juki LZ-2290SS INSTRUCTION MANUAL

Download

Page 1

1. SPECIFICATIONS

(1) Specifications of the machine head

Model Application

Max. sewing speed

Max. zigzag width

Max. feed amount

(Normal/reverse) Stitch pattern

Needle

Dimension of the bed

Number of revolution

of resistor pack Needle bar stroke

Bobbin winder

Wiper (WB only)

Automatic reverse

stitching Lubrication

Lift of the presser foot

(by hand lifter) Lift of the presser foot

(by knee lifter) Lift of the presser foot

(by AK auto-lifter) Kind of the hook

(Part No.) Bobbin case (asm.)

Height of the feed dog

Lubrication of the face

plate section Drive system

Transmission function

Motor output

Operating power

Solenoid drive power

Additional function

Device and optional

LZ-2290SS / –7

Light- to medium-weight materials

5,000 rpm (*1)

10 mm (*2)

5 mm/4 mm (*3)

(Stepless fine adjustment)

8 kinds 14 patterns (Custom pattern : 64 stitches, 8 kinds can be stored.)

SCHMETZ 134UK, 438, ORGAN DPX5 : #65 to #90

178 mmX517 mm

4,000 rpm (Excluding a certain territory of export)

33.4 mm

Built-in in the upper face of machine head type

(with bobbin thread retaining plate)

Electromagnetic front-wiping system

Built-in electromagnetic system

Lubrication system to oil tank for hook lubrication

JUKI New Defrix Oil No. 1 is used.

Plunger pump is employed.

5.5 mm

10 mm

6 to 6.5 mm

22525877

23537350 (with idle-prevention spring)

1.2 mm Minute quantity lubrication by oil wick

Direct drive system (compact AC servo motor)

Timing belt system

Rated output 450W

3-phase 200V, Single phase 100V

DC34V

Presser foot micro-lifting screw is provided as standard.

AK-121 (auto-lifter device)

500 g tin of exclusive grease for maintenance (Part No. : 23640204)

Touch-back kit (asm.) (Part No. : 23546658)

LZ-2290SU / –7

4,500 rpm (*1)

2.5 mm/2.5 mm (*3)

(Stepless fine adjustment)

1.4mm

* 1 : The sewing speed is regulated in accordance with the destination at the time of delivery. (Zigzag width is

also regulated.)

* 2 : Zigzag width is regulated to 8 mm at the time of delivery. (Max. 10 mm is only for 2-step and 3-step zigzag

machines.)

* 3 : Normal and reverse feed amounts are regulated to 2 mm at the time of delivery.

− 1 −

Page 2

(2) Stitch pattern table

Name of pattern Stitch pattern

Straight stitch

Standard zigzag stitch

2-step zigzag stitch

3-step zigzag stitch

Scallop (right)

Standard scallop

（

）

Crescent scallop

）

（

Equal-width scallop

Number of stitches for pattern

Max. zigzag width

–

Pattern selection key Remarks

（

Equal-width scallop

（

Scallop (left)

Blind stitch (right)

Blind stitch (left)

Standard scallop

（ ）

Crescent scallop

（

Equal-width scallop

（

Equal-width scallop

（

）

Scroll can be performed by pressing again.

2+a

Custom pattern

–

Up to 64

− 2 −

Page 3

(3) Cautions in operation

1) Be sure to drain oil in the oil tank and attach the air vent cap (red rubber cap) supplied with the machine to the air vent (golden bushing) located on the side face of the machine bed when transporting the sewing machine.

2) In the case where placing SS or SU type machine on a stand or the like before setting the machine to the machine table, to protect the oil tank from damage, take care if there is any protruding object under the stand or the like.

3) Be sure to securely set the connector of the safety switch to the control box to prevent accidents at the time of maintenance.

4) Oil is kept in the gear box for lubrication. It is not necessary to replace the oil. Do not remove the gear box cover except when it is necessary. * When the box cover has been removed, it is necessary to replace the packing.

5) Be sure to operate the sewing machine with the bobbin case removed when making the sewing machine run idle. If the bobbin thread is in the bobbin case, the thread protrudes from the bobbin case and is entangled in the hook race or the hook shaft. As a result, the trouble will be caused.

− 3 −

Page 4

2. NAME OF EACH COMPONENT

1 Needle thread draw-out device 8 Knee lifter lever !5 Tension controller No. 1 2 Wiper evice 9 Power switch !6 Thread stand 3 Thread take-up cover !0 Hand switch !7 Setting display section 4 Finger guard !1 Stitch length dial !8 Reverse feed stitching lever 5 Thread tension controller !2 Condensation dial 6 Control box !3 Control panel 7 Pedal !4 Bobbin winder

− 4 −

Page 5

1 Needle thread draw-out device

This device draws out needle thread at the time of thread trimming.

2 Wiper device

This device wipes needle thread after thread trimming from the cloth by means of the wiper signal which is output from the PSC box.

3 Thread take-up cover

This is a cover to protect the human body from the contact with the thread take-up.

4 Finger guard

This is a guard to protect the human body (mainly fingers) from the contact with needle.

5 Thread tension controller 6 Control box

This box contains circuit to control sewing machine and motor, output circuits to activate respective outputs (thread trimming solenoid, reverse feed stitching solenoid, etc.), pedal sensor to detect pedal action, and power circuit to activate respective functions.

7 Pedal

This pedal performs sewing machine speed control, thread trimming action, presser lifting action (for AK118 only), etc. by operation of depressing the front part of pedal or the back part of pedal.

8 Knee lifter lever 9 Power switch

This is the power switch for motor, PSC, operation panel, etc.

!0 Hand switch

This is an operation switch to perform reverse feed stitching, inverting of scallop pattern, etc. by means of the manual switch.

!1 Stitch length dial !2 Condensation dial !3 Control panel

This panel is used for setting automatic reverse feed stitching, pattern stitching, zigzag width, etc.

!4 Bobbin winder

This is a bobbin winder which is built in the machine head.

!5 Tension controller No. 1 !6 Thread stand

!7 Setting display section !8 Reverse feed stitching lever

− 5 −

Page 6

3. STANDARD ADJUSTMENT

(1) Height and inclination of the feed dog

Standard Adjustment

Standard height : 1.2 mm : LZ-2290SS

: 1.4 mm : LZ-2290SU

Inclination : The feed dog should be almost

leveled when the top surface of the ascending feed dog is flush with the top surface of the throat plate.

1.2 mm Operator’s

side

LeveledLeveled

Hole for screwdriver

Reference for the height and inclination of the feed dog ™ When the respective marker dots are

leveled, the height is 1.2 mm and the inclination is leveled.

1.2 mm

Throat plate

Feed dog

Position of marker dot

(Inclination)

Position of marker dot (Height)

(2) Adjusting the feed timing

Marker line engraved on thread takeup

Standard Adjustment

Timing mark G engraved on face plate

Timing mark F engraved on face plate

A B

Feed rocker cam

Feed rocker rod

Alignment of timing marks

Top suface of throat plate

Comes down.

−6 −

Page 7

Adjustment Procedures Results of Improper Adjustment

1) Set the feed amount to 2.5mm. (2 mm at the time of delivery) Note, however, that the feed amount has to be set to “0” mm only for LZ-2290SU.

2) Adjusting the height of the feed dog Loosen screw 1 and adjust the height of the feed dog by turning feed driving link shaft 2.

3) Adjusting the inclination of the feed dog Loosen screw 3. Put a screwdriver through the hole for the screwdriver and adjust the inclination of the feed dog by turning the feed rocker shaft with the screwdriver.

(Caution) 1. If the feed rocker shaft is not pressed in the direction A

( ➡ ) during the adjustment procedure, there will be a play at the feed bar or washer will come off. So, be sure to adjust the feed dog with the feed rocker shaft pressed in the direction A ( ➡).

2. Check to be sure that the feed dog is leveled with the feed amount currently used when the top surface of the ascending feed dog is flush with the top surface of the throat plate.

™ Perform the adjustment of the

inclination of the feed dog according

to the sewing process. (Example) ™ When the feed force is required in

such a process of tape attaching or

the like :

Adjust so that this side of the feed

dog is raised. ™ When using the slippery material in

such a process of attaching a facing

of girdle :

Adjust so that the feed dog should

be leveled.

Adjustment Procedures Results of Improper Adjustment

A. Adjusting procedure by removing the gear box cover

1) Remove the gear box cover. (Refer to the item “4-(1).)

2) Adjust the marker line engraved on the thread take-up to the timing mark G engraved on the face plate.

3) Set the feed amount to 2.5 mm. However, the feed amount has to be set to “0” mm only for LZ-2290SU.

4) In the aforementioned state, loosen the setscrew in the hook driving shaft sprocket and adjust the timing mark engraved on the feed rocker cam to the timing mark engraved on the feed rocker rod.

(Caution) In this case, the hook timing (thread trimming timing for the

machine equipped with a thread trimmer) changes. Be sure to perform re-adjustment.)

B. Adjusting procedure with the gear box cover attached (For fine

adjustment)

1) Set the feed amount to 2.5 mm. * Refer the adjusting procedure for LZ-2290SU to page 11.

2) Adjust the marker line engraved on the thread take-up to the marker line engraved on the face plate.

3) In the aforementioned state, loosen the setscrew in the hook driving shaft sprocket. Now, turn the hook driving shaft to adjust so that the feed dog comes down. Adjust so that the top surface of the feed dog is aligned with the top surface of the throat plate when the feed dog comes down.

* There is a slight inclination at the feed dog. Adjust the feed dog so that “0”

to 6 teeth come out from the top surface of the throat plate.

(Caution) After the aforementioned adjustment, “hook timing” and

further “thread trimming cam timing” for the machine equipped with a thread trimmer will change. Be sure to re-adjust them properly.

−7 −

Page 8

(3) Adjusting the feed amount

Standard Adjustment

LZ-2290SS

Feed crank stud

Timing mark

Reverse feed amount regulation metal fitting

Feed adjusting link

LZ-2290SU

Normal feed amount

regulation metal fitting

(4) Position of the feed dog

Condition : Feed amount : maximum

Feed bar

Feed spring hook

Standard Adjustment

Feed converting arm A (asm.)

−8 −

Page 9

Adjustment Procedures Results of Improper Adjustment

[Feed “0” adjustment]

1) Set the stitch length dial at “0”.

2) Loosen screw 1, and align the timing mark on the feed crank stud with that on the feed crank stud support. (The position of the timing mark differs with models.)

3) When loosening screw 1, confirm that there is no axial play at the feed converting arm A (asm.) and tighten screw 1.

[Normal feed adjustment]

4) Set the stitch length dial at the maximum value of the gauge to be used.

Max. normal feed amount of the mechanism

* Normal feed is regulated to 2 mm at the time of delivery.

5) Loosen screw 2, make the feed adjusting link come in contact with the screw and tighten screw 2.

LZ-2290SS=5 mm LZ-2290SU=2.5 mm

[Reverse feed adjustment]

6) Loosen screw 3, pushing the feed lever down to make the sewing machine enter the reverse feed stitching mode, press reverse feed amount regulation metal fitting against the projecting section of the reverse feed adjusting link B. Now, tighten screw 3. (Set the condensation stitch length adjusting dial to the maximum value on the scale.)

Max. reverse feed amount of the mechanism

* Reverse feed is regulated to 2 mm at the time of delivery.

7) To decrease the reverse feed stitching length for fastening stitching, use the condensation stitching function. (Refer to “Adjusting the condensation stitching mechanism” in the Instruction Manual for the LZ-2290 Series.)

™ The engraved dot is for reference only and fine adjustment is

necessary. When the ratio of sewing length (as many as 10 stitches) of normal and reverse feed is approximately 90% in case of straight stitch feed amount of 2 mm, the adjustment is OK.

LZ-2290SS=4 mm LZ-2290SU=2.5 mm

In case of thread trimming ™ If the timing marks are not aligned

with each other, the actual feed amount will be different from the feed amount specified on the stitch length dial. If the timing marks greatly separate from each other, the normal or reverse feed amount will be increased causing the feed dog to come in contact with the thread trimming counter knife.

Normal feed → large Reverse feed → small

Nomal feed → small Reverse feed → large

Adjustment Procedures Results of Improper Adjustment

1) Set the stitch length dial at the maximum.

2) Turn the handwheel, and fix the feed dog so that the clearances in front and rear are the same at the position where the feed dog does not come in contact with the throat plate.

™ In the case where the gear box (large) cover is not opened, loosen

screw 1 to adjust the position.

™ In the case where the gear box (large) cover is opened, loosen screw

2 to adjust the position.

−9 −

™ The feed dog will come in contact

with the throat plate.

Page 10

(5) Adjusting the slippage of materials (For LZ-2290SU only)

Standard Adjustment

Standard state of engraved marker

dot of vertical feed link shaft

Standard height of feed dog

Sewing direction

Lower material

Minus slippage of material

Upper material

“0” slippage of material

Upper material

1.4mm

1.4 mm

Operator’s side

Lower material

Plus slippage of material

Upper material

Lower material

Standard position

−10 −

Page 11

Adjustment Procedures Results of Improper Adjustment

1) To adjust the height and inclination of the feed dog, loosen setscrews 1 in the vertical feed link shaft and turn vertical feed link shafts 2 and 3 with a screwdriver.

2) The standard inclination is the position where the engraved marker dots of vertical feed link shafts 2 and 3 face in the direction of 9 o’clock (left side).

3) The standard height of the feed dog is 1.4 mm from the top surface of the throat plate.

™ The height 1.4 mm of the feed dog

has been factory-set at the time of delivery. Change the height in accordance process the process. (Characteristic of slippage of materials changes. So, be careful.

◎ This machine can adjust “Amount of slippage of materials” by

adjusting the height and inclination of the feed dog.

4) Mainly adjust vertical feed link shaft 3.

The amount of slippage of materials can be adjusted by the position

of the engraved marker dot which means the size of each theta θ of the inclination of the feed dog.

* Points of adjustment ™ Quality of finished products is improved when the slippage of materials

is slightly adjusted to the minus state. (Operator’s hand pressure should be considered in actual sewing.)

™ When performing the adjustment, simultaneously adjusting vertival

feed link shafts 2 and 3 makes it difficult to see the characteristic of the slippage of the material. So, set 2 to the standard state (reference) and mainly adjust 3.

™ In the case where the slippage of material (0 to minus) cannot be

obtained by adjusting vertical feed link shaft 3 only, adjust vertical feed link shaft 2 so that theta θ , inclination of the feed dog is increased.

™ Characteristic of slippage of

materials changes in accordance with materials. (The relation between the direction of the engraved dot and slippage of materials described in the Engineer’s Manusl is the standard of adjustment.)

™ Adjust on the left-hand side the

adjusting positions of the engraved marker dots of vertical feed link shafts 2 and 3. If the position of the engraved marker dot is on the right-hand side, the effect of prevention of slippage of material is difficult to be obtained.

* 1 Set the feed pitch to “0” mm.

2 Adjust with the hook driving shaft sprocket so that the feed dog

on this side is aligned with the top surface of the throat plate when the marker line engraved on the thread take-up is aligned with mark A on the face plate.

To align

Operator’s side

−11 −

Range of use of engraved marker dot

™ When the adjustment of the height

of the feed dog has been performed, the sewing pitch is different from the scale on the stitch length dial. Readjust the scale with the actual sewing pitch.

Left Right

Page 12

(6) Adjusting the origin of the needle rocking motor

Standard Adjustment

™ Adjustment of the origin is performed when the needle rocking amount in terms of the center is not

equal, or the motor or the sensor is required to be replaced.

1) 2), 5)

Needle rocking motor cover

Needle rocking unit base

Origin sensor

(asm.)

Sensor installing base

90˚

<Condition of the origin “0”> When the link is at 90˚, move the light-up sensor from the rightend to the left. The position of the origin “0” is when the sensor gose out.

Assemble link 9 and motor shaft so as to be flush with each other.

Motor

90˚

−12 −

Positioning jig

Page 13

Adjustment Procedures Results of Improper Adjustment

1) Remove four setscrews 1 in the needle rocking motor cover.

2) Remove three setscrews 2 and counter sunk screw 3.

(At this time, loosen setscrew 4 in the needle bar support

base shaft connecting stud as well. Refer to the item “(7) Adjusting the needle entry position”.)

* When assembling, after temporarily tightening screws 3 and

2, tighten in the order of 3 and 2.

3) Move the needle bar in the direction of the face plate, draw out the needle bar support base shaft from the needle bar support base shaft connecting stud, and remove the shaft together with the needle rocking unit base from the machine arm.

In case of replacing or adjusting the needle rocking motor

* For the replacement of the sensor, refer to the item of the

sensor.

4) Loosen setscrew 5 in the motor link bracket and remove link

5) Loosen four setscrews 6 in the needle rocking unit base and remove the motor to replace.

6) Tighten setscrew 5 in the motor link bracket.

(Check also setscrew 7 in the motor link.)

In case of replacing or adjusting the sensor

7) Confirm that the sensor lamp lights up in the hook adjusting mode.(See p.18.)

8) Loosen setscrews 8 in the sensor installing plate, move the sensor installing plate to the right-hand end once, and gradually move it to the left-hand side. Tighten setscrews 8 when the sensor lamp goes out. This state is “0” of the origin. (However, it is when the link is at 90˚.)

™ To determine the position of the sensor, it is convenient to

make a positioning jig as shown in the figure on the left.

−13 −

Page 14

(7) Adjusting the needle entry position (In terms of needle rocking direction)

Standard Adjustment

(8) Adjusting the longitudinal play at the needle bar

Standard Adjustment

It is not necessary to remove the face plate.

As observed from the face plate side

Needle bar support base shaft connecting stud

For an

excessive play

For an excessive play

Engraved marker dot

Needle bar support base guide shaft

Needle bar

(9) Adjusting the needle entry position (In terms of longitudinal direction)

Standard Adjustment

Needle enters the center of needle slot.

Adjusting needle

entry position

−14 −

Page 15

Adjustment Procedures Results of Improper Adjustment

1) Loosen setscrews 2 and remove bobbin winder unit 1.

2) Set both zigzag width and stitch base line to the position of “0”.

Set the position of the needle to the center and teporarily tighten it.

3) Set the zigzag width to 8 mm which is factory-adjusted at the time of delivery, and securely tighten screw 3 at the position where the clearances of zigzag widths A and B are equal.

Conditions : Needle enters the center of zigzag width.

: Max. zigzag width (8 mm)

(Caution) Do not flap or strongly press the needle bar at the time of

adjustment.

A = B

Adjustment Procedures Results of Improper Adjustment

1) Loosen screw 1 in the face plate.

2) Remove rubber cap 2. Then tighten screw 1 while pressing pin 3 in the needle bar support base guide located inside the face plate with a screwdriver.

3) At this time, move the needle bar to the right and left by hand to confirm that there is neither extra load nor a longitudinal play.

4) If the load applied to the needle bar and the longitudinal play existing at the needle bar at the rightmost needle throw position differ from those at the leftmost needle throw position, perform the adjustment by turning pin 3 in the needle bar support base guide to change the orientation of the engraved marker dot (toward the direction where the load and play are larger).

(Caution) Be sure to check the longitudinal play at the needle bar

support base. In the case where there is any longitudinal play or extra load, the needle throwing action will be affected.

™ Thread will not be uniformly tensed

when the needle throws to the right and left, or thread breakage or needle breakage will result.

Adjustment Procedures Results of Improper Adjustment

1) Loosen the screw, which can be observed through the hole for adjustment, in the needle bar support base guide shaft with the face plate attached.

2) Move the needle bar back or forth to adjust so that the needle enters the center of the needle slot in the throat plate.

3) Fix the needle bar support base guide shaft.

4) Be sure to check the needle throw torque applied to the needle bar support base.

(Caution)

1. The needle entry position in terms of the longitudinal direction should be finely adjusted. If the needle bar has to be moved by a large margin for the adjustment of the needle entry position in case of replacement of gauges, carry out the adjustment referring to “(10) Position of the needle bar connection guide”.

2. Be sure to check the left/right plays at the needle bar support base. In the case where there is any extra load applied to the base, needle throwing action will be affected.

−15 −

Page 16

(10) Position of the needle bar connection guide

Standard Adjustment

Needle bar

support base

Needle bar connection guide

Needle bar crank

rod guide

(11) Height of the needle bar

Conditions : Zigzag width : “0” Position of needle position changing lever : Center

Woodruff plate

™ Part No. of engraved indication E

: 22536502 Dimension a: 12.2 mm Dimension b: 3.4 mm

Standard Adjustment

Engraved indication

Timing gauge

−16 −

Page 17

Adjustment Procedures Results of Improper Adjustment

1) Loosen the screw in the needle bar support base shaft referring to “(7) Adjusting the position of needle entry (in terms of the needle rocking direction)”.

2) Remove the thread take-up cover, thread take-up and face plate. Then loosen screws 2 and 3 in the needle bar connection guide together with screws 4 and 5 in the needle bar crank rod guide.

3) Loosen screw 1 in the needle bar support base guide shaft and adjust the needle entry point in terms of longitudinal direction. Then tighten the screw. (Refer to “(9) Adjusting the needle entry position (in terms of longitudinal direction”.)

4) Bring the needle bar to the lower dead position. Move the needle bar support base in the needle rocking direction until a position at which the base smoothly slide without a play is found. Now, temporarily tighten screw 3 in the needle bar connection guide.

5) Bring the needle bar to the upper dead position. Move the needle bar support base in the needle rocking direction until a position at which the base smoothly slide without a play is found. Now, temporarily tighten screw 2 in the needle bar connection guide.

6) Sliding the needle bar support base, tighten screws 2 and 3 in the needle bar connection guide.

7) Tighten screws 4 and 5 in the needle bar crank rod guide the same as the steps 4), 5) and 6).

* Set the needle throw torque at the needle bar support base to 500g or

less.

8) Tighten the screw in the needle bar support base shaft referring to “(7) Adjusting the position of needle entry (in terms of the needle rocking direction”.

9) Attach the thread take-up cover, thread take-up and face plate in position.

(Caution) Be sure to check the longitudinal play at the needle bar

support base. In the case where there is any longitudinal play or extra load, the needle throing action will be affected.

Adjustment Procedures Results of Improper Adjustment

1) Set the mode to the hook adjusting mode. (See p.18.)

2) Remove the presser foot, throat plate, woodruff plate and feed dog.

3) Place the woodruff plate on the surface of the machine bed onto which the throat plate is to be attached. Now, loosen screw 1 and adjust so that the distance from the top face of the woodruff plate to the bottom end of the needle bar is equal to the height ofthe “1” side of the timing gauge.

(Caution) Thickness of the throat plate may be different from

that of the woodruff plate. So, be sure to use the woodruff plate for the adjustment. (Thickness of the woodruff plate : 2 mm)

™ Engraved indication “1” side is the height of the needle bar and

“2” side the needle-to-hook timing.

(Caution) Even when the timing gauge is used, the indented

part of the needle may come in contact with the blade point of the hook in accordance with the kind or size of the needle. In this case, slightly lower the needle bar to adjust the height to the indented part of the needle. For the LZ-2290 Series, use timing gauge E.

−17 −

Page 18

(12) Adjusting the needle-to-hook timing and the needle guard

Standard Adjustment

™ Hook adjusting mode

™ Lifting amount of the nedle (bar) : 3.4 mm

Or,

Woodruff plate

™ When the zigzag width is maximized, a distance of

0.2 to 0.5 mm should be provided between the top end of the needle eyelet and the blade point of the hook when the needle reaches the leftmost end of the zigzag stroke.

0.2 to 0.5 mm

™ The needle guard :

• has to guard the needle both on the right- and left-

hand sides.

• A clearance of 0 to 0.05 mm should be provided

between the needle and the blade point of the hook (when the needle reaches the rightmost end of the zigzag stroke).

Remarks Marker lines engraved on the face plate ™ The needle-to-hook timing is adjusted using the

timing gauge as described above. However, you can use the marker lines engraved on the face plate for reference when adjusting it.

™ Be sure to remember that the marker lines are used

only for reference. So, it is recommended to use the timing gauge for adjusting the needle-to-hook relation so as to make the most out of many functions of the LZ-2290 Series models of sewing machine.

Fig. 1

Fit the blade point of the

hook onto the indented

part of the needle.

(Approximately 0.05 mm)

Fig. 2

Blade point

of the hook

Fig. 3

0 to 0.05 mm

Needle

Needle guard

−18 −

Page 19

Adjustment Procedures Results of Improper Adjustment

1) Pressing setting switch 1, turn ON the power when performing hook adjustment.

2) At this time, bobbin thread counter 2 displays lateral three bars.

3) The sewing machine does not run even when depressing the front part of pedal during the hook adjusting mode.

4) Zigzag operation works by turning the handwheel by hand.

5) For hook adjustment, make use of 2-step zigzag pattern 3 to adjust left/right/center.

6) To return from hook adjusting mode to normal sewing mode, turn off/on the power.

7) Set the needle bar to the position of zizag width “0”, and adjust so that the blade point of the hook is brought to the center of the needle at the height of the timing gauge on which “2” is engraved. (Fig. 1)

8) At this time, adjust so that the blade point of the hook slightly comes in cotact with the needle when the needle guard does not come in contact with the needle (Fig. 2). Then tighten the screw in the hook.

9) Maximize the zigzag width (see the table below). Adjust by bending the needle guard so that the needle comes in contact with the needle guard and does not come in contact with the blade point of the hook at both the rightmost and leftmost needle throwing positions. At this time, adjust so that a clearance of 0 to 0.05 mm is provided between the needle and the blade point of the hook at the rightmost needle throwing position. (Fig. 3)

Name of pattern Stitch pattern Max. zigzag width

Standard zigzag 8 mm

™ If the timing relation between the

needle and the blade point of the hook is excessively advanced, smaller thread loops will be made particularly when the needle throws to the right or stitch skipping and thread breakage will result.

™ If the timing relation between the

needle and the blade point of the hook is excessively retarded, larger thread loops will be made particularly when the needle throws to the left resulting in tilted thread loops and stitch skipping.

™ If the needle guard does not

come in contact with the needle, the needle vibrates when the sewing machine runs at high speed resulting in thread breakage and stitch skipping.

™ If the needle comes in contact

with the blade point of the hook, the blade point will be damaged resulting in an extraordinary shortened service life of the hook.

2-step zigzag 10 mm

3-step zigzag 10 mm

Scallop 8 mm

Blind stitch 8 mm

Custom pattern – 8 mm

(Caution)

1. Hook is common to the LZ-2290 Series. Part No. is 225258. Designate the hook with the part No. when replacing it.

2. When changing the kind or size of the needle, be sure to check the clearance between the needle and the blade point of the hook.

3. The maximum zigzag width is regulated to 8 mm since the standard gauge is 8 mm at the time of delivery.

−19 −

Page 20

(13) Position of the bobbin case stopper

Standard Adjustment

™ The bobbin case stopper should be located within the range from the position at which top end A

of the bobbin case stopper is aligned with line B to the position that is 0.5 mm away from line B in direction C.

Bobbin case stopper 2

Screw 1

(14) Orientation of the needle bar thread holder

Standard Adjustment

™ The needle bar thread holder varies

in accordance with the needle bar.

1) In case of no flat portion at the bottom end of needle bar

™ There are three different kinds of the needle

bar thread holders.

Install the holder so that the flat portion at the bottom end of needle bar faces to this side, or the right end faces to the rear end.

Front (Good) (No good)

2) In case where the flat portion is at the bottom end of needle bar

Install the holder so that the thread hole faces to this side.

(1) (2) (3)

(1).... In ase of without auxiliary thread take-up

and without flat portion at the bottom of needle bar

(2).... In case of with auxiliary thread take-up and

with flat portion at the bottom of needle bar

(3).... In case of without auxiliary thread take-up

and with flat portion at the bottom of needle bar (Used for the machine equipped wuth the wiper)

Needle bar

Without flat portion (Part No. : 22507800)

With flat portion (Part No. : 22507503)

Front (Good) (No good)

−20 −

Page 21

Adjustment Procedures Results of Improper Adjustment

1) Loosen screw 1 and adjust the position of bobbin case stopper 2 by turning the entire unit of the bobbin case stopper.

(Caution) After the position of the bobbin case stopper has

been adjusted, turn the bobbin case by fingers in the reverse direction of rotation to confirm that the bobbin case will never slip out of the small claw.

Adjustment Procedures Results of Improper Adjustment

™ Loosen needle clamp screw 2 or needle bar thread holder

screw 1, and adjust the position of needle bar thread holder 3 with respect to the needle bar.

™ Loosen the screw in the needle bar connection, and adjust the

entire unit of the needle bar and needle bar thread holder.

™ If the orientation of the needle

bar thread holder is not properly adjusted, the thread is likely to untwist resulting in thread breakage.

−21 −

Page 22

(15) Auxiliary thread take-up lever

™ Vertical position

When the needle bar is in the lowest position of its stroke, the distance from the top end of the eyelet in the needle bar thread holder to the bottom end of the auxiliary thread take-up lever should be 0 to 1 mm.

Needle bar thread holder

0 to 1 mm

Standard Adjustment

Auxiliary thread

take-up lever

Auxiliary thread take-up lever

Center

™ Longitudinal position

The auxiliary thread take-up lever, as observed sideways, moves the center of the needle bar and needle bar thread holder while keeping in parallel to the needle rocking stroke.

Needle bar thread holder

Auxiliary thread take-up lever

In parallel to the needle rocking stroke

Even when the auxiliary thread take-up lever is positioned with its left-hand side raised, no problem will result. ( ○)

The position of the auxiliary thread take-up lever is not acceptable when it is positioned with its left-hand side lowered. (X)

−22 −

Page 23

Adjustment Procedures Results of Improper Adjustment

Auxiliary thread take-up lever mounting bracket

Auxiliary thread take-up lever base

1) Loosen screw 1, and adjust the vertical position of the auxiliary thread take-up lever. At this time, carefully position the auxiliary thread take-up lever so that it is leveled or its left-hand side is raised.

2) Loosen screws 2, and adjust the longitudinal position of the auxiliary thread take-up lever. Use a thicker one of the hexagon wrench keys supplied with the machine as accessories. At this time, adjust so that the auxiliary thread take-up lever is in parallel to the needle rocking stroke and tighten the screws.

™ If the auxiliary thread take-up

lever is lowered from the correct vertical position, the thread takeup amount of the auxiliary thread take-up lever will be decreased and larger thread loops will be produced.

™ On the contrary, if the auxiliary

thread take-up lever is raised, the thread take-up amount of the auxiliary thread take-up lever will be increased and smaller thread loops will be produced.

™ If the auxiliary thread take-up

lever is excessively raised from the correct vertical position, the auxiliary thread take-up lever will come in contact with the needle bar thread holder. So, be careful.

™ If the longitudinal position of the

auxiliary thread take-up lever is not proper or the auxiliary thread take-up lever is not in parallel to the needle rocking stroke, thread breakage and stitch skipping will be caused.

−23 −

Page 24

(16) Position of the thread tension

Striking face on the machine arm

Thread tension controller

Standard Adjustment

(17) Position of the pre-tension

Setscrew nut 1

Almost in parallel to the machine arm

Standard Adjustment

Thread should rnter the rotary disk straight.

Thread tension controller

Fig. 1 Longitudinal position

Fig. 2 Orientation

−24 −

Page 25

Adjustment Procedures Results of Improper Adjustment

1) Loosen screw 1, and adjust the position of the thread tension in the state that the thread tension controller is pushed to the striking face on the machine arm.

Adjustment Procedures Results of Improper Adjustment

1) Loosen setscrew nut 1, and adjust the longitudinal position of the pre-tension so that the thread is in parallel to machine arm as illustrated in Fig. 1.

2) Adjust the orientation of the pre-tension so that the thread enters the rotary disk straight.

3) Adjust the pressure of the pre-tension so that the rotary disk rotates smoothly.

™ If the orientation of the pre-

tension is improper, the thread is bent, and unstable tension and slip of the rotary disk will occur resulting thread breakage or stitch skipping.

1) Pressure of the pre-tension is excessively low :

Rotary disk does not rotate

smoothly, and defective stitching or thread breakage will occur.

2) In case of the sewing machine with thread trimmer, if the pressure of the pre-tension is excessively high :

Thread slip at the needle top

after thread trimming or thread slip at the needle top at the start of sewing will occur.

−25 −

Page 26

(18) Position of the thread take-up spring guard

Standard Adjustment

Tension disk

Stopper rubber

(19) Installing the thread take-up thread guide B

Standard Adjustment

Thread take-up spring guard

( X )

(20) Installing the thread take-up

Standard Adjustment

™ Fix the thread take-up with pressed in the direction of rotation.

Direction of rotation

−26 −

Page 27

Adjustment Procedures Results of Improper Adjustment

™ Loosen screw 1, and adjust the position of the thread take-up

spring guard so that the stopper rubber does not come in contact with the outer periphery of the thread tension disk.

Adjustment Procedures Results of Improper Adjustment

™ Loosen the screw, and adjust the position of the thread take-

up thread guide B so that is installed with leveled.

Adjustment Procedures Results of Improper Adjustment

™ Slightly tighten the three screws. Then securely tighten them

with the thread take-up pressed in the direction of rotation.

™ If the thread take-up guide B is

installed with faced upward, the thread will come in contact with the edge of the machine arm. This will adversely affect the quality of the finished seam.

™ If the thread take-up is not fixed

taking the correct method, timing of the thread take-up with respect to the needle bar and the feed mechanism will change. This will change the feeling of finished seam or cause thread breakage.

−27 −

Page 28

(21) Installation of the presser foot

Standard Adjustment

™ The top surface of the throat plate should be closely fitted on the reverse side of the presser foot.

Screw 1

Throat plate

(22) Installing and adjusting the bobbin winder unit

Standard Adjustment

™ A clearance of 1 mm should be provided between the end of needle rocking motor installing boss

and the bobbin winder driving wheel (asm.). At this time, tilt the bobbin winder lever in the direction A and adjust so that the bobbin winder shaft does not rotate when turning the bobbin winder shaft by hand.

Needle rocking motor

installing boss

Main shaft

Rubber ring 3

Screw 1

Bobbin winder driving wheel 2

Bobbin winder

lever 4

Bobbin winder shaft 5

−28 −

Page 29

Adjustment Procedures Results of Improper Adjustment

1) Put the pressser foot in the presser bar, and insert screw 1, At this time, do not tighten screw 1.

2) Turn the handwheel until the feed dog descends under the top surface of the throat plate.

3) Applying a pressure onto the presser foot, tighten screw 1 with the sole of the presser foot closely fitted on the top surface of the throat plate.

Adjustment Procedures Results of Improper Adjustment

1) Loosen screws 1.

2) In the state that bobbin winder lever 4 is tilted in the direction A, slightly press bobbin winder driving wheel 2 to rubber ring 3 of the bobbin winder unit.

3) Temporarily tighten screws 1 and in the state that bobbin winder lever 4 is tilted in the direction A, turn bobbin winder shaft 5 by hand, and check that the bobbin winder shaft does not rotate.

If bobbin winder driving wheel 2 and rubber ring 3 shift with

each other, adjust again.

4) Securely tighten screws 1.

(Caution) The rubber ring is the article for consumption. If

the rubber ring is excessively worn out, replace it with a new one. Part No. : A321600100A

™ If the presser foot is not closely

fitted on the throat plate, the material will not be fed straight and the material will flop causing thread breakage and stitch skipping.

™ When turning the bobbin winder

shaft by hand in the state that the bobbin winder lever is tilted in the direction A, if the bobbin winder shaft rotates, the bobbin thread is not completely wound up.

™ If the bobbin winder driving

wheel and the rubber ring are strongly pressed with each other, the service life of the rubber ring is shortened.

−29 −

Page 30

(23) Adjusting the amount of oil in the hook

Standard Adjustment

Race surface

Approx. 1.5 mm

Appropriate amount of oil (large)

Race surface

Decrease Increase

Approx. 0.5 mm

Appropriate amount of oil (small)

Oil splash on a sheet of paper while the machine is operating for 5 seconds (4,000 rpm)

(24) Adjusting the thread trimming unit

Standard Adjustment

3 Slide plate

1 Counter knife

2 Moving knife

4 Clamp plate

5 Screw

6 Moving knife pin

(39)

(Frontmost)

(34 ± 0.5)

−30 −

Page 31

Adjustment Procedures Results of Improper Adjustment

The amount of oil in the hook can be adjusted with oil amount adjusting screw 1.

1) Adjusting procedure

Turning (clockwise) oil amount adjusting screw 1 increases

the oil amount in the hook and turning (counterclockwise) it decreases the oil amount in the hook.

Adjustment Procedures Results of Improper Adjustment

™ Move 2 moving knife forward until it will go no further (by

approximately 39 mm) and confirm that the end of 3 slide plate is spaced 34 ± 0.5 mm from the top of the moving knife.

™ 1 Adjust the opersting pressure of 1 counter knife and 2

moving knife by tightening 5 screw in 4 clamp plate.

At this time, the force to move 6 moving knife pin in the direction

of the arrow is more or less than 600 gf.

™ If 5 screw is excessively loose, defective thread trimming may

occur.

™ When the moving knife is properly positioned :

Needle thread on the material side

Needle eyelet

Needle thread on the needle side

Knife base

Bobbin thread

™ When the moving knife is

positioned in the front :

1) In the case where the needle thread is trimmed twice :

Needle eyelet

™ When the moving knife is

positioned in the rear :

2) In the case where the needle thread is not trimmed :

Needle eyelet

How to solve the aforementioned troubles

1) In the case where the needle

thread is trimmed twice : Slightly loosen screws 1 to 4, and slant the knife base in the direction A. Then tighten screws 1 to 4.

2) In the case where the thread is not trimmed :

Slightly loosen screws 1 to 4, and slant the knife base in the direction B. Then tighten screws 1 to 4.

−31 −

Page 32

(25) Initial position of the moving knife

Standard Adjustment

™ Moving knife pin 1 should be aligned with marker dot 2. ™ Acceptable range of the position of moving knife is as wide as the marker dot.

Knife driving arm 7

Moving knife

pin 1

Marker dot 2

(26) Timing of the thread trimming cam

Marker dot

(Rearmose)

Roller arm 6

Latch

Nut 3

(Frontmost)

Cam 8

Roller 4

Screw 5

Standard Adjustment

(See the figure shown above.) ™ Press roller arm 6 until roller 4 fits in the groove in thread trimming cam 8. Now, lightly turn the

main shaft handwheel carefully in the reverse direction until it stops. At this time, the marker dot engraved on the machine arm should be aligned with the red marker dot engraved on the handwheel. Adjust the thread trimming cam longitudinally within the width of a dot.

Machine arm Width of adjustment

−32 −

Page 33

Adjustment Procedures Results of Improper Adjustment

1) Loosen nut 3 in the knife driving arm, and adjust the initial position of the moving knife.

Loosen/tighten nut 3 after roller has fitted in the groove on

the thread trimming cam by pressing roller arm 6 with fingers. This will prevent knife driving arm 7 from moving out of position thereby allowing you to perform the adjustment in safety.

2) After adjusting the initial position of the moving knife, turn the handwheel in the state that roller 4 has fitted in the groove on the thread trimming cam, and check that the latch has securely entered when the moving knife moves forward or backward until it will go no further. (You can hear “click” when the latch has entered.)

™ If the initial position of the moving

knife is not properly adjusted, the moving knife will fail to cut the thread or cut the thread at a wrong position reducing the length of remaining thread after thread trimming.

Adjustment Procedures Results of Improper Adjustment

™ If the timing of the thread trimming cam is not correct, adjust it

in the following steps of procedure.

1) Loosen two screws 5 in the cam.

2) Turn the main shaft handwheel until the red marker dot engraved on the handwheel is aligned with the marker dot engraved on the machine arm.

3) Push roller arm 6 until the roller fits in the groove on the cam. Lightly push the cam on the pulley side and turn it in the reverse direction until it will go no further. Now, tighten the screws.

™ If the timing of the thread

trimming cam is excessively advanced, the knife will fail to cut the thread or the length of the thread remaining after thread trimming will be decreased resulting in slip-off of the thread.

™ If the timing of the thread

trimming cam is excessively retarded, the knife will fail to cut the thread or the moving knife will fail to fully return to the home position making the moving knife projects at the start of sewing.

−33 −

Page 34

(27) Installing/removing the knife unit

Standard Adjustment



Fixing plate



(28) Stop position of the needle after thread trimming

Standard Adjustment

Moving knife

Moving knife pin

™ The standard stop position of the needle (position at which the marker dot engraved on the machine

arm is aligned with the white marker dot engraved on the handwheel) is when the marker line engraved on the thread take-up is aligned with the marker line engraved on the face plate (60˚).

™ Adjusting range is within one engraued marker dot in front and rear.

Handwheel

Machine

(Advances)

arm

(29) Clearance provided between the main shaft handwheel and the stator

Standard Adjustment

1 mm

Adjusting range Handwheel

(Retards)

−34 −

Page 35

Adjustment Procedures Results of Improper Adjustment

1) Loosen screw 1.

2) Remove screw 2, and the knife unit will come off.

Installation is carried out analogously in reverse order.

(Caution) When installing the knife unit, take care to allow

the moving knife pin to securely rest on the knife yoke.

Adjustment Procedures Results of Improper Adjustment

™ Stop the needle in its upper stop position. Loosen screw A in

the figure and adjust the stop position of the needle by moving the screw within the slot.

™ To advance the stop position → in the direction 1 ™ To retard the stop position → in the direction 2

(Caution) Do not rotate the sewing machine with screws A

and B loosened during performing adjustment. Be sure only to loosen screws A and B and not to remove them.

Adjustment Procedures Results of Improper Adjustment

1) Provide a clearance of 1 mm between handwheel 1 and the pulley cover. If the clearance is excessively narrow, the position detecting magnet comes in contact with the synchronizer, and if it is excessively wide, defective detection may occur.

2) Be sure to adjust screw No. 1 in the handwheel to the flat portion of the motor shaft and tighten the screws in the order of No. 1 and No. 2.

−35 −

Page 36

(30) Position of the automatic reverse stitching magnet

Standard Adjustment

Reverse stitching magnet

™ Max. feed amount

LZ-2290SS = 5 mm LZ-2290SU = 2.5 mm Standard delivery : 2 mm

Rubber cushion

™ Max. reverse feed amount

LZ-2290SS = 4 mm LZ-2290SU = 2.5 mm

Plunger

Standard delivery : 2 mm

(31) Adjusting the thread tension releasing solenoid

Standard Adjustment

™ The presser plate of the thread tension releaser should be engaged with the roll pin and the

auxiliary pin of the thread tension releaser.

™ When the solenoid is pushed by fingers in the direction A, it should move smoothly. Also, when

the solenoid is released, it should smoothly return to its home position.

™ When the solenoid is pushed in the direction A, the tension disk should rise.

Thread tension

releasing solenoid

Screw

Nut

Presser plate of the thread tension releaser

Return spring

Roll pin (Inside the machine arm)

Auxiliary pin of the thread tension releaser

−36 −

Page 37

Adjustment Procedures Results of Improper Adjustment

™ Loosen two screws 1. Adjust the position of the automatic

reverse stitching magnet by moving it.

™ At the max. feed amountpress down the feed lever until the

plunger moves in the direction of the arrow (➡). At this time, the rubber cushion should turn while being applied with a little load.

Adjustment Procedures Results of Improper Adjustment

1) If the thread tension releasing solenoid fails to move smoothly when it is pressed in the direction A, loosen the four screws and adjust the center of the solenoid.

2) If the tension disk fails to rise when the thread tension releasing solenoid is pressed in the direction A, check first the position of the thread tension controller, then remove the solenoid. Then loosen the nut and adjust the position of the presser plate of the thread tension releaser.

™ If the thread tension releasing

solenoid fails to be engaged with the auxiliary pin of the thread tension releaser, the tension disk will not rise at the time of thread trimming resulting in slip-off of the thread.

™ If the thread tension releasing

solenoid fails to be engaged with the roll pin, the return spring lacks, or the solenoid fails to smoothly return to its home position, the tension disk will be held raised after thread trimming.

−37 −

Page 38

(32) Adjusting the stitch length dial

Standard Adjustment

(a) Assembling the stitch length dial (b) Assembling the condensation dial

* The name of part or the like in the parentheses ( )in the description is the description in

case of assembling the condensation dial.

1) Apply the exclusive grease to feed adjusting screw 1 and feed adjusting shaft 2 (condensation adjusting shaft 2).

2) Screw feed adjusting screw 1 in feed adjusting shaft 2 (condensatin adjusting shaft 2) and temporarily connect them.

3) Insert feed adjusting screw 1 which has been temporarily connected in step 2) into the stitch length dial section (condensation dial section) until it will go no further.

4) Attach feed adjusting base 3 onto the machine srm with two setscrews 4.

5) Turn clockwise feed adjusting screw 1 until it will move no further using a slit screwdriver.

6) Tighten setscrew 5 in the feed controller.

(Caution) Note that the end face of the feed controller shaft should be flush with that of the

feed controller.

™ At this time, the feed controller and the components of the feed controller and the stitch length dial

are in the alignment and the components are in the state of being fixed.

(Caution) If the components should move, perform the work again from step 5).

7) Place washer 6 and flat washer 7 in order, adjust the scale “0” on stitch length dial 8 (scale “1” on condensation dial 9) to the marker dot engraved on the machine arm, insert the dial into the machine arm, and fix stitch length dial 8 (condensation dial 9) with setscrew !0.

8) (Turn condensation dial 9 and adjust the scale “0” to the marker dot engraved on the machine arm.)

9) (Press condensation stopper (asm.) !1 to condensation adjusting shaft 2 from the back of the machine arm and tighten setscrew !2 to fix the stopper. Fix it without any play in the thrust direction.)

Apply grease.

Stitch length dial

−38 −

Condensation dial

Page 39

Adjustment Procedures Results of Improper Adjustment

™ When the work of step 7) (work of step 9) has been completed,

turn stitch length dial 8 (condensation dial 9) and check that the dial moves as specified in the scale.

™ When the marker dot engraved on the machine arm cannot be

adjusted, check and re-adjust from the work of step 5).

<REFERENCE> Max. scale of the stitch length dial

Model Max. scale Part No. of stitch length dial LZ-2290SS 5 mm 11071909 LZ-2290SU 2.5 mm 26302000

Condensation dial specifications

Model LZ-2290SS LZ-2290SU Shape

Part No. 23534407 23545007 Max. scale –4 mm –2.5 mm

−39 −

Page 40

(33) Adjusting the lubrication mechanism

Standard Adjustment

™ Forced lubrication is performed to the hook by means of the plunger pump placed in the hook shaft

front bushing in the machine head

Upper marker line

Lower marker line

(34) Adjusting the position of the thread draw-out wire

Standard Adjustment

Marker line

A≒ B

−40 −

0.5 to 1 mm

8 to 12

Page 41

Adjustment Procedures Results of Improper Adjustment

1) When the top end of the gauge of oil amount indicating window 1 comes down to the lower marker line, fill JUKI Defix Oil No. 1 from the oil inlet up to the marker line of oil tank 2 with the sewing machine tilted.

Even when the gauge comes down to the lower marker line,

oil in the oil tank remains for safety. It is recommended to fill oil as soon as possible.

™ The amount of oil to be filled is approximately 150 cc.

2) For the adjustment of the amount of oil in the hook, check the amount in the hook after making the sewing machine run idle continually for approximately 30 seconds and stabilizing the amount of oil.

(Caution)

1. When using the sewing machine with it tilted to the front, the state of the oil amount indicating window is not useful. So, be careful.

2. If the oil amount adjustment screw is excessively loosened, the O ring comes off and oil spouts out. Do not loosen it more than 5 turns.

3. The oil pipe which has been removed once is likely to easily come off. As a result, oil leakage may be caused. Be sure to replace the pipe with a new one when it is removed.

4. When assembling the respective pipes, take care not to allow you to come in contact with the moving parts.

Adjustment Procedures Results of Improper Adjustment

™ Standard position of the thread draw-out wire

1) Loosen setscrew 1.

2) Turn the thread draw-out wire together with thread draw-out wire installin base 2, adjust the installing position of the thread draw-out wire so that a distance of 8 to 12 mm is provided between the top end of thread draw-out wire 3 and the guide portion of thread take-up thread guide A 4, and tighten screw

(Caution)

1. At this time, leave a space of 0.5 to 1 mm between the thread draw-out wire and the top surface of the thread take-up thread guide A.

2. After the completion of adjustment, be sure to operate the thread draw-out wire and check that the thread drawout wire does not come in contact with the thread takeup thread guide A.

3) Finely adjust with setscrews 5 so that the top end of the thread draw-out wire is placed approximately in the center (A≒B) of the thread take-up thread guide A.

™ When turning OFF the thread draw-out unit :

It is possible to turn OFF with the function setting No. 89

describred in the function setting list.

™ If the stroke of the thread draw-

out wire is insufficient, the length of the needle thread remaining after thread trimming will be reduced resulting in stitch skipping and slip-off of the thread at the start of sewing. If the stroke of the thread drawout wire is excessive, thread breakage will occur at the start of sewing.

−41 −

Page 42

(35) Adjusting the stroke of the thread draw-out wire

Standard Adjustment

Thread drawout wire

Thread guide

Thread draw-out wire installing base 2

Hexagon wrench key

Setscrew 1

Thread

Not to come in contact with each other

Thread guide

Not to come in contact with each other

(36) Installing the wiper base

Standard Adjustment

™ As observed from from the operator, the wiper should be leveled.

Leveled

Wiper

Wiper base

Auxiliary thread take-up lever installing base

−42 −

Page 43

Adjustment Procedures Results of Improper Adjustment

1) Loosen setscrew 1 with the hexagon wrench key supplied with the machine as accessory.

2) Turn the thread draw-out wire together with thread draw-out wire installing base 2 and adjust up or down the top end of the thread draw-out wire.

(Caution)

1. When making the remaining amount of needle thread longer, adjust the position of the thread draw-out wire to the position where the wire does not come in contact with needle thread.

2. When making the remaining amount of needle thread shorter, take care so that the thread draw-out wire and the thread guide do not come in contact with each other.

3. When turning OFF the thread draw-out unit, it can be turned OFF with the function setting No. 89 of the control box.

Adjustment Procedures Results of Improper Adjustment

™ Loosen two setscrews 1 and adjust the installing position of

the wiper base.

The setscrews are used commonly to fix the wiper base and

auxiliary thread take-up lever installing base. So, it is necessary to adjust the installed state of the wiper base while checking the respective bases for inclination and torsion.

™ When the auxiliry thread take-up lever is not used, enter two

each of spacers (WP04808568P + WP0482086SD) as thick as the auxiliary thread take-up lever installing base.

−43 −

Page 44

(37) Adjusting the wiper solenoid

Standard Adjustment

™ When the wiper solenoid is OFF (in the normal state), the pin should be lightly fitted onto the

leftmost end of the slot while providing no clearance between them. (State A) Confirm that the pin comes in contact with the rightmost end of the slot at position C when the wiper solenoid is actuated (when it is pressed in direction B).

Wiper solenoid

Light contact

Pin A

Wiper base

Comes in contact during operation

(38) Position of the wiper

Standard Adjustment

™ When the wiper is in operation, it should not come in contact with the auxiliary thread take-up

lever.

™ When needle stops in its upper stop position, a clearance of approximately 2 mm should be provided

between the needle tip and the wiper.

™ When the wiper is operated after the presser foot has been raised by operating the presser bar

lifting lever, it should not come in contact with the presser foot.

™ When the presser foot is raised as high as 10 mm by operating the knee-lifter, the wiper should not

come in contact with the presser foot. (If the wiper comes in light contact with the presser foot, no problem will result.)

Marker dot on machine arm

White marker dot

10 mm (knee-lifter)

−44 −

Needle

2 mm

Upper stop position

5.5 mm (presser bar lifting lever)

Page 45

Adjustment Procedures Results of Improper Adjustment

™ Loosen setscrews 1 and 2 when the solenoid is not actuated

(OFF). Adjust the state A by moving the entire unit of solenoid up or down.

Adjustment Procedures Results of Improper Adjustment

™ Loosen setscrews 1 (one each for both sides) and adjust the

position of the wiper.

Carefully tightn the setscrews while preventing the wiper from

twisting.

−45 −

Page 46

4. PROCEDURES OF DISASSEMBING/ASSEMBLING AND CAUTIONS

(1) Adjusting and assembling of the gear box (large)

Procedures of disassembling/assembling

™ Loosen setscrews 1 and remove the gear

box cover.

™ Centering the horizontal feed cam

1) Loosen setscrew 3 in the horizontal feed cam rod.

2) Loosen setscrews 2 in the feed adjuster cover

Hook driving gear Feed adjuster

and adjust so that horizontal feed rod 4 can smoothly move up or down. Then tighten setscrews 2.

3) Turn the handwheel and tighten setscrew 3 in the horizontal feed cam rod while performing the centering of the horizontal feed cam.

Horizontal feed cam

Horizontal feed shaft

Feed adjuster cover

Horizontal feed cam rod 4

Horizontal feed cam rod setscrew 3

−46 −

Page 47

Caution in disassembling Caution in assembling

™ For removing/installing the gear box cover, be sure to refer to

the item “(4) Removing/installing the gear box cover” and carefully perform the work.

™ The horizontal feed cam and

hook driving gear are mounted in the gear box (large). In the case where centering and adjustment of play of the aforementioned components are not securely performed when assembling and adjusting, seizure due to the torque of the sewing machine, abnormal heat, or defective return of the lever will be caused.

−47 −

Page 48

(2) Replacing the motor

Procedures of disassembling/assembling

1) Loosen the setscrews in the handwheel in the order of screw No. 2 2 and screw No.

1. 1.

2) Remove four setscrews 4 in pulley cover 3 with the hexagon wrench key of 4 mm.

3) Remove the pulley cover while paying attention to LED 5 of the synchronizer.

4) Remove the window plate, and loosen coupling setscrews 8 fixed on the motor shaft in the order of screw No. 2 and screw No. 1.

5) Remove four motor setscrews 7 with the hexagon wrench key of 4 mm.

6) Quietly pull out the motor, loosen setscrews 6 in the coupling, and remove the coupling from the motor.

7) Fit the coupling the hole diameter of which is smaller to the new motor, adjust screw No. 1 of setscrews 6 to the flat portion of the motor and tighten it. At this time, set the clearance between the motor and the coupling to 0.5 mm.

8) Insert the motor into the machine arm, adjust screw No. 1 of coupling setscrews 8 to the flap portion of main shaft and tighten it.

9) After installing the pulley cover, tighten the setscrews in the order of screw No. 1 and screw No. 2 at the position where a clearance of approximately 1 mm is provided between the handwheel and the pulley cover.

−48 −

Page 49

Caution in disassembling Caution in assembling

(Caution) There is the release secton A at the shaft section

of the encoder case B in the rear of the motor. When the handwheel is held removed, dust or the like enters from the part and the sensor section is damaged. As a result, malfunction of the motor may be caused. Take care of the dust when replacing the motor and install the handwheel quickly. When storing the motor itself for a long period, install the encoder cover (installed at the time of delivery of the motor).

−49 −

Page 50

(3) Replacing the timing belt

Procedures of disassembling/assembling

* The timing belt (22505705) of the highest quality is used, and it is not necessary to replace it

unless a special trouble occurs.

1) Perform removing/installing of the motor in accordance with the steps of the item (2) Replacing the motor.

2) Tilt the sewing machine, remove backmagnet setscrews 9 and remove backmagnet !0.

3) Pressing timing belt !1 in the right-hand direction, turn the timing belt to the front by fingers, then the timing belt can be removed.

4) Replace the timing belt with a new one and install again the the reverse order.

Back-magnet !0

Rubber cushion

(4) Removing/installing the gear box cover

Procedures of disassembling/assembling

Do not open the gear box cover unless a trouble occurs. When it is compelled to open it, take care of the following matters. * Start the work after preparing a new gear box cover packing (23526601).

1) Tilt the sewing machine and prepare an oil receiver under the gear box.

2) Loosen the setscrew of the pipe presser and remove it from the cover.

3) Remove the gear box setscrews and drain oil inside the gear box.

4) When the maintenance of the inside has been completed, close the gear box cover. At this time, replace the packing with a new one. In addition, cleanly wipe oil on the connected face of the cover and the machine bed. Turn the setscrew once more to securely tighten after all setscrews have been tightened once.

5) Remove stop plug 1 in the front of the machine bed and fill 200 cc of JUKI Defrix Oil No. 2.

Plunger

−50 −

Page 51

Caution in disassembling Caution in assembling

™ When removing/installing the motor, unless the motor is

defective, loosen coupling setscrew 8 without loosening coupling setscrews 6 and remove the motor with the coupling installed.

* When the motor is separated

from the coupling, set the clearance between the end face of the motor and that of the coupling to 0.5 mm when reassembling.

0.5 mm

Caution in disassembling Caution in assembling

−51 −

Page 52

5. SCREWS FOR ATTACHMENTS

The machine arm and bed are provided with screws that can be used for installing attachments for the sewing machine. Locations and sizes of the screws are as shown below.

10.5

35.5 6-3/16 28-thread

depth 7

65.5

Ruler stop seat 22902605

13.5

2-3/16 28-thread

depth 6

41.3

9/64 40-thread depth 6

73 19 1957.5

19 19

3/16 32-thread

3/16 32-thread depth 7

11/64 40-thread

depth 6

178

48.5

451.5

2-3/16 32-thread

6. SPARE PARTS

1) Without the thread trimmer

Feed base spacer (Part No. : 10025906) Enter this spacer between the feed base and the feed dog when desired to increase the feed dog height in the case where prevention of inactive feed at the overlapped section, prevention of the material-turn at the overlapped section or feed dog height adjustment when the commercially-available feed dog is used.

2) With the thread trimmer

Use the following spacers (feed base, throat plate) if the counter knife comes in contact with the feed dog when performing the adjustment of feed dog height or feed timing, or the commercially-available feed dog is used.

Feed base spacer (Part No. : 10025906) Throat plate spacer (Part No. : 22503908)

3) Exclusive grease

* Exclusive grease (23640204) is applied to the parts for which lubrication is necessary except the

lubricating section. Never use any grease other than the exclusive grease. Addition of the grease is not necessary for general use of the sewing machine. In the case where the sewing machine is used under the specially severe conditions, it is effective to periodically fill the exclusive grease (once in one to two years).

t=0.5

To keep the space

− 52 −

Page 53

7. TROUBLES AND CORRECTIVE MEASURES (WITH REGARD TO LUBRICATION)

1) Oil fails to come to oil wick of the face plate.

Trouble

Oil wick of the face plate has dried out.

• Check whether the route of oil wick from the float case is interrupted.

• Fill oil to oil wick as pump priming in case of a long period of disuse.

2) Oil amount in the hook is not obtained or insufficient.

Trouble

Plunger pump fails to operate. (Oil coming out from the joint section of machine bed does not move.)

Hook driving

shaft

Plunger screw

Pump metal fixing

screw

• Plunger is not fitted in the groove of plunger of the hook driving shaft. Remove plunger screw, spring and plunger, and check that the groove of plunger is in the center of the hole of machine bed.

Longitudinal position of the hook driving shaft is slipped or the position of pump metal is slipped.

Adjusting the longitudinal position of hook driving shaft Finely adjust so that the groove of plunger of the hook driving shaft is aligned with the plunger hole. At this time, loosen the thrust screw of the hook driving shaft.

Adjusting the position of pump metal Move the pump metal to the right or left (fine adjustment) and determine the position of pump metal so that work holes in the machine arm (plunger hole) are aligned with the plunger holes of pump metal. (Be sure to check that the plunger smoothly enters.) In addition, an O ring is mounted on the pump metal. So, be careful at the time of adjustment. After determining the position, fix the pump metal fixing screw. (Tightening torque : 25 Nm)

Cause and corrective measure

↓ At the time of NG

Hook shaft setscrew

Hook

driving

shaft

Hook shaft

Pump metal

Plunger

hole

Screw

Oil in the pipe is moving, however, the amount of oil is insufficient.

•When the position of the pump metal is properly adjusted, correct the position of the hook shaft. (Adjust the groove of plunger to the center of the hole of machine bed.)

Loosen the setscrews in the hook shaft and adjust the position of the hook shaft to 9 mm from the end face. Adjust the backlash of the hook bevel gear when tightening the setscrews.

(Open the gear box cover and correction of the gear position, hook shaft bearing support and position of thread trimmer cam are necessary.)

Worn-out or burr of the top end of the plunger

↓ At the time of NG

Replace the plungrer.

• The shape of the top end of the oil amount adjustment screw is

defective.  Replace it.

• The hook shaft front stop plug felt clogs.  Replace the felt.

• The oil hole of the lubricating hook clogs.  Replace the hook.

• Re-check the adjustment of the oil amount.

− 53 −

Page 54

3) Gear is noisy.

Trouble

Oil is not contained in the gear box.

Cause and corrective measure

• Oil in the gear box has leaked since the air vent cap was not put at the

time of transportation. Remove stop plug 1 in the front of the machine bed, insert a piece of stiff thread or the like into the gear box, and check whether oil is fully contained inside. When oil is insufficient, open the gear box cover or draw out all the oil inside the gear box with a vinyl pipe, and fill 200 cc of JUKI Defrix Oil No. 2.

− 54 −

Page 55

Reduce the stroke of the thread take-up spring.

Stroke of the thread take-up spring is too

Re-adjust the hook timing properly using a timing gauge.

Lower the auxiliary thread take-up lever.

large.

The hook timing is excessively advanced.

Reduce the tension to balance the needle thread and bobbin

thread.

Properly adjust the height of the needle bar using a timing gauge.

Lengthen the stroke of the thread take-up spring.

The auxiliary thread take-up lever

excessively works.

Both the needle thread tension and bobbin

thread tension are too high.

Height of the needle bar is defective.

Stroke of the thread take-up spring is too

Re-adjust the hook timing properly using a timing gauge.

Properly adjust the auxiliary thread take-up lever.

small.

The hook timing is excessively retarded.

Increase the needle tension to balance the needle thread tension

and bobbin thread tension.

Properly adjust the height of the needle bar using a timing gauge.

If the needle guard works excessively, raise the needle guard.

The auxiliary thread take-up lever fails to

work.

Both the needle thread tension and bobbin

thread tension are too low.

Height of the needle bar is defective.

Adjust the needle-to-hook relation again.

Replace the throat plate with another throat plate which has a

smaller needle slot.

Loosen the screw in the presser foot, and re-tighten it with the

presser foot closely fitted onto the throat plate.

Replace the presser foot with another one which has a smaller

recess.

Use a needle which has a round tip. We recommend the 438SKL

needle.

Needle slot in the throat plate is too Iarge.

The sole of the presser foot is not closely

fitted onto the throat plate surface.

The recess on the sole of the presser foot is

too large.

The needle sticks in fabric yarn and the

thread is retained by the fabric yarn.

Replace the needle with a new one.

(Particularly when power net is sewn with

span thread)

The needle has a blunt tip.

Smaller thread loops are produced.

Thread breakage

occurs when the

needle throws to

the right.

not properly

formed.

(Lower cloth)

1-1) Stitches are

Thread knots are

made.

Larger thread loops are produced and they

tilt.

Thread breakage

occurs when the

needle throws to

the left.

An excessive clearance is provided

between the blade pointer the hook and

the needle.

The material flops.

Trouble Description Cause 1 Cause 2 Corrective measure and adjusting procedure

breakage

8. TROUBLES AND CORRECTIVE MEASURES (WITH REGARD TO SEWING)

1. Thread

−55−

Page 56

Correct the blade point of the hook or replace the hook with a

new one.

Adjust the needle guard so that it works more effectively.

Increase the needle thread tension. Then balance the tension

of needle and bobbin threads.

Lengthen the stroke of the thread take-up spring.

The needle thread tension is too low.

The stroke of the thread take-up spring is

Increase the tension of the thread take-up spring.

Increase the tension provided be the pre-tension disk.

too small.

The tension of the thread take-up spring is

too low.

The tension provided by the pre-tension disk

Adjust the position of the bobbin case stopper by moving it away

from the needle.

is too low.

The bobbin case holder stopper is positioned

too near to the needle.

Set the thread tension at a higher value. (For reference, 65 g for

the needle thread and 25 g for the bobbin thread)

Replace the presser foot with a new one, or correct the presser

bar.

Return the micro-lifting mechanism to the home position, or

readjust the position of the presser bar bracket.

Replace the presser foot with a new one.

The needle slot in the presser foot is located

this side of the needle slot in the throat plate.

The presser foot rises.

Recess on the sole of the presser foot is

smaller for the stitch length employed.

Increase the needle thread tension.

The stroke of the thread take-up spring is

too small.

Tension of the thread take-up spring is too

Maximize the distance between the bobbin case and the hook

as long as the bobbin case does not rotate.

1ow.

Blade point of the hook is defective.

The needle vibrates during sewing.

The time when the needle and bobbin

threads go over the hook is too late. As a

result the threads break under the hook.

reaches the lowest position of its

stroke.

1-2) The thread breaks when the needle

(Lower cloth)

Trouble Description Cause 1 Cause 2 Corrective measure and adjusting procedure

The sewing machine fails to perform

sewing with consistency because of

excessively low thread tension.

Same causes as "I-1) Stitches are not

properly formed."

joining section between scallops

Thread breakage occurs when sewing

1-3) Miscellaneous

2. Stitch skipping

Presser foot components are defective.

3. Isolated idling loops

−56−

The needle thread tension is insufficient.

The thread take-up spring has been

improperly adjusted.

The bobbin case holder stopper is

defective.

Page 57

Increase the needle thread tension and bobbin thread tension.

Adjust so that a bobbin is evenly wound with thread.

Bobbin has been unevenly wound causing

Replace the bobbin with a new one and increase the bobbin

winding tension.

Replace the bobbin or bobbin case with a new one.

Reduce the stroke of the thread take-up spring.

hindrance.

The bobbin is deformed.

Lower the tension of the thread take-up spring.

Failed engagement between the bobbin and

the bobbin case

The stroke of the thread take-up spring is

too large.

Tension of the thread take-up spring is too

Increase the tension provided by the pre-tension disk or lower

high.

Thread slips in the tension disk.

the tension provided by the thread tension controller.

Replace the tension disk with a new one.

Replace the felt with a new one.

Irregular rotation of the machine because

of the failed tension disk.

Irregular rotation of the machine because

Adjust the position of the tension controller to prevent the tension

disk from keeping held raised.

Re-fix the pre-tension disk at a position where the disk does not

come in contact with the machine arm.

Correct the pre-tension disk or adjust the position of the disk.

of worn-out felt.

Failed position of the tension controller.

The pre-tension disk comes in contact with

the machine arm.

The orientation of the pre-tension disk is

defective. As a result, the disk rises in

Adjust the position of the bobbin case holder stopper.

accordance with the tension it applies.

Re-install the bobbin in the bobbin case while facing it in the

correct direction.

The needle thread tension and bobbin

thread tension are insufficient.

Failed bobbin and bobbin case

The thread take-up spring has been

improperly adjusted.

Trouble Description Cause 1 Cause 2 Corrective measure and adjusting procedure

4. Irregular stitches

Tension controller components are

defective.

−57−

The pre-tension disk is defective.

The position of the bobbin case holder

stopper is too near to the needle.

The installing direction of the bobbin in the

bobbin case is not correct.

Page 58

Finish the thread path to smoothen its surface.

Adjust the feed timing to the proper one.

Enter thread in hole A of the bobinn case.

Thread path has been poorly finished.

Feed timing is excessively advanced.

Thread enters in hole B in the bobinn case.

Increase the presser foot pressure.

Re-attach the presser foot so that it closely fitted onto the throat

plate. or replace the presser foot with a new one.

Replace the throat plate with another throat plate which has a

smaller needle slot in accordance with the needle used and the

zigzag width specified.

Replace the presser foot with another one which has a smaller

recess or no recess.

The presser foot pressure is too low.

Failed parallelism of the presser foot

Needle slot in the throat plate is too large.

The recess on the sole of the presser foot is

too large.

Replace the needle with a new one.

The needle has a blunt tip.

Lower the presser foot pressure. ' If an aluminum presser bar.

that is optionally available. is used. only the presser foot pressure

Presser foot pressure is too high.

can be lowered without reducing efficiency of feed.

Buff up the sole of the presser foot to enable the material to be

smoothly fed under the presser foot.

Adjust the inclination of the feed dog to the standard state (where

the feed dog is positioned with its front side lowered.)

Adjust the height of the feed dog to the standard height (0.8

mm) or slightly lower the feed dog below the standard height.

The sole of the presser foot has been poorly

finished.

Failed inclination of the feed dog.

Height of the feed dog is excessive.

The needle thread tension and bobbin

thread tension are too high.

Stitches gather at the center of the material.

Trouble Description Cause 1 Cause 2 Corrective measure and adjusting procedure

sewn part.

5. Material swells at the

The presser foot is defective.

The material flops.

−58−

The presser foot is defective.

The upper cloth and lower cloth shift in the

feeding direction.

6. Uneven material feed

The feed mechanism is defective.

Page 59

432

3rd stitch

2nd stutch

1st stitch

1.6

Loosen the pre-tension disk as long as the thread slips in the tension disk.

Inspect the thread tension releasing solenoid components and adjust them, if necessary.

is too high.

1)-A Tension provided by the pre-tension disk

Correct the position of the tension disk and thread take-up spring guard so that they do not

come in contact with each other.

Properly adjust the cam timing.

Lengthen the stroke of the thread feeding wire.

thread trimming.

1)-B The tension disk fails to rise at the time of

thread take-up spring guard.

1)-C The tension disk comes in contact with the

1)-D The cam timing is excessively advanced.

Properly adjust the position of the thread feeding wire.

Re-thread the thread feeding wire and take-up thread guide. If the thread frequently slips off

the thread feeding wire, replace the wire with a new one.

Reduce bobbin thread tension to such an ertent that thread tension is sufficiently obtained.

small.

improperly positioned.

2)-A Stroke of the thread feeding wire is too

2)-B The thread feeding wire has been

and take-up thread guide.

2)-C The thread slips off the thread feeding wire

3)-A Bobbin thread tension is too high.

Enter 3 stitches at soft start (1,200 rpm).

high. This prevents the needle thread and

4)-A

5)-A Sewing speed at the start of sewing is too

Create a custom pattern as shown below and make a larger back-tack stitch length than the

needle hole width of the presser. The stitch length of 1.6 to 2 mm is recommended for reference.

bobbin thread from smoothly interlacing

with each other.

presser foot and the throat plate.

6)-A Needle thread is not early retained with the

Place the threads under the presser foot and start the sewing machine while holding the threads

there.

not interlace with each other because the

material makes no resistance to the

threads.

7)-A The needle thread and bobbin thread do

trimming is too short.

1-1) Length of thread remaining after thread

insufficient.

1-2) Needle thread feeding amount is

bobbin thread is too short.

1-3) Thread trimming failure because the

1-4) Failed clamp of the bobbin thread

do not neatly interlace with each other

at the start of sewing.

presser foot when the wiper sweeps the

thread and is free.

1-5) The needle thread and bobbin thread

1-6) The needle thread is not under the

sewing.

l-7) Idle stitches are made at the start of

Trouble Cause 1 Cause 2 Corrective measure and adjusting procedure

off at the start of sewing.

9.TROUBLES AND CORRECTIVE MEASURES (WITH REGARD TO MECHANICAL COMPONENTS)

1. Several stitches skip or thread comes

−59−

Page 60

Increase the tension applied by the pre-tension disk.

1)-A Tension applied by the pre-tension disk is

Adjust the thread trimming cam timing to the correct value.

Place the needle thread under the presser foot at the start of sewing, thereby preventing the

thread from being tangled up. (Particularly when reverse feed stitches are made at the start of

sewing)

Properly adjust the thread trimming cam timing.

too low.

excessively retarded.

1)-B Thread tmming cam timing has been

1)-A Thread trimming cam timing has been

Re-install the knife unit or replace the knife unit with a new one.

excessively advanced.

1)-B Locus of the moving knife is defective.

Reduce the needle thread feeding amount.

To start sewing with a small stitch length, place the needle thread end under the presser foot

and start the sewing machine.

length.

point since the stitch length is small.

2)-A The thread slacks because of small stitch

2)-B The needle repeatedly enters the same

2)-C Thread tension fluctuates because of

tangle-up thread.

needle eyelet is excessive.

2-1) Length of thread remaining at the

wrong side of the material appears on

the right side of the material.

2-2) Top end of tangled-up thread on the

threads and trims the thread at the

needle.

3-1) The moving knife fails to separate the

Trouble Cause 1 Cause 2 Corrective measure and adjusting procedure

material at the start of sewing.

2. Needle thread end rests on the

immediately atter thread trimming.

3. Thread slips off the needle eyelet

the time of thread trimming is

excessive. causing the thread to break

when the needle reaches the lowest

position of its stroke at the start of

sewing.

4-1) The needle thread feeding amount at

4. Thread breaks at the start of sewing.

4-2) Stitch length is too short

−60−

Page 61

Reduce the needle thread tension.

The needle thread tension may have been increased because of isolated idling loops. S0, also

refer to the description of "Isolated idling loops."

Adjust the needle entry point.

Decrease the zigzag width or replace the throat plate with an appropriate one.

in the throat plate.

1)-A Needle thread tension is too high.

1)-B The needle fails to enter the needle slot

2)-A Zigzag width is wider than the needle

Return the needle throw positioning lever to the home position and make the stopper work at a

position where the needle does not come in contact with the throat plate.

slot.

needle slot since the needle throw

positioning lever has been moved too

far.

2)-B The needle throwing range exceeds the

Increase the thread tension provided by the pre-tension disk. (6 g or higher)

skipping."

1)-A Refer to the description of "Stitch

1)-B Thread tension is insufficient at the time

Increase the thread tension provided by the pre-tension disk.

Lengthen the stroke of the needle thread feeding device. (The needle thread is tensed by

steeply bending the thread path.)

Increase the bobbin thread tension, then balance the needle thread and bobbin thread.

of thread trimming.

2)-A Thread tension is insufficient at the time

1)-A Bobbin thread tension is too low.

side of the needle slot in the throat plate.

5-1) The needle breaks when it hits against this

sides of the needle slot in the throat plate.

5-2) The needle breaks when it hits against both

6-1) The last stitch skips.

Trouble Cause 1 Cause 2 Corrective measure and adjusting procedure

5. Needle breakage

6. Needle thread cannot be cut.

thread.

6-2) The moving knife spreads the thread loops.

7-1) The moving knife spreads the bobbin

7. Bobbin thread cannot be cut.

−61−

Page 62

Adjust and lower vertical feed link shaft.

Adjust and raise vertical feed link shaft.

ADjust the direction of the marker dots of vertical feed link shafts

on the left side.

Adjust and raise vertical feed link shaft.

Adjust and lower vertical feed link shaft.

Adjust the direction of the marker dots of vertical feed link shafts

on the left side.

Change the position to the rear.

Lower the rear end of the feed dog.

Raise the front end of the feed dog.

Raise the rear end of the feed dog.

Lower the front end of the feed dog.

Adjust vertical feed link shafts lower the height of the feed dog.

Inclination of the feed dog is insufficient.

8-1) Minus slippage of cloth is difficult.

Direction of marker dots of vertical feed link

shafts is on the left side.

Inclination of the feed dog is insufficient.

Direction of marker dots of vertical feed link

shafts is on the left side.

Position of the presser fulcrum is in the front

8-2) Plus slippage of cloth is difficult.

Trouble Description Cause 1 Cause 2 Corrective measure and adjusting procedure

of cloth is difficult.

For LZ-2290SU only

8. Adjustment of slippage

side.

Height of the feed dog is too high.

Sewing products flop.

(Caution) For the details, refer to the item “(5) Adjusting the slippage of materials”.

is difficlt.

9. Straight sewing of cloth

−62−

Page 63

10. FOR GENERAL EXPORT

Supply voltage Single phase 200V / 220V / 240V 3-phase 200V / 220V / 240V Frequency 50 Hz / 60 Hz Rated currency 4.6A / 4.3A / 4.0A 3.0A / 2.7A / 2.3A

Operating environment

Temperature : 0 to 40˚C Humidity : 90% or less

11. SETTING FOR FUNCTIONS

(1) Names and functions of the respective sections of the electrical box (SC-905).

Setting

No.

Setting contents

Selection and setting of the various functions can be performed with four setting switches and an indicator of the SC-905.

1 Switch for confirming the contents of change and updating setting No. in DOWN direction (SET-) 2 Switch for confirming the contents of change and updating setting No. in UP direction (SET+) 3 Down switch (DOWN) 4 Up switch (UP)

(Caution) Do not perform switch operations other than those described in the following explanations.

Be sure to re-turn the power switch ON after one second or more has passed. If the power is turned ON immediately after turning it OFF, the sewing machine may not work normally. In this case, turn ON the power again.

WARNING :

To avoid possible personal injuries caused by movement other than that you desired, do not operate the switches in the procedure other than those required, as described below, to specify the functions.

(2) How to change over to the function setting mode

1) Turn OFF the power to the unit.

2) Pressing switch 4, turn ON the power to the unit.

− 63 −

Page 64

3) Indication 5 will be shown on the display. (If the indication fails to change, re-perform the procedures

1) to 3).

4) When you want to advance the setting No., press switch 2 to advance the setting No. When you want to return the setting No., press switch 1 to return the setting No.

(Caution) Keep pressing switch 2 or switch 1,

and the setting No. will advance (return) continuously. When the setting No. is advanced (returned), the contents which are before by one (after by one) will be determined. So be careful when changing the contents (up / down switch is touched.)

EXAMPLE) CHANGING THE FLICKER REDUCING FUNCTION (SETTING No. 5)

Press switch 2 four times to set the setting No. to “5”. Press switch 4 five times to change the set No. to “5” since the current set value is displayed on LED 6. (Standard : “0”)

(Reference)

Keep pressing switch 4 or switch 3, and the setting value can be changed continuously.

5) When the change has been completed, press switch 1 or 2 to specify the changed value.

(Caution) 1. When turning OFF the power before

performing this work, the contents which have been changed are not updated.

2. Press switch 2, and screen display will change to the contents of next setting No.

3. Press switch 1, and screen display will change to the contents of previous setting No. After completing the operation, turn OFF the power. The machine returns to the normal operation by turning ON the power again.

− 64 −

Page 65

12. FUNCTION SETTING LIST

No.

Item

Soft start function

Maker’s function

Flicker reducing function

Bobbin thread counting function

Unit of bobbin thread counting down

Number of rotation of reverse feed stitching

Maker’s function

Setting of needle bar stop position when the sewing machine stops.

Click sound of key switch mounted on PSC

Optional switch function selection

Function of prohibiting start of the sewing machine by bobbin thread counter

Maker’s function

The number of stitches to be sewn at a low speed when the soft-start function is used at the start of sewing.

0 : Soft-start function is not operative.

Do not change the set value. It is very dangerous if the value is changed since the machine will break.

Flicker reducing function (If the hand lamp flickers.)

0 : Flicker reducing function is not operative. 1 : Less effective ıî 8 : Highly effective

Bobbin thread counting function

0 : Bobbin thread counting function is not operative. 1 : Bobbin thread counting function is operative.

Unit of bobbin thread counting down

0 : Count/10 stitches 1 : Count/15 stitches 2 : Count/20 stitches

Sewing speed of reverse feed stitching

Do not change the set value. It is very dangerous if the value is changed since the machine will break.

Position of needle bar is specified when the sewing machine stops.

0 : Predetermined lowest position 1 : Predetermined highest position

Click sound of key switch mounted on PSC is specified.

0 : Click is not operative. 1 : Click is operative.

Switching of functions of optional switch

0 : No function 1 : Needle up/down compensating stitching 2 : No function 3 : No function 4 : Thread trimming function 5 : Presser foot lifting function 6 : One stitch compensating stitching

7 : No function Do not set to 2, 3 and 7. If these numbers are set, trouble or accident will be caused.

Function of prohibiting start of the sewing machine by bobbin thread counter (After thread trimming)

0 : When counting is out (-1 or less), function of prohibiting start of the

sewing is not operative.

1 : When counting is out (-1 or less), function of prohibiting start of the

sewing machine is operative.

2 : Function of “1” + counter (-1 or less) stop (temporary stop) Do not change the set value.

It is very dangerous if the value is changed since the machine will break.

Do not change the set value. It is very dangerous if the value is changed since the machine will break.

Description

Setting

range

0 to 9

(Stitches)

0/1

0 to 19

(Stitches)

0 to 8

0/1

0 to 2

180 to 3,000

(r.p.m.)

0/1

0 to 6

0 to 2

0/1

0 to 19

0/1

Indication of standard

function setting

1350

Ref. page

Inst.manual

* Do not change the set values with asterisk (*) mark as they are functions for maintenance. If the standard set value set at the time of

delivery is changed, it is in danger of causing the machine to be broken or the performance to be deteriorated. If it is necessary to change the set value, please purchase the Engineer's Manual and follow the instructions. (Descriptions of setting in this list are the standard values at the time of delivery of LZ-2290.) However, contents of function setting are subject to change for improvement of function and performance without notice.

− 65 −

Page 66

No.

Item

Maker’s function

Description

Do not change the set value. It is very dangerous if the value is changed since the machine will break.

Setting

range

0/1

Indication of standard

function setting

Ref. page

Inst.manual

Function of neutral presser lifting

Function of changeover of compensating switch on the operation panel function

Function of fine adjustment of number of rotation

Function of reverse feed stitching on the way

Number of stitches of reverse feed stitching on the way

Effective condition of reverse feed stitching on the way when the sewing machine is stopping.

Thread trimming function by reverse feed stitching on the way

Number of rotation at a low speed

Function of lifting presser foot when the pedal is in neutral position.

0 : Function of neutral automatic presser lifting is not operative.

1 : Selection of function of neutral presser lifting.

Function of needle up/down compensating switch on the operation panel can be changed.

0 : Needle up/down compensation

1 : One stitch compensation

Number of rotation can be compensated. Be sure to normally use this function with "0".

Function of reverse feed stitching on the way

0 : Function of reverse stitching on the way is not operative.

1 : Function of reverse feed stitching on the way is operative.

Number of stitches of reverse feed stitching on the way.

Effective condition of reverse feed stitching on the way

0 : Function is not operative when the sewing machine stops.

1 : Function is operative when the sewing machine stops.

Thread trimming function by reverse feed stitching on the way

0 : Automatic thread trimming function after completion of reverse feed

stitching on the way is not operative.

1 : Automatic thread trimming after completion of reverse feed stitching

on the way is performed.

Lowest speed by pedal

0/1

-1.5% to

1.5%

(0.1 %)

0/1

0 to 19

(Stitches)

0/1

20 to 400

(r.p.m.)

200

Number of rotation of thread trimming

Number of rotation of softstart

Maker’s function

Thread trimming speed

Sewing speed at the start of sewing (soft-start)

Do not change the set value. It is very dangerous if the value is changed since the machine will break.

20 to 250

(r.p.m.)

130 to 5500

(r.p.m.)

180

37 1200

38 2000

Pedal stroke at the start of rotation

Low speed section of pedal

Position where the sewing machine starts rotating from pedal neutral position (Pedal stroke)

Position where the sewing machine starts accelerating from pedal neutral position (Pedal stroke)

10 to 50

(0.1 mm)

10 to 100

(0.1 mm)

Starting position

of lifting presser foot by pedal

Starting position

of lowering presser foot

* Do not change the set values with asterisk (*) mark as they are functions for maintenance. If the standard set value set at the time of

Position where the cloth presser starts lifting from pedal neutral position (Pedal stroke)

Starting position of lowering presser foot Stroke from the neutral position

–60 to –10

(0.1mm)

8 to 50

(0.1 mm)

-21

− 66 −

Page 67

No.

Item

Pedal stroke 2 for starting thread trimming

Pedal stroke for reaching the maximum number of rotation

Compensation of neutral point of the pedal

Auto-lifter selecting function

Holding time of lifting auto-lifter

Description

Position 2 where the thread trimming starts from pedal neutral position (When the function of lifting presser foot by pedal is provided.) (Pedal stroke)

Position where the sewing machin reaches its highest sewing speed from pedal neutral position (Pedal stroke)

Compensation value of the pedal sensor

Auto-lifter selection

0 : Solenoid drive system

1 : Pneumatic drive system

Limitation time of waiting for lifting solenoid type auto-lifter device

Setting

range

–60 to –10

(0.1 mm)

10 to 150 (0.1 mm)

–15 to 15

0/1

10 to 600

(second)

Indication of standard

function setting

-51

150

Inst.manual

Pedal stroke 1 for starting thread trimming

Lowering time of presser foot

Position where thread trimming starts from pedal neutral position (Standard pedal) (Pedal stroke)

Lowering time of presser foot after the pedal has been depressed. (Start of rotation of the sewing machine is delayed during this time.)

–60 to –10

(0.1 mm)

0 to 250 (10 ms)

-35

140

Compensation of solenoid-on timing of reverse feed stitching at the start of sewing

Compensation of solenoid-off timing of reverse feed stitching at the start of sewing

Compensation of solenoid-off timing of reverse feed stitching at the end of sewing

Foot lift after thread trimming

Reverse revolution to lift the needle after thread trimming

Maker’s function

Compensation of starting the solenoid for reverse feed stitching when reverse feed stitching at the start of sewing is performed.

Compensation of releasing the solenoid for reverse feed stitching when reverse feed stitching at the start of sewing is performed.

Compensation of releasing the solenoid for reverse feed stitching when reverse feed stitching at the end of sewing is performed.

Function of lifting presser foot at the time of (after) thread trimming

0 : Not provided with the function of lifting presser foot after thread

trimming

1 : Provided with the function of lifting presser foot automatically after

thread trimming

Function of reverse revolution to lift the needle at the time of (after) thread trimming

0 : Not provided with the function of reverse revolution to lift the needle

after thread trimming

1 : Provided with the function of reverse revolution to lift the needle

after thread trimming

Do not change the set value. It is very dangerous if the value is changed since the machine will break.

–36 to 36

(10˚)

–36 to 36

(10˚)

–36 to 36

(10˚)

0/1

-0

Function of

holding predetermined upper/lower position of the needle bar

Function of

Auto/Manual change-over of reverse feed stitching at the start of sewing

Function of stop

immediately after reverse feed stitching at the start of sewing

* Do not change the set values with asterisk (*) mark as they are functions for maintenance. If the standard set value set at the time of

Function of holding predetermined upper/lower position of the needle bar

0 : Not provided with the function of holding predetermined upper/lower

position of the needle bar

1 : Provided with the function of holding predetermined upper/lower

position of the needle bar

This function can specify the sewing speed of reverse feed stitching at the start of sewing.

0 : The speed will depend on the manual operation by pedal, etc.

1 : The speed will depend on the specified reverse feed stitching speed

(No. 8).

Function at the time of completion of reverse feed stitching at the start of sewing

0 : Not provided with the function of temporary stop of the sewing

machine at the time of completion of reverse feed stitching at the start of sewing

1 : Provided with the function of temporary stop of the sewing machine

at the time of completion of reverse feed stitching at the start of sewing.

0/1

Ref. page

− 67 −

Page 68

No.

Item

Maker’s function

Change-over speed of condensation stitch or EBT (end back tack)

Maker’s function

Function of soft-down of presser foot

Description

Do not change the set value. It is very dangerous if the value is changed since the machine will break.

Initial speed when starting EBT

Do not change the set value. It is very dangerous if the value is changed since the machine will break.

Presser foot is slowly lowered.

0 : Presser foot is rapidly lowered.

1 : Presser foot is slowly lowered.

Setting

range

0/1

0 to 250 (r.p.m.)

–36 to 0

(10˚)

–36 to 0

(10˚)

0 to 9

(Stitches)

0 to 35

(10˚)

0 to 35

(10˚)

0/1

Indication of standard

function setting

170

-15

Ref. page Inst.manual

Function of limitation of reacceleration from reduction of speed

Function of limitation of acceleration at the start of rotation

Retry function

Rotating direction of motor

Function to select the startup speed of the sewing machine

Function of pedal curve selection

Speed limitation is performed at the time of re-acceleration on the way of reducing speed of the sewing machine. It is effective when operating inching sewing.

Speed limitation is performed at the time of start-up of the sewing machine (excluding the start of sewing). It is effective when operating inching sewing.

This function is used when needle cannot pierce materials .

0 : Normal

1 : Retry function is provided.

Normal rotating direction of motor

0 : Clockwise

1 : Counterclockwise

Starting curve of the sewing machine is selected.

0 : Normal curve

1 : More sharp curve

Pedal curve is selected. (Improving pedal inching operation)

Number of rotations

Pedal stroke

0 to 9

(1/step)

0 to 9

(1/step)

0/1

0/1/2

* Do not change the set values with asterisk (*) mark as they are functions for maintenance. If the standard set value set at the time of

− 68 −

Page 69

No.

Item

Return of needle thread feed

Function of prohibiting compensation operation after turning handwheel by hand

Function of reducing speed of reverse feed stitching at the start of sewing

Function added to needle up/ down compensating switch

Maker’s function

Max. number of rotation setting

Description

Return of feed function

0 : Without function

1 : With function

Function of compensating stitching when turning handwheel by hand at the time of completion of constant-dimension stitching

0 : Function of compensating stitching is effective.

1 : Function of compensating stitching is prohibited.

Function to reduce speed at the time of reverse feed stitching at the start of sewing.

0 : Speed is not reduced.

1 : Speed is reduced.

Operation of needle up/down compensating switch is changed after turning ON the power or thread trimming.

0 : Normal (needle up/down compensating stitching only)

1 : One stitch compensating stitching is performed only when

aforementioned changeover is made. (Upper stop ıî upper stop)

Do not change the set value. It is very dangerous if the value is changed since the machine will break.

Max. number of rotation of the sewing machine head can be set. * Setting varies in accordance with resistance pack to be connected.

Setting

range

0/1

50 to MAX

(r.p.m.)

Indication of standard

function setting

96 4000

Ref. page Inst.manual

* Do not change the set values with asterisk (*) mark as they are functions for maintenance. If the standard set value set at the time of

13. DETAILED EXPLANATION OF SELECTION OF FUNCTIONS

The functions that cannot be described in the Instruction Manual are described below.

1 Unit of bobbin thread counting down (Function setting No. 7)

Unit of bobbin thread counting down (subtraction) can be changed.

2 Function of prohibiting start of the sewing machine by bobbin thread counter

(Function setting No. 13)

This is a function to prohibit start of the sewing machine when the value of the bobbin thread counter reaches - (minus) 1 or less.

0 : 1 count-down per 10 stitches 1 : 1 count-down per 15 stitches 2 : 1 count-down per 20 stitches

0 : Even when counting is out (-1 or less), function of prohibiting start of the sewing

machine is not operative.

1 : When counting is out, the sewing machine stops. (Start of the sewing machine

is prohibited after completing the process during sewing.)

2 : Temporary stop with function of “1” + counter (-1 or less)

3 Number of rotation of reverse feed stitching (Function setting No. 8)

This function sets the number of rotation of reverse feed stitching at the start of sewing, at the end of sewing and at the overlapping stitching.

1900

Setting range 180 to 3,000 [rpm] <10/rpm>

− 69 −

Page 70

 Adjusting the pedal stroke (Function setting Nos. 39, 40, 41, 43, 44 and 48)

No.43 No.48 No.41 No.39 No.40 No.44

(PFL)

Start of thread trimming

(Standard)

Start of presser foot lifting

(PFL)

Start of rotation of

sewing machine

Low speed section

Point of reaching the max.

sewing speed

Low speed

section

Speed in accordance with depressing

amount of pedal

-7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Direction of depressing back part of pedal

Direction of depressing front part of pedal

Pedal neutral position

No.48

No.43 a) b)

No.42 No.39

No.40

No.44

No.41

Adjustment available range

5 Compensation of neutral point of the pedal (Function setting No. 45)

This function displays the compensation value of the neutral point of the pedal. Setting of the compensation value of the neutral point of the ledal is performed by means of the automatic compensation of the neutral position of the pedal.

Setting range

-15 to 15

Automatic compensation of the neutral position of the pedal

Be sure to execute the following operations when the pedal sensor spring or the like is replaced.

1) Pressing switch 1, turn ON the power switch.

2) Indication on the screen will be as illustrated in 2.

At this time, the value indicated in the 7 segments of four figures is the compensation value.

(Caution) At this time, the pedal sensor does not

work properly if the pedal is depressed. Do not place the foot or any object on the pedal.

3) Turn OFF the power switch once, and turn ON the power switch to return to the normal mode.

− 70 −

Page 71

14. EXTERNAL OUTPUT/INPUT CONNECTORS

The following convenient signals are prepared in the case where the counter or the like is set up after setting up the sewing machine.

(Caution) Consult the engineeers who have

CN23

Table of allocation of the connector and signal

CN23

Name of signal

+5V

LSWINH

SOFT

DDET

UDET

S.STATE

SGND

N.C.

Output/input

– Input Input

Output Output Output

–

Output

Power source Rotation by pedal is prohibited while “L” signal is inputted. Speed of rotation is limited to soft-speed while “L” signal is

imputted. “L” is output when the needle bar is in its lower position. “L” is output when the needle bar is in its upper position. “L” is output when the sewing machine is in stopping state. 0V Pulse is output in accordance with rotation of the sewing

machine. (45/rotation) Not connected.

Description

electrical knowledge when using the connectors.

Electric spec.

DC5V, 100 mA

DC5V, –5 mA DC5V, –5 mA

DC5V, 1 mA DC5V, 1 mA DC5V, 1 mA

DC5V, 1 mA

JUKI genuine Part No. Part No. of connector HK024910090 Part No. of pin contact HK032040000

(1) Connector connection diagram

Machine head solenoid

CN 5

CN 6

1 2

CN 2

Presser lifting solenoid

1 2

CN 4

1-4 TRM (Thread trimming) Approx. 7.5 Ω 2-5 BT (Reverse feed stitching) Approx. 6.5 Ω

4-9 WP (Wiper) Approx. 8.5 Ω 5-10 TL (Thread release) Approx. 12.5 Ω

1-2 TLSUB (Thread feeding) Approx. 27 Ω

1-2 FL (Presser lifting) Approx. 5.4 Ω

− 71 −

Page 72

15. FUNCTION SETTING OF THE OPERATION PANEL

!6 !7

1 Pattern selection switch 2 Zigzag width switch 3 Stitch base line switch 4 Automatic reverse feed stitch at sewing start switch 5 Automatic reverse feed stitch at sewing end switch 6 Zigzag display switch 7 Zigzag indicator 8 Specifying zigzag stop position switch 9 Number of stitches switch (At the time of setting mode)

(1) Initializing the panel data

!0 Setting switch (Setting mode input switch) !1 Detail setting switch (Detail setting mode input switch) !2 Bobbin thread counter reset switch !3 Bobbin thread amount setting switch !4 Bobbin thread counter !5 Needle up/down compensating switch !6 Thread trimming prohibiting switch (LZ-2290 (U)-7) !7 Power display LED !8 Max. speed limitation variable resistor

1) The panel data can be returned to the initial state at the time of delivery.

2) Initializing procedure (1) Turn OFF the power. (2) Simultaneously pressing custom pattern switch

!7 and “–” switch !3 of the bobbin thread amount setting switch, turn ON the power.

The count value of the bobbin thread counter cannot be initialized.

− 72 −

Page 73

(2) Setting of the key lock

1) The contents of the key lock can be changed. There are two kinds of the key lock level, L_0 and L_1. The level has been set to L_0 level at the time of delivery. (1) Functions that cannot be locked at the L_0 level

1 ON/OFF of the automatic reverse feed stitching 2 Prohibition of thread trimming 3 Specifying the stop position 4 Bobbin thread counter

(2) Functions that cannot be locked at the L_1 level

1 Zigzag pattern 2 ON/OFF of the automatic reverse feed stitching 3 Prohibition of thread trimming 4 Specifying the stop position 5 Bobbin thread counter

←→

2) Setting procedure (1) Pressing setting switch !0, press detail setting

switch !1 to enter the detail setting mode.

(2) Press left blind stitch switch @0. LED of left blind

stitch switch @0 flashes on and off and the level of key lock is displayed in zigzag indicator 7.

(3) Change over the display with zigzag display

switch 6.

(4) Press setting switch !0 to determine the setting.

− 73 −

Page 74

16. ERROR CODE LIST

(1) PSC box

No.

Description of error detected

Er0

Execution of data initialization (This is not the error.)

Er1

Phase missing of power

Er2

Fall detection switch failure

Er3

Disconnection of synchronizer connector

Er4

Synchronizer lower position sensor failure

Er5

Synchronizer upper position sensor failure

Er6

Operation panel transmission failure

Cause of occurrence expected

• When the machine head is changed.

• When 3-phase input is missing, and single phase operation is performed.

• When input voltage is less than the guaranteed voltage.

• When fall detection switch is inputted in the state that the power is turned ON.

• When position detection signal is not inputted from the sewing machine head synchronizer.

• When the synchronizer has broken.

• Disconnection of operation panel cord

• Operation panel has broken.

Items to be checked

• Check the power plug and receptacle for loose connection and disconnection.

• Check the power switch terminal for loose connection and disconnection.

• Check whether power fuse has blown.

• Check whether input voltage is lower by -10% than the rated voltage.

• Check whether the machine head is tilted without turning OFF the power switch (sewing machine operation is prohibited for safety sake).

• Check whether the fall detection switch cord is caught in the sewing machine or the like and has broken.

• Check whether the fall detection switch lever is caught in something.

• Check the synchronizer connector (CN2) for loose connection and disconnection.

• Check whether the synchronizer cord has broken since the cord is caught in the machine head or the like.

• Check the operation panel connector (CN3) for loose connection and disconnection.

• Check whether the operation panel cord has broken since the cord is caught in the machine head or the like.

Er7

Overload of motor

Er8

Machine head connector failure

Er10

Solenoid short-circuit

Er11

Overvoltage

Er13

Low voltage

Er24

Motor driver failure

Er30

Encoder failure

Er31

Motor hole sensor failure

Er43

Bobbin thread remaining amount sensor unit failure

• When the machine head is locked.

• When sewing extra-heavy material beyond the guarantee of the machine head.

• When the motor does not run.

• When the machine head connector is not properly read.

• When the short-circuited solenoid is desired to be driven.

• When voltage upper than guaranteed one is inputted.

• When 200V is inputted for 100V setting.

• When voltage lower than guaranteed one is inputted.

• When 100V is inputted for 200V setting.

• Motor driver has broken.

• When the motor signal is not properly inputted.

• When the position of the detection bar of the AE device is shifted from the home position.

• Check whether the thread has been entangled in the motor pulley.

• Check the motor output connector (4P) for loose connection and disconnection.

• Check the machine head connector (CN7) for loose connection and disconnection.

• Check whether the solenoid is short-circuited.

• Check whether the applied power voltage is higher than the rated voltage + (plus) 10% or more.

• Check whether 100V/200V changeover connector is set by mistake. In the above cases, POWER circuit board has broken.

• Check whether the votage is lower than the rated voltagw - (minus) 10% or less.

• Check whether 100V/200V changeover connector is set by mistake.

• Check the motor signal connector (CN12) for loose connection and disconnection.

• Check whether the motor signal cord has broken since the cord is caught in the machine head or the like.

• Check whether the detection bar of the AE device has returned to the correct position.

• Check whether the function setting No. 57 has been mistakenly set.

• Check the AE device connectors (CN53, CN57) for loose connection and disconnection.

• Chreck whether the AE device cord has broken since the cord is caught in the machine head or the like.

− 74 −

Page 75

(2) Operation panel error

No.

PE 0

PE 1

Description and place to be checked

• UP position detection error at the time of turning ON the power

The sewing machine does not stop at UP position.

Trouble of synchronizer

Disconnection/looseness of synchronizer connector

• Max. zigzag width limitation error 1 When the value of max. zigzag width limitation is changed or zigzag

width of zigzag pattern is larger than max. zigzag width limitation.

2 Zigzag width of the pattern which has been copied from the pattern

copy between panels is larger than max. zigzag width limitation.

Max. zigzag width limitation

Corrective measure

• Turn the sewing machine handwheel by hand and adjust the marker dot of the sewing machine.

• Insertion of synchronizer

• Replace synchronizer.

• Make the zigzag width of pattern smaller than max. zigzag width limitation.

PE 2

Zigzag width of zigzag pattern

• Stitch base line position error 1 When the value of max. zigzag width limitation is changed, the zigzag

width is within the value of max. zigzag width limitation. However, when the zigzag width is out of the area of max. zigzag width limitation due to the position of stitch base line of the zigzag pattern.

2 Zigzag width of the pattern which

has been copied from the pattern copy between panels is within max. zigzag width limitation. However, when the zigzag width is out of the area of max. zigzag width limitation due to the position of stitch base line.

Max. zigzag

width limitation

Position of stitch base line

− 75 −

• Set the position of the stitch base line within the area of max. zigzag width limitation.

Page 76

No.

Description and place to be checked

Corrective measure

PE 3

PE 4

PE 5

• Custom pattern pitch error The max. traveling amount of 1 Step exceeds 8.0 mm at the position specifying data of the custom pattern.

Max. zigzag

width limitation

8.5 mm

•Condensation custom pattern pitch error The max. traveling amount of 1 Step exceeds 8 mm at the position specifying data of the condensation custome pattern.

•Panel communication error

1 Disconnection of the panel cord 2 Slackness of the panel cord connector 3 Needle rocking control error

•Set the max. traveling amount of 1 Step to less than 8 mm.

• Set the max. traveling amount of 1 Step to less than 8 mm.

• Check or replace the panel cord.

• Re-connect the connector.

• Turn ON / OFF power.

PE 6

BTSW

LED

Flashing

1 time

BTSW

LED

Flashing

2 times

BTSW

LED

Flashing

3 times

•Communication between panels error

1 Disconnection of the panel cord 2 Slackness of the panel cord connector

•Communication between panels error

1 Disconnection of the panel cord 2 Slackness of the panel cord connector

•Overheat error An error that occurs when the temperature of the radiator on CTL circuit board inside the control box has risen more than the specified temperature.

•Needle rocking drive origin error An error that occurs when the detection of the needle rocking origin is performed and the origin is not detected at the time of turning ON the power.

1 Disconnection of PM relay cable 2 Trouble of the origin sensor 3 Disconnection of the power transformer connector pin 4 F1 fuse has blown.

• Check or replace the panel cord.

• Re-connect the connector.

• Check or replace the panel cord.

• Re-connect the connector.

• Clean the filter of cooling fan.

• Re-connect the connector.

• Check the connector pin.

• Remove the cause of blown-out and replace the fuse.

• Re-connect the connector.

• Check the connector pin.

• Remove the cause of blownout and replace the fuse.

− 76 −

Page 77

(3) Way of referring to the error history

You can check the error information occurred in the past. Error information can be recorded up to 127 cases. (Error information more than 127 cases is overwritten from older one.)

1) Pressing switch 1 inside the front cover, turn ON the power switch.

2) LED displays the latest error information with “peep” sound. (If there is no error, indication 2 changes to indicate “Er0”.)

3) When switch 3 is pressed, old error information in the error history can be called. (When the information reaches the last, an alarm sound “peeps”.

4) When switch 4 is pressed, new error information in the error history can be called. (An alarm sound “peeps” at the latest information.)

(Caution) Refer to “16. Error code list” for error

No. and the description.

17. OPTIONAL COED

(1) Relay cord A asm. for standing machine (Part No. M9701351AA0)

Approx. 1.5 mm

1) Wiring diagram of variable pedal PK-70, -71

CN 56

BROWN

5 V

ORANGE

SPEED VARIABLE RESISTOR

S GND

PRESSER LIFTER SWITCH

S GND

THREAD TRIMMING SWITCH

S GND

HIGH SPEED SWITCH

3 4 5 6 7 8 9

YELLOW GREEN BLUE PURPLE GRAY

WHITE

VR(1 KΩ) 2

To be used with variable between 1 and 2V (Acceleration / retardation) Neutral position : 1V ± 0.05V (between 3 and 4)

S GND

LOW SPEED SWITCH

S GND

LIGHT BLUE

PINK

BLACK

• Power source section A sorted by color for each signal appears from the relay cord A asm. for standing machine. Perform connection of the switches and the speed variable resistor according to the wiring diagram.

• Use this cord by inserting it into the connector (CN10) of pedal for standing machine in PSC box.

− 77 −

Page 78

2) Wiring diagram of fixed max. speed

CN 55

5 V

SPEED VARIABLE RESISTOR

S GND

PRESSER LIFTER SWITCH

S GND

THREAD TRIMMING SWITCH

S GND

HIGH SPEED SWITCH

S GND

LOW SPEED SWITCH

S GND

1 2 3 4 5 6 7 8

9 10 11 12

BROWN

ORANGE YELLOW

GREEN BLUE

PURPLE GRAY WHITE

LIGHT BLUE

PINK BLACK

Use this cord by inserting it into the connector (CN10) of pedal for standing machine in PSC box.

(Caution) When decreasing the speed of the high speed switch, use the max. speed limitation variable

resistor located on the panel.

(2) Relay cord A asm. for DC24V (Part No. M9703351AA0)

1 2

Approx. 1.5 m

Wiring diagram

CN 15

DC24 V

GND

Use this cord by inserting it into the yellow connector (CN15 2P) of DC24v in PSC box.

* Reference for use is approximately one solenoid valve. (Up to 100mA)

− 78 −

Page 79

18. BLOCK DIAGRAM

POWER SW * ASM.

LAMP FUSE HOLDER A ASM.

MAIN SHAFT MOTOR

THREAD TRIMMING SOLENOID REVERSE STITCH SOLENOID SAFETY SWITCH

STANDING PEDAL

THREAD DRAW-OUT SOLENOID

NEEDLE THROW MOTOR ORIGIN SENSOR WIPER SOLENOID TENSION RELEASE SOLENOID

REVERSE STITCH SWITCH MIRROR LED AUXILIARY SWITCH

PRESSER LIFTER SOLENOID

RESISTOR PACK

− 79 −

Page 80

− 80 −

Page 81

CUSTOM PATTERN NEEDLE ENTRY POSITION DATA SHEET

–5.0 –4.0 –3.0 –2.0 –1.0 0.0 1.0 2.0 3.0 4.0 5.0

1 2

3 4

5 6

7 8 9

10 11

12 13

14 15

16 17

18 19

20 21

22 23

24 25

26 27 28

29 30

31 32

33 34

35 36

37 38

39 40

41 42

43 44

45 46

47 48

49 50

51 52

53 54

55 56

57 58

59 60

61 62 63 64

− 81 −

Step No

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64

Needle entry

position

Feed

direction

Page 82

19. DRAWING OF TABLE

(2 places)

X-X rubber cushion installing drawing for reference

(2 places) (2 places) (2 places)

(2 places)

C1.5 to C2.5 (for the hinge side only)

Dimension drawing indetail (2 : 1)

Style of type : Helvetica Reg. Condensed

Thickness : 1.5

Condensed voided letters

A : 4-ø3.4 on the bottom surface, depth 20 (Drill a hole at the time of set-up)

B : Installing position of stopper for drawer (on the reverse side) C : JUKI logo type D : ø16, depth 30

Y-Y rubber cushion installing drawing for reference

E : 9 drill X ø20 chamfered, depth 17 F : 2-ø3, depth 10 G : 2-ø3.4 depth 10 (on the bottom surface)

(Drill a hole at the time of set-up)

Thickness : 0.8 Thickness : 0.5 Thickness : 1.5

H : ø18 drill hole I : 2-ø3 depth 10 J : 3-ø13 drilled hole

− 82 −

Page 83

Direct-drive, Computer-controlled, High-speed, 1-needle, Lockstitch, Zigzag Stitching Machine

LZ-2290 Series

CP-760 / SC-905

ENGINEER’S MANUAL

29345808

No.00

Page 84

PREFACE

This Engineer’s Manual is written for the technical personnel who are responsible for the service and maintenance of the sewing machine. This manual describes “Adjustment Procedure”, “Results of Improper Adjustment”, and other functions which are not covered by the Instruction Book intended for the maintenance personnel and sewing operators at a sewing factory. All personnel engaged in repair of LZ-2290 Series • CP-760 / SC-905 are required to carefully read Section 2 “Standard Adjustment” which contains important information on the maintenance of LZ-2290 Series • CP-760 / SC-905. The “Standard Adjustment” consists of two parts ; the former part presents illustration and simplified explanation for the convenience of reconfirmation of the required adjustment values in carrying out actual adjustment after reading this manual once; and the latter part provides “Results of Improper Adjustment” in which sewing and/or mechanical failures, and the correcting procedures are explained for those persons who perform such adjustment for the first time. It is advisable to use “LZ-2290 Series • CP-760 / SC-905 Parts Book” together with this Engineer’s Manual.

Page 85

CONTENTS

1. SPECIFICATIONS ......................................................................................1

(1) Specifications of the machine head.......................................................................... 1

(2) Stitch pattern table.................................................................................................... 2

(3) Cautions in operation................................................................................................ 3

2. NAME OF EACH COMPONENT ................................................................4

3. STANDARD ADJUSTMENT ......................................................................6

(1) Height and inclination of the feed dog ...................................................................... 6

(2) Adjusting the feed timing .......................................................................................... 6

(3) Adjusting the feed amount........................................................................................ 8

(4) Position of the feed dog............................................................................................ 8

(5) Adjusting the slippage of materials (For LZ-2290SU only) ..................................... 10

(6) Adjusting the origin of the needle rocking motor .................................................... 12

(7) Adjusting the needle entry position (In terms of needle rocking direction) ............. 14

(8) Adjusting the longitudinal play at the needle bar .................................................... 14

(9) Adjusting the needle entry position (In terms of longitudinal direction) .................. 14

(10) Position of the needle bar connection guide......................................................... 16

(11) Height of the needle bar ....................................................................................... 16

(12) Adjusting the needle-to-hook timing and the needle guard .................................. 18

(13) Position of the bobbin case stopper ..................................................................... 20

(14) Orientation of the needle bar thread holder.......................................................... 20

(15) Auxiliary thread take-up lever ............................................................................... 22

(16) Position of the thread tension ............................................................................... 24

(17) Position of the pre-tension.................................................................................... 24

(18) Position of the thread take-up spring guard.......................................................... 26

(19) Installing the thread take-up thread guide B......................................................... 26

(20) Installing the thread take-up ................................................................................. 26

(21) Installation of the presser foot .............................................................................. 28

(22) Installing and adjusting the bobbin winder unit..................................................... 28

(23) Adjusting the amount of oil in the hook................................................................. 30

(24) Adjusting the thread trimming unit ........................................................................ 30

(25) Initial position of the moving knife......................................................................... 32

(26) Timing of the thread trimming cam ....................................................................... 32

(27) Installing/removing the knife unit .......................................................................... 34

(28) Stop position of the needle after thread trimming................................................. 34

(29) Clearance provided between the main shaft handwheel and the stator............... 34

(30) Position of the automatic reverse stitching magnet .............................................. 36

(31) Adjusting the thread tension releasing solenoid ................................................... 36

(32) Adjusting the stitch length dial .............................................................................. 38

(33) Adjusting the lubrication mechanism .................................................................... 40

(34) Adjusting the position of the thread draw-out wire................................................ 40

Page 86

(35) Adjusting the stroke of the thread draw-out wire .................................................. 42

(36) Installing the wiper base ....................................................................................... 42

(37) Adjusting the wiper solenoid................................................................................. 44

(38) Position of the wiper ............................................................................................. 44

PROCEDURES OF DISASSEMBING/ASSEMBLING AND CAUTIONS ......

(1) Adjusting and assembling of the gear box (large) .................................................. 46

(2) Replacing the motor ............................................................................................... 48

(3) Replacing the timing belt ........................................................................................ 50

(4) Removing/installing the gear box cover.................................................................. 50

5. SCREWS FOR ATTACHMENTS .............................................................52

6. SPARE PARTS.........................................................................................52

7. TROUBLES AND CORRECTIVE MEASURES

(WITH REGARD TO LUBRICATION) ......................................................53

8. TROUBLES AND CORRECTIVE MEASURES

(WITH REGARD TO SEWING) ................................................................55

9. TROUBLES AND CORRECTIVE MEASURES

(WITH REGARD TO MECHANICAL COMPONENTS) ............................59

10. FOR GENERAL EXPORT ......................................................................63

11. SETTING FOR FUNCTIONS ..................................................................63

(1) Names and functions of the respective sections of the electrical box (SC-905)..... 63

(2) How to change over to the function setting mode .................................................. 63

12. FUNCTION SETTING LIST ....................................................................65

13. DETAILED EXPLANATION OF SELECTION OF FUNCTIONS............69

14. EXTERNAL OUTPUT/INPUT CONNECTORS.......................................71

(1) Connector connection diagram............................................................................... 71

15. FUNCTION SETTING OF THE OPERATION PANEL ...........................72

(1) Initializing the panel data ........................................................................................ 72

(2) Setting of the key lock ............................................................................................ 73

16. ERROR CODE LIST ...............................................................................74

(1) PSC box ................................................................................................................. 74

(2) Operation panel error ............................................................................................. 75

(3) Way of referring to the error history........................................................................ 77

17. OPTIONAL COED ..................................................................................77

(1) Relay cord A asm. for standing machine (Part No. M9701351AA0) ...................... 77

(2) Relay cord A asm. for DC24V (Part No. M9703351AA0) ....................................... 78

18. BLOCK DIAGRAM .................................................................................79

CUSTOM PATTERN NEEDLE ENTRY POSITION DATA SHEET ............................. 81

19. DRAWING OF TABLE............................................................................83

Page 87

INTERNATIONAL SALES H.Q.

8-2-1, KOKURYO-CHO, CHOFU-SHI, TOKYO 182-8655, JAPAN

PHONE : (81)3-3430-4001 to 4005 FAX : (81)3-3430-4909 • 4914 • 4984 TELEX : J22967

Please do not hesitate to contact our distributors or agents in your area for further information when necessary.

＊The description covered in this engineer's manual is subject to change for improvement of the

commodity without notice.

00 · 06 Printed in Japan (E)