juki MF-7000 INSTRUCTION MANUAL

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Page 1

2-3 Needle Flat Bed Coverseam Machine

MF-7000 Series

2-3 Needle Cylinder Bed Coverseam Machine

MFC-7000 Series

ENGINEER’S MANUAL

29275609

No.02

Page 2

PREFACE

This Engineer’s Manual is written for the technical personnel who are responsible for the service and maintenance of the machine. This manual describes “Standard Adjustment” , “Adjustment Procedures” , “Results of Improper Adjutment”, and other important information which are not covered by the Instruction Manual. It is advisable to use the relevant Instruction Manual and Parts List together with this Engineer’s Manual when carrying out the maintenance of these machines. This manual gives the “Standard adjustment” on the former page under which the most basic adjustment value and on the latter page the “Results of improper adjutment” under which errors and troubles arise.

Page 3

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

2. MOTOR AND BELT..................................................................................................................... 2

3. MODEL NUMBERING SYSTEM ................................................................................................. 3

4. STANDARD ADJUSTMENT ....................................................................................................... 7

(1) MF ............................................................................................................................................................................ 7

1) Timing relation between the needle and the feed .............................................................................................. 7

2) Adjusting the timing relation between the needle bar and looper (synchronization) : Without gauges ........................... 7

3) Returning amount of the looper ......................................................................................................................... 9

4) Height of the needle bar..................................................................................................................................... 9

5) Clearance between the looper and needle ...................................................................................................... 11

6) Adjusting amount of the looper-avoid .............................................................................................................. 11

7) Position of the needle guard ............................................................................................................................ 13

8) Position of the feed dog ................................................................................................................................... 15

9) Spreader .......................................................................................................................................................... 17

10) Looper thread cam ........................................................................................................................................... 19

11) Position of the presser bar ............................................................................................................................... 21

12) Position of the needle thread tension release (without thread trimmer)........................................................... 21

13) Position and height of the presser foot ............................................................................................................ 23

14) Position of the thread guide ............................................................................................................................. 23

(2) Thread trimmer device (MF) ................................................................................................................................ 27

1) Adjustment of the thread trimmer device ......................................................................................................... 27

2) Thread tension release (Looper thread trimmer device) .................................................................................. 29

(3) MFC ....................................................................................................................................................................... 31

1) Timing relation between the needle and the feed ............................................................................................ 31

2) Adjusting the timing of the needle bar and looper (Synchronization) : Without gauges................................... 31

3) Returning amount of the looper ....................................................................................................................... 33

4) Height of the needle bar................................................................................................................................... 33

5) Position of the needle guard ............................................................................................................................ 35

6) Clearance between the looper and needle ...................................................................................................... 35

7) Adjusting amount of the looper-avoid .............................................................................................................. 37

8) Position of the feed dog ................................................................................................................................... 39

9) Spreader .......................................................................................................................................................... 41

10) Looper thread cam ........................................................................................................................................... 43

11) Looper thread wrap-up preventing cam (Old type) .......................................................................................... 43

12) Position of the presser bar ............................................................................................................................... 45

13) Position of the needle thread tension release (without thread trimmer)........................................................... 45

14) Position and height of the presser foot ............................................................................................................ 47

15) Position of the thread guide ............................................................................................................................. 47

(4) Thread trimmer device (MFC) ............................................................................................................................. 51

1) Stroke adjustment (common to both elctromagnetic and pneumatic type) ...................................................... 51

2) Adjustment of the right position of movable knife (return)................................................................................ 51

3) Adjustment of stationary knife and looper thread clamp spring ....................................................................... 53

4) Adjustment of the position of movable knife’s pointed end .............................................................................. 53

5) Adjustment of operating speed of thread trimmer (pneumatic type) ................................................................ 55

6) Confirmation of thread trimming....................................................................................................................... 55

7) Adjustment of pneumatic lifter.......................................................................................................................... 57

8) Adjustment of tension release (equipped with thread trimmer)........................................................................ 59

9) Adjustment of proximity switch......................................................................................................................... 59

10) Adjustment of top covering thread trimmer ...................................................................................................... 61

5. ASSEMBLING AND ADJUSTMENT OF FIXED CAM THREAD TAKE-UP ............................. 63

(1) Parts used............................................................................................................................................................. 63

(2) Needle bar cam plate and needle bar fork thread take-up ............................................................................... 65

(3) Needle thread guide and medium thread path base......................................................................................... 65

(4) Spreader thread guide ......................................................................................................................................... 67

1) Parts used ........................................................................................................................................................ 67

2) Assembling and adjustment of spreader thread guide..................................................................................... 67

6. OTHER PRECAUTIONS ........................................................................................................... 68

(1) Points to which Locktite is applied .................................................................................................................... 68

7. TROUBLES AND CORRECTIVE MEASURES......................................................................... 69

8. DRAWING OF TABLE............................................................................................................... 84

(1) Semi-submerged type for MF ............................................................................................................................. 84

(2) Desktop type for MF ............................................................................................................................................ 86

(3) Desktop type for MF with fabric under trimmer ................................................................................................ 87

(4) Desktop type for MFC .......................................................................................................................................... 88

(5) Semi-submerged type for MFC ........................................................................................................................... 89

(6) Semi-submerged down table for MFC ............................................................................................................... 90

(7) Table for MFC with tension roller ....................................................................................................................... 91

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1. SPECIFICATIONS

MF-7000 Series

MF-7406 MF-7407 MF-7602 MF-7605 Sewing speed 6,500 r.p.m. (Max) Stitch length 1.6 to 3.2 mm No. of needle 2 3 2 3 Needle gauge 3.2, 4.0 4.8, 5.6, 6.4 3.2, 4.0 4.8, 5.6, 6.4 Top covering Without With Diff. feed ratio Gathering stitch 1 : 1.5 Stretching stitch 1 : 0.6 Needle UY128GAS #65 / 025 to #90 / 036 Presser foot lift 8.1 mm Lubricating oil JUKI specified oil (equivalent to ISO VG32) : Part No. 30149207

MFC-7000 Series

MFC-7406 MFC-7407 MFC-7602 MFC-7605 Sewing speed 6,500 r.p.m. (Max) Stitch length 1.6 to 3.2 mm No. of needle 2 3 2 3 Needle gauge 3.2, 4.0, 4.8 5.6, 6.4 3.2, 4.0, 4.8 5.6, 6.4 Top covering Without With Diff. feed ratio Gathering stitch 1 : 1.5 Stretching stitch 1 : 0.6 Needle UY128GAS #65 / 022 to #90 / 036 Presser foot lift 7 mm Lubricating oil JUKI specified oil (equivalent to ISO VG32) : Part No. 30149207

− 1 −

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2. MOTOR AND BELT

MF-7000 Series

50 Hz 60Hz

Sewing speed

(r.p.m.)

6500 140 35 120 35 6000 125 35 105 35 5500 110 35 90 34 5000 100 34 85 34 4500 90 34 75 34 4000 80 34 70 34 3500 70 34 60 33

1) Use a clutch motor of 1/2 HP (400W).

2) Use an M type V belt.

3) The table above shows the sewing speed obtained by the use of motor pulleys with different diameters and V belts with different lengths.

4) Note that the effective diameter of the pulley of the machine head is 49 mm.

Motor pulley

Outer dia. (mm)

V belt (inch) Motor pulley

Fully-submerged

type

Semi-submerged

type

Outer dia. (mm)

V belt (inch)

Fully-submerged

type

Semi-submerged

type

MFC-7000 Series

50 Hz 60Hz

Sewing speed

(r.p.m.)

Motor pulley

Outer dia. (mm)

V belt (inch) Motor pulley

Top mount type Top mount type

Semi-submerged

type

Outer dia. (mm)

V belt (inch)

6500 145 43 40 120 41 38 6000 135 43 40 110 41 38 5500 120 41 38 100 41 38 5000 110 41 38 90 39 37 4500 95 41 38 80 39 37 4000 85 39 37 70 39 37 3500 75 39 37 60 38 35

1) Use a clutch motor of 1/2 HP (400W).

2) Use an M type V belt.

3) The table above shows the sewing speed obtained by the use of motor pulleys with different diameters and V belts with different lengths.

4) Note that the effective diameter of the pulley of the machine head is 57.5 mm.

Semi-submerged

type

− 2 −

Page 6

Devices and attachments

CC1 PL5 TC2

MD1 UT12 TC3

MD2 UT13 TC4

MD6

Needle gauge

32.......3.2 mm

40.......4.0 mm

48.......4.8 mm

56.......5.6 mm

64.......6.4 mm

tightened. Suitable

for short stitch

Shape of the throat

plate stitch tongue

A : Needle thread is

Sub-class

C02 H01 U03

E12 L01 U06

B :Medium stitch

between A and C

loosened. Suitable

for long stitch

Countermeasure

C : Needle thread is

for bulge

elastic tape

applications

D : For collarette and

Model classification Sub-class classification Designation classification

M F - 7 4 0 6 - E 1 2 - B 5 6 / / /

3. MODEL NUMBERING SYSTEM

MF-7000 Series

Gauge used

Without mark : For domestic market

U : For general export

T : For JE, JME, Turkey

covering stitch

Stitch type

(Conforms to USA standard)

406 : 2-needle bottom covering stitch

407 : 3-needle bottom covering stitch

602 : 2-needle top and bottom

Model No. code

Flat bed

coverseam

stitch

605 : 3-needle top and bottom coverig

− 3 −

Page 7

Devices and attachments

UT1 PL1

UT2 PL4

UT3

UT4

UT5

Needle gauge

32.......3.2 mm

40.......4.0 mm

48.......4.8 mm

56.......5.6 mm

64.......6.4 mm

tightened. Suitable

for short stitch

Shape of the throat

plate stitch tongue

A : Needle thread is

B : Medium stitch

between A and C

loosened. Suitable

for long stitch

Countermeasure

C : Needle thread is

for bulge

elastic tape

applications

D : For collarette and

Model classification Sub-class classification Designation classification

Sub-class

C02 H01 K02

E11 H11 U03

Gauge used

Without mark : For domestic market

U : For general export

H31

E61 H21 U06

T : For JE, JME, Turkey

MFC-7000 Series

covering stitch

M F C - 7 4 0 6 - H 0 1 - B 5 6 / / /

− 4 −

Stitch type

(Conforms to USA standard)

406 : 2-needle bottom covering stitch

407 : 3-needle bottom covering stitch

602 : 2-needle top and bottom

Model No. code

Cylinder bed

coverseam

605 : 3-needle top and bottom

Page 8

MF-7000 Series

Code Specification Description of sub-class

C02 For collarette Basic style E12 For elastic tape attaching Fabric under trimmer and metering device (Upper side) H01 For hemming Baisc style with hem guide L01 For lap seam Basic style U03 Universal Differential feed dog 3-row U06 Universal Differential feed dog 4-row

MFC-7000 Series

Code Specification Description of sub-class

C02 For collarette Basis style E11 E61

For endless elastic tape attaching For endless elastic tape attaching

With fabric under trimmer

With fabric under trimmer and cloth puller H01 For hemming Basic style with hem guide H11 For hemming With cloth puller H21 For hemming Left hand fabric under trimmer H31 For hemming Left hand fabric under trimmer with cloth puller K02 Covering With adjustable seam guide for medium- to heavy-weight fabrics U03 Universal Differential feed dog 3-row U06 Universal Differential feed dog 4-row

Elastic tape cutter (MF-7000 Series)

Code Description Applicable model

TC2 Pneumatic type tape cutter Single action air cylinder knee switch E12, C02 TC3 Solenoid type tape cutter Knee switch E12, C02 TC4 Pneumatic type fast-action tape cutter Double action air cylinder knee switch E12, C02

− 5 −

Page 9

Under-bed thread trimming device

Solenoid type Pneumatic type

Code Applicable model

Thread trimmer

Needle

thread wiper

Top covering

thread

trimmer

Auto-lifter

Thread

trimmer

Needle thread wiper (Mechanical)

Needle thread wiper (Pneumatic)

Top covering

thread

trimmer

Auto-lifter

UT1 MFC7406,7407 ○○ ○ UT2 MFC7602,7605 ○○○ UT3 MFC7406,7407 ○○ ○ UT4 MFC7406,7407 ○○○

UT5 MFC7602,7605 ○○○ UT12 MF7406,7407 ○○ UT13 MF7602,7605 ○○○

Elastic tape metering device

Code Description Applicable model

MD1 MD2 MD6

Metering device (Upper side) Electric single stage Metering device (Upper side) Electric two stage Metering device (Upper side) Mechanical type

MF 7406, 7407, 7602, 7605-E12 MF 7406, 7407, 7602, 7605-E12 MF 7406, 7407, 7602, 7605-E12

Under-bed thread trimming device

Code Description Applicable model

CC1

Pneumatic type chain-off thread cutter

Horizontal type MF7602, MF7605

Cloth puller

Code Description Applicable model

PL1 Cloth puller MFC 7406, 7407, 7602, 7605 PL4 Cloth puller Can be installed after machine set-up. MFC 7406, 7407, 7602, 7605 PL5 Cloth puller Can be installed after machine set-up. MF 7406, 7407, 7602, 7605

− 6 −

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4. STANDARD ADJUSTMENT

(1) MF

Standard Adjustment

1) Timing relation between the needle and the feed

First screw A in operating direction on double eccentric 1 of feed drive assembly must be straight up, when the needle bar is at bottom of stroke.

2) Adjusting the timing relation between the needle bar and looper (synchronization) : Without gauges

A=B

Move to the left

Looper

Move to the right

Looper

Align

Left needle

When the blade point of the looper moves to the left in the rear of the needle and to the right in front of the needle, align the upper end of the eyelet of the left needle with the lower face of the looper so that the distance between A and B, the side of the left needle to the blade point of the looper, should be equal.

−7 −

Page 11

Adjustment Procedures Results of Improper Adjustment

™ Remove top cover, feed cover, gasket and cloth plate. ™ Loosen screws B of sprocket 2. ™ Rotate lower main shaft in operating direction counterclockwise,

until the first screw A on double eccentric 1 is straight up.

™ Holding pulley to prevent it from turning, rotate handwheel of

upper main shaft until needles are at top of their stroke.

™ Adjust the torque of screws B to 5.2 to 5.4 Nm and tighten the

screws.

™ Replace top cover, feed cover, gasket and cloth plate.

™ Needle breakage ™ Looper fails to catch needle

thread.

Note : Earlier machines have (4) screws.

™ Dimension A : Turn handwheel in operating direction until

bottom of looper is even with top of needle eye.

™ Dimension B : Continue turning handwheel in operating

direction until bottom of looper is even with top of needle eye when looper is in front of needle.

™ If dimension A is greater than dimension B

1) Loosen C on sprocket 3.

2)Fixing looper, turn pulley and tighten screws C so that sprocket 3 can turn in operating direction.

Repeat above steps until dimension A = dimension B.

™ If dimension A less than dimension B

1) Loosen screws C on sprocket 3.

2)Fixing looper, turn pulley and tighten screws C so that sprocket 3 can turn in reverse direction.

Repeat above steps until dimension A = dimension B.

™ If the timing is not correct, skip

stitching may occur.

−8 −

Page 12

Standard Adjustment

3) Returning amount of the looper

When the looper is in the extreme right position,the distance between the blade point of the looper and the center of the right needle is 4.4 ± 0.1 mm.

Right needle

Looper

4.4 ± 0.1 mm

4) Height of the needle bar

When the looper moves to the left and the blade point of the looper comes out from the left side of the left needle by 0.7 to 1.0 mm, the lower face of the looper aligns with the upper end of the eyelet of the left needle.

0.7 to 1.0 mm

Looper

Align

Left needle

−9 −

Page 13

Adjustment Procedures Results of Improper Adjustment

™ Loosen the looper base setscrew 4 and adjust the returning

amount of the looper. (Use a 5/32 inch hexagonal wrench.)

™ If the returning amount is large,

skipping stitch and tangling stitch may occur and the range of the thickness of the cloth to be sewn is reduced.

™ If the returning amount is small,

skipping stitch and tangling stitch may occur.

™ Loosen the needle bar holder screw 5 and adjust the height

of the needle bar.

(Caution) After the adjustment, check that the direction of

the needle clamp is correct and the respective needles enter the center of the holes of the throat plate.

™ If the distance of C is large, skip

stitching and tangling stitch may occur.

™ If the distance of C is small, skip

stitching and tangling stitch may occur.

™ If defective stitch occurs with the

wooly nylon thread, make the distance C as small as possible.

−10 −

Page 14

Standard Adjustment

5) Clearance between the looper and needle

Clearance between the blade point of the looper and the grooves of the right/left needles is 0 to 0.05 mm. (Clearance of the middle needle becomes larger a little.)

Right needle

0 to 0.05 mm

Needle

Top end of looper

Looper

6) Adjusting amount of the looper-avoid

When the needle descends, the top point of the needle touches the back of the looper at the position of 2/3 from the upper side of the looper.

Needle descends

Back of looper

2/3

1/3

−11 −

Page 15

Adjustment Procedures Results of Improper Adjustment

™ Loosen the looper base setscrew 4 and adjust by moving the

looper base back and forth.

™ If the clearance is too large, the

loop of the needle thread is not scooped and the back of the looper hits strongly the top point of the needle which causes the damage of the needle point.

™ If the clearance is too small,

skipping stitch will occur due to the damage of the tip of the looper, the needle breakage, and the large clearance between the back of the looper and the needle.

™ Loosen the two screws 6 and adjust by rotating the eccentric

pin 7.

™ Amount of the avoid increases in the direction of +. ™ Amount of the avoid reduces in the direction of –.

(Caution) After the adjustment, check again the clearance

between the blade point of the looper and the groove of the needle. Then check the contact on the back of the looper.

Old type New type

™ If the amount of the avoid is

large, the clearance of the back of the looper and the needle becomes large, and skipping stitch and tangling stitch will occur.

™ If the amount of the avoid is

small, the needle hits strongly the back of the looper. This causes the damage of the needle point, the needle breakage and the damage on the back of the looper.

−12 −

Page 16

Standard Adjustment

7) Position of the needle guard

1 Rear needle guard

™ The height of the rear needle guard is in the position that the rear needle guard is 0.8 mm above

the top of the needle when the looper moves to the left as shown in the figure.

™ The longitudinal position and inclination of the rear needle guard are in the position that when the

right side of the respective needles comes to the blade top of the looper, the top of the needle slightly touches the rear needle guard.

0.8 mm

Rear needle guard

Slightly touch

2 Moving needle guard

™ When the looper advances, the clearance between the needle and the moving needle guard is

0.05 to 0.13 mm.

0.05 to 0.13 mm

−13 −

Page 17

Adjustment Procedures Results of Improper Adjustment

™ Loosen the screw 8 and adjust the height and inclination of

the rear needle guard 9. Loosen the screw !0 and adjust the longitudinal position of the rear needle guard 9.

(Caution) Check that the rear needle guard does not break

the loop of the needle thread by touching the groove of the needle.

™ Loosen the screw !1 and adjust the clearance between the

moving needle guard !2 and the needle.

(Caution) Check that the needle is never caught between the

moving needle guard and rear needle guard in any case.

−14 −

Page 18

Standard Adjustment

8) Position of the feed dog

™ The clearance of the left/right sides of the feed dog should be equal in the slots of the throat plate. ™ At the maximum travel, the clearance of the main feed dog and differential feed dog is equal to A

= A’, B = B’.

™ The height of the feed dog is 1.1 mm at the top of their stroke. ™ The tilt of the feed dog is parallel to the throat plate when the needle bar is at the highest position.

1.1 mm

−15 −

Page 19

Adjustment Procedures Results of Improper Adjustment

Open the cover located at the rear side of the needle entry. ™ Adjust the longitudinal position of the main feed dog after

loosening the nut !3 and rotating the eccentric nut !4.

™ Adjust the longitudinal position of the differential feed dog after

loosening the nut !5 and rotating the eccentric nut !6.

™ Adjust the inclination of the feed dog after loosening the screw

!7 and rotating the eccentric shaft inside with a slit-screwdriver through the hole !8.

™ If the left/right positions of the

feed dog are incorrect, the left/ right sides and the throat plate will wear out.

™ Heating and abnormal noise will

be produced.

™ The feed components will wear

out early. And, the looseness, bending and abnormal noise will be produced.

™ If the inclination of the feed dog

is raised toward you, starting of the workpiece will be affected.

™ If the inclination of the feed dog

is lowered toward you, it may cause the irregular stitching and puckering.

™ Loosen the screw !9 and adjust the height of the main feed

dog @0.

™ Loosen the screw @1 and adjust the height of the differential

feed dog @2.

™ If the position of the feed dog is

high, it causes the return feed, skip stitching and defective chain-off.

™ If the main feed dog, differential

feed dog and throat plate come in contact each other, it will cause the breakage.

™ If the position of the feed dog is

low, the stitch length becomes short when the sewing is finished.

−16 −

Page 20

9) Spreader

1 Timing

Descend

Standard Adjustment

2 Stroke

Highest point

2.5 ± 0.1 mm

Return

Just when the needle descends 2.5 mm from the highest point of the needle bar, the spreader begins to return from its extreme left position.

3 Position of spreader

™ The height is 11.5 ± 0.5 mm. (4.8 mm or less

needle gauge) (11.1 ± 0.5 mm for 5.6 mm and 6.4 mm gauges)

™ When the spreader is in the extreme left

position, the distance between the center of the left needle and the top blade of the spreader is 5.5 ± 0.1 mm.

™ When the spreader returns to the right, the

clearance between the spreader and the left needle is 0.3 to 0.5 mm.

4 Fixing spreader thread guide

™ When the spreader is in the extreme right

position, the top blade of the spreader should be between left side and middle of the spreader thread guide groove.

™ The height is 0.8 to 1.2 mm from the surface

of the spreader.

Direction of cloth feeding

5.5 ± 0.1 mm

Left needle

0.3 to

0.5 mm

Groove

Top blade should be between left side and middle of the groove.

19 ± 0.1 mm

11.5 ± 0.5 mm

Spreader

Extreme right

Show spreader at extreme right position when setting height

(11.1 ± 0.5 mm throat plate for 5.6 mm or more needle gauge)

Return

0.8 to

1.2 mm

5 Needle clamp spreader thread guide

™ When the needle bar is in the lowest position,

the clearance between the needle clamp spreader thread guide and the upper face of the fixing spreader thread guide is 4 ± 0.5 mm.

™ The center of the hole of the thread guide

aligns with the left side of the fixing spreader thread guide groove.

Fixing spreader

thread guide

4 ± 0.5 mm

Needle clamp spreader thread guide

−17 −

Page 21

Adjustment Procedures Results of Improper Adjustment

™ Adjust the timing by loosening screw

#0

of the spreader

eccentric cam @9 and rotate the spreader eccentric cam @9.

™ Adjust the stroke by loosening the nut #1 and move back and

forth. If it is moved toward you, the stroke becomes small, and to the back it becomes large.

™ Adjust the height of the spreader by loosening the screw #3

and moving the spreader #2 up and down.

™ Adjust the clearance between the spreader and left needle by

loosening the screw #3 and move the spreader #2 back and forth.

™ Adjust the extreme left position by loosening the screw #4 and

move the spreader #2 to the left and right.

–

™ If the timing is too advanced, the

needle does not catch the covering thread when it descends. This is likely to cause the skipping stitch. On the contrary, if the timing is too retarded, the right needle is likely to break as the resistance when the covering thread is pulled from the spreader becomes large.

™ If the movement amount of the

spreader is not set right, it will cause skip stitching of the top covering thread.

™ If the height of the spreader is not

set right, it will cause skip stitching of the top covering thread.

™ If the clearance between the

spreader and needle is small, it will

cause the needle breakage. If it is large, it will cause skip stitching of the top covering thread.

™ If the protruding amount of the

spreader is large, it will cause uneven stitching of the top covering thread. If it is small, it will cause skip stitching of the top covering thread.

 Adjust the fixing spreader thread guide #5 by loosening the

screw #6.

™ Adjust the needle clamp spreader thread guide #7 by loosening

the screw #8.

™ If the height of the fixed spreader

thread guide is set as high as 4 mm, the top covering performance by the spun thread is improved. But, defective looping may occur when other threads are used.

™ If the position of the fixed spreader

thread guide is not correct, it will cause skip stitching of the top covering thread.

™ If the position of the needle clamp

spreader thread guide is not correct, it will cause skip stitching of the top covering thread.

−18 −

Page 22

Standard Adjustment

10) Looper thread cam

1 Timing

™ When the looper thread is pulled from the highest point of the looper thread cam, the top point of

the left needle aligns with the lower face of the looper.

Looper

Needle descends

Back of looper

thread

Align with lower face of looper

Looper thread cam

2 Position of looper thread guide plate and looper thread cam pawl wire

™ The height of the looper thread guide plate is 1.6 mm from the lowest part of the looper cam to the

upper part of the looper thread guide plate.

™ The rear side of the looper thread cam pawl touches the wire, and its front side is 9.6 mm above

the upper face of the wire at the highest place of the inside.

™ The looper thread cam pawl and wire are to be positioned in the center of the looper thread cam

plate.

Wire

Touch

1.6 mm

Looper thread guide plate

Looper thread cam pawl

Looper thread cam

9.6 mm

3 Position of thread guide and auxiliary thread tension

™ The position of the thread guide is to be set at the position that the looper thread just becomes tight

when the looper is in the extreme left.

™ Adjust the tension of the auxiliary thread tension to make as low as the thread is just stabilized.

Thread guide

Looper thread guide plate

Looper thread cam

Wire

−19 −

Auxiliary thread tension

In the center

Page 23

Adjustment Procedures Results of Improper Adjustment

™ Adjust the timing of the looper thread cam by loosening the

two screws #9.

™ Adjust the height of the looper thread guide plate by loosening

the screw $0 and move the looper thread guide plate $1 up and down. Adjust the looper thread cam pawl by loosening the screw $2 and move the looper thread cam pawl $3 up and down. Adjust the lateral relation of the looper thread guide plate by loosening the screw $4 and move the looper thread guide plate

$1 to the left and right.

™ If the timing of the looper thread

cam is too advanced, the skip stitching on the back of the looper will occur. If it is too retarded, the tightening of the thread will be inferior.

™ If the clearance between the

looper thread cam pawl and the wire is large, the looper thread suddenly slackens and skip stitching on the back side will occur.

™ If the looper thread cam is not in

the center, the cam will be damaged.

(Caution) Use a 3/32" hexagonal wrench for the screw #9.

™ Adjust the position of the thread guide by loosening the two

screws $5 and move the thread guide $6 (2 pcs.) up and down.

™ If the thread guide is raised, the

looper thread after sewing will be slack.

™ If the thread guide is lowered, the

looper thread after sewing will be tight.

−20 −

Page 24

Standard Adjustment

11) Position of the presser bar

The clearance between the presser bar bracket and the presser bar bushing is 0.8 mm when the feed dog is under the throat plate and the bottom face of the presser foot touches the upper face of the throat plate at the time that the needle bar is in the lowest point.

Presser bar bracket

0.8 mm Presser bar

bushing

12) Position of the needle thread tension release (without thread trimmer)

When the presser foot is raised by 3 mm, the thread tension opening pawl C touches the thread tension D and when the presser foot is in the highest position, the thread tension disc opens and there is no tension on the thread.

3 mm

Throat plate

−21 −

Page 25

Adjustment Procedures Results of Improper Adjustment

™ Adjust by loosening the two screws %4 and move the presser

bar bracket %5 up and down.

™ If the clearance between the

presser bar bracket and the presser bar bushing is small, the bottom face of the presser foot can not contact tightly to the throat plate.

™ If the clearance is large, the lifting

amount of the presser foot will be reduced.

™ Adjust by loosening the screw %6 and move the bracket %7.

−22 −

Page 26

Standard Adjustment

13) Position and height of the presser foot

1 Adjust the position of the presser foot so that the needles enter the center of the needle entry holes

in the presser foot on condition that the presser foot is set correct to the presser bar.

2 Adjust the height of the presser foot so that when the needle bar is in its highest point, the needle

point does not come out from the lower face of the presser foot.

Lower bushing

0.2 mm

Needles

14) Position of the thread guide

1 Middle thread guide and thread guide holder

Spun thread 27 mm 25 mm 23 mm

Throat plate

Left needle

thread

Needle

Middle needle

thread

Spreader

Max. 8.1 mm

Right needle

thread

Cotton thread 27 mm 25 mm 23 mm Wooly nylon thread 27 mm 25 mm 23 mm Tetoron thread 27 mm 25 mm 23 mm

( Fix at the extreme right position of the slot. )

−23 −

Page 27

Adjustment Procedures Results of Improper Adjustment

™ Adjust the position by loosening the screw %8 and move the

presser foot %9 to the left and right.

™ Adjust the height by loosening the nut ^3 and rotate the screw

^4 and hit it to the lever ^2 so that the needle top comes 0.3

mm over from the lower part of the presser foot when the needle is in its highest point. At this time, loosen the two screws ^1 and fix the collar ^0 so that the clearance between the collar and the lower bushing is 0.2 mm. Adjust by loosening the nut ^5 and rotate the screw ^6 so that the clearance between the top end of the screw ^6 and the lever ^2 becomes 0.5 mm on condition that the presser foot descends and rests tightly on the throat plate.

^6 ^5

0.5 mm

™ If the position of the presser foot

is not correct, it will cause defective and non-straight sewing.

™ If the height of the presser foot

is not correct, it will cause breakage of the spreader, the needle scratch on workpiece, defective sewing and the lack of feeding force.

™ Loosen the screw %8 and fix the thread guide attaching base

^0 to the extreme right. Loosen the screw %9 and adjust the

respective heights R referring to the left table. Make the fine adjustment watching the actual stitching.

™ If it is raised, the needle thread

is tightened.

™ If it is lowered, the needle thread

slackens.

™ The tightened stitches of the

right needle and left needle can be simply slackened if the thread guide holder is moved to the left.

−24 −

Page 28

Standard Adjustment

2 Needle bar needle thread release

™ When the loop of the needle thread is not easily formed, raise the needle thread release as shown

in the figure at the time of the lowest point of the needle bar.

Lowest point of needle bar

Needle bar eyelet

Needle thread release

™ If the needle thread is a cotton thread, raise the right needle thread release so that the right needle

thread only touches at the time of the lowest point of the needle bar.

Lowest point of needle bar

Needle thread release

Right needle thread release

™ If the needle thread is a spun thread, lower the needle thread release so that the needle thread

does not touch it.

Lowest point of needle bar

Needle bar balance

Needle thread release

3 Spreader balance thread guide

When the spreader moved to the extreme left position, it should be positioned that the top covering thread does not slacken and the spreader does not pull out the thread.

Not slacken

Thread guide

4 Needle thread nipper

For general thread and materials, perform sewing making thread free without using nipper.

Pass needle thread through nipper when needle thread loop is not well shaped with stretchy thread or the like.

−25 −

Page 29

Adjustment Procedures Results of Improper Adjustment

™ Loosen screw ^1 and adjust by moving the needle thread release

^2 up and down.

™ Loosen screw ^3 and adjust by moving the right needle thread

release ^4 up and down.

™ If it is raised, the loop of the

needle thread becomes large.

™ If it is lowered, the loop of the

needle thread becomes small.

™ If the loop is not formed (the loop

is too small) and skip stitching occurs, raise the needle thread release.

™ If the loop is excessively formed

(the loop is too large) and the skip stitching occurs, lower the needle thread release.

™ Loosen screw ^5 and adjust by moving the thread guide ^6 up

and down.

−26 −

™ If it is raised, the thread

slackens.

™ If it is lowered, the thread

tightens.

™ Use of the nipper for the threads

used

Not used for cotton thread and

tetoron thread.

Used for wooly nylon thread and

spun thread (stretching thread).

™ Use of the nipper for the cloth

used

Not used for general light-weight

jersey, knit and cloth.

Used for heavy-weight jersy, knit

and cloth.

Page 30

(2) Thread trimmer device (MF)

1) Adjustment of the thread trimmer device

Standard Adjustment

3 mm

7.5 mm

0.5 mm

1.2 mm

0.05 to 0.1 mm

−27 −

Page 31

Adjustment Procedures Results of Improper Adjustment

™ Loosen screws 3 to such an extent that bracket 1 in terms of

support 2 moves.

™ Align engraved marker dot on the frame with that on the hand

pulley when needle is at its upper dead point, and perform all adjustments.

™ Install the thread trimmer device on the sewing machine with

screws 4, adjust so that the top end of lower knife comes at the position of 3 mm from the right-hand side of the base of looper. As shown in the figure on the left-hand side, securely tighten screws 4 so that the top end of lower knife comes flush at the center of the upper section of the looper.

(Caution) When the position of the air cylinder is not set right,

make sure that the top surface of bracket 1 is flush with that of 5, and fix the cylinder with screw 6. By so doing, the upper knife can be kept flush at the time of thread trimming.

™ Loosen screw 7, and adjust upper knife 8 to the position of

7.5 mm from the right edge of feed dog. At this time, make sure with screw 7 that the vertical pressure is not applied to the lower knife, and adjust by eye observation so that both upper and lower knives are flush with each other.

™ Adjust so that upper knife 8 overlaps with the lower knife by

0.5 mm at the waiting position. At this time, determine the position with screw 9 and fix with nut !0.

™ Temporarily tighten screws !1, stretch the lower knife over the

looper, and set the height of the knife to 0.05 mm to 0.1 mm at the upper section of the looper. Adjust the clearance between the knife and looper with screw !2 and securely tighten screws !1.

™ Adjust so that the blade section for needle thread comes to

the position of 1.2 mm from the left needle when the lower knife is operating. To adjust, loosen screw !3 once, determine the positions of stopper !4 and washer !5, and tighten screw !3.

−28 −

Page 32

Standard Adjustment

2) Thread tension release (Looper thread trimmer device)

−29 −

Page 33

Adjustment Procedures Results of Improper Adjustment

™ Set tongue 2 of thread tension disk separating plate to such a

near position where the tongue hardly comes in contact with thread tension disks 1. Thread tension disk 1 starts floating immediately after the start of thread trimming.

™ Adjust so that the thread tension disk separating plate can

move smoothly and freely among thread tension disks 1. Thread trimming mechanism and thread tension release mechanism are interlocked.

™ Loosen screw 3 and turn eccentric shaft 4 located in the

rear of screw 3 to set lever 5.

™ Loosen screw 3 again, and make sure that there is no

interference in any place.

™ Adjust thread tension release lever 6 so that thread is released

and the separating plate works smoothly. Thread tension release is simultaneously performed with the start of thread trimmer device.

™ Adjust the length of remaining needle thread after thread

trimming with thread tension release pins 7 of needle thread.

™ Adjust the shortest length of remaining thread with thread

tension release pins 7 so that the next stitches can be formed within one to two stitches.

™ Adjust thread tension release pin 8 for top covering thread so

that spreader thread (top covering thread) is securely hauled at the time of thread trimming and the next stitch can be formed from the first stitch.

™ Part 9 is for looper thread and securely hauls the looper thread

at the time of thread trimming.

(Caution) Move downward thread tension release pins 7 to

haul thread longer and upward thread tension release pins 7 to shorten the length of remaining thread.

−30 −

Page 34

(3) MFC

Standard Adjustment

1) Timing relation between the needle and the feed

First screw A in operating direction on double eccentric 1 of feed assembly must be straight up, when the needle bar is at top of stroke.

2) Adjusting the timing of the needle bar and looper (Synchronization) : Without gauges

A=B

Move to the right

Looper

Left needle

Align

Move to the left

Looper

Left needle

When the blade point of the looper moves to the left in the rear of the needle and to the right in the front of the needle, and the top end of the hole of the left needle aligns with the lower part of the looper, the distance between the left side of the left needle and the blade point of the looper should be equal to the distance A and B.

−31 −

Page 35

Adjustment Procedures Results of Improper Adjustment

™ Remove top cover, feed cover, gasket and cloth plate. ™ Loosen screws B of sprocket 2. ™ Rotate lower main shaft in operating direction clockwise, until

the first screw A on double eccentric 1 is straight up.

™ Holding pulley to prevent it from turning, rotate handwheel of

upper main shaft until needles are at top of their stroke.

™ Adjust the torque of screws B to 5.2 to 5.4 Nm and tighten the

screws.

™ Replace top cover, feed cover, gasket and cloth plate.

™ Needle breakage ™ Looper fails to catch needle

thread.

Note : Earlier machines have 4 screws.

™ Dimension A : Turn handwheel in operating direction until

bottom of looper is even with top of needle eye.

™ Dimension B : Continue turning handwheel in operating

direction until bottom of looper is even with top of needle eye when looper is in front of needle.

™ If dimension A is greater than dimension B

1) Loosen C in connector 3.

2) Move connector 3 away from connector D. Tighten C.

Repeat above steps until dimension A = dimension B.

™ If dimension A less than dimension B

1) Loosen screw C in connector 3.

2) Move connector 3 toward D. Tighten C.

Repeat above steps until dimension A = dimension B.

A < B

™ If the timing is not set right, it is

likely to occur skipping and tangling stitches.

A > B

−32 −

Page 36

MFC

Standard Adjustment

3) Returning amount of the looper

When the looper is at the extreme right position, the distance between the blade point of the looper and the center of the right needle is 4.8 ±0.1 mm.

Right needle

Looper

4.8 ±0.1 mm

4) Height of the needle bar

When the looper moves to the left and the point of the looper comes out from the left side of the left needle by 0.5 mm, the lower part of the looper aligns with the top end of the hole of the left needle.

0.5 mm

Move to the left

Align

Looper

Left needle

−33 −

Page 37

Adjustment Procedures Results of Improper Adjustment

™ Adjust the returning amount by loosening the looper holder

binder screw 4.

4.8 ± 0.1 mm

If the returning amount is large, skipping stitch and tangling stitch will occur. And the thickness of the material to be sewn will be reduced. If the returning amount is small, skipping stitch and tangling stitch will occur.

™ Loosen the screw 5 of the needle bar binder bracket inside

the face cover and adjust the height of the needle bar.

(Caution) After the adjustment, check that the direction of

the needle clamp is right and that the respective needles enter the center of the holes of the throat plate.

If the measurement of C is large, skip stitching and thread tangling occur. If the measurement of C is small, skip stitching and thread tangling occur.

−34 −

Page 38

MFC

Standard Adjustment

5) Position of the needle guard

1 The height of the rear needle guard is adjusted so that the point of the right needle comes to the 1/

2 height of the contact surface of the rear needle guard when the blade point of the looper aligns with the right side of the right needle.

Adjust the pushing amount so that the right needle and the middle needle are slightly pushed, and

so that the left needle just comes in contact with the rear needle guard and should not be pushed. (The blade point of the looper should not contact the respective grooves of the all needles.)

Align

No contact

1/2

Contact surface of rear needle guard

Pushing amount : Slightly push right needle and middle needle.

Make the left needle just come in contact with the rear needle guard and do not push it.

2 The height of the front needle guard is 1.75 ±0.1 mm from the lower part of the looper.

The face of the guard position is parallel to all needles having a clearance of 0.25 ±0.1 mm.

Looper

0.25 mm

1.75 mm

Front needle guard

Needle

Front needle guard

6) Clearance between the looper and needle

Clearance between the blade point of the looper and the grooves of the right and left needles is 0 to

0.05 mm. (Clearance of the middle needle is a little larger.)

0 to 0.05 mm

Top point of looper

Right needle

Looper

0 to 0.05 mm

Needle

−35 −

Page 39

Adjustment Procedures Results of Improper Adjustment

™ Adjust the height of the rear needle guard by loosening the

screw !2 and move the rear needle guard !1 up and down. Adjust the pushing amount by loosening the screw !3 and move the rear needle guard back and forth.

™ Adjust the height of the front needle guard by loosening the

screw !5 and move the front needle guard !4 up and down. Adjust the inclination at the same time. Adjust the clearance for the needle by loosening the screw !6 .

(Caution) Use a 3/32" hexagonal wrench for the screw !3.

Check that there is no looseness on the left/right sides of the rear needle guard when tightening the screw !3.

(Old type) (New type)

™ If the clearance between the rear

needle guard and the needle is large, it causes the skipping stitch, the damage of the blade point of the looper and needle breakage.

™ If the rear needle guard and the

needle hits strongly, it will cause the damage of the needle top.

™ If the clearance between the

front needle guard and the needle is large, the loop becomes small and the skipping stitch will occur.

™ If the front needle guard and the

needle hits strongly, the loop becomes large and the skipping stitch, the damage of the needle point and the damage of the blade point of the looper will occur.

™ Adjust by loosening the looper base setscrew 4 and move

the looper holder back and forth.

™ If the clearance is large, skipping

stitch of the needle thread scooping occurs. And the damage of the needle point will occur due to the strong hit on the back of the looper.

™ If the clearance is small, the

damage of the blade point of the looper and the needle breakage will occur. And, the skipping stitch will occur as the clearance between the back of the looper and the needle becomes large.

−36 −

Page 40

MFC

Standard Adjustment

7) Adjusting amount of the looper-avoid

™ When there is only one adjustment line in the sewing machine, adjust so that the looper path

shifting cam is placed 8 mm from the adjustment eccentric line.

(Measurement of 8 mm should be performed on the top surface of the looper path shifting cam.)

New type

Adjustment line

Adjustment

eccentric line

8 mm

Looper path shifting cam

Setscrew

Logitudinal moving

amount of looper

(Ref. 1.54 mm)

Left needle

Right needle

Locus of looper

™ When the looper moves to the right, the tip of the left needle contacts the back of the looper at the

position of 2/3 from the upper side of the looper.

Left needle

Looper

Needle tip

2/3 1/3

(Adjust when the needle is replaced with an excessively different sized needle. Check that the clearance between the looper and the needle is correct and the needle tip contacts the back of the looper at the position of 2/3 from the upper side of the looper.)

−37 −

Page 41

Adjustment Procedures Results of Improper Adjustment

1 Adjustment of looper path

Engrared

Setscrew

Looper path shifting cam

Engrared

line C

line E

Old type

Engrared

line D

3 mm (Standard)

Looper path shifting cam

2 Adjustment of avoid

Amount of avoid small Amount of avoid large

Loosen the screw 9 and nut 8 of the looper cam guide !0. Then move the screw 9 back and forth to adjust. (Use a 3/8" spanner for 8.)

Needle Path of looper

Avoid large

Avoid small

Setscrew

Left needle

Right needle

Position of D-C

™ If the engraved line E is turned

more than 3 mm from D, the looper path is left downward. The damage of the blade point of the looper and needle breakage occur.

™ If the amount of avoid is large,

the clearance between the needle and the back of the looper becomes large. In this case, skipping stitch and tangling stitch occur.

™ If the amount of avoid is small,

the hitting of the needle and the back of the looper becomes strong. In this case, the damage of the needle top, needle breakage and scratch on the back of the looper occur.

(Caution) After the adjustment, check again the clearance

between the blade point of the looper and the groove of the needle. Use a 1/8" hexagonal wrench for the setscrew 6.

−38 −

Page 42

MFC

Standard Adjustment

8) Position of the feed dog

™ The clearance between the slot on the throat plate and the left/right sides of the feed dog should

be equal.

™ In the maximum stroke end of the main feed dog and differential feed dog, the clearance should be

equal to A = A’ and B = B’.

™ Height of the feed dog is 1.1 mm at the top of their stroke. ™ Tilt of the feed dog is parallel to the throat plate when the needle bar is in its highest position.

A’

B’

1.1 mm

™ Adjust so that the throat plate and the main feed dog do not contact each other even if the main

feed dog is in its maximum stroke end.

™ Adjust so that the throat plate and the differential feed dog do not contact each other even if the

stroke is maximized.

−39 −

Page 43

Adjustment Procedures Results of Improper Adjustment

™ Loosen screw !8 to adjust the left/right position of the main feed

dog !7 .

™ Loosen screw @2 to adjust the left/right position of the differential

feed dog @1 .

™ Loosen screw !9 and move the main feed dog back and forth

to adjust the longitudinal position of the main feed dog !7 .

™ Loosen screw @3 and rotate the eccentric nut to adjust the

longitudinal position of the differential feed dog @1 .

™ Loosen screw @0 to adjust the height of the main feed dog !7

and the differential feed dog @1 .

™ To adjust the maximum stroke of the main feed dog, loosen

screw @4 and rotate spacing stop @5 so that it contacts the pin @6 when the main feed dog has reached its maximum stroke and while the throat plate does not contact the main feed dog.

™ To adjust the maximum stroke of the differential feed dog,

loosen screw @7 and enter the stopper pin @8 to the end when the differential feed dog has reached its maximum stroke and while the differential feed dog does not contact the throat plate and the front end of the main feed dog.

™ If the lateral position of the feed

dog is not correct, the left/right sides of the feed dog and the throat plate will wear out. Heating and abnormal noise will be produced. Also, the feed components will wear out quickly and looseness and bending of the components will occur. Also, abnormal noise from the components will be produced.

™ If the height of the feed dog is

low, the stitch length at the finish of sewing becomes smaller.

™ If the height of the feed dog is

high, it will cause the return feed, skipping stitch and defective chain-off.

™ If the main feed dog, differential

feed dog, and throat plate come in contact with each other, it will cause breakage.

−40 −

Page 44

MFC

9) Spreader

Standard Adjustment

1 Timing

2.5 ±0.1 mm

Descend

Highest point

Return

Just when the needle descends 2.5 mm from the highest point of the needle bar, the spreader begins to return from the extreme left position.

3 Position of spreader

5.5 ±0.1 mm

10.5 ±0.5 mm

Throat plate

Left needle

2 Stroke

Direction of cloth feed

19 ±0.1 mm

™ Height of the presser foot is 10.5 ± 0.5 mm. ™ When the spreader is in the extreme left

position, the distance between the center of the left needle and the blade point of the spreader is 5.5 mm ±0.1 mm.

™ When the spreader returns to the right, the

clearance between the spreader and the left needle is 0.3 to 0.5 mm.

0.3 to

0.5 mm

4 Fixing spreader thread guide

Spreader

Extreme right position

Groove

Blade top should be between the left end and the middle of the groove.

Show spreader at extreme right position when setting height

5 Needle clamp spreader thread guide

Fixing spreader thread guide

Return

4 ±0.5 mm

™ When the spreader is in the extreme right

position, the blade top should be between the left end and the middle of the groove of the fixing spreader thread guide.

™ The height is 0.8 to 1.2 mm from the upper

face of the spreader.

0.8 to

1.2 mm

™ When the needle bar is in the lowest position,

the clearance between the needle clamp spreader thread guide and the upper face of the fixing spreader thread guide is 4 ± 0.5 mm.

™ The center of the thread guide hole aligns

with the left end of the groove of the fixing spreader thread guide.

Needle clamp spreader thread guide

−41 −

Page 45

Adjustment Procedures Results of Improper Adjustment

 Adjust the timing by

loosening the screw #0 of the spreader eccentric cam @9 and rotating the spreader eccentric cam @9 .

 Adjust the stroke by loosening

the nut #1 and moving it back

–

and forth. If it is moved toward you, the stroke becomes small. If it is moved to the back, the stroke becomes large.

 Adjust the height of the

spreader by loosening the screw #3 and move the spreader #2 up and down.

 Adjust the clearance

between the spreader and the left needle by loosening

the screw #3 and moving the spreader #2 back and forth.

 Adjust the extreme left

position by loosening the screws #4 and move the spreader #2 to the left and right.

™ If the timing is too advanced,

skipping stitch is likely to occur as when the needle decends, the needle does not catch the covering thread.If the timing is too retarded, the right needle is likely to be broken as the resistance of the covering thread becomes strong when it passes the covering thread looper.

™ If the movement amount of the

spreader is not set right, skipping stitch of the top covering thread occurs.

™ If the height of the spreader is

not set right, skipping stitch of the top covering thread occurs.

™ If the clearance between the

spreader and the needle is small, the needle breaks. If it is large, skipping stitch of the top covering thread occurs.

™ If the protruding amount of the

spreader is large, uneven stitch of the top covering thread occurs. If it is small, skipping stitch of the top covering thread occurs.

 Adjust the fixed spreader

thread guide #5 by loosening the screws #6 .

 Adjust the needle clamp

spreader thread guide #7 by loosening the screw #8 .

™ If the height of the fixed spreader

thread guide is set about 4 mm, the performance of the top covering with the spun thread is improved. But, for other threads, it is likely to cause the defective pick-up of the thread.

™ If the position of the fixed

spreader thread guide is not set right, skipping stitch of the top covering thread occurs.

™ If the position of the needle

clamp spreader thread guide is not set right, skipping stitch of the top covering thread occurs.

−42 −

Page 46

MFC

Standard Adjustment

10) Looper thread cam

1 Timing of the looper thread cam

1/2

2 Position of the looper thread cam thread guide

Highest point of looper thread cam

Wooly nylon thread

When the needle bar descends and the tip of the left needle aligns with the lower part of the looper, the looper thread can be cast off from the highest point of the looper cam.

The looper thread cam thread guide is to be set in the center of the slot. (In case of wooly nylon thread, at the upper end of the slot.)

11) Looper thread wrap-up preventing cam (Old type)

1 Height of the looper thread thread guide base

0 to 0.5 mm

1.0 mm

The position is that the highest point of the looper thread tangling preventing cam is 0 to 0.5 mm lower than the upper part of the thread control finger.

Timing of the looper thread tangling preventing cam and position of the thread control finger. When the looper thread is cast off out of the highest point of the looper thread cam, the horn of the looper thread tangling preventing cam comes 1.0 mm toward you from the hole of the thread guide of the thread control finger.

−43 −

Page 47

Adjustment Procedures Results of Improper Adjustment

Looper thread

4.0 mm

™ Timing of the looper thread

cam is adjusted by loosening the screw $6 and rotating the looper thread cam $5 . At this time, set so that the collar %0 contacts $5 . In case of lateral adjustment, loosen the screw %1 of the collar %0 and adjust on condition that the looper thread cam $5 contacts the collar %0 .

™ Loosen the screw $8 for the

parallel and the screw $9 for the clearance so that the middle latch $7 is parallel to the looper thread guide base and the clearance is

4.0 mm.

™ Loosen the screws %2 and

$1 , and adjust by moving

the left needle thread guide %3 and the thread control finger $2 up and down.

™ If the timing of the looper thread

cam is too advanced, skip stitching on the back of the looper occurs.

If the timing of the looper is too

retarded, thread tightening is not well.

™ If the looper thread cam is not

set in the center, the cam is scratched.

™ If the clearance between the

middle latch and the looper thread guide base is more than 4 mm, the looper thread suddenly slackens and skip stitching on the back of the looper occurs.

™ If the thread guide is raised too

high, the looper thread after the sewing is finished becomes tight.

™ If the thread guide is lowered too

much, the looper thread after the sewing is finished becomes slack.

(Caution) Use a 3/32" hexagonal wrench for the screws $6 ,

$8 and $9 .

™ Adjust the height of the

looper thread guide base by loosening the screw #9 and inclining the latch base $0 .

™ The looper thread anti-wrap

cam $3 comes to the center of the slit of the thread control finger $2 and the horn part of the periphery of the cam aligns with the hole of the thread guide. Adjust the looper thread tangling preventing cam $3

by loosening the screw $4 .

™ The looper thread may be cut if

the looper thread tangling preventing cam contacts the slot of the thread control guide.

™ If the timing of the looper thread

anti-wrap cam and the position of the thread guide are not set right, the thread may be entangled.

(Caution) Use a 3/32" hexagonal wrench for the screw #9.

−44 −

Page 48

MFC

Standard Adjustment

12) Position of the presser bar

When the feed dog is under the lower part of the throat plate and the bottom face of the presser foot contacts the upper face of the throat plate at the lowest point of the needle bar, the clearance between the presser bar bracket and the upper end of the presser bar bushing is 0.8 mm.

Presser bar bracket

Presser bar bushing

0.8 mm

13) Position of the needle thread tension release (without thread trimmer)

When the presser foot is raised by 3.0 mm, the thread tension opening pawl C contacts the thread tension disc D , and when the presser foot is raised at its highest point, the thread tension disc opens and there is no tension on the thread.

Throat plate

−45 −

3 mm

Page 49

Adjustment Procedures Results of Improper Adjustment

™ Loosen the two screws %4 and adjust the position by moving

the presser bar bracket %5 up and down.

™ If the clearance between the

presser bar bracket and the presser bar bushing is too small, the bottom face of the presser foot is not closely fitted on the throat plate. If the clearance is too large, the lifting amount of the presser foot becomes small.

™ Loosen screw %6 and adjust by moving the bracket %7 .

−46 −

Page 50

Standard Adjustment

14) Position and height of the presser foot

1 Adjust the position of the presser foot so that the needles are positioned to enter the centers of the

holes of the needle entry of the presser foot on condition that the presser foot is set right to the presser bar.

2 Adjust the height of the presser foot so that the needle top does not come out from the bottom face

of the presser foot when the needle bar is in its highest point.

Lower bushing

0.2 mm

Needles

15) Position of the thread guide

1 Middle thread guide and thread guide attaching base

Spun thread 16 mm 14.5 mm 13 mm Cotton thread 16 mm 21 mm 21 mm

Throat plate

Left needle

thread

Needle

Middle needle

thread

Spreader

Max. 7 mm

Right needle

thread

(Fix at the extreme

right point of the slot.)

Wooly nylon thread 16 mm 21 mm 21 mm Tetoron thread 16 mm 21 mm 21 mm

−47 −

Page 51

Adjustment Procedures Results of Improper Adjustment

™ Adjust the position by loosening the screw %8 and move the

presser foot %9 to the left and right.

™ Adjust the height by loosening the nut ^3 and rotate the screw

^4 and hit it to the lever ^2 so that the needle top comes 0.3

0.5 mm

™ If the position of the presser foot

is not correct, it will cause defective and non-straight sewing.

™ If the height of the presser foot

is not correct, it will cause breakage of the spreader, the needle scratch on workpiece, defective sewing and the lack of feeding force.

™ Loosen the screw %8 and fix the thread guide attaching base

^0 to the extreme right.

Loosen the screw %9 and adjust the respective heights “R” referring to the left table. Make the fine adjustment watching the actual stitching.

™ If it is raised, the needle thread

is tightened.

™ If it is lowered, the needle thread

slackens.

™ The tightened stitches of the right

needle and left needle can be simply slackened if the thread guide attaching base is moved to the left.

−48 −

Page 52

MFC

2 Needle bar needle thread release

Lowest point of needle bar

Needle bar balance

Needle thread release

Standard Adjustment

™ When the loop of the needle thread is not easily formed,

raise the needle thread release as shown in the left figure at the time of the lowest point of the needle bar.

Lowest point of needle bar

Needle thread release

Lowest point of needle bar

Needle bar balance

Right needle thread release

Needle thread release

3 Spreader balance thread guide

Not slacken

™ If the needle thread is a cotton thread, raise the right needle

thread release so that the right needle thread only touches at the time of the lowest point of the needle bar.

™ If the needle thread is a spun thread, lower the needle thread

release so that the needle thread does not touch it.

When the spreader moved to the extreme left position, it should be positioned that the top cover thread does not slacken and the spreader does not pull out the thread.

4 Needle thread nipper

For general thread and materials, perform sewing making thread free without using nipper.

Thread guide

Pass needle thread through nipper when needle thread loop is not well shaped with stretchy thread or the like.

−49 −

Page 53

Adjustment Procedures Results of Improper Adjustment

™ Loosen screw ^1 and adjust by moving the needle thread

release ^2 up and down.

™ Loosen screw ^3 and adjust by moving the right needle thread

release ^4 up and down.

™ If it is raised, the loop of the

needle thread becomes large.

™ If it is lowered, the loop of the

needle thread becomes small.

™ If the loop is not formed (the loop

is too small) and the skip stitching occurs, raise the needle thread release.

™ If the loop is excessively formed,

(the loop is too large) and the skip stitching occurs, lower the needle thread release.

™ Loosen screw ^5 and adjust by moving the thread guide ^6 up

and down.

−50 −

™ If it is raised, the thread slackens. ™ If it is lowered, the thread is

tightened.

™ Use of the nipper for the threads

used Not used for cotton thread and tetoron thread. Used for wooly nylon thread and spun thread (stretching thread).

™ Use of the nipper for the materials

used Not used for the light-weight materials of jersey, knit and cloth. Used for the heavy-weight materials of jersey, knit and cloth.

Page 54

(4) Thread trimmer device (MFC)

Standard Adjustment

1) Stroke adjustment (common to both elctromagnetic and pneumatic type)

Stroke A 17mm : Gauge 4.8mm or less 18mm : Gauge 5.6mm or more

2) Adjustment of the right position of movable knife (return)

Space between lower knife 7 and lever 8 is to be 0.4 mm

0.4 mm

−51 −

Page 55

Adjustment Procedures Results of Improper Adjustment

Loosen the nut 1 , and make adjustment by moving the block 2 along the shaft 3 .

Shorter stroke

Longer stroke

™ Too short stroke disables thread

cutting.

™ Too large stroke disables looper

thread from being clamped.

Remove hinge screw 4 , remove driving lever 5 , and make adjustment by turning round the connecting bar 6 .

™ Too little clearance could

generate abnormal wear of thread trimmer mechanism, breakage and falling off of the parts.

™ Too large clearance could

generate interference of knife with looper.

−52 −

Page 56

MFC

Standard Adjustment

3) Adjustment of stationary knife and looper thread clamp spring

Overlapping amount between the catching part in pointed end of movable knife !0 and pointed end of stationary knife 9 is to be 0.5 mm.

The distance from pointed end of movable knife !0 to clamp spring !1 is to be 3.2 mm from stationary knife 9 to the top end of flat spring !2 to be 0.5 mm.

3.2 mm

0.5 mm

4) Adjustment of the position of movable knife’s pointed end

™ Position of stopper plate

Looper

12.5 mm

0.1 mm

Looper

12.5 mm

Clamp spring is not permitted to contact the rear of looper

™ The movable knife’s pointed end is to be

™ Stopper plate !5 is to be in contact with the

Looper

When looper moves forward all the way to its limit, push on the thread trimmer cylinder by hand so that the distance from the pointed end of stationary knife to the rear of looper is to be 12.5 mm under the state mentioned below.

in line with the ridgeline in the flat section of looper top face.

lever @1 .

Movable knife’s pointed end

To be in line with this line

−53 −

Page 57

Adjustment Procedures Results of Improper Adjustment

For the adjustment of stationary knife 9 and clamp spring !1 , loosen 2 screws 7 and a screw 8 . Be sure to retain the screw 8 which adjusts the clamping pressure after thread trimming and make adjustment of clamping pressure so that looper thread comes off about 3 stitches after start of sewing. Mount the clamp spring !1 and stationary knife 9 so that they are parallel to the side of movable knife !0.

™ Too small overlapping amount of

catching part in pointed end of movable knife with the stationary knife disables cutting of looper thread.

™ Too much distance from the

pointed end of movable knife to the top end of clamp spring disables clamping.

™ Too small distance from the

stationary knife to the top end of flat spring could cause improper clamping; too much distance could disturb smooth thread threading.

When looper moves forward all the way to its limit, push on the solenoid so that the pointed end of stationary knife is situated

12.5 mm ahead from the rear of looper. In this state : ™ Loosen the screw !9 so that the pointed end of stationary knife

comes to the ridgeline in the flat section of looper top face(Refer to the left illustration), and make adjustment by turning the eccentric @0 .

™ Adjust stopper plate !5 by loosening 2 screws !4, adjust stopper

plate so as clamp spring just clears rear of looper.

™ Loosen the 2 screws !8 , and move up and down the guide !6

so that the guide !6 is in contact with the underside of movable knife !7 and the clearance between the movable knife !0 and the upper face of lower looper !3 is to be 0.1mm.

!4 !5

™ Incorrect adjustment could

cause the failure of thread cutting and the thread cast-off at the start of sewing.

−54 −

Page 58

MFC

Standard Adjustment

5) Adjustment of operating speed of thread trimmer (pneumatic type)

Forward travel of movable knife

Backward travel of movable knife

6) Confirmation of thread trimming

−55 −

Page 59

Adjustment Procedures Results of Improper Adjustment

™ The speed of the forward travel of movable knife is reduced by

turning the screw of speed controller @2 clockwise and increased counter-clockwise.

™ The speed of the backward travel of movable knife is reduced

by turning the screw of speed controller @3 clockwise and increased counterclockwise.

Old type

New type

™ Incorrect adjustment could

cause abnormal wear of mechanism of thread trimmer or failure of thread trimming by insufficient stroke.

After making adjustment of thread trimmer, thread the machine and try to sew and cut off the electric power in a state that the needle bar is situated at the top dead point to disable the operation of the sewing machine and push on the solenoid to confirm the following. ™ Movable knife passes through the needle thread loop @4 and

makes the looper thread @5 bent.

™ Movable knife starts moving backward after it reaches the end

of the left travel, when the looper thread is caught in @6 section of movable knife while the needle thread is caught in @7 section and cut by stationary knife and the looper thread only is retained by the clamp spring.

−56 −

Page 60

MFC

7) Adjustment of pneumatic lifter

Standard Adjustment

Left needle

Spreader

At the time of bottom dead point of needle bar the presser foot should not contact the underside of spreader when lifted.

Max. 7.0 mm

At the time of top dead point of needle bar the left needle point should not go beyond the bottom of presser foot when presser is lifted.

−57 −

Page 61

Adjustment Procedures Results of Improper Adjustment

™ Make adjustment by loosening the screw inside @9 so that @9

is mounted around the intermediate point between 2 holes for the hook of lifter lever.

™ Adjust the lifting amount of presser foot by turning the cylinder

rod #2 loosening the rod end nut #1. (If the cylinder rod becomes too small to turn remove the collar #0.)

™ Make adjustment by loosening the nut #3 and turning the screw

#4 so that the clearance between the hinge screw #5 and the

top end of screw is to be around 1 mm when the presser foot goes down.

Old type

Presser foot lifting lever

1 mm

™ Too short stroke could cause the

insufficient lifting amount.

™ Too large stroke could cause the

breakage of the spreader, needle clamp and thread guide.

™ No clearance made between the

hinge screw and stopper screw could cause the presser foot floating.

−58 −

Page 62

MFC

Standard Adjustment

8) Adjustment of tension release (equipped with thread trimmer)

1 Disk floating timing

2 Thread hauling amount

When the presser foot is lowered :

™ Tongue #6 in 5 places is near thread tension disk

#7 and should not come in contact with it. (0.8

mm)

™ Thread tension disk #7 should open immediately

after the start of thread trimming.

™ Tongue #6 should enter thread tension disk #7

smoothly.

(Caution) The thread trimming mechanism and

thread tension release mechanism are interlocked. When they do not work smoothly, check the thread tension release mechanism.

0.8 mm

™ Adjust the length of remaining needle thread from

the needle eyelet after thread trimming with thread tension release hook for needle thread $3 in 3 places.

™ Raise thread tension release hook $3 to shorten

the length of the remaining thread and lower thread tension release hook $3 to lengthen the length of the remaining thread.

™ Adjust thread tension release hook for top

covering thread $4 so that top covering thread is correctly clamped after thread trimming.

™ Adjust thread tension release hook for looper

thread $5 so that looper thread is correctly clamped after thread trimming.

9) Adjustment of proximity switch

This is a contactless switch which prevents the sewing machine from turning due to the defective return of thread trimmer solenoid. Adjust the thread trimmer solenoid so that LED lights up when it returns and is turned off during the thread trimming. The clearance is to be 0.5 mm to 0.8 mm.

0.5 to 0.8 mm

−59 −

LED

Page 63

Adjustment Procedures Results of Improper Adjustment

1 Disc float timing

™ Make a provisional adjustment by

loosening screw #8 so that it is situated at the center of eccentric nut #9 adjusting range.

™ Loosen the screw $0 . Move the

thread tension release lever $1 so that the tongue #6 just contacts the thread tension disc #7 .

™ Remove the hinge screw $2 to confirm

that thread trimmer mechanism and thread tension release mechanism work smoothly.

™ Loosen the screw $6 , and move up

and down the thread tension release hook $7 .

™ Incorrect adjustment could

cause defective stitch or stitch skip.

™ Too short length of remaining

needle thread could cause the needle thread to pull out of needle eye cause stitch skip at the start of sewing.

™ Too long length of remaining

needle thread could produce foul seam at the start of sewing.

Loosen the nut. Make the adjustment of clearance between the contactless switch and plate %00 by moving the contactless switch $8 by loosening 2 nuts $9. Confirm the LED’s OFF during operation and ON under the normal state by actually cutting the thread several times.

−60 −

™ Too large clearance disables the

running of motor.

™ Too short clearance enables the

running of motor due to the defective return of thread trimmer, which could be the cause of the motor damage.

Page 64

MFC

Standard Adjustment

10) Adjustment of top covering thread trimmer

Make adjustment such that the top covering thread cutting movable knife %1 comes to the center in Vshaped slot of spreader when the sewing machine is at rest, and does not contact the spreader %2 and the top covering thread when the movable knife %1 is open.

(Old type)

%7 %9

Adjusting cover thread trimme

The following adjustments are made with the needles at top dead center.

(New type)

Clearance between top end of

moving knife and spreader

0.2 to 0.4 mm

Movable

knife

±0.5 mm

Movable knife open

Top covering thread

1.5 to 2mm

Clearance between top end of moving knife and left side of left needle

0.2 to 0.4 mm

−61 −

Page 65

Adjustment Procedures Results of Improper Adjustment

™ Loosen the 2 screws %3. Move the holder %4 so that the movable

knife %1 can come to the center in V-shaped slot of spreader.

™ Loosen the nut %5 . Make adjustment by turning the rod %6

such that the pointed end of movable knife coincides with the pointed end of stationary knife ( ±0.5 mm) when the movable knife is closed, and the movable knife catches and cuts the top cover thread when opened. When the movable knife and stationary knife is found not to be well engaged, loosen the 2 screws %8 and adjust the stationary knife %9 .

™ Adjust the retaining pressure by the screw %7 so that the top

cover thread is clamped after thread trimming. (An appropriate pressure may be such that the clamp spring is 1/2 turned after contacting the stationary knife.)

™ Incorrect adjustment could

cause breakage of spreader, defect of top cover thread trimming or thread breakage of top cover thread during sewing.

In case of the pneumatic type ™ Set the air pressure of moving knife ^0 to “0” and adjust the

knife so that it cuts the thread retained by spreader ^2.

™ The trimmer activates and the hook of moving knife ^0 picks

up the thread from the underside where the thread goes from spreader ^2 to the stitch side.

™ Loosen screws ^3 and ^4 and adjust so that the bottom of

moving knife ^0 should be 1.5 to 2 mm above the top surface of presser foot &0 when moving knife ^0 is opened to the maximum.

™ Loosen screw ^6 and adjust so that the clearance between

the top end of moving knife ^0 and the left side of the left needle ^1 should be 0.4 to 0.8 mm. In addition, loosen screw ^5 and adjust so that the clearance between the top end of moving knife ^0 and spreader ^2 should be 0.2 to 0.4 mm. Loosen screws ^3 and ^4 and adjust the angle of moving knife ^0 so that it should pick up the thread retained by spreader ^2.

™ When the adjustment of the trimmer is completed, do not

remove collar setscrews ^4 since collar ^8 holds the adjusted position of the trimmer.

™ When removing the trimmer unit since the trimmer is not used,

loosen screw ^3 and lift the main body ^0 while turning it and there is a position where the unit is drawn. When installing the unit, adjust the groove of collar ^8 to pin ^7 on the installing base and tighten screw ^3 to place it to the home position.

™ Similarly adjust the solenoid type needle thread trimmer.

(Caution) Adjust so that the presser foot does not interfere

with the trimmer.

−62 −

Page 66

5. ASSEMBLING AND ADJUSTMENT OF FIXED CAM THREAD TAKE-UP

(1) Parts used

Standard Adjustment

−63 −

Page 67

Adjustment Procedures Results of Improper Adjustment

Deleted parts Added parts

Name of part

Needle thread strike-off asm.

Needle bar guard

Needle bar thread guide

Part No.

US00050366B

US00050317C US00050323P

Name of part

Needle bar cam plate

Needle bar guard

Needle bar fork thread take-up

Medium thread path base

Screw

Part No.

US00050358Z

US00050317E US0050363CL

US00050362R

SS6110480SP

The screws for 1 to 3 are used again when assembling 4 to 7. So, do not lose them.

(Caution) The parts 9 to !1 are not the deleted ones but those

to be removed for performing the work. So, be careful.

™ Remove needle thread strike-off asm. 1, needle bar guard 2

and needle bar thread guide 3, and assemble needle bar cam plate 4, needle bar guard 5 and needle bar fork thread takeup 6.

™ Temporarily tighten needle bar cam plate 4 and needle bar

guard 5 with screw 8 for easy assembling.

−64 −

Page 68

(2) Needle bar cam plate and needle bar fork thread take-up

Standard Adjustment

(3) Needle thread guide and medium thread path base

Standard Adjustment

53 mm

−65 −

Page 69

Adjustment Procedures Results of Improper Adjustment

™ Adjust the vertical position of needle bar cam plate 4 and

longitudinal position of needle bar fork thread take-up 6 so that the hole for the right needle of needle bar fork thread takeup 6 is as shown in the figure on the left-hand side when the needle bar is at its lower dead point. At this time, assemble so that the clearance in the lateral direction between needle bar fork thread take-up 6 and needle bar cam plate 4 should be equal.

(Caution) See the item (1) Parts used.

<When excessively hard-to-slip thread is used> Needle bar cam plate ... Set it higher by 1 to 1.5 mm. Needle bar fork thread take-up ... Adjust it to the front side.

<When easy-to-slip thread is used> Needle bar cam plate ... Keep as it is. Needle bar fork thread take-up ... Adjust it to the rear side.

Adjustment Procedures Results of Improper Adjustment

™ Remove needle thread eyelet installing base !0 with the thread

guide !1 from silicone thread lubricator (asm.) 9.

™ Temporarily set needle thread eyelet installing base !0 to

medium thread path base 7.

™ Tighten medium thread path base 7 by using the setscrew

located at the upper side of the auxiliary thread take-up cover.

™ Adjustment value of needle thread eyelet !1 is as described

below.

MFC MF A (left) 15 mm 22 mm B (center) 19 mm 25 mm C (right) 21 mm 29 mm

(Caution) See the item (1) Parts used.

Horizontal direction : 53 mm from the right-hand side of “needle bar cam plate 4” Height direction : (From the top end of needle thread eyelet installing base to the bottom end of the hold of the thread guide)

<When desired to decrease the tension with light-weight materials> Increase the whole adjustment values by 1 to 2 mm.

<When thread breakage occurs frequently with heavy-weight materials> Decrease the whole adjustment values by 1 to 2 mm.

−66 −

Page 70

(4) Spreader thread guide

1) Parts used

Standard Adjustment

2) Assembling and adjustment of spreader thread guide

To align height of holes (At the time of needle bar upper dead point)

Use the thread hole located in extreme rear position.

Normally, use the hole on lower side.

−67 −

Page 71

Adjustment Procedures Results of Improper Adjustment

Deleted parts Added parts

Name of part

Eyelet

Part No.

US00050392T

Name of part Spreader thread guide

Part No.

US0050392BG

™ Remove eyelet !2 and install spreader thread guide !3. ™ Adjust the vertical position of the spreader thread guide so

that the relation between the thread hole position of auxiliary thread take-up thread guide !4 and the spreader thread guide !3 is as shown in the figure at the time of the lowest point of the needle bar.

The hole on the left-hand side of the spreader thread guide :

<When general thread is used> Use the hole located on the lower side.

<When stretchy thread is used> Use the hole located on the upper side.

6. OTHER PRECAUTIONS

(1) Points to which Locktite is applied

Locktite 222

Auxiliary take-up thread guide

−68 −

Page 72

Refer to threading diagram.

Thread caught in thread guide, Incorrect

Remove the flaw, burr etc. and process the thread guide

finish. However, replace such important parts as looper or

throat plate etc. with the new part because their shape is

changed by being processed.

In case needle exchanger, or looper needle guard is worn

out, replace it with the new part.

Replace it with an appropriate needle.

threading

Resistance produced by flaw, burr, rust

etc. around needle entry of throat plate,

stitch tongue, looper, spreader, needle

thread take-up nipper, needle guide,

thread tension disc etc.

Strong contact of needle against needle

guard produces a sharp edge in needle

guard resulting in thread breakage.

Too thin needle for the thread used

Use thinner needle. Reduce the sewing speed. Use silicon

oil lubricant device.

Needle is heated depending on fabric type,

number of fabrics, sewing speed resulting

Replace it with the thread of good quality.

Reduce thread tension. Intermediate thread guide is

positioned too high making the thread tension too strong.

Mount it in the correct position.

in thread breakage.

Poor quality and weakness of thread

Too strong thread tension

Interference with feed dog, throat plate due

Remove the flaw, burr etc.

to the incorrect mounting height of looper

Flaw produced in stitch tongue in throat

plate, feed dog, tongue in presser foot,

Remove the flaw, burr etc. and process the thread guide

finish. However, replace such parts as looper with the new

part because its shape is changed by being processed.

underside in presser foot

Resistance produced by flaw, burr, rust

etc. in stitch tongue in throat plate, looper,

looper thread cam, thread guide, thread

Refer to standard adjustment.

tension disc

Excessive tension applied due to the

Reduce the thread tension while checking to see the tension

balance against the needle thread, top covering thread.

incorrect position of looper thread cam

timing, thread guide

Too strong tension of looper thread

Threading

Thread path

Needle guard

Needle

Needle heat

Thread

Thread tension

Interference

Troubles Cause (1) Cause (2) Corrective measures

7. TROUBLES AND CORRECTIVE MEASURES

1. Thread breakage

−

69 −

Chain-off thread defect

Thread guide

2. Looper thread breakage

Looper thread cam adjustment

Thread tension

To the next page

Page 73

Replace it with good quality of thread.

Adjust moving amount, front and rear of looper so that

looper contacts the needle at 2/3 height of top of the back.

Refer to needle heat in needle breakage

Poor quality and weakness of thread

Too strong contact of looper back with

needle resulting in thread breakage

In case needle heat is generated looper

thread’s contact with needle causes thread

breakage, specially at the time machine

Align the needle entry to the needle.

is at rest.

Needle hits the throat plate or presser foot

because the needle entry is not correctly

Refer to standard adjustment

positioned for the plate or foot.

Too little clearance between spreader and

needle

Make adjustment so that looper does not hit the looper. For

the correction of the contact at looper’s back, adjust the

moving amount, front and rear.

Refer to standard adjustment

Needle hits looper resulting in needle

breakage.

Too strong contact against needle guard

Use thicker needle.

Reduce the needle thread tension.

Refer to standard adjustment value.

or needle point hits needle guard due to

incorrect position.

Too thin needle for fabric used

Needle thread tension is too strong.

Feed dog is too high or needle height is

too low resulting in needle breakage due

Check to see the height of needle guard and clearance

between needle guard and needle.

to needle swerve.

Incorrect height or incorrect position, front

and rear

Adjust moving amount, front and rear and correct the

incorrect position of looper’s back and the contact when it

returns.

Moving amount, front and rear is ill

balanced.

Thread

Looper avoid

Needle heat

From the previous page

Troubles Cause (1) Cause (2) Corrective measures

Needle entry

3. Needle breakage

Spreader

Interference of looper with scooping

movement of needle

−

Needle guard

70 −

Needle thickness No.

Thread tension

Feed height, Needle height

Needle guard

Interference with looper

4. Worn out needle point

Page 74

Replace it with the genuine part.

Replace the needle with new one, Correct the

mounting direction, Use UY121GJS CS100, UY128

GBS FS300.

Use nipper.

Correct the height to appropriate height.

Refer to standard adjustment.

Refer to threading diagram.

Incorrect shape of pointed end of

looper disables scooping a loop.

Needle bend, incorrect needle

mounting direction, wrong needle

Not used.

Too high

Needle bar position is too high.

Incorrect threading

Use needle guard.

Reduce the tension.

Same described in page “ Thread breakage by

needle heat”

Refer to standard adjustment.

Not used.

Spreader thread tension is too strong.

Stitch skip occurs before thread

breakage produced by needle heat.

Incorrect clearance adjustment,

incorrect returning amount adjustment

Incorrect contact amount, incorrect

height

Replace it with the genuine part.

Replace the needle with new one, Correct the

mounting direction, Use UY121GJS CS100, UY128

GBS FS300

Do not use nipper.

Correct height position to appropriate height.

Refer to standard adjustment.

Refer to threading diagram.

Incorrect shape of pointed end of

looper disables scooping a loop.

Needle bend, incorrect needle

mounting direction, wrong needle

Being used.

Height is too low.

Needle bar height is too low.

Incorrect threading

Looper

Needle

right needle thread.

Troubles(1) Troubles(2) Cause (1) Cause (2) Corrective measures

Stitch skipping Looper does not scoop the

Nipper

Intermediate thread guide

Needle height

Threading

Needle guard

Spreader

Needle heat

Left Right Left Right

71 −

−

Looper adjustment

Needle guard, front and rear

Looper

Needle

Looper does not scoop the

middle needle thread.

Nipper

Intermediate thread guide

Needle height

Threading

To the next pageTo the next page

Left Right Left Right

Page 75

Do not use.

Reduce the tension.

Same described in page “Thread breakage by

needle heat”

Refer to standard adjustment.

Being used.

Spreader thread tension is too strong.

Stitch skip occurs before thread

breakage produced by needle heat.

Incorrect clearance adjustment,

Refer to standard adjustment.

incorrect returning amount adjustment

Incorrect contact amount, incorrect

height

Replace it with the genuine part.

Replace the needle with new one, Correct the

mounting direction, Use UY121GJS CS100, UY128

GBS FS300.

Do not use nipper.

Correct height position to appropriate height.

Refer to standard adjustment.

Refer to threading diagram.

Incorrect shape of pointed end of

looper disables scooping a loop.

Needle bend, incorrect needle

mounting direction, wrong needle

Being used.

Height is too low.

Incorrect threading

Do not use.

Refer to standard adjustment.

Same described in page “Thread breakage by

needle heat”

Refer to standard adjustment.

Being used.

Too near to the left needle

Stitch skip occurs before thread

breakage produced by needle heat.

Incorrect clearance adjustment,

Refer to standard adjustment.

incorrect returning amount

Incorrect contact amount, incorrect

height

Needle thread guard

Spreader

Needle heat

From the previous pageFrom the previous page

Troubles(1) Troubles(2) Cause (1) Cause (2) Corrective measures

Looper adjustment

Needle guard, front and rear

Looper

Needle

Looper does not scoop the left

needle thread.

−

72 −

Nipper

Intermediate thread guide

Needle height

Threading

Needle guard

Left Right Left Right

Spreader

Needle heat

Looper adjustment

Needle guard, front and rear

To the next page

Page 76

Replace it with the genuine part.

Replace the needle with the new one.

Refer to standard adjustment.

Refer to threading diagram.

Refer to standard adjustment.

Increase tension.

Refer to standard adjustment.

Ventral shape is incorrect.

Looper

Needle does not scoop the

looper thread. (Triangle stitch

skip) Middle needle Left

needle

Needle bend

Needle bar position is too high.

Incorrect threading

Needle

Needle height

Threading

Incorrect clearance adjustment,

incorrect returning amount

Tension is too weak.

Looper thread cam timing is too fast.

Looper adjustment

Stitch skip by middle needle

Looper thread tension

Looper thread cam timing

Slack of looper thread

Stitch skip by left needle

Slack of looper thread

From the previous page

Troubles(1) Troubles(2) Cause (1) Cause (2) Corrective measures

−

To the next page

73 −

Page 77

Replace it with the genuine part.

Replace the needle with the new one, Use

UY121GJS CS100, UY128 GBS FS300.

Refer to standard adjustment.

Incorrect shape of pointed end of

spreader disables scooping a thread.

Needle bend, wrong needle

Incorrect height, protruding amount,

position, front and rear

Incorrect height, position

Refer to standard adjustment.

Needle bar position is too low.

Refer to threading diagram.

Refer to standard adjustment.

Increase tension.

Refer to standard adjustment.

Incorrect threading

Incorrect height, position, front and

rear

Spreader thread tension is too weak.

Incorrect drawing-in amount of thread

Correct

Skipping in top covering stitch by right needle

Simultaneous skip by left and middle needle

Right needle

Incorrect

Spreader does not fetch the top covering thread.

Failure of

catching thread

Spreader

Needle

Skipping in top cover stitch

(right)

From the previous page

Spreader adjustment

Stationary spreader thread

guide

Needle height

Threading

Needle clamp spreader

thread guide

Skipping in top covering stitch by right needle

Spreader thread tension

Spreader take-up thread

drawing-in amount

Correct

Incorrect

Right needle does not stride over the top

covering thread.

MiddleLeft Right

Troubles(1) Troubles(2) Cause (1) Cause (2) Corrective measures

−

To the next page

74 −

Page 78

Replace the needle with the new one, Use

UY121GJS CS100, UY128GBS FS300.

Refer to standard adjustment.

Needle bend, wrong needle

Incorrect height, protruding amount,

Refer to standard adjustment.

Refer to threading diagram.

Increase tension.

position, front and rear

Incorrect needle bar position

Incorrect threading

Spreader thread tension is too weak.

Refer to standard adjustment.

Incorrect drawing-in amount of thread

Incorrect height and position

Middle

needle

Incorrect

Middle

needle

Skipping in top covering stitch by middle needle

Middle needle does not scoop top covering thread.

Correct

Middle

Middle needle strides over top covering thread sometimes.

Left Middle Right

needle

Correct Incorrect

Needle

Spreader adjustment

Skipping in top covering stitch

(Middle)

From the previous page

Troubles(1) Troubles(2) Cause (1) Cause (2) Corrective measures

Needle height

Threading

Spreader thread tension

Spreader pull-off

Stationary spreader thread

guide

75 −

−

To the next page

Page 79

Replace it with the genuine part.

Replace needle with new one, Use UY121GJS

CS100, UY128GBS FS300.

Refer to standard adjustment.

Incorrect shape of pointed end

disables scooping a thread.

Needle bend, wrong needle

Incorrect height, protruding amount,

position, front and rear

Incorrect height and position

Refer to standard adjustment.

Needle bar position is too low.

Refer to threading diagram.

Increase tension.

Refer to standard adjustment.

Incorrect threading

Spreader tension is too weak.

Incorrect drawing-in amount of thread

Left

needle

Incorrect

needle

Correct

Spreader

Needle

Skipping in top covering stitch

(Left)

From the previous page

Troubles(1) Troubles(2) Cause (1) Cause (2) Corrective measures

Spreader adjustment

Stationary spreader thread

guide

Needle height

Threading

Spreader thread tension

Spreader pull-off drawing-in

amount of thread

76 −

−

Skipping in top covering stitch by left needle

Left needle does not scoop top covering thread.

To the next page

Page 80

Replace the needle with the new one, Use

UY121GJS CS100, UY128GBS FS300.

Refer to standard adjustment.

Refer to threading diagram.

Increase R. Polish correctly.

Needle bend, wrong needle

Needle bar position is too high.

Incorrect threading

R of stitch tongue in throat plate is too

small.

Replace it with the genuine part.

Incorrect polishing

R of looper’s ventral section is too

large and ridgeline is not tense, for

which needle thread is likely to slip

Refer to standard adjustment.

from looper.

Too little contact amount between

Increase tension.

Lift thread guide position.

Refer to standard adjustment.

looper’s back and needle

Thread tension is too weak.

Low position of thread guard results

in too large needle thread loop.

Thread guard position is too high.

Do not use nipper.

Reduce drawing-in amount of thread.

Use of nipper could easily generate

this trouble.

Drawing-in amount of looper thread is

too much.

Needle

Needle height

Threading

Single chain thread cast-off

(Right, Middle, Left)

From the previous page

Troubles(1) Troubles(2) Cause (1) Cause (2) Corrective measures

Throat plate

Looper

Looper adjustment

77 −

−

Thread tension

Intermediate thread guide

position

Thread guard position

Nipper

Looper thread cam thread

guide position

To the next page

Page 81

One chain stitch by right needle

One chain stitch by middle needle

One chain stitch by left needle

Right needle thread miss

Middle needle thread miss

−

78 −

Page 82

Replace it with the genuine part.

R of stitch tongue in throat plate is too

large. Stitch tongue is too short.

Replace needle with new one, Use UY121GJS

CS100, UY128GBS FS300.

Replace the looper when modified or its shape is

changed too much.

Refer to standard adjustment.

R Length of stitch tongue

Worn out needle point, needle bend,

wrong needle

Flaw in looper’s ventral section,

incorrect polishing

Needle bar position is too low.

Refer to threading diagram.

Increase tension.

Lift the thread.

Incorrect threading

Tension is too weak.

Thread guide position is too low.

Do not use nipper.

Use of nipper is likely to generate this

trouble.

Throat plate

Double bonding stitch

(Middle, Left)

From the previous page

Troubles(1) Troubles(2) Cause (1) Cause (2) Corrective measures

Needle

Looper

Needle height

Threading

Needle thread tension

Right needle enters middle

needle loop.

Intermediate thread guide

position

Nipper

Middle needle enters left

needle loop.

79 −

−

To the next page

Page 83

Polish correctly.

Refer to standard adjustment.

Replace the looper when modified or its shape is

changed too much.

Refer to standard adjustment.

Incorrect polishing

Stroke of spreader is too large.

Worn out looper’s pointed end and

incorrect polishing

Drawing-in amount of top covering

thread is too much.

Increase tension.

Refer to threading diagram.

Increase tension.

Reduce drawing-in amount of thread.

Needle thread tension is too weak.

Incorrect threading

Thread tension is too weak.

Drawing-in amount of looper thread is

too much.

Correct or replace part.

Incorrect polishing, Too long stitch

tongue

Replace needle with new one, Use UY121GJS

CS100, UY128GBS FS300.

Replace the looper when modified or its shape is

changed too much.

Refer to standard adjustment.

Refer to threading diagram.

Increase tension.

Lift the position

Reduce tension.

Worn out needle point, needle bend,

wrong needle

Worn out looper’s pointed end,

incorrect polishing

Needle bar position is too low.

Incorrect threading

Tension is too weak.

Thread guide position is too low.

Tension is too strong.

Increase drawing-in amount of thread.

Drawing-in amount of looper thread is

too little.

Throat plate

Spreader adjustment

Looper

Irregular stitches

(Left, Middle, Right)

From the previous page

Troubles(1) Troubles(2) Cause (1) Cause (2) Corrective measures

Top covering thread take-up

Needle thread tension

Threading

Top covering thread tension

Looper thread cam thread

guide position

−

80 −

Throat plate

Ill-tensed seam

Needle

Looper

Needle height

Threading

Needle thread tension

Intermediate thread guide

position

Looper thread tension

Looper thread cam thread

guide position

To the next page

Page 84

Replace when modified or its shape is changed too

much.

Flaw in pointed end of spreader

obstructs smooth thread threading.

Refer to standard adjustment.

Replace when modified or its shape is changed too

much.

Refer to standard adjustment.

Flaw

Spreader stroke is too large.

Flaw, burr in slot

Drawing-in amount of top covering

Increase tension.

Refer to threading diagram.

thread is too much or too little.

Needle thread tension is too weak.

Incorrect threading

Increase tension.

Reduce drawing-in amount of thread.

Replace when modified or its shape is changed too

much.

Use throat plate provided with long stitch tongue.

1st thread tension is too weak.

Drawing-in amount of looper thread is

too much.

Thread threading is not smooth due

to incorrect shape of stitch tongue.

Stitch tongue is too short.

Refer to threading diagram.

Reduce tension.

Increase drawing-in amount.

Incorrect threading

Tension is too strong.

Drawing-in amount of upper thread is

too little.

Spreader

Irregular stitches in top

covering stitches

From the previous page

Troubles(1) Troubles(2) Cause (1) Cause (2) Corrective measures

Spreader adjustment

Thread guide

Top covering thread take-up

Needle thread tension

Threading

Top covering thread tension

Looper thread cam thread

guide position

81 −

−

Stitch tongue of presser foot

Throat plate

Threading

Bulge

Needle thread tension

Looper thread tension

Looper thread cam thread

guide position

To the next page

Page 85

Replace when polished or its shape is changed too

much.

Refer to standard adjustment.

Thread threading is not smooth due

to incorrect polishing in stitch tongue.

Stitch skip in top covering stitch due

Refer to standard adjustment.

Increase tension.

Refer to threading diagram.

to incorrect adjustment

Stitch skip due to incorrect adjustment

Drawing-in amount of top covering

thread is too much or too little.

Needle thread tension is too weak.

Incorrect threading

Increase tension.

1st thread tension is too weak.

Replace when its shape is modified or changed too

much.

Replace needle with new one, Use UY121GJS

CS100, UY128GBS FS300.

Modify or replace.

Refer to standard adjustment.

Thread threading is not smooth due

to incorrect shape of stitch tongue.

Worn out needle point, needle bend,

wrong needle

Flaw on surface in feed dog

Remaining thread is too short by

Increase clamping force.

Increase pulling-in amount.

double cutting.

Clamping force is too weak.

Pulling-in amount of thread is too little

at time of thread trimming.

Increase clamping force.

Correct direction so that remaining thread flows to

presser bar side.

Increase falling speed. (to get rid of shaky

movement etc.)

Clamping force is too weak.

Needle is entangled with thread by

incorrect direction of air blow outlet.

Falling speed of presser is too slow in

automatic lifter.

Throat plate

Spreader adjustment

Defective chain-off thread

(with top covering stitch)

From the previous page

Troubles(1) Troubles(2) Cause (1) Cause (2) Corrective measures

Looper adjustment

Top covering thread take-up

Needle thread tension

Threading

Top covering thread tension

Stitch tongue of presser foot

−

Needle

82 −

Feed dog

Double cutting

Stitch skip & stitch missing at

Looper thread clamp

Pulling-in of thread

start of sewing after thread

trimming (thread trimmer

sewing machine, bottom

covering stitch)

Mechanical wiper

Pneumatic wiper

Presser foot

To the next page

Page 86

Increase clamping force.

Increase pulling-in amount.

Clamping force is too weak.

Pulling-in amount of covering thread

Refer to standard adjustment.

is too little at time of thread trimming.

Insufficient returning amount of

movable knife disables engagement

Sharpen or replace edge.

with stationary knife.

Worn out edge, nicked edge disables

Refer to standard adjustment.

sharp cutting.

Incorrect looper stopping position

Inappropriate stroke

Incorrect position, front and rear, of

movable knife against looper’s

backposition

Refer to standard adjustment.

Engaging pressure is too weak.

Lift the position.

Thread guide position is too low.

Sharpen or replace edge.

Refer to standard adjustment.

Worn out edge, nicked edge disables

sharp cutting.

Incorrect position of knife against

Make adjustment so that sewing machine is brought

to rest at the top dead point of needle bar.

Refer to standard adjustment.

spreader

Incorrect spreader stopping position

(Sewing machine is at rest)

Insufficient engaging amount disables

cutting of thread.

Refer to standard adjustment.

Insufficient opening amount of

Refer to standard adjustment.

movable knife disables catch of

thread.

Clamping pressure is too weak.

Top covering thread clamp

Pulling-in of covering thread

From the previous page

Troubles(1) Troubles(2) Cause (1) Cause (2) Corrective measures

Returning position of movable

knife

Unable to trim needle thread,

looper thread

Defective thread

trimmer

Stationary knife

Timing of thread trimming

Movable knife stroke

Clearance between movable

knife and looper

Engaging pressure (Movable

and stationary knife)

Intermediate thread guide

position

Unable to trim top covering

thread

83 −

−

Stationary knife

Initial position

Spreader stopping position

Engagement between

movable and stationary

knives

Opening amount of movable

knife

Clamping pressure

Page 87

8. DRAWING OF TABLE

(1) Semi-submerged type for MF

1200

346 ±1 346 ±1 183

5-ø8.5, ø26 Counterbore 1 deep with slot

4-R30

17 drill

570

390

100

Drawer installing position

Drawer stopper installing position (back side)

JUKI logotype

(810)

312.3

45°

39.2

264

R10

780

R25

81.5

120

185

234

18 24

445

305 ±1

307

R30

16070

93.5

R25

50.5

R30

160

Stand installing position

305 ±1

(360)

Push button switch mounting position

125 30

305

130

151

120

110

2.5

Right side

Z-Z (5 places)

(ø26)

Y-Y

30°

(1)

(ø8.5)

8574

− 84 −

Table Part No.30148654

− 84 −

Page 88

4-R30

(22)

738

346 ±1 346 ±1

159 ±1

125 ±1

349

3-ø8.5, ø26 Counterbore 5 deep

5-ø10

R23.5

2-R25

ø40

305 ±1

173 ±1

3-ø27 Counterbore

234.5

66.5 ±1

264 ±1

R23.5

R25

379 ±1

2-R25

2 5

Z-Z

Y-Y

ø40

305 ±1

417.5

359.5

ø32

208 ±1

337.5

225

R2 (Entire round)

105

130

24.5

R30

R25

R23.5

523

533

30˚

R23.5

200

(82.5)

121

183

(ø27)

90.5

1114

(ø27)

1114

− 85 −

Table Part No.30148803

− 85 −

Page 89

(2) Desktop type for MF

1200

159±1

682

308

4-R30

570

390

21 50

100

Drawer installing

position

Drawer stopper installing position (back side)

JUKI logotype

295

ø40

3-R10

173±1

136.5

R25

R13.5

R23.5

(810)

R23.5

66.5±1

Right side

2-ø27

3-ø8.5, ø26 Counterbore 1 deep with slot

R25

80 152.5

379±1

264±1

ø17 drilled hole

R23.5

R13.5

R25

R23.5

500500

600

243.5

(241.5)

ø40

ø32

125

280

191

Stand installing position

Push button switch mounting position

130

Z - Z (2 places)

(360)

208±1

420

390

118.5±1

120

14 11

Detailed measurement (2 : 1)

0.8 0.8

Thickness : 1.5

Thickness : 0.8 Thickness : 0.5 Thickness : 1.5

11.5

7.5

0.5

7.5

120˚

5-R1

5x20=1000

Extracted characters : Helvetica Reg. Condensed Outline number

Y - Y (3 places)

(ø26)

30˚

(1)

(ø8.5)

Table Part No. 30162002

− 86 −

Page 90

(3) Desktop type for MF with fabric under trimmer

1200

709

159±1308

4-R30

570

390

ø17 drilled hole

3-ø8.5, ø26 Counterbore 1 deep with slot

R13.5

280

489

(241.5)

ø40

ø32

191

Stand installing position

Push button switch mounting position

30125

130(810)

100

Drawer installing

Drawer stopper installing position (back side)

position

JUKI logotype

66.5±1

R13.5

ø40

295

3-R10

173±1

136.5

97.5

R10

R20

2-ø27

R10

R20

R10

379±1

R10

264±1

R10

152.580

Z - Z (2 places)

(360)

208±1

420

398

9.5

120

118.5±1

R2 R2

Right side

R2 R2

Y - Y (3 places)

30˚

(1)

(ø26)

(ø8.5)

Table Part No. 30162101

− 87 −

Page 91

(4) Desktop type for MFC

5-ø26, 19 deep

R15

78.5

ø20

98 375

220180

416

305

66.5 ±1

552

54 ±1

262 ±1

242 ±1

ø32

(810)

130

(360)

ø53

232

125

184.5

306

5021

500

1200

70 ±1

340

600

500

R30

ø17

R30

164 ±1

6 0

159 ±1

100

390

570

120

3-ø8.5, ø26 Counterbore 1 deep with slot

Stand installing position

JUKI logotype

Drawer stopper installing position (back side)

Drawer installing position

Right side

30˚

(ø8.5)

(ø26)

Z-Z

Push button switch mounting position

− 88 −

Table Part No.30148001

Page 92

(5) Semi-submerged type for MFC

1200

413 ±1

159 ±1

54 ±1

237

306

390

R30

100

Drawer installing position

Drawer stopper installing position (back side)

416

305

ø17

7-ø8.5, ø26 Counterbore 1 deep with slot

66.5 ±1

ø53

R15

143 ±196

202

185 ±1

626

110

R10

473

R15

170150

197

Stand installing position

R10

R30

(360)

570

R15

R30

5021

JUKI logotype

Right side

500

Z-Z (7 places)

30˚

(ø26)

(ø8.5)

7 11.5

0.8

0.5

7.5

0.8

5-R1

Detailed measurement (2:1)

20 ±1

R15

120 ±1 125

500

600

Extracted characters:Helvetica Reg. Outlined number

Thickness:1.5

Push botton switch mounting position

R30

130(810)

120

− 89 −

120˚

5 x 200 = 1000

Thickness:0.8 Thickness:0.5 Thickness:1.5

Table Part No.30148100

− 89 −

Page 93

(6) Semi-submerged down table for MFC

214

143 ±1

116

5-ø26, 19 deep

262 ±1 242 ±1

413 ±1

185 ±1

ø20

70 ±1

143

164 ±1

125

143

78.5123.5

ø32

258

136

(40)

R2 (Entire round)

20 ±1

32 ±1

471

4-ø10

120 ±1

R2 (Entire round)

− 90 −

Table Part No.30148308

− 90 −

Page 94

(7) Table for MFC with tension roller

R30

1200

159±1

3-8.5, 26 Counterbore 1

deep with slot

54±1306

ø17

375

R30

390

Drawer stopper installing position

position

JUKI logotype

(back side)

66.5±1

5-ø26, 19 deep

450

164±1

380

339

154

118

R30

290

R30

(810)

262±1

R8 45

ø53

70±1

242±1

ø20

220

625

R15

214

340

ø32

218.5 78.5

100

Drawer installing

R30

232

552

Stand installing position

Push button switch mounting position

125

130

(360)120

570

R30

Right side

Z-Z

(ø26)

30˚

(ø8.5)

Table Part No. 19254705

− 91 −

Page 95

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 · 12 Printed in Japan (E)

juki MF-7000 INSTRUCTION MANUAL

Specifications and Main Features

Frequently Asked Questions

User Manual

CONTENTS

1. SPECIFICATIONS

2. MOTOR AND BELT

3. MODEL NUMBERING SYSTEM

4. STANDARD ADJUSTMENT

(1) MF

1) Timing relation between the needle and the feed

2) Adjusting the timing relation between the needle bar and looper (synchronization) : Without gauges

3) Returning amount of the looper

4) Height of the needle bar

5) Clearance between the looper and needle

6) Adjusting amount of the looper-avoid

7) Position of the needle guard

8) Position of the feed dog

9) Spreader

10) Looper thread cam

11) Position of the presser bar

12) Position of the needle thread tension release (without thread trimmer)

13) Position and height of the presser foot

14) Position of the thread guide

(2) Thread trimmer device (MF)

1) Adjustment of the thread trimmer device

2) Thread tension release (Looper thread trimmer device)

(3) MFC

1) Timing relation between the needle and the feed

2) Adjusting the timing of the needle bar and looper (Synchronization) : Without gauges

3) Returning amount of the looper

4) Height of the needle bar

5) Position of the needle guard

6) Clearance between the looper and needle

7) Adjusting amount of the looper-avoid

8) Position of the feed dog

9) Spreader

10) Looper thread cam

11) Looper thread wrap-up preventing cam (Old type)

12) Position of the presser bar

13) Position of the needle thread tension release (without thread trimmer)

14) Position and height of the presser foot

15) Position of the thread guide

(4) Thread trimmer device (MFC)

1) Stroke adjustment (common to both elctromagnetic and pneumatic type)

2) Adjustment of the right position of movable knife (return)

3) Adjustment of stationary knife and looper thread clamp spring

4) Adjustment of the position of movable knife’s pointed end

5) Adjustment of operating speed of thread trimmer (pneumatic type)

6) Confirmation of thread trimming

7) Adjustment of pneumatic lifter

8) Adjustment of tension release (equipped with thread trimmer)

9) Adjustment of proximity switch

10) Adjustment of top covering thread trimmer

5. ASSEMBLING AND ADJUSTMENT OF FIXED CAM THREAD TAKE-UP

(1) Parts used

(2) Needle bar cam plate and needle bar fork thread take-up

(3) Needle thread guide and medium thread path base

(4) Spreader thread guide

1) Parts used

2) Assembling and adjustment of spreader thread guide

6. OTHER PRECAUTIONS

(1) Points to which Locktite is applied

7. TROUBLES AND CORRECTIVE MEASURES

8. DRAWING OF TABLE

(1) Semi-submerged type for MF

(2) Desktop type for MF

(4) Desktop type for MFC

(5) Semi-submerged type for MFC

(7) Table for MFC with tension roller