JUKI HZL-25Z User manual

HZL-25Z
SERVICE MANUAL
®
SEWING MACHINE

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1
1
[ 1 ] DISASSEMBLING OF OUTER PARTS
1. Base cover
1. Lower presser foot and lay machine.
2. Remove 3 screws (1) and take out base cover (2).
* Re-assembling should be done in the reverse way.
2. Gear cover
1. Remove screw (1) and take out gear cover (2).
* Re-assembling should be done in the reverse way.

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1
2
3. Face cover
Disassembling
1. Raise presser foot lifter (1).
2. Remove screw (2) and take out face cover (3).
Re-assembling
1. Raise presser foot lifter (1).
2. Insert presser foot lifter (1) into small window (4) of face cover (3).
3. Insert jut (6) of face cover (3) into hole (5) of arm.
4. Fixscrew(2)ttingfacecoverproletoarmprole.

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1
3
4. SIDE COVER
Disassembling
1. Remove screw (1), (9).
2. Pushcover(2)asindicatedbyarrowinsertingyourngerintothebobbin
winder hole (3) and take out cover (2).
〔Cover(2)hasttinghook(4).〕
3. When it cannot be removed by the above way, take out base cover (5) and
remove cover (2) from lower part.
Re-assembling
1. Insert hook (6) of cover (2) into small window (7) of base cover (5).
2. Sethook(4)ofcover(2)intotheinsideoffrontcover(8)andxbyscrew(1),(9).

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1
4
5. FRONT COVER
Disassembling
1. Remove side cover and face cover.
〔See page 2 and 3. 〕
2. Remove screws (1), (2), (3) and then securing plate (4).
3. Take out face cover (8) removing hook (7) from small window (6) of base
cover (5).
Re-assembling
1. Insert hook (7) of front cover (8) into small window (6) of base cover (5).
2. Fixscrews(1),(2)and(3)puttingfrontcover(8)uponarmprole.Alsox
securing plate (4).

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1
5
6. SHUTTLE COVER
Disassembling
1. Remove screw (1) and take out securing plate (2).
2. Remove shuttle cover (3) extracting as indicated by arrow.
* Re-assembling should be done in the reverse way.

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1
6
7. Hand wheel
Re-assembling
1. Set washer (a) and washer (b) in position as illustrated and fix them by
tightening stud screw (c) by hand.
2. Set clutch wheel (d) in position so that its projected portion may be posi-
tioned as illustrated.
3. Fix clutch wheel (d) with screw and tighten it clockwise.
** Disassembling should be done in reverse way.

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2 - 0
1
[ 2 ] ADJUSTMENTS
* Adjustment can be made with or without removal of outer parts.
Adjustment
Without
removing
outer
parts
Removing outer parts
Front
cover
Face
cover
Side
cover
Gear
cover
Base
cover
2 - 1 L-R positioner ○
2 - 2 Needle position
Straight and Zigzag max ○
2 - 3 Needle side motion ○
2 - 4 Clearance cam and cam follower ○
2 - 5 Feed dog height ○
2 - 6 Feed dog longitudinal positioning ○
2 - 7 Feed dog lateral positioning ○
2 - 8 Feed dog timing
Vertical Movement ○
2 - 8 Feed dog timing
Lateral Movement ○
2 - 9 "0"-Feeding needle position ○
2 - 10 Buttonhole sewing -"0" feeding ○
2 - 11 Balance of reverse stitch length ○
2 - 12 Balance of stitch length - stretch stitch ○
2 - 13 Presser foot height ○
2 - 14 Needle height ○
2 - 15 Needle clearance to Shuttle ○ ○
2 - 16 Needle timing to Shuttle ○
2 - 17 Control panel pointer positioning ○
2 - 18 Belt tension ○
2 - 19 Hooking Fork Position of
Needle Threader ○
2 - 20 Bobbin winder ○
2 - 21 Rubber foot height ○

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2 - 1
1
2 - 1 L - R positioner
Checking:
1. Move the needle to the left end by hand.
2. Check if the needle touches the left end of needle hole of needle plate.
Adjustment:
1. Lay the machine.
2. Loosen screw (1) and move L - R positioner (2) to left or right for adjust-
ment.
3. Tighten screw (1).
NOTE: * Needle will be broken if needle is outside of left end of needle hole.
* Selector dial can not be turned smoothly if there is clearance of
more than 0.3 mm between left end of needle hole and needle.

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2 - 2
1
2 - 2 Needle position - Straight stitching and Zigzag stitching,
maximum width
Checking:
1. Remove presser foot.
2. Set machine at "straight stitching A" by turning selector dial.
3. Turning hand wheel by hand, lower the needle and check if needle point
comes to the center of needle plate hole.
4. Set machine at "zigzag stitching C (maximum width)" by turning selector dial.
5. Turning hand wheel by hand, move needle to right and left end, and check if
each clearance between needle and needle hole end of needle plate is equal.
Adjustment:
1. Remove face cover.
2. Loosen screw (1).
3. Turning eccentric pin (2), adjust needle position.
4. Tighten screw (1) after adjustment.
Straight stitching A Zigzag stitching C
(maximum width)

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2 - 3
1
2 - 3 Needle Position at Zigzag Stitching
Checking:
1. Set machine at "zigzag stitching C, (maximum width)" by turning selector dial.
2. Bring needle to right hand lowest position. Slowly lift up needle and ob-
serve its leftward movement when leaving upper surface of needle plate.
3. Needle should move to left in the range of 0.1 - 0.3 mm when needle point
comes about 1 mm above the needle plate surface.
4. Following ( × ) marked illustrations indicate wrong situation.
Adjustment:
1. Remove front cover.
2. Loosen one out of 2 screws (2) on worm gear (1). Another should be set
temporarily.
3. Holding hand wheel, turn worm gear (1), and adjust the angle of worm gear
against gear.
If side motion too early ðTurn worm gear (1) towards you.
If side motion too late ðTurn worm gear (1) away from you.
4. Tighten 2 screws (2) securely after adjustment.
Too late Too early
Gear
NOTE: While adjustment, do not move worm gear along shaft. (Otherwise,
engagement with gear and needle side motion is seriously changed.)

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2 - 4
1
2 - 4 Clearance between zigzag cam and cam follower
Checking:
1. Remove presser foot.
2. Set machine at "zigzag stitching C, (maximum width)" by turning selector dial.
3. Lower needle to left side and its lowest position.
4. Turn selector dial towards you (anti-clockwise) and set it between "zigzag
stitching (maximum width)" and "blind stitching".
5. Check if needle point moves about 0.35 mm from above "3" position to left.
Adjustment:
1. Remove side cover.
2. Turn screw (1).
Less than 0.35 mm ðTurn it clockwise.
More than 0.35 mm ðTurn it anti-clockwise.

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2 - 5
1
2 - 5 Feed Dog Height
Checking:
1. Set stitch length control at "Maximum", and selector dial at "Straight Stitching A".
2. Remove needle and presser foot.
3. Set feed dog at highest position by turning hand wheel by hand.
4. Check to see if feed dog height (A) is 1.0 mm from needle plate.
Adjustment:
Adjust feed dog height by inserting the minus screw driver into feed lifting arm
(1) and moving it up or down.
Feed dog too low ðTurn the screw driver clockwise.
Feed dog too high ðTurn it anti-clockwise.

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2 - 6
1
2 - 6 Feed dog Longitudinal positioning
Checking:
1. Set stitch length at maximum, and selector dial at "Straight Stitching A".
2. Turning hand wheel, move feed dog to the rear end position, and see if rear
edge of center front dog keeps clearance (A) to the needle plate hole.
3. Move feed dog to the front end, and see if front edge of center dog keeps
clearance (B) to the needle plate hole.
Adjustment:
1. Remove side cover.
2. Move feed dog to its extreme front end position.
3. Loosen screw (2). Moving feed dog forward or backward, adjust the angle
of arm (3) against feed shaft (4).
4. Tighten screw (2) securely after adjustment, keeping the angle of the arm
as adjusted.

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2 - 7
1
2 - 7 Feed Dog Lateral positioning
Checking:
1. Set machine for "maximum stitch length".
2. Check if the groove of needle plate touches left end of feed dog.
3. Check if noise is not made.
4. Check if feed dog keeps alignment against groove of needle plate.
Adjustment:
1. Remove gear cover.
2. Adjustment for above (Checking 2 and 3)

Loosen screw (2) of setting plate (1), and adjust by moving horizontal
shaft assy (3).
3. Adjustment for above (Checking 4).

Loosen 2 screws (4). Feed dog (5) must touch groove (6) of needle plate
correctly.

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2 - 8
1
2 - 8 Feed Dog Timing
Vertical Movement
* * Before checking, follow Section 2 - 5 Feed Dog Height.
Checking:
1. Set machine for maximum stitch length.
2. Turning hand wheel, move down feed dog.
3. Check if vertical clearance (P) between needle point and needle plate sur-
face is within the range of 4 - 6 mm when top of feed dog reaches needle
plate surface level.
Adjustment:
1. Remove base cover.
2. Loosen screw (2) of feed lifting cam (1).
3. Adjust feed dog timing to needle by slightly rotating feed lifting cam (1) in
either direction as shown.
To retard timing ðTurn the cam to A - direction.
To advance timing ðTurn the cam to B - direction.
4. Tighten screw (2) after adjustment.

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2 -8
2
Lateral Movement
Checking:
1. Set machine for maximum stitch length.
2. Set feed dog at the start of its movement (when cam (1) starts to activate
forked connection).
3. Turning hand wheel, bring up needle bar to its highest dead point (A).
4. Check if total lateral movement (B) of feed dog during the period from Step
2 to Step 3 above is within the range of 0.1 - 0.3 mm.
Adjustment:
1. Remove face cover.
2. Loosen the screw (2) of feed rocking cam (1).
3. Holding feed rocking cam, turn hand wheel and adjust the angle of the cam
to upper shaft.
To retard timing ðTurn hand wheel towards you.
To advance timing ðTurn hand wheel away from you.
4. Tighten set screw (2) securely after adjustment.
Step 2 Step 3

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2 - 9
1
2 - 9 "0" - Feeding Needle Positioning
Checking:
1 Set stitch length control at "0", and selector dial at "Straight Stitching A".
2. Place paper under presser foot and take 11 stitches without thread.
3. Deviation of all stitches must be within 0.6 mm in forward direction (about
2/3 of needle thickness).
Adjustment:
1. Inserting the plus screw driver through the hole and adjust the screw inside
of the machine.
Fig. a ) ðTurn anti-clockwise.
Fig. d ) ðTurn clockwise.

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PAGE
2 - 10
1
2 - 10 Buttonhole sewing - "0" feeding
Checking:
1. Set stitch length control "4".
2. Set machine at "BH No.1, 3" by turning selector dial. (Use buttonhole guide.)
3. Place the paper under buttonhole guide and take 11 zigzag stitches without
thread.
4. Deviation of all stitches must be within 0.6 mm in forward direction (about
2/3 of needle thickness).
Adjustment:
1. Remove side cover.
2. Insert the minus screw driver into the hole (1).
3. Adjust the stitch length within the range of 0 - 0.6 mm by turning driver anti-
clockwise or clockwise.

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Upward
Downward
2 - 11
1
2 - 11 Balance of reverse stitch length
Checking:
Reverse stitch length is within the range of 3.0 - 3.7 mm.
Adjustment:
1. Remove side cover.
2. Loosen screw (3).
3. Holding reverse lever (1), adjust the reverse lever arm (2) upward or
downward and tighten screw (3).
Reverse stitch length is short ðTighten the screw (3) lifting (2) up.
Reverse stitch length is long ðTighten the screw (3) lowering (2).