HIGHLEAD GC24818-1D User manual

Parts Catalog
SHANGHAI HUIGONG NO.3 SEWING MACHINE FACTORY
GC24818-1D
Post Bed Basting Machine with auto trimmer
Instruction Manual

--- CONTENTS ---
Instruction Manual
CAUTIONS ON USE .......................................................... 1
1. Cautions on operation.................................................................... 1
2. Precautions before starting operation ....................................................... 1
3. Precautions for operating conditions ....................................................... 1
4. Connection of control box ............................................................... 1
5. Adjustment of needle bar stop position ..................................................... 1
CAUTIONS ON USE ......................................................... 2
1. Lubrication (1) ....................................................................... 2
2. Lubrication (2) ...................................................................... 2
OPERATION .................................................................. 3
1. Attaching the needle ................................................................... 3
2. Winding the bobbin thread ............................................................. 3
3. Threading the machine ................................................................. 3
4. Setting of bobbin ..................................................................... 3
5. Leading out the bobbin thread ............................................................ 3
6. Thread tension......................................................................... 3
7. Bobbin thread tension adjustment ......................................................... 4
8. Needle thread tension adjustment ......................................................... 4
9. Adjustment of thread tension regulator ..................................................... 5
10. Presser foot pressure adjustment ......................................................... 5
11. Adjustment of presser foot height ........................................................ 5
12. Timing of hook and needle ............................................................. 5
13. Timing between hook motion and take-up lever motion ....................................... 6
14. Timing between hook motion and opener motion............................................. 7
ADJUSTMENT OF THREAD TRIMMER ................................. 7
1. Driving knife adjustment ............................................................... 7
2. Adjusting the fixed knife position and bobbin thread clamping. ................................. 7
3. Adjustment of trimmer cam ............................................................. 8
1

2
Parts Catalog
A.ARM BED MECHANISM .............................................................. 9
B.THREAD TENSION REGULATOR MECHANISM ......................................... 11
C. NEEDLE BAR AND THREAD TAKE-UP MECHANISM .................................... 13
D. NEEDLE BAR & PRESSER FOOT MECHANISM .......................................... 15
E. HOOK SADDLE MECHANISM ........................................................ 17
F. KNIFE MECHANISM ................................................................ 20
G. LOWER SHAFT & OIL LUBRICATION MECHANISM ..................................... 22
H. ACCESSORIES ...................................................................... 24

CAUTIONS ON USE
1.Cautions on operation
1）When the power is turned on and off, keep your foot away from the pedal. Note that the needle goes up
to the UP position when the power switch is turned on.
2）Note that braking does not work if the power is turned off, or power failure takes place, during machine
operation.
3）Since dust or other foreign matter entering into the control box may cause malfunction or trouble, be
sure to keep control box cover closed during operation.
4）Do not use a multimeter to check the control circuit. Otherwise, semiconductors in the control circuit
might be damaged by voltage from the multimeter.
2. Precautions before starting operation：
1）Never operate the machine before filling the machine’s oil pan.
2）When a new sewing machine is first turned on, verify the rotational direction of the pulley with the
power on.
3）Verify the voltage and phase (single or three) with those given on the machine nameplate.
3. Precautions for operating conditions：
1）Avoid using the machine at abnormally high temperatures（35℃or higher）or low temperatures（5℃
or lower）.
2）Avoid using the machine in dusty conditions.
4. Connection of control box
The control box should be connected as shown to the right.
Note: (1) Be sure to turn the power switch off for safety before connecting or disconnecting the connectors.
(2) The combination of the machine heads with the motor control panels are specified below. Use special
care for the correct combination when replacing the machine head or motor control panel.
5. 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.
—1 —

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 pulley, insert the “adjusting
tool” in the hole “A”, then remove the tool.
2）Adjust of “Down” position: When the pedal is
“Neutral” the machine stops at “Down” position. If the marks
deviate large than 5 mm, adjust as follows.
（1） Disconnect the plug (12 pins) of cable from the machine head.
（2） Run the machine and stop at “Down” position.
（3） While holding the pulley, insert the “adjusting tool” in the hole “B”, then remove the tool.
3）Confirm the stop operation, then set the plug (12 pings) coming from the machine head into the
receptacle.
CAUTIONS ON USE：
1. Lubrication(1)(Fig.4)
Pour oil up to position “H” of the oil tank.
During operation, check the oil level periodically, and in
cases where the oil level is below position “L”, replenish the
oil supply up to position “H”.
Use white spindle oil.
2.Lubrication (2)(Fig.5)
When a new sewing machine is used for the first time, or
sewing machine left out of use for a long time is used again,
replenish a suitable amount of oil to the portions indicated by
arrow in the fig.
Note: Lubricate the Hook Base everyday.
○ 1-2 drops
● 3-4 drops
—2 —

OPERATION
1.Attaching the needle(Fig.7)
１）For needle, use “Mt×190”
２）Determine the needle gauge for thickness lf thread used.
３）Loosen the needle clamp screw.
４）Hold the needle with the prime groove turned to the front and
put it into the needle socket until it stops.
５）Tighten the needle clamp screw.
2.Winding the bobbin thread(Fig.8)
3.Threading the machine(Fig.9)
The needle should be threaded in the order numbered in the
right figure.
4.Setting of bobbin (Fig.10)
１）Raise flap 1 and remove the empty bobbin.
２）Insert bobbin 2 in such a way that when the thread is
unwound from it moves in the opposite direction to the
gripper.
３）Pass the thread through slit 5 and below spring 6, pass
the thread through slit 3 and pull about 3 cm through.
４）Close flap 1 and pass the thread through the flap’s guide 4.
5.Leading out the bobbin thread(Fig. 11)
Pick up the end of needle thread by left hand and lightly press down the pedal by toe to run the machine one
turn. When the needle thread is pulled up, the bobbin thread will be drawn out as shown in the right figure.
6.Thread tension (Fig.12)
—3 —

7.Bobbin thread tension adjustment( Fig.13)
The lower-thread tension should be set in accordance with the type of seam required. Adjust the tension
with screw 1. (Fig.13)
8.Needle thread tension adjustment
The needle thread tension can be adjusted by changing pressure of the tension disk, and force and stroke of
the thread take-up spring.
1）Tension disk pressure adjustment (Fig.14)
(1) In most cases, thread tension can by properly adjusted only by changing tightness of the tension
regulator thumb nut.
(2) To increase pressure, turn the nut clockwise.
(3) To decrease pressure, turn the nut counter-clockwise.
2）Thread take-up spring force/stroke adjustment（Fig.15）
Apply a screwdriver to the thread take-up spring stud and turn the stud. Spring force increases when the
screwdriver is turned counter-clockwise, and decreases when turned clockwise. If the stud is tight, remove the
face plate and loosen the screw of tension regulator slightly.
3）Thread take-up spring force/stroke adjustment（Fig.15）
—4 —

Loosen the stop screw, adjusting the stopper block, After the adjustment, be sure to tighten the set screw.
The standard stroke of thread take-up spring is from 6mm to 8mm.
9.Adjustment of thread tension regulator（Fig. 16）
—5 —
1）Adjustment of thread tension
regulator setting position. The
standard gap is about 0.5mm when
the tension release cam salience is in
contact with the tension release pin.
To adjust, loosen screw A and change
position of the thread tension
regulator properly.
２）Tension release timing adjustment. The tension release cam should
be set so that the tension release disks come to close at the time the needle
plunges into the throat plate.
10.Presser foot pressure adjustment（picture 17）
Loosen the pressure adjusting screw lock nut and turn the pressure
adjusting screw ③. Turn the screw clockwise to increase the pressure. Turn
the screw counter-clockwise to decrease the pressure.
Note: Do not change setting of screw ④. If the screw is too tight,
clapping noise may occur during operation.
11.Adjustment of presser foot height（picture 17）
１）Height of presser foot
The standard height of the presser foot at its lowest position is 1.0 mm
measured between the presser foot bottom surface and the throat plate top surface (see the detail of part ”A”).
To adjust the height of the presser foot, loosen the set screw ②used to secure the presser bar guide
bracket and vertically move the presser bar.
２）Stroke of presser foot
loosen screw ①and adjust position of presser bar lifting bracket so
that the presser foot starts going up when the needle point reaches
0.5mm-1.0mmabove the presser foot bottom surface.(When this adjustment
is made, the height of the presser foot at stop of the machine is about
26.5mm over the throat plate.)
12.Timing of hook and needle(Fig.18)
１）When the needle is at 2.2mm above its lowest position, the hook

and the needle should be located as described below.
The upper edge of needle eye is 1.3mm below the hook tip.
The clearance between the hook tip and the needle side surface is 0.05mm.
2）The relative positions of the hook and the needle can be adjusted as described below.
*The adjustment is easier when the presser foot and the throat plate are previously removed.
Adjustment of hook tip position (Fig.19.Fig.20.Fig.21)
a.Lean outward the machine head. Loosen three hook shaft gear screws.
b.Rotate the balance wheel by hand to position the needle to 2.2mm
above the needle DOWN position.
c.Rotate the hook by hand to align the hook tip with the center of the
needle.
d.Adjust the lateral position of the hook saddle so that the clearance between the hook tip and the needle
side surface is 0.05mm. To adjust, loosen screws ①, ②and ③.
Note: Use care not to loosen set screw ③excessively, and not to disengage the hook shaft gear (small)
from the gear (large).
e.Tighten the loosened screws in the
following order:
3) Lightly press the gear (large)
against the side wall of hook saddle and
tighten set screw ③first.
4) Check the clearance between
the needle and the hook and then tighten
screw ①.
5) Finally tighten screw ②.
13.Timing between hook motion and take-up lever motion(Fig.22)
When the toothed belt is removed for replacement, the timing between the hook motion and the take-up
lever motion should be adjusted as follow：
１）Turn the balance wheel by land to locate the take-up lever to
its highest position.
２）Lean outward the machine head to make sure the arrow mark
(timing mark) on the toothed belt pulley meets the black line put on
the bearing bracket.
３）If the arrow mark is not in line with the black line, remove
the toothed belt and install again so that the two marks are in line, as
shown in the right figure.
—6 —

14.Timing between hook motion and opener motion(Fig.21)
１）Rotate the balance wheel by hand to locate the opener holder to the farthest position away from the
throat plate.
２）Make sure the clearance between the portion ①of bobbin case and the opener is about 0.2mm as
shown in the right figure.
３）If the clearance is too large or small, loosen opener screw ②and adjust position of the opener.
ADJUSTMENT OF THREAD TRIMMER
1.Driving knife adjustment
In resting position the rear edge of the driving knife should be flush with the front edge of the counter-knife.
The fixed knife should abut on the thread pulling knife along its total width.
The pivoting driving knife should abut on the fixed knife after approx.1/3 of its width.
The driving knife must not collide with the bobbin case.
The clearance between the lower blade edge of the driving knife a and the lower surface of the inner rotary
hook b should be 0.3-0.4mm.
Checking: Loosen two screws 1 for adjusting the resting position of the driving knife and adjust the
knife according to the standard, then tighten screws 1.
tightening the screws 1. The driving knife must be easily
2. Adjusting the fixed knife position and bobbin thread clamping.
g 5 has the function to hold the cut bobbin thread in order to avoid skipped stitches at the
seam beginning.
Attention:
Check the axial clearance of the knife shaft when
movable and the axial clearance as low as possible.
Checking:
The clamping sprin
—7 —