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SERVICE MANUAL
MODEL: NH7
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CONTENTS
WHAT TO DO WHEN
................................................................................. 1-3
SERVICE ACCESS
FACE PLATE .................................................................................. 4
REAR COVER ............................................................................... 5
FRONT COVER ............................................................................. 6
MECHANICAL ADJUSTMENT
TOP TENSION ............................................................................... 7
BOBBIN TENSION ......................................................................... 8
PRESSER BAR HEIGHT AND ALIGNMENT ................................ 9
NEEDLE SWING ........................................................................... 10
NEEDLE DROP ............................................................................. 11
CLEARANCE BETWEEN NEEDLE AND HOOK (NO.1) ............... 12
CLEARANCE BETWEEN NEEDLE AND HOOK (NO.2) ............... 13
FEED DOG HEIGHT
...................................................................... 14
NEEDLE BAR HEIGHT .................................................................. 15
NEEDLE TIMING TO SHUTTLE .................................................... 16
BUTTONHOLE FEED BALANCE .................................................. 17
ADJUSTMENT OF RIGHT HAND LINE TACK WIDTH AND
CAM FOLLOWER RELEASE AMOUNT ........................................ 18
MOTOR BELT TENSION ................................................................ 19
WIRING
...................................................................................................... 20
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WHAT TO DO WHEN
CONDITION CAUSE HOW TO FIX REFERENCE
1. SKIPPING 1. NEEDLE IS NOT INSERTED INSERT THE NEEDLE PROPERLY.
STITCHES PROPERLY.
2. NEEDLE IS BENT OR WORN. CHANGE THE NEEDLE.
3. INCORRECTLY THREADED RETHREAD.
4. NEEDLE OR THREAD ARE USE THE RECOMMENDED
INAPPROPRIATE FOR SEWING NEEDLE AND THREAD.
FABRIC BEING SEWN.
5. SEWING ON STRETCH USE A #11 BLUE TIP NEEDLE.
FABRIC
6. INAPPROPRIATE NEEDLE SEE MECHANICAL P.15
BAR HEIGHT ADJUSTMENT
“
NEEDLE BAR HEIGHT.”
7. INAPPROPRIATE NEEDLE SEE MECHANICAL P.16
TO HOOK TIMING ADJUSTMENT “NEEDLE
TIMING TO SHUTTLE.”
8. INAPPROPRIATE NEEDLE SEE MECHANICAL P.12,13
TO HOOK CLEARANCE ADJUSTMENT “CLEARANCE
BETWEEN NEEDLE AND
HOOK.”
2. FABRIC NOT 1. INCORRECT SEE MECHANICAL P.14
MOVING FEED DOG HEIGHT ADJUSTMENT “FEED DOG
HEIGHT.”
2. THREAD ON BOTTOM SIDE MAKE SURE TO BRING
OF FABRIC IS JAMMED UP. BOTH NEEDLE AND BOBBIN
THREAD UNDER THE FOOT
WHEN STARTING SEWING.
3. FEED DOG TEETH ARE CHANGE THE FEED DOG.
WORN.
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CONDITION CAUSE HOW TO FIX REFERENCE
3. BREAKING 1. INITIAL SEWING SPEED IS START WITH MEDIUM SPEED.
UPPER TOO FAST.
THREAD 2. THREAD PATH IS USE THE PROPER THREAD
INCORRECT. PATH.
3. NEEDLE IS BENT OR DULL. REPLACE WITH A NEW NEEDLE.
4. UPPER THREAD TENSION IS ADJUST UPPER THREAD
P. 7
TOO STRONG. TENSION CORRECTLY.
5. NEEDLE SIZE IS USE APPROPRIATE NEEDLE
INAPPROPRIATE FOR AND THREAD FOR FABRIC
FABRIC. IN USE.
6. NEEDLE EYE IS WORN. CHANGE THE NEEDLE.
7. NEEDLE HOLE IN NEEDLE REPAIR THE HOLE OR
PLATE IS WORN OR BURRED. REPLACE THE NEEDLE PLATE.
4. BREAKING 1. INCORRECTLY THREADED THREAD BOBBIN CASE
BOBBIN BOBBIN CASE. CORRECTLY.
THREAD 2. TOO MUCH THREAD IS ADJUST THE POSITION OF
AROUND ON THE BOBBIN. STOPPER.
3. LINT IS STUCK INSIDE THE CLEAN THE HOOK RACE.
HOOK RACE.
4. THREAD QUALITY IS CHANGE TO A HIGH QUALITY
TOO LOW. SEWING THREAD.
5. THREAD IS JAMMING CLEAR OUT THE JAMMING
AROUND THE BOBBIN. THREAD.
6. BOBBIN THREAD TENSION IS ADJUST BOBBIN THREAD
P. 8
TOO STRONG. TENSION CORRECTLY.
5. NEEDLE 1. NEEDLE IS HITTING THE SEE MECHANICAL
P.11
BREAKS NEEDLE PLATE. ADJUSTMENT “NEEDLE DROP.”
2. NEEDLE IS BENT OR WORN. CHANGE THE NEEDLE.
3. NEEDLE IS HITTING THE SEE MECHANICAL
P.12, 13
HOOK RACE. ADJUSTMENT “CLEARANCE
BETWEEN NEEDLE AND HOOK”.
4. THE FABRIC MOVES WHILE SEE MECHANICAL
P.10
THE NEEDLE IS PIERCING ADJUSTMENT “NEEDLE SWING”.
IT, OR THE NEEDLE ZIGZAGS
WHILE IN FABRIC.
5. FABRIC IS BEING PULLED TOO GUIDE THE FABRIC GENTLY
STRONGLY WHILE SEWING. WHILE SEWING.
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CONDITION CAUSE HOW TO FIX REFERENCE
6. NOISY 1. BACKLASH BETWEEN SEE MECHANICAL P.13
OPERATION SHUTTLE HOOK GEAR AND ADJUSTMENT “CLEARANCE
LOWER SHAFT GEAR IS TOO BETWEEN NEEDLE AND HOOK
GREAT. (NO.2)”.
2. LOWER SHAFT GEAR IS ELIMINATE THE LOOSENESS.
LOOSE.
3. INAPPROPRIATE BELT SEE MECHANICAL P.19
TENSION. ADJUSTMENT “MOTOR BELT
TENSION”.
4. UPPER SHAFT GEAR IS LOOSE. ELIMINATE THE LOOSENESS.
5. NOT ENOUGH OIL. OIL ALL MOVING PARTS.
7. DEFORMATION 1. INAPPROPRIATE ZIGZAG SEE MECHANICAL P.10
PATTERN SYNCHRONIZATION. ADJUSTMENT “NEEDLE
SWING”.
2. INAPPROPRIATE SEE MECHANICAL P.18
DISENGAGEMENT OF CAM ADJUSTMENT
FOLLOWER. “DISENGAGEMENT OF CAM
3. UPPER THREAD TENSION ADJUST UPPER THREAD P.7
IS TOO STRONG. TENSION CORRECTLY.
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SERVICE ACCESS
FACE PLATE
TO REMOVE:
1. REMOVE THE CAP AND SETSCREW. REMOVE THE FACE PLATE.
TO ATTACH:
2. FOLLOW THE ABOVE PROCEDURE IN REVERSE.
CAP
SETSCREW
FACE PLATE
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SERVICE ACCESS
REAR COVER
REAR COVER
TO REMOVE:
1. REMOVE THE FACE COVER (SEE PAGE 4).
2. OPEN THE SHUTTLE COVER AND REMOVE THE SETSCREWS (A).
3. REMOVE THE SETSCREWS (B), (C), (D) AND RUBBER CUSHION (E) (2 PCS.), AND
THEN REMOVE THE REAR COVER.
TO ATTACH:
4. MOUNT THE REAR COVER IN REVERSE PROCEDURE OF THE REMOVING.
A
C
E
D
E
B
CAP
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SERVICE ACCESS
FRONT COVER
A
B
G
F
E
C
TO REMOVE:
1. REMOVE THE FACE COVER AND REAR COVER (SEE PAGE 4-5).
2. PULL OUT THE PATTERN SELECTOR DIAL.
3. LOOSEN THE SETSCREWS (A), (B) AND REMOVE THE SETSCREWS (C), (D), (E), (F)
AND RUBBER CUSHION (G), THEN REMOVE THE FRONT COVER.
TO ATTACH:
4. MOUNT THE FRONT COVER IN REVERSE PROCEDURE OF THE REMOVING.
D
PATTERN SELECTOR DIAL
FRONT COVER
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B
C
E
D
TOP TENSION
TO CHECK:
THE STANDARD UPPER THREAD TENSION SHOULD BE 65 - 95g WHEN PULLING
THE THREAD (COTTON THREAD #50) IN THE DIRECTION OF (B) WITH SETTING THE
TENSION DIAL AT “3”. (MAKE SURE THE FOOT SHOULD BE LOWERED.)
IF THE TENSION IS OUT OF THE STANDARD RANGE, ADJUST IT AS FOLLOWS:
ADJUSTMENT PROCEDURE:
1. REMOVE THE FRONT COVER UNIT (SEE PAGE 6).
2. TURN THE ADJUSTING NUT (C) IN THE DIRECTION OF (D) WHEN THE UPPER
THREAD TENSION IS TOO TIGHT.
TURN THE ADJUSTING NUT (C) IN THE DIRECTION OF (E) WHEN THE UPPER
THREAD TENSION IS TOO LOOSE.
3. ATTACH THE FRONT COVER UNIT.
MECHANICAL ADJUSTMENT
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BOBBIN TENSION
TO CHECK:
SET THE BOBBIN IN THE BOBBIN CASE AND PASS THE THREAD (COTTON #50)
THROUGH THE TENSION SPRING.
THE BOBBIN THREAD TENSION SHOULD BE 45 - 55g WHEN PULLING THE THREAD IN
THE DIRECTION OF (B).
IF THE TENSION IS OUT OF THE RANGE, ADJUST IT AS FOLLOWS:
ADJUSTMENT PROCEDURE:
1. TURN THE ADJUSTING SCREW (C) IN THE DIRECTION OF (D) WHEN THE
BOBBIN THREAD TENSION IS TOO TIGHT.
2. TURN THE ADJUSTING SCREW (C) IN THE DIRECTION OF (E) WHEN THE
BOBBIN THREAD TENSION IS TOO LOOSE.
MECHANICAL ADJUSTMENT
COTTON THREAD #50
B
C
D
E
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PRESSER BAR HEIGHT AND ALIGNMENT
TO CHECK:
1. RAISE THE PRESSER FOOT LEVER.
2. THE DISTANCE BETWEEN THE PRESSER FOOT (C) AND THE NEEDLE PLATE (D)
SHOULD BE 6.0MM (0.24").
ADJUSTMENT PROCEDURE:
1. REMOVE THE FACE PLATE (SEE PAGE 4).
2. REMOVE THE SCREWS (A) AND TAKE THE LAMP SOCKET OFF.
3. RAISE THE PRESSER FOOT LEVER AND LOOSEN THE SCREW (B) ON THE
PRESSER BAR HOLDER.
ADJUST THE DISTANCE BETWEEN THE PRESSER FOOT (C) AND THE
NEEDLE PLATE (D) TO 6.0MM (0.24").
4. TIGHTEN THE SCREW (B) SECURELY.
5. TIGHTEN THE SCREWS (A) TO SECURE THE LAMP SOCKET.
6. ATTACH THE FACE PLATE.
NOTE: WHEN YOU TIGHTEN THE SCREW (B), MAKE SURE THAT BOTH SIDES
OF THE PRESSER FOOT ARE PARALLEL TO THE FEED DOG SLOTS (E)
ON THE NEEDLE PLATE.
MECHANICAL ADJUSTMENT
B
A
D
C
E
6.0MM
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NEEDLE SWING
TO CHECK:
ADJUST THE NEEDLE SWING ACCORDING TO THE FOLLOWING PROCEDURE, IF THE
NEEDLE BAR STARTS MOVING SIDEWAYS WHILE THE NEEDLE IS IN THE FABRIC AT
SEWING THE ZIGZAG PATTERN (WITH MAXIMUM ZIGZAG WIDTH).
ADJUSTMENT PROCEDURE:
1. SET THE PATTERN SELECTOR DIAL WITH MAXIMUM ZIGZAG WIDTH, AND
REMOVE THE FRONT COVER (SEE PAGE 6).
2. LOOSEN TWO SETSCREWS.
3. ADJUST THE NEEDLE SWING BY TURNING THE BALANCE WHEEL, WHILE
PRESSING THE WORM SO AS NOT TO ROTATE IT, UNTIL THE NEEDLE SWING
STARTS AT 2 - 3MM ON THE NEEDLE PLATE AFTER THE NEEDLE HAS COME
OUT OF THE RIGHT SIDE OF THE NEEDLE HOLE.
4. TIGHTEN TWO SETSCREWS.
5. MOUNT THE FRONT COVER.
NOTE: AFTER ADJUSTING THE NEEDLE SWING, CHECK THAT THE UPPER
SHAFT WORM AND GEAR ROTATE SMOOTHLY WITHOUT ANY
BACKLASH BETWEEN THEM.
MECHANICAL ADJUSTMENT
UPPER SHAFT WORM
GEAR
SETSCREW (2 PCS.)
2-3MM
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NEEDLE DROP
TO CHECK:
WHEN THE NEEDLE SWINGS IN MAXIMUM ZIGZAG WIDTH, THE DISTANCE BETWEEN
THE BOTH ENDS OF NEEDLE HOLE ON THE NEEDLE PLATE AND THE NEEDLE DROP
POSITIONS SHOULD BE EQUAL.
IF NOT, MAKE AN ADJUSTMENT AS FOLLOWS:
ADJUSTMENT PROCEDURE:
1. REMOVE THE FACE PLATE (SEE PAGE 4).
2. SET THE PATTERN SELECTOR DIAL AT MAXIMUM ZIGZAG WIDTH.
3. TURN THE SCREW TO ADJUST THE LEFT AND RIGHT NEEDLE DROP
POSITIONS.
4. ATTACH THE FACE PLATE.
NOTE: CHECK THE HOOK TIMING AFTER THIS ADJUSTMENT.
MECHANICAL ADJUSTMENT
BOTH CLEARANCE SHOULD BE EQUAL
setscrew
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CLEARANCE BETWEEN NEEDLE AND HOOK (NO.1)
TO CHECK:
THE CLEARANCE BETWEEN NEEDLE AND SHUTTLE RACE SHOULD BE –0.05 - 0.10MM.
IF NOT, MAKE AN ADJUSTMENT AS FOLLOWS:
ADJUSTMENT PROCEDURE:
1. REMOVE THE FACE PLATE (SEE PAGE 4).
2. SET THE PATTERN SELECTOR DIAL AT MAXIMUM ZIGZAG WIDTH, AND TURN THE
HANDWHEEL TOWARD YOU TO BRING THE NEEDLE AT LEFT NEEDLE POSITION.
3. LOOSEN 2 SCREWS, SLIDE THE NEEDLE BAR SUPPORTER ADJUSTING PLATE
IN THE DIRECTION OF ARROW AS SHOWN BELOW, AND ADJUST THE CLEARANCE
BETWEEN NEEDLE AND SHUTTLE HOOK TO –0.05 - 0.10MM.
TIGHTEN SCREWS.
* IF THE CLEARANCE IS TOO LARGE (MORE THAN 0.10 MM), SLIDE THE NEEDLE BAR
SUPPORTER ADJUSTING PLATE IN THE DIRECTION OF "B".
* IF THE CLEARANCE IS TOO SMALL (LESS THAN –0.05 MM), SLIDE THE NEEDLE BAR
SUPPORTER ADJUSTING PLATE IN THE DIRECTION OF "C".
NOTE: AFTER THIS ADJUSTMENT, CHECK IF THE CLEARANCE BETWEEN NEEDLE AND
NEEDLE PLATE IS MORE THAN 0.15MM AS SHOWN IN FIGURE D.
IF NOT, ADJUST THE CLEARANCE BETWEEN NEEDLE AND SHUTTLE RACE BY
USING METHOD OF ADJUSTMENT NO.2 IN PAGE 13 AFTER READJUST THE
CLEARANCE BETWEEN NEEDLE AND NEEDLE PLATE MORE THAN 0.15MM.
4. ATTACH THE FACE PLATE.
MECHANICAL ADJUSTMENT
CLEARANCE BETWEEN NEEDLE AND
NEEDLE PLATE IS MORE THAN 0.15MM
FIGURE D
–0.05 – 0.10MM
SETSCREW A (2 PCS.)
DIRECTION C
DIRECTION B
NEEDLE BAR SUPPORTER
ADJUSTING PLATE
PROJECTIONS
(2 SPOTS)
SET PLATE
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CLEARANCE BETWEEN NEEDLE AND HOOK (NO.2)
TO CHECK:
USE THIS ADJUSTMENT NO.2 WHEN ADJUSTMENT NO.1 CAN NOT BE USED.
THE CLEARANCE BETWEEN NEEDLE AND SHUTTLE RACE SHOULD BE –0.05-0.10MM.
ADJUSTMENT PROCEDURE:
1. SET THE PATTERN SELECTOR DIAL AT MAXIMUM SIGZAG WIDTH, AND TURN THE
HANDWHEEL TOWARD YOU TO ERING THE NEEDLE TO THE LEFT NEEDLE POSITION.
2. OPEN THE SHUTTLE COVER AND LOOSEN THE LOWER SHAFT BUSHING
(FRONT) SETSCREW "A". THEN SLIDE THE LOWER SHAFT TO THE RIGHT
SIDE SLIGHTLY (APPROXIMATELY 0.5 MM) NOT TO DISENGAGE THE GEARS,
AND TIGHTEN THE SCREW TEMPORARY.
3. LOOSEN THE SCREWS "B" (2 PCS) THROUGH THE HOLES IN THE REAR
COVER, AND SLIGHTLY MOVE THE SHUTTLE BODY UP OR DOWN TO ADJUST
THE CLEARANCE BETWEEN NEEDLE AND SHUTTLE HOOK TO –0.05 – 0.10MM,
AND TIGHTEN THE SCREWS "B" TEMPORARY.
4. TURN THE HANDWHEEL TO CHECK THE CLEARANCE BETWEEN SHUTTLE RACE
SPRING AND NEEDLE IN LEFT AND RIGHT POSITIONS. IF THE CLEARANCE IS NOT
EQUAL, ADJUST IT BY TURNING THE SHUTTLE RACE BODY.
5. TIGHTEN THE TWO SHUTTLE RACE SETSCREWS "B" (2 PCS).
6. LOOSEN THE SETSCREW ON LOWER SHAFT BUSHING AND SLIDE THE
GEAR BACK TO THE ORIGINAL POSITION WHILE ADJUSTING THE BACKLASH.
7. TIGHTEN THE SCREW A FIRMLY.
NOTE: THE BACKLASH PLAY SHOULD BE LESS THAN 0.3MM AND LOWER SHAFT TURNS
SMOOTHLY.
AFTER THE ADJUSTMENT, CHECK THE HOOK TIMING.
MECHANICAL ADJUSTMENT
SETSCREW "A"
–0.05 – 0.10MM
CLEARANCE SHOULD BE EQUAL
SHUTTLE RACE SPRING
NEEDLE
LOWER SHAFT BUSHING
(FRONT)
SHUTTLE RACE
SETSCREW "B"
(2 PCS.)
HOLE S I N THE
REAR COVER
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FEED DOG HEIGHT
MECHANICAL ADJUSTMENT
TO CHECK:
1. LOWER THE PRESSER FOOT.
2. TURN THE HANDWHEEL TOWARD YOU TO BRING THE FEED DOG TO ITS HIGHEST
POSITION. THE HEIGHT OF THE FEED DOG FROM THE NEEDLE PLATE SHOULD BE
0.75 – 0.90MM.
IF IT IS NOT IN THE RANGE, ADJUST AS FOLLOWS.
ADJUSTMENT PROCEDURE:
1. OPEN THE SHUTTLE COVER.
2. LOWER THE PRESSER FOOT AND TURN THE HANDWHEEL TOWARD YOU UNTIL THE
FEED DOG COMES TO ITS HIGHEST POINT.
3. TURN THE ADJUSTING SCREW TO ADJUST THE HEIGHT OF FEED DOG
(0.75 – 0.90 MM).
4. TURN THE HANDWHEEL TOWARD YOU TO RECHECK THE HEIGHT OF FEED DOG.
0.75 – 0.90MM
ADJUSTING SCREW
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NEEDLE BAR HEIGHT
MECHANICAL ADJUSTMENT
TO CHECK:
WHEN THE TIP OF SHUTTLE HOOK MEETS THE LEFT SIDE OF THE NEEDLE IN ASCENDING
TRAVEL OF THE NEEDLE FROM ITS LEFT AND LOWEST POSITION, THE DISTANCE BETWEEN
THE TOP OF THE NEEDLE EYE AND THE TIP OF THE SHUTTLE HOOK SHOULD BE IN THE
RANGE OF 2.9 – 3.5 MM.
ADJUSTMENT PROCEDURE:
1. REMOVE THE FACE PLATE.
2. SET THE PATTERN SELECTOR DIAL AT " " (MAXIMUM ZIGZAG) WITH AND NEEDLE DROP
POSITION IS AT "LEFT".
3. OPEN THE SHUTTLE COVER.
4. REMOVE THE SHUTTLE RACE RING.
5. TURN THE HANDWHEEL TOWARD YOU UNTIL THE TIP OF THE SHUTTLE HOOK MEETS THE
LEFT SIDE OF THE NEEDLE.
6. LOOSEN THE NEEDLE BAR CONNECTING STUD SCREW (A).
7. ADJUST THE HEIGHT OF THE NEEDLE BAR BY MOVING THE NEEDLE BAR UPWARD OR
DOWNWARD WITHOUT TURNING IT.
8. TIGHTEN THE SCREW (A).
9. ATTACH THE SHUTTLE RACE RING AND FACE PLATE.
10. ATTACH THE FACE COVER.
SCREW (A)
NEEDLE BAR
2.9–3.5 MM
TIP OF SHUTTLE HOOK MEETS
LEFT SIDE OF NEEDLE
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TO CHECK:
THE HEIGHT OF THE NEEDLE POINT FROM ITS LOWEST POINT OF TRAVEL
SHOULD BE IN THE RANGE OF 1.4-2.0 MM WHEN THE TIP OF THE SHUTTLE
HOOK JUST MEETS THE LEFT SIDE OF THE NEEDLE AT THE LEFT NEEDLE
POSITION.
ADJUSTMENT PROCEDURE:
1. SET THE PATTERN SELECTOR DIAL AT " ".
2. SET THE PATTERN SELECTOR DIAL AT MAXIMUM ZIGZAG WITH AND NEEDLE
DROP POSITION IS AT "LEFT".
3. OPEN THE SHUTTLE COVER.
4. REMOVE THE SHUTTLE RACE RING.
5. TURN THE HANDWHEEL TOWARD YOU UNTIL THE TIP OF THE SHUTTLE HOOK
MEETS THE LEFT SIDE OF THE NEEDLE.
6. LOOSEN THE LOWER SHAFT CRANK ARM SCREWS (A).
7. WHILE HOLDING THE SHUTTLE HOOK SO IT DOESN'T TURN, TURN THE
HANDWHEEL TOWARD YOU UNTIL THE NEEDLE COMES TO ITS LOWEST
POSITION.
THEN, FURTHER TURN THE HANDWHEEL TO RAISE THE NEEDLE ABOUT 1.7 MM
FROM ITS LOWEST POSITION.
8. TIGHTEN THE SETSCREWS (A).
9. TURN THE HANDWHEEL TOWARD YOU TO CHECK IF THE HEIGHT IS IN THE
RANGE OF 1.4-2.0 MM.
IF IT IS NOT IN THIS RANGE, REPEAT THE ABOVE PROCEDURE.
10. ATTACH THE SHUTTLE RACE RING.
NEEDLE TIMING TO SHUTTLE
MECHANICAL ADJUSTMENT
SCREWS (A)
LOWEST POSITION
1.4-2.0 MM
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BUTTONHOLE FEED BALANCE
TO CHECK:
WHEN SEWING BUTTONHOLE, THE STITCHES ON EACH SIDE OF BUTTONHOLE SHOULD
BE THE SAME STITCH DENSITY.
THE RANGE OF 9-11 STITCHES IN THE RIGHT SIDE ROW “BACKWARD FEEDING”
AGAINST 10 STITCHES IN THE LEFT SIDE ROW “FORWARD FEEDING” IS CONSIDERED
ACCEPTABLE.
ADJUSTMENT PROCEDURE:
1. CONFIRM THE STITCHES BY SEWING BUTTONHOLES, AND REMOVE THE
CAP.
2. TURN THE ADJUSTING SCREW IN THE DIRECTION OF "C" IN CASE OF "A"
(RIGHT STITCHES ARE ROUGH), OR IN THE DIRECTION OF "D" IN CASE OF
"B" (LEFT STITCHES ARE ROUGH).
3. MOUNT THE CAP.
MECHANICAL ADJUSTMENT
CAP
NOTCH
ADJUSTING SCREW
D
C
FORWARD FEEDING
BACKWARD FEEDING
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ADJUSTMENT OF RIGHT HAND LINE TACK WIDTH AND CAM FOLLOWER RELEASE
AMOUNT
* THE WIDTH OF THE LEFT AND RIGHT SIDE LINE TACK OF BUTTONHOLE SHOULD BE
EQUAL. IF THERE IS LARGE DIFFERENCE BETWEEN LEFT AND RIGHT LINE TACK
WIDTH, THE CAM FOLLOWER MAY BE HINDERED WITH THE ZIGZAG CAM BLOCK WHEN
YOU TURN THE PATTERN SELECTOR DIAL.
1. SEW A BUTTONHOLE AND CHECK THE DIFFERENCE IN BOTH LINE TACK WIDTHS.
2. REMOVE THE FRONT COVER (SEE PAGE 6).
3. ADJUST THE LINE TACK WIDTH BY TURNING THE ADJUSTING SCREW.
* THE RIGHT SIDE OF THE LINE TACK IS FIXED SO THE ADJUSTMENT SHOULD BE
DONE ON THE LEFT SIDE LINE TACK.
IF THE LEFT SIDE LINE TACK IS WIDER THAN THE RIGHT SIDE:
TURN THE ADJUSTING SCREW IN THE DIRECTION OF “A”
IF THE RIGHT SIDE LINE TACK IS NARROWER THAN THE LEFT SIDE:
TURN THE ADJUSTING SCREW IN THE DIRECTION OF “B”
.
MECHANICAL ADJUSTMENT
"B"
"A"
ADJUSTING SCREW
LEFT SIDE LINE
TACK WIDTH
RIGHT SIDE LINE
TACK WIDTH
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MOTOR BELT TENSION
TO CHECK:
1. TOO TIGHT OR TOO LOOSE MOTOR BELT TENSION MAY CREATE BELT NOISE
AND ALSO TOO TIGHT MOTOR BELT TENSION CAN CAUSE THE MACHINE TO
RUN SLOW AND WILL OVERLOAD THE MOTOR.
TOO LOOSE MOTOR BELT TENSION MAY CAUSE JUMPING OF THE BELT
TEETH ON THE MOTOR PULLEY.
2. THE CORRECT MOTOR BELT TENSION IS THAT THE DEFLECTION OF MOTOR
BELT IS ABOUT 7MM (0.28") - 9MM (0.36") WHEN PUSHING THE MOTOR BELT
BY FINGER AT ABOUT 300 GRAMS LOAD.
ADJUSTMENT PROCEDURE:
1. REMOVE THE FRONT COVER. (SEE PAGE 6.)
2. LOOSEN THE SCREWS (A) AND (B).
3. MOVE THE MOTOR UP OR DOWN TO ADJUST THE DEFLECTION ABOUT
7MM (0.28") - 9MM (0.36").
4. TIGHTEN THE SCREWS (A) AND (B).
5. ATTACH THE FRONT COVER.
MECHANICAL ADJUSTMENT
300g LOAD
DEFLECTION 7-9MM
A
B
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WIRING FOR MACHINE SOCKET UNIT
WIRING
MOTOR
LAMP
(BLUE)
(BLUE)
(BROWN)
(BROWN)
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