13) Adjustment of feed timing
(1) Adjust by changing the position of the vertical
feed eccentric ring.
(2) As a standard, the vertical feed timing Is set to
when the screw ①on the bearing bushing is
linear with screw ②on the vertical feed eccen-
tric ring.
(3) When the eccentric ring is moved in the direction
of a, the vertical feed dog will rise earlier.
(4) When the eccentric ring is moved in the direction
of b, the vertical feed dog will rise later.

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8
14) Adjustment of forward/backward stitch length
(1) Loosen screw ①on the right of the adjustment arm.
(2) Turn the eccentric shaft ②and adjust.
(3) The forward stitch length will increase and the backward
length will decrease when the eccentric shaft ②is turned
counterclockwise.
(4) The forward stitch length will decrease and the backward
length will increase when the eccentric shaft ②is turned
clockwise.
15) Adjustment of knife engagement
a. Position of fixed knife
(1) As a standard, the dimension between the fixed
knife's end and the needle center is 2.5mm.
(2) The standard relation of the knife (left) and fixed
knife is shown in the figure. As a standard, Di-
mension A is 0.3mm.
(3) When Dimension A is too large, the three piece
of threads will be cut, and can cause the needle
thread to come out from needle after trimming. If
too small, the thread may not be trimmed cor-
rectly.
(4) Adjust by adjusting the installation of the fixed
knife.
b. Knife engagement amount
(1) When the sewing machine is rotated while the
solenoid is activated, the knife (left) will be rotated by
the thread trimming cam.
As a standard, the knife engagement amount should be
1.5 to 2.0mm when the knife (left) moves the most.
(2)Adjust by adjusting the installation of the drive arm.
c. Adjustment of knife engagement pressure
(1)As a standard, the knife (left) and fixed knife should
start contacting at the position shown in the figure.
2) To adjust the engagement pressure, loosen the lock nut ②and then adjust the adjustment screw ①.

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9
16). Installing of the neddle plate
To attach the needle plate, bring the cloth-cutting knife to its lowest position, and gradually tighten the two
set screws alternately while lightly pressing the needle plate onto the cloth-cutting knife.
17) Cloth cutting knife
1) Operation of the cloth cutting knife
(1) To actuate the cloth-cutting knife, press
down knife setting plate 1.
(2) To stop the cloth-cutting knife and reset
the machine to the normal lockstitching
mode, pull knob 2 in the direction of the
arrow.
2) Attaching the cloth cutting knife
(1) Raise or lower the cloth-cutting knife so
that section A of the cloth-cutting knife
is positioned 0-0.5 mm below the top
face of the needle plate when the knife is
in its lowest position.
(2) Loosen two knife set screws 1, and re-
place the cloth-cutting knife.
3) Changing the cutting width
(1) The needle plate decides the cutting
width. When the needle plate is replaced,
loosen knife guiding shaft set screw 1 so
that proper parallelism is obtained and
the sharpness of the knife blade is increased as shown in the figure.
(2) When the position of the knife is changed in accordance with the change of the needle plate size,
loosen set screw 2, and position the knife so that the blade of the needle plate comes in contact
with the knife blade. Then tighten set screw 2.
(3) For the standard machine, a 3.2 mm wide needle plate is installed at the time of delivery.

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10
18) Other replacement parts
The standard cutting width of the machine is 1/8” (3.2mm). We offer the other specs according to your need.
Please choose as follow sheet.
Cutting width Needle plate Feed dog Presser
1/ 8＂（3.2） H5716B7101 H5705B8001 H5705G7101
3/16＂（4.8） H5724B7101 H5705B8001 H5705G7101
1/ 4＂（6.4） H5725B7101 H5706B8001 HA316H0070
5. SPECIFICATIONS
Note: Always use a hook and bobbin case dedicated for the thread trimmer use a high quality bobbin that
will not deform.
Material weight GC1998-MCDZ
Max. speed 4500rpm
Stitch length 0 to 4mm
Needle bar stroke 31.8mm
Presser foot
clearance
Hand Lifter 6 mm
Knee lifter 13 mm
Needle type DB×1 #14
Hook (for thread trimming) Full rotation automatic lubrication (standard)
Touch back yes
Thread trimming method Left knife rotating, right knife fixed engagement type
Working dimensions 300×135 mm

A.ARM BED AND ITS ACCESSORIES
— 11 —

Fig.
No. Part No. Description Pcs. Remarks
A01 HB2252N072 Bobbin winder base 1
A02 H6723N8001 Cam shaft 1
A03 H6722N8001 Wash 1
A04 H007013050 E-type stop ring 2
A05 HA100H2150 Screw 1
A06 H6721N8001 Adjust plate 1
A07 H3200B2100 Screw 1
A08 H6720N8001 Spanner 1
A09 H6717N8001 Seat 1
A10 H6716N8001 Shaft 1
A11 H6715N8001 Spring 1
A12 H6724N8001 Spring 1
A13 H6711N7101 Winch 1
A14 H431040060 Screw 2
A15 H6719N8001 Rubber rub 1
A16 H6718N8001 Rub ring 1
A17 H6725N8001 Cam 1
A18 H431050060 Screw 1
A19 HE71B88001 Side cover 1
A20 HA300B2170 Screw 8
A21 HA300B2160 Screw 4
A22 HA307B0674 Rubber plug 4
A23 HE71B68001 Face plate 1
A24 HE71B78001 Gasket for face plate 1
A25 H6732P8001 Holder 1
A26 H6731P8001 Felt 1
A27 H6705H8001 Needle bar connecting linkGuide 1
A28 HA300C2030 Screw 2
A29 H3204G0652 Felt 1
A30 HA300B2090 Rubber plug 1
A31 HA307B0673 Rubber plug 1
A32 HA700B2060 Screw 1
A33 HA700B2050 Thread guide 1
A34 H3107G0662 Screw 3
A35 H6756B8001 Thread cutter 1
A36 H6762B8001 Screw 2
A37 HA710B0671 Nut 2
A38 H6739B8001 Thread tension spring 1
A39 HA310B0705 thread tension discs 2
A40 H6735B8001 Screw 1
A41 H6736B8001 Thread guide 1
A42 H6737B8001 Spacer 1
A43 HG50Q78001 Motor cover 1
A.ARM BED AND ITS ACCESSORIES
— 12 —

Fig.
No. Part No. Description Pcs. Remarks
A44 HZ11050200
Screw
5
A45 H6760B8001
Spacer
1
A46 H8844B8001
Bed stud (right)
1
A47 HA104F0654
Screw
3
A48 HA800F2020
Screw
2
A49 HA710B0672
Pre-tension spring
1
A50 HA112B0693
Thread tension discs
2
A51 HA710B0673
Screw
1
A52 HA710B0674
Thread guide
1
A53 HA100B2110
Screw
1
A54 H6764B7101
Screw
1
A55 H6758B8001
O-ring
1
A56 HA106B0676
Screw
3
A57 HA100B2140
Thread guide
1
A58 HB2251I081
Thread take-up cover
1
A59 HA300B2080
Screw
1
A60 HDB8168001
Chip guide piate
1
A61 H5727B8001
Screw
2
A62 HA500C2060
Thread guide
1
A63 HA106B0675
Thread guide
1
A64 H6725B8001
Pin
1
A65 HA115B7011
O-ring
1
A66 HA115B0708
Screw
1
A67 HA310B0703
Thread tension regulator bushing
1
A68 HA115B0706
Thread take-up spring
1
A69 HA115B0701
Thread tension stud
1
A70 HA310B0702
Thread tension releasing discs
1
A71 HA115B0703
Thread tension spring
1
A72 HA115B7010
Thumb nut revolution stopper
1
A73 HA310B0701
Thumb nut
1
A74 H6727B8001
Bed stud (left)
1
A75 HA124B0711
Slide plate
1
A76 HA124B0712
Spring for slide plate]
1
A77 HA124B0713
Screw
2
A78 H5716B7101
Needle plate
1
A79 HA300B2190
Screw
4
A80 H8810P8001
Screw
1
A81 H8812P8001
Washer
1
A82 H5727B8001
Screw
2
A83 HK62B38001
Chip funnel plate
1
A84 HK61B58001
Chip funnel
1
A85 H5721I8001
Clip plate
1
A.ARM BED AND ITS ACCESSORIES
— 13 —

B.NEEDLE BAR AND THREAD TAKE-UP MECHANISM
— 14 —— 14 —

Fig.
No. Part No. Description Pcs. Remarks
B01 HM00C48001 Upper shaft 1
B02 HK60C68001 Crank 1
B03 HA100C2070 Screw 1
B04 HA307C0662 Screw 2
B05 HA100C2060 Screw 1
B06 H3208H0661 Ball bearing 1
B07 H6711C8001 Bushing 1
B08 H431060080 Screw 2
B09 H6713C8001 Bobbin winder driving wheel 1
B10 H431060080 Screw 5
B11 H6708C8001 Belt pulley (upper) 1
B12 H6715C8001 Screw 2
B13 H8805C8001 Belt 1
B14 H3205J0662 Ball bearing 1
B15 H6717C8001 Bushing 1
B16 H6706I7101 Thread take-up lever assy. 1
B17 H6710I8001 Thread take-up lever link 1
B18 H6711I8001 Thread take-up crank 1
B19 H6712I7101 Needle bar link assy. 1
B20 H6715I8001 Screw 1
B21 HA104C0658 Needle bar holder 1
B22 H2204C0651 Screw 1
B23 H24211D405 Oil wick 1
B24 H24211D305 Plug 1
B25 HA100C2020 Screw 1
B26 H6716I8001 Thread take-up support shaft 1
B27 H6717I8001 Bearing 1
B28 H6718I8001 Bearing support 1
B29 H6719I8001 Thrust collar 2
B30 HA100B2110 Screw 1
B33 HA300B2090 Bushing 1
B34 HK61C38001 Needle bar（φ1.62） 1
B35 HA500C2030 Thread guide 1
B36 Needle 1 DB×1 #14
B37 HA100C2170 Screw 1
B38 H6706H8001 Square block 1
B.NEEDLE BAR AND THREAD TAKE-UP MECHANISM
— 15 —

C.FEEDING AND FEED LIFTING MECHANISM
— 16 —— 16 —

Fig.
No. Part No. Description Pcs. Remarks
C01 HK61D78001 Pin 1
C02 HK61D88001 Shaft 1
C03 HK61D38001 Guide crank 1
C04 HA300B2160 Screw 1
C05 HA100C2020 Screw 5
C06 HK61D68001 Eccentric shaft 1
C07 HA104C0656 Screw 1
C08 HK60D98001 Thrust collar 1
C09 H9116E8001 Link 1
C10 H431050050 Screw 1
C11 HK60D78002 Feed lifting connecting rod 1
C12 H6724D8001 Connecting stud 1
C13 H9108D8001 Bearing support 2
C14 HK60D68002 Needle bearing 2
C16 HK61D18001 Bushing 1
C17 HA307C0662 Screw 6
C18 H6711D8001 Ball bearing 1
C20 H6714B8003 Bushing 1
C21 H6745B8001 Oil seal 2
C22 H9106D8001 Feed lifting rock shaft 1
C23 H6708D7101 Gear(large) 1
C24 H6705E8001 Lever feed eccentric cam 1
C25 H6720E8001 Needle bearing 1
C26 H8807D8001 Belt pulley(lower) 1
C27 H431060080 Screw 2
C28 H3208H0661 Ball bearing 1
C29 H8812D8001 Ball bearing 1
C30 H6714B8001 Bushing 1
C31 HA7311C306 Screw 3
C32 H30211C406 Thrust collar 1
C33 H6706E8001 Lever feed connecting rod 1
C34 HA706C11B1 Pin 1
C35 H6724E8001 Link 2
C36 H6709E8001 Link 2
C37 HA7311C806 Screw 3
C38 H6709F8001 Oil seal 1
C39 H6716B8002 Lower shaft bushing(left) 1
C40 H6747B8001 Oil seal 1
C41 H6711F7101 Rotary hook assy. 1
C42 HA300E2050 Rotating hook positioner 1
C43 HA100E2150 Screw 1
C44 HA700E2060 Bobbin
C45 HA708E0068 Bobbin case assy. 1
C.FEEDING AND FEED LIFTING MECHANISM
— 17 —

Fig.
No. Part No. Description Pcs. Remarks
C46 H6709D8001 Gear(small) 1
C47 H8832B8001 Lower shaft bushing(right) 1
C48 H6747B8001 Oil seal 1
C49 H6707F8001 Ball bearing 1
C50 H6708F8001 Bushing 1
C51 HA300B2130 Screw 2
C52 HA710E0691 Thread trimmer cam 1
C53 HA710E0692 Screw 1
C54 H8804F8001 Lower shaft 1
C55 H6712F8001 Oil wick 1
C56 H6726E8001 Screw 1
C57 HA706C11B2 Pin 2
C58 HA7311C606 Screw 1
C59 H6707E8001 Feed rock shaft crank 1
C60 H6748B8001 Oil seal 1
C61 H8829B8001 Bushing 1
C62 H8807E8001 Feed rock shaft 1
C63 H007009150 Retaining ring-C type 1
C64 HA300J2280 Screw 1
C65 HA108G0661 Thrust collar 1
C66 HA105D0662 Screw 2
C67 H8828B8001 Bushing 1
C68 HA104G0012 Screw 1
C69 H6715E8001 Crank 1
C70 H6717E8001 Eccentric shaft 1
C71 H9115E8001 Feed bar 1
C72 HA104G0653 Feed dog 1
C73 HA104G0654 Screw 2
C.FEEDING AND FEED LIFTING MECHANISM
— 18 —