typical GC0303D User manual

GC0303D
OPERATION INSTRUCTION / PARTS MANUAL
DIRECT-DRIVE AUTO-LUBRICATION UPPER &
LOWER FEED LOCKSTITCH SEWING MACHINE
DIRECT-DRIVE AUTO-LUBRICATION UPPER & LOWER FEED
LOCKSTITCH SEWING MACHINE WITH THICK THREAD
GC0303DCX

ADD: WANPING TOWN, WUJIANG CITY, JIANGSU
PROVINCE, CHINA
TEL: [phone]
FAX: [phone]
POST. CODE: 215223
Http://www.typicalwpchina.com
E-mail:[email protected]
TYPICAL SEWING MACHINE WANPING MACHINERY CO.,LTD.
Please don't adjust and repair the machine by non-professionals,except adjusting stitch.
Specifications subject to change without notice
2012.4

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Brief introduction
Machine specification
Installing the oil pan and safety switch magnet
Installing the machine head
Installing the knee lifter assy.
Adjusting the knee lifter
Lubrication
Test operation
Installing the needle
Removing the bobbin case
Winding the bobbin thread
Threading the bobbin thread
Threading the needle thread
Adjusting the stitch length
Sewing and backtacking
Adjusting the thread tension
Adjusting the presser foot pressure
Adjusting the thread tension spring
Adjusting the upper thread guide
Adjusting the presser foot height
Adjusting the feed dog height
Adjusting the feed dog angle
Adjusting the difference of stitch length between the forward and backtacking
Adjusting the tension release
Adjusting the timing of needle and feed mechanism
Adjusting the rotary hook lubrication amount
Adjusting the height of needle bar and the timing with hook
Adjusting the oil pump
Adjusting the lifting amount of presser feet
Clean
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Casting mechanism
Needle bar and thread take-up mechanism
Presser foot mechanism
Feed mechanism
Upper feed mechanism
Hook mechanism
Lubrication mechanism
Accessories
CONTENTS
Operation Instruction
Parts Manual

Operation Instruction

1
3
2
4
5
GC0303D GC0303DCX
8mm
37mm
3.5-5.5mm
DP×17 23#
8mm
16mm
750W
1
-1-
12mm
6
1. Brief introduction
This machine is designed with link type feed
mechanism and link lever thread take-up
mechanism and full lubrication by pump. It's
suitable for sewing leather, canvas and other
heavy weight materials, such as suitcase, car
seat, tent, sofa, etc.
2. Main specifications
Model
Applications
Max sewing speed
Max stitch length
Needle bar stroke
Lifting amount
of presser feet
Needle
By knee
Hook
Lubrication
Motor output
By hand
Presser foot
lifting height
Medium & heavy weight materials
2000 s.p.m 1800 s.p.m
Large lubrication hook
Automatic lubrication
3. Installing the oil pan and safety
switch magnet (Fig.1)
1.Insert the two head cushion ② into the front
corners of the oil pan ①;
2.Insert the two head cushion ③ into the back
corners of the oil pan ①;
3.Place the oil pan ④ into the cutouts of table;
4.Insert the two rubber cushion ⑤ into the
notches of table.
5.Insert the safety switch magnet ⑥ into the
hole of the table near oil pan cutout.
DP×17 25#

-2-
1
2
5
2
3
3
2
3
4
1
2
3
4. Installing the machine head (Fig.2)
1.Insert the knee lifter lifting bar ①.
2.Insert the two hinges ② into the holes in the
machine bed.
3.Clamp the two hinges onto the rubber
cushions ③ in the work table, and the place the
machine head onto the head cushions ④ which
are on the top of the oil pan corners.
4.Tap the rest bar ⑤ into the table hole.
NOTE: Tap the rest bar securely into the table
hole, if not, the machine head will not be safe
when it is tilted back.
5. Installing the knee lifter assy. (Fig.3)
Insert the knee lifter assy. ① into the shaft ②
under the oil pan, and slightly tight the screw ③.

4
8
8mm
2mm
5
7
6
3
16mm
2
2
1
4
-3-
A
HOIL
L
B
C
5
6. Adjusting knee lifter(Fig.4)
1.Lower the presser foot ② by turning the
presser foot bar lifter ①.
2.Loosen the nut ③.
3.Turn the screw ⑥ to adjust the bracket ⑤ to
2mm play.
4.Securely tighten the nut ③.
5.Loosen the nut ⑦.
6.Turn the screw ⑧ until the distance between
the end of the screw and bracket is
approximately 8mm.
7.Turn the adjusting screw ⑧ to adjust, so that
the presser foot is at the desired position within
a distance of 16mm above the needle plate
when the knee lifter plate ④ is fully pressed.
8.After adjustment, tighten the nut ⑦.
7. Lubrication(Fig.5)
1.Oil amount
Please fill the oil according to the mark indicated
on the oil pan. Mark (A) means the highest
position. Mark (B) means the lowest position. If
the oil amount is lower than the Mark (B), oil will
not be pumped and machine will be jammed.
2.Fill the oil
Please fill the 18# sewing oil into the oil pan until
to the Mark (A)
3.Change the oil
①Uninstall the screw (C), and drain out the used
oil
②Clean the oil pan, and tighten the screw (C ),
fill the fresh oil again according the requirement.

6
AC
-4-
8. Test operation(Fig.6)
Carry out the test operation when start up a
new sewing machine for the first time, or
restart after a long period of non-use.
Remove the rubber cap (A) on the top of the
arm and face plate, fully lubricate the parts
showed by the arrows.
Install the face plate again, lift the presser foot
and operate the machine at a lower speed of
1000-1500spm, and observe the oil running
through the oil gauge window.
After one month, then the speed can be
increased according to the different sewing
operation.

-5-
1
2
3
1
2
7
8
9
9. Installing the needle (Fig.7)
1.Turn the machine pulley to move the needle
bar ① to its highest position;
2.Loosen the screw ②
3.Insert the needle ③ in a straight line as far
as it will go, making sure that the long groove
on the needle is at the left, and then securely
tighten the screw ②
Groove leftward
Front
Long groove in needle
6
4
32
80%
Standard thread
winding amount
10. Removing the bobbin case(Fig.8)
1.Turn the machine pulley to lift the needle bar
to its highest position. Pull the latch ① of the
bobbin case upward and then put the bobbin
into the bobbin case, finally insert the complete
bobbin case with bobbin into the hook shaft.
2.To remove the bobbin case, pull the latch and
draw the bobbin case out of the hook.
11. Winding the bobbin thread (Fig.9)
1.Turn the power on;
2.Place the bobbin ① onto the bobbin winder
shaft ②;
3.Wind the thread several circles around the
bobbin in the direction indicated by arrow;
4.Push down the bobbin presser arm ③;
5.Lift the presser foot;
6.Depress the treadle, the winding operation
will start;
7.Once finished, the bobbin presser arm ③ will
recover automatically.
＊If the thread winding is not neat and even,
loosen the screw ④ to adjust the position of
bobbin winder base.
＊Turn the screw ⑥ to adjust the bobbin
winding amount
● Tighten the screw to increase the winding
amount;
● Loosen the screw to decrease the winding a
mount.
Note:
The proper winding amount should be around
80% of the bobbin capacity.

-6-
10
11
1
4
2
3
1
4
4
3
3
11
9
6
7
8
5
5
10
11
9
8
12
13
14
7
6
21
50mm
22
11
12. Threading the bobbin thread (Fig.10)
1.Turn the machine pulley to lift the needle to its
highest position;
2.The bobbin thread should be right twist, place
the bobbin into the bobbin case;
3.Pass the thread through the slot ① and spring
plate ②, and finally pull it out of the notch ③;
4.Check that the bobbin should turn clockwise if
the thread is pulled;
5.Hold the latch ④, and place the bobbin case in
the hook.
13. Threading the needle thread (Fig.11)
Raise the thread take-up lever to its highest position. This will make threading easier and will prevent
the thread from coming out at the sewing start.
50mm thread trails
Threading as below if
the resistance of thread
is large

1
2
3
4
5
6
7
8
PUSH
I
1
-7-
12
13
2
2
1
2
3
4
5
6
7
8
PUSH
I
3
1
2
14. Adjusting the stitch length (Fig.12)
While press the stopper ②, turn the stitch length
dial ① to make the number on the dial align with
the mark on the stopper ②. The number is the
stitch length in mm.
＊The larger the number, the longer the stitch
length will be.
＊When turn the dial from a larger setting to a
smaller setting, it will be easy to turn if the
reverse lever ③ is pressed down.
15. Sewing and backtacking (Fig.13)
1.Turn the power on;
2.Depress the treadle to start sewing.
When the reverse lever ① is pressed or the
backtacking button is on during sewing, the feed
will be reversed. After release, the feed will
recover to normal.

-8-
14
15
2
5
1
3
4
16. Adjusting the thread tension (Fig.14)
1
2
Needle thread
Bobbin thread
●Stitch seam when needle thread tension is too weak
●increase the needle thread tension
●decrease the bobbin thread tension
●Stitch seam when needle thread tension is too strong
●decrease the needle thread tension
●increase the bobbin thread tension
Bobbin thread
Decrease increase
Increase
decrease
Normal stitch
17. Adjusting the presser foot pressure
(Fig.15)
Decrease
Increase
Decrease Increase
<Bobbin thread tension>
Adjust by turning the screw ① until the bobbin case
drops gently by its own weight while the thread end
coming out of the bobbin case is held.
<Needle thread tension>
After adjust the bobbin thread tension, adjust the
needle thread tension so that a good, even stitch
seam is obtained.
1.Lower the presser foot;
2.Adjust by turning the thread tension nut ②.
<Adjusting the presser foot pressure>
1.Loosen the lock nut ①;
2.Turn the adjusting screw ② to adjust the
pressure of presser foot, if it's not enough,
please turn the screw ⑤ to increase the
pressure.
＊The pressure should be as week as possible,
but strong enough so that the material doesn't
slip.
3. Tighten the nut ①.
<Adjusting the walking foot presser>
4. Loosen the nut ③;
5. Turn the screw ④ clockwise to increase the
pressure, on the contrary, turn the screw ④
counterclockwise to decrease the pressure;
6. Tighten the nut ③.

-9-
16
2
5
6
7
3
1
0.3 ~ 0.6N
0.1
0.2
0.4
0.6
0.8
(N)
4
1
5 ~ 8mm
3
5
3
18. Adjusting the thread tension spring
(Fig. 16)
Scale
★The standard position of the thread tension
spring ① is 5-8mm above the upper surface of
the thread guide ③ when the presser foot ② is
lowered.
1.Lower the presser foot ②;
2.Loosen the screw ④;
3.Turn the thread tension bracket ⑤ to adjust
the spring position;
4.Tighten the screw ④.
★The standard tension of the spring is 0.3-0.6N.
5.Push the needle thread with your finger until it
is slightly higher than the thread tension bracket
⑤ and so that the upper thread is not pulled out;
6.Pull the needle thread down until the spring ①
is at the same height with the upper surface of
thread guide ③, and then measure the tension
of the spring.
7.Insert a screwdriver into the slot of the thread
tension stud ⑥, and turn the stud to adjust the
tension of the spring ①.
Note:
If using a tension gauge ⑦ to measure the
tension, take the reading from the scale on the
side of the red line.

-10-
17
18
19
1
2
3
4
2
1
8mm
1
1.2mm
2
3
19. Adjusting the upper thread guide
(Fig. 17)
The standard position of upper thread guide ①
is where the screw ② is in the center of the
adjustable range of upper thread guide.
To adjust the position, loosen the screw ② and
move the thread guide.
If stitch the heavy materials, move the thread
guide leftward. (To increase the thread take-up
tension)
If stitch the light materials, move the thread
guide rightward. (To decrease the thread
take-up tension)
Decrease Increase
20. Adjusting the presser foot height
(Fig. 18)
The standard height of presser foot ① is 8mm
when it is lifted by hand.
1.Loosen the screw ③ to lift the presser bar
2.Put a measurement gauge with 8mm height
under the presser foot;
3.Loosen the screw ④ and adjust the height of
presser foot;
4.Tighten the screw ④.
21. Adjusting the feed dog height (Fig. 19)
1.Set the stitch length maximum, when the feed
dog ① is at its highest position above the needle
plate, the standard height is 1.2mm
2.Loosen the screw ② and turn the feed lifting
arm ③ to adjust the height of feed dog.

1
-11-
20
21
22
2
1
7
5
Mark
Standard
(Fig. A)
Lower the front
(Fig. B)
Raise the front
2
1
Left RightLeft Right
22. Adjusting the feed dog angle (Fig. 20)
The standard angle of the feed dog is: when the
feed dog is at its highest position above the
needle plate, the Mark on the feed bracket shaft
is on the horizontal position.
1.Turn the machine pulley to lift the feed dog to
its highest position;
2.Loosen the screw ⑦;
3.Turn the feed bracket shaft in the direction of
the arrow within a range of 90 with respect to
the standard angle position.
＊In order to prevent puckering, lower the front
of the feed dog (Fig. A)
＊In order to keep the materials straight, raise
the front of the feed dog (Fig. B)
4.Securely tighten the set screw ⑦.
It's necessary to adjust the feed dog height
again after this adjustment.
23. Adjusting the difference of stitch length
between the forward and backtacking (Fig. 21)
1.Remove the back cover;
2.Loosen the screw ① and turn the connecting
stud ②
＊Turn the stud ② clockwise, the forward stitch
length will be longer and the backtacking stitch
length will be shorter;
＊Turn the stud ② counterclockwise, the
forward stitch length will be shorter and the
backtacking stitch length will be longer;
3.Tighten the screw ①.
24. Adjusting the tension release (Fig. 22)
The opening time of the thread tension discs
can be adjusted.
Remove the rubber cap on the rear of arm, and
turn the screw ①, then the thread release cam
② can be moved left or right.
Move the cam rightward, the release time will
be slow
Move the cam leftward, the release time will be
quick.

-12-
23
4
5
6
6
1
2
7 8
A
A B
B
24
Needle timing advanced Standard Needle timing retarded
1
Oil amount
Small Big
25. Adjusting the timing of needle and
feed mechanism (Fig. 23)
The standard timing is when the feed dog is
lowered from its highest position until it is flush
with the top of the needle plate ②, and the
needle eye ③ is also aligned horizontally with
the surface.
Adjust by changing the phases of feed cam and
eccentric wheel UD
1.Remove the rear cover
2.Turn the machine pulley in reverse direction,
set the second screw ④ on the gear of upper
shaft as reference mark, make the third screw
⑤ of eccentric wheel UD slightly lower than the
reference mark screw ④;
3.Continue to turn the machine pulley, set the
second screw ⑥ of eccentric wheel UD as
reference mark, make the third screw ⑦ of feed
cam slightly higher than the reference mark
screw ⑥.
4.If need a non-timing position, loosen the three
screws of eccentric wheel UD, adjust the
eccentric cam ⑧ in the direction of arrow (A) or
(B)
To increase the tension of thread, turn the
eccentric cam ⑧ to direction (A)
To avoid the needle bent, turn the eccentric cam
⑧ to direction (B)
5.After adjustment, tighten all of the screws.
26. Adjusting the rotary hook lubrication
amount (Fig. 24)
Tilt back the machine head, and turn the oil
adjustment screw ① to adjust the hook oiling
amount.

25
26
1
2
DP X 17
B
6
5
2.0mm
1.3~1.8mm
7
6
5
0.05mm
DP×17
A
2
1
4
3
0.5 ~ 1.0mm
2
1
-13-
27. Adjusting the height of needle bar
and the timing with hook (Fig. 25)
When the needle bar ① is at its lowest position,
the top reference line (A) on the needle bar
should be aligned with the bottom edge of the
needle bar bush ②.
1.Turn the machine pulley to lower the needle
bar to its lowest position;
2.Take out the rubber cap ③;
3.Loosen the screw ④, and move the needle bar
① to proper position;
4.Tighten the screw ④;
5.Close the rubber cap ③.
Lift the needle bar ① from the lowest position,
when the second reference line (B) on the needle
bar is aligned with the bottom edge of the needle
bar bush ②, the tip ⑤ of the hook should be
aimed at the center of needle ⑥.
1.Turn the machine pulley to raise the needle
bar ① from its lowest position until the reference
line (B) is aligned with the bottom edge of the
needle bar bush ②
＊When the needle bar moves up 2mm, the clear
ance between the upper of needle hole and the
hook tip should be 1.3-1.8mm
2.Loosen the screw ⑦, and make the hook tip
aimed at the center of needle ⑥, the clearance
between the hook tip and needle should be
0.05mm
3.Tighten the screw ⑦.
28. Adjusting the oil pump (Fig. 26)
If the oil is not circled observed from the oil
gauge window at a lower sewing speed, turn the
oil adjustment plate ① to cover the oil hole.

-14-
4
3
12
5
2
1
C
6
27
7
8
A
Left Right
Smaller
Larger
Needle plate
Upward
Downward
29. Adjusting the lifting amount of
presser feet (Fig. 27)
1.Vertical movement of presser foot and walking
foot
★The presser foot ① and walking foot ② move
vertically one after another
★Usually the stroke of walking foot and presser
foot is same or the stroke of walking foot is
slightly lower.
Place the thread take-up lever at the lowest
position, and lower the presser bar lifter, loosen
the screw ③ and move the upper feed lifting cam
④.
Move it rightward to make the stroke of two feet
be equal
Move it leftward to make the stroke of presser
foot be smaller.
2.Adjusting the lifting amount of presser feet
Adjust the lifting amount of two feet to match the
materials to be sewn.
Loosen the screw ⑤, and move the screw
upward to increase the lifting amount or move
the screw downward to decrease the lifting
amount.
3.Adjusting the forward/backward clearance of
the two feet
To keep the front groove of presser foot not strike
the rear of the walking foot, the clearance of C
must be kept about 3mm.
Loosen the screw of feed arm R, and then turn
the feed rock shaft ⑥ to adjust.
4.Adjusting the feed amount of walking foot
(Fig. A)
★The standard ration of feed amount between
feed dog and walking foot is 1:1
The feed amount of walking foot can be adjusted
to suit for the materials to be sewn.
Loosen the nut ⑦, and move the slide block ⑧
Upward: decrease the distance L to make the
feed amount be smaller
Downward: increase the distance L to make the
feed amount be larger

-15-
28
1
2
3
1
2
1
5
4
4
A
30.Clean (Fig. 28)
1.Raise the presser foot;
2.Remove the two screws ① and needle plate ②;
3.Clean the feed dog with a soft brush;
4.Install the needle plate ② by two screws ①.
5.Turn the machine pulley slowly and check if the
needle drops into the hole center of needle plate
★If not
●Check if the needle is bent
●Loosen the screw ①, and reinstall the needle
plate ②
6.Turn the machine pulley and lift the needle
above the needle plate, check if the needle tip is
blunt, if yes, change a new one.
7.Tilt back the machine head
8.Remove the bobbin case ④
9.Clean the hook with a soft cloth and check if
the hook is worn out
10.Take out the bobbin from the bobbin case,
and clean the bobbin case with a soft cloth
11.Insert the bobbin into the bobbin case and
place the bobbin case back into the machine
12.Clean the dust on the filter (A) of oil pump.

Parts Manual