AZ7000G-8 class - Nähmaschine Yamato - Kostenlose Bedienungsanleitung

BEDIENUNGSANLEITUNG AZ7000G-8 class Yamato

1jamato®

Instruction Manual

SUPER HIGH SPEED OVERLOCK & SAFETY STITCH MACHINE

AZ7000G-8 class

(including AZ7120G-8, AZ7125G-8)

AZ7500G-8 class

Technical line drawing of a sewing machine with multiple rollers and a base (no text or labels)

Thank you for purchasing the Model AZ7000G-8/7500G-8 class.

Before using your AZ7000G-8/7500G-8 class, please read the instruction manual and understand the contents well.

After reading the instruction manual, please keep it in a location where it is easily accessible to the operator.

Safety instructions i - iv

1. Name of each part 1

2. Installation 2

2.1 Semi-submerged type 2

2.1.1 Table cutting diagram 2

2.1.2 Installation 3

2.2 Fully-submerged type 4

2.2.1 Table cutting diagram 4

2.2.2 Table cutting diagram for fully-submerged type with a device 6

2.2.3 Installation 7

2.3 Motor, belt and pulley 8

2.4 Hanging belt 9

2.5 Belt cover 9

2.6 Eye guard and finger guard 9

3. Sewing speed and rotating direction of pulley 10

4. Lubrication 11

4.1 Lubricating oil 11

4.2 Lubricating 11

4.3 Changing oil 12

4.4 Checking and replacing oil filter 12

5. Proper operation 13

5.1 Needle system 13
5.2 Installing needles 13
5.3 Adjusting thread tension 14
5.4 Pressure of presser foot 15
5.5 Releasing presser foot 15
5.6 Opening cover 16
5.7 Adjusting differential feed dog 16
5.8 Adjusting stitch length 17
5.9 SP device and HR device 18
5.10 Cleaning the machine 19

1. Adjustment of sewing machine 20

6.1	Needle thread tension for overlock stitch	20
6.2	Looper thread tension for overlock stitch	21
6.3	Needle thread tension for double chainstitch	22
6.4	Looper thread tension for double chainstitch	23
6.5	Width of overedge seam	24
6.6	Upper and lower knives	25
6.7	Height of feed dogs	27
6.8	Tilt of feed dog	28
6.9	Needles and loopers	29
6.10	Needle and double chaining looper	33
6.11	Needle and needle guards for AZ7000G-8 class	34
6.12	Needle and needle guards for AZ7500G-8 class	35
6.13	Position of presser foot	36

1. SC10 device 37

7.1	Outline	37
7.2	Adjusting ventilating amount	37
7.3	Installation	38

1. Specificaitons 40

8.1	AZ7000G-8 class	40
8.2	AZ7500G-8 class	41

Attention

This instruction manual is designed mainly for technicians, but it is advisable that also operators read the instructions with mark to use the machine properly.

◇ The numbers in lower left corners of figures are figure numbers. We use them in texts as needed for your reference.

Attention

The description in this instruction manual is subject to change for improvements of the commodity without notice.

1. To ensure safe use

Always observe the following instructions to ensure the safe use of the industrial sewing machines and devices.

1-1 Application and purpose

The sewing machine is designed to improve productivity in the sewing industry and must not be used for other applications and purposes. Do not use this sewing machine until it can be confirmed that safety measures for the drive units have been taken.

1-2 Before use

Read all instruction manuals thoroughly before starting the use of this machine and follow them.

Also, read the instruction manual for the installed drive unit.

1-3 Working environment

DO NOT WORK IN THE FOLLOWING ENVIRONMENTS:

• Place where atmosphere temperature and humidity give a bad influence the performance of sewing machines.
• Outdoors and place where the sewing machines are exposed to sunlight directly.
• Atmosphere containing dust, corrosive gases or flammable gases.
• Place where voltage fluctuation exceeds ± 10 % of the rated voltage.
• Place where power capacity necessary for the used motor specifications cannot be secured.
• Place where strong electric or magnetic fields are generated such as near large-output high frequency transmitters or high frequency welding machines.

1-4 Unpacking and transportation

(1) Unpack from the top.
(2) Never hold the parts near the needle or threading parts when removing the sewing machine head from the buffer of box.
(3) When carrying the sewing machine head, have an assistant.
(4) Pay attention not to get excessive impact or shock when moving the sewing machine

head with a pushcart.

2. Installation and preparation

2-1 Instruction and training

Operators and workers, who supervise, repair or maintain the machine head and machine unit, are required to have the adequate knowledge and operation skills to do the job safely. In order to establish such necessary conditions, it needs for the employer to plan and enforce the safety education and training to those workers.

2-2 Sewing table and motor

(1) Prepare a machine table that has enough strength to withstand the weight of the sewing head and any reaction while operating.
(2) Maintain a comfortable working environment with considering the lighting and the arrangement of sewing machine so that the operators can work smoothly.
(3) When installing the control box and the related parts on the sewing machine, take care about the posture of the worker.
(4) Install the drive unit correctly according to the instruction manual.

2-3 Wiring

(1) Never connect the plug for power supply until assembly is finished.
(2) Fix the connectors securely to the sewing machine head, motor, and electric apparatus.
(3) Do not apply excessive force to the connection cords.
(4) Connect the cords away from the driving parts.
(5) Place the ground wire securely to the designated position on the machine head.

2-4 Before operation

(1) Take care not to attach lubricant, silicone oil, and grease on the eyes or skin.

Keep them away from children.

(2) Be sure to fill or drop lubrication oil before operating the sewing machine. Use the Yamato SF oil as specified.
(3) Never put your hand under the needle or near the moving parts of the machine when turning on power supply switch.
(4) When operating a new sewing machine, make sure the rotating direction of pulley agrees with the rotating-direction mark.

2-5 During operation

(1) Be sure to operate the sewing machine with the safeguards such as belt cover, finger guard, and eye guard.
(2) Never place the finger, hair or objects under the needle or close to the moving parts while operating the sewing machine.
(3) Be sure to turn off the power supply switch when threading or replacing the needles.
(4) Never place your hands close to the knives when operating the sewing machine with the trimming devices.
(5) Be sure to turn off the power supply switch when terminating the sewing work or leaving the sewing machine.
(6) If the sewing machine malfunctions, abnormal sound or smell something unusual while operating, be sure to turn off the power supply switch.

2-6 Removal

(1) Turn off the power supply switch if removed or replaced any parts or during adjustment of sewing machine.
(2) Do not pull the cord when removing the plug. Be sure to hold the plug itself.
(3) A high voltage is applied inside the control box. Turn off the power supply switch and wait more than 5 minutes before opening the cover.

3. Maintenance, inspection, and repair

(1) Follow the instruction manuals for maintenance, inspection, and repair.
(2) Entrust the maintenance, inspection, and repair to specially trained personnel.
(3) Be sure to turn off the power supply switch and make sure the sewing machine and motor completely stop before the maintenance, inspection, and repair. (If using a clutch motor, take care that the motor keeps turning for a while even after turning off the power supply switch.)
(4) Do not modify the sewing machine by the customer's judgment.
(5) Be sure to use original replacement parts for repairs or maintenance.

4. Caution signs and alert pictorial markings

This instruction manual contains the following caution signs and alert pictorial markings to prevent you from injuring yourself or the sewing machine from being damaged.

Please follow the instructions.

4-1 Meanings of caution signs

WARNING indicates potentially hazardous situations which, if not heeded, could result in death or serious injury to you and others.

Caution indicates hazardous situations which, if not heeded, may result in minor or moderate injury to you and others, or may result in machine damage.

NOTE is used to emphasize essential information.

4-2 Alert pictorial markings

This mark indicates the warning which, if not heeded, could result in death or Serious injury.

This mark indicates the caution for high temperature.

This mark indicates the warning which, if not heeded, could result in death or Serious injury.

High-voltage applies in the control box. This label indicates that electric shock may be caused.

This mark indicates the caution which, if not grounded, the machine or device could malfunction and could result in personal injury.

5. Warning labels on sewing machines

Warning panel with safety symbols and numbered instructions for lighting or repair techniques

This label indicates that removal of the safeguards and works except for sewing performance while the power supply switch is on are prohibited. (For details, see the next page.)

このカバーを開けるときは、電源スイッチを切った後、5分たってから開けること。

To open this cover, turn off power supply and wait more than 5 minutes before opening.

High-voltage applies in the control box. This label indicates that electric shock may be caused.

This label is affixed on the safeguards. Considering the operation, it is not affixed on the finger guard and eye guard. Be sure to operate with the finger guard and eye guard in position.

高温注意 CAUTION

Stepping motor and solenoid may overheat if used continuously. To prevent a burn, take care not to touch.

If not connected earth line, static electricity may be generated and inflict injury on person. In addition, the malfunction of electric system may cause injury to person.

Two black arrows pointing in opposite directions: one curved and one upward, with no text or symbols present.

Check the rotating direction of machine pulley agrees with 'ROTATING-DIRECTION SYMBOL'.

ケガ注意 CAUTION ↑ ケガ注意 CAUTION

6. Handling the machine

When handling the machine, do not carry the cloth plate cover.

Illustration of a hand operating a mechanical device with a tool, no text or symbols present

Illustration of a hand operating a small mechanical device with a circular inset showing a ring (no text or symbols)

1. Name of each part

Oil cap OIL-IN Presser foot release lever Cloth plate Thread tension spring cap SP device Eye guard Front cover Finger guard Oil reservoir Screw for draining oil Presser foot

Fig. 1

2.1 Semi-submerged type

2.1.1 Table cutting diagram

4-Ø 16 16 4-Ø 9 Section X - X 3- Ø9.5 Installing hole for motor (281) Center of machine pulley 75 Ø 16 75 317 C D 98 35 260 R20 R10 R5 R10 R10 Y 32 156 32 50 181 190 40 R20 R5 R20 R5 47 R10 (194) 104 102 61 R10 Z R10 Z 28 15 104 165 330 343 287 4-R20 Refer to the instruction manual of the motor for dimensions A, B, C, and D. Section Y - Y 50 5 50 operator

Fig. 2

2.1.2 Installation

Install a machine correctly referring to Fig. 3 and 4.

③ machine table ④ supporting board ⑤ supporting board rubber cushion ⑥ chute (upper) support ⑦ chute

Fig. 3

① ② ③ rubber cushion ④

Fig. 4

Table 1 The number of spacers ① and ②

Thickness of table	pcs. of 1	pcs. of 2
40mm	4	4
45mm	4	not necessary

Size of spacers: ①=15 mm ②=5 mm

2.2 Fully-submerged type

2.2.1 Table cutting diagram

(installing hole 3-ø9.5 for motor) 0.5(clearance) 211 260 40 75 ø16 250 B A (281) 75 E G H C D center of machine pulley I R10 80 106 156 E T1 G H 30 40 30 95.5 223 R10 R20 R30 R60 R90 (32) J (176) 147 276 183 70 (407) 28 (80) 32 K R90 R60 96 63 0.5(clearance) 0.5(clearance) 494 198 520 287 448 327 auxiliary table operator

Refer to the instruction manual
of the motor for dimensions A,
B, C, and D.

Section E-E Section I - I r' - r' View F Section J-J auxiliary table auxiliary table Section G - G G' - G' Section K - K K' - K' drilling φ30 60 10 39 39 16 R95 R95 9.5 2.5 19 (25) 16 9 (20) 30 10

Fig. 5

Cutting diagram of auxiliary table

79 223.5 80 227 58.5 25 K' 150 (277.5) 447 133.5 90 X R10 24 R10 I' X R20 I' R20 303 110 G' G' 25 R10 70 190 W

auxiliary table 60 16 Section X - X

R9.5 R9.5 2.5 19 9.5 View W

Fig. 6

2.2.2 Table cutting diagram for fully-submerged type with a device

To set up the machine with a device, install the device with below dimensions referring to "2.2.1 Table cutting diagram" (Fig. 5 and 6).

R20 44 48

AZ7500G-8 class with K1 device

275 22 68 25.5

AZ7000G-8 class with K2 device

27 R10 R10 R10 52 10 19 24 51

AZ7000G-8, AZ7500G-8 classes with MT22 device

R10 27 49 R20 19 44 51 R10 52

AZ7000G-8, AZ7500G-8 classes with MU44, 45 device

R20 R60 R30 R90 160 R90 R60 180 R90 96

Using a servomotor
Fig. 7

2.2.3 Installation

Install the machine correctly by referring to Fig. 8 and 9.

Adjust the position of supporting board so that the machine can be set horizontally and the cloth plate can be set on the same height or a little higher than the machine table.

supporting board connector
④ supporting board rubber cushion

2.3 Motor, belt and pulley

See the instruction manual for the motor to use and install the motor properly.

To install the clutch motor, align the center of the machine pulley with that of the motor pulley when the motor pulley shifts to the left by toeing down the pedal.

NOTE: Table 2 shows the outside diameter of the motor pulley, rpm of the machine, and size of the belt when using the clutch motor of 3-phase, 2-pole, 400W(1/2HP).

The outside diameter on the table shows the nearest size to the calculated values based on the commercial pulleys at intervals of 5 mm.

CAUTION

Use only those motor pulleys applicable to the machine. If not, the sewing speed will be over maximum and the machine will be damaged.

Servomotor:

Calculate the outside diameter of a motor pulley from the formula as below.

Or see Table 3 to select a proper motor pulley.

$$ \begin{array}{l} \text { Outside diameter } \ \text { of motor pulley } \end{array} = \frac {\text { Usual sewing speed }}{\text { Servomotor speed }} \times 4 8. 5 + 5 \mathrm{mm} $$

48.5mm 40° 5.5mm 10mm V-belt of M-type

Fig. 10

Outside diameter of pulley (mm)	rpm of machine		Size of belt
	50Hz	60Hz	Semi-submerged	Fully-submerged
90		6000	M34	M29
95		6400	M34	M30
100		6700	M35	M30
105	5900	7000	M35	M30
110	6200		M35	M31
115	6500		M36	M31
120	6700		M36	M32
125	6850		M37	M32
130	7000		M37	M32

Table 2

rpm of machine(rpm)	Outside diameterof motor pulley (mm)
	rpm of servomotor
	3000 rpm	3600 rpm
6000	102	86
6200	105	89
6500	110	93
6700	113	95
7000	118	99

Table 3

2.4 Hanging belt

WARNING

Before hanging belt, ALWAYS turn the motor switch OFF and check that the motor has already stopped.

Use the V-belt of M-type.

(1) Hang the belt ① on the machine pulley ②, and then on the motor pulley ③ while rotating the machine pulley.
(2) Adjust the belt tension so that the belt has 10 - 20 mm slack when its center is pressed with 10 N (1.02 kgf).
(3) Lock the motor with the adjusting bar ④.

① ② 10 - 20 mm ③ ④

Fig. 11

2.5 Belt cover

WARNING

To prevent you from getting injured and a material from being caught by the belt, be sure to install the belt cover.

(1) Install the auxiliary belt cover⑤ as shown in the figure.
(2) Install the belt cover ⑥ as shown in the figure.

Technical diagram of a mechanical assembly with numbered components and labeled parts

Fig. 12

2.6 Eye guard and finger guard

To ensure safe use, ALWAYS install the eye guard ⑦ and the finger guard ⑧ on the prescribed position during operation.

Technical line drawing of a mechanical assembly with no visible text or symbols

Fig. 13

Technical line drawing of a mechanical assembly with no visible text or symbols

Fig. 14

3. Sewing speed and rotating direction of pulley

Table 4 shows the maximum sewing speed of each model. Run a new machine at 15 - 20% lower rotating speed of its maximum rpm during the first 200 hours (for about one month) so that the machine can offer a long service life in good condition.

The rotating direction of the motor pulley ① and the machine pulley ② is clockwise as shown in the figure.

CAUTION

If rotating in reverse direction, oil can not be supplied properly, and the machine can be damaged.

Technical diagram of a mechanical device with labeled parts and directional arrows indicating motion or force

Fig. 15

Model	Max. sewing speed (rpm)
AZ7000G-8 class	7000
AZ7120G-8, AZ7125G-8	6500
AZ7500G-8 class	7000

Table 4

4.1 Lubricating oil

Use YAMATO SF OIL No. 28.

CAUTION

NEVER add additives to the oil. If added, it can cause the deterioration of the oil and the damage to the machine.

4.2 Lubricating

When using a new machine or a machine which has not been run for a while, supply a few drops of oil to the needle bar① and the looper bar ②.

Remove the oil cap ③ indicated “OIL-IN” and supply oil to the upper line of the oil sight gauge ④.

Make sure that the oil splashes from the nozzle inside the oil cap ③ when running the machine.

If oil does not splash from the nozzle, see "4.4 Checking and replacing oil filter" on page 12.

CAUTION

Too much oil or insufficient oil can cause oil leakage and machine trouble. Be sure to keep the oil level between the lines. Also too much lubrication can cause oil scatter and material stain.

SF OIL ④

Fig. 18

G_{Ax} ①

Fig. 16

Technical diagram of a mechanical clamp or bracket assembly with labeled parts and directional arrow

Fig. 17

Technical diagram showing mechanical components with numbered labels and annotations

Fig. 19

4.3 Changing oil

Period :

When using a new machine, change the lubricating oil after running the machine for 200 hours (for about one month). After that, change the oil once or twice a year.

Procedure :

(1) Remove the belt cover. (See page 9)
(2) Remove V-belt from the motor pulley. (See page 9)
(3) Remove the machine from the machine table.
(4) Set a container under the screw ① to receive the oil.
(5) After removing screw①, the oil will drain out.

NOTE

Be careful not to soil the V-belt and the machine pulley with the oil.

(6) Reset the screw ①.
(7) Change the oil. (See "4.2 Lubrication" on page 11)
(8) Reinstall the machine on the machine table.
(9) Hang the V-belt on the motor pulley and reinstall the belt cover. (See page 9)

Technical diagram showing a mechanical device with labeled component '①' and a pipe pouring into a container.

Fig. 20

4.4 Checking and replacing oil filter

◆ If the oil filter② is clogged with dust, lubrication cannot be done properly.
◆ Remove the oil filter cap ③ and the oil filter ② to check them every six months. If clogged or cracked, clean or replace the oil filter.
◆ If the oil splashes from the nozzle insufficiently or includes many bubbles even though oil is sufficiently kept, check or replace the oil filter.

NOTE

Be careful the oil may spill out from the oil filter ②, when loosening the screw ④.

Technical diagram of a mechanical assembly with numbered components, likely illustrating a gear or cam mechanism.

Fig. 21

5. Proper operation

5.1 Needle system

AZ7000G-8 class : DC × 1(or 81 × 1)

AZ7500G-8 class : DC × 27(or B27, 1886)

Select a proper needle in size according to the thickness and the type of the material.

Japanese standard	8	9	10	11	12	13	14
Metric standard	60	65	70	75	80	85	90

Table 5

5.2 Installing needles

WARNING

Before installing the needles, ALWAYS turn the motor switch OFF and check that the motor has already stopped.

(1) Loosen the screw① with a screw driver. (Fig. 22)

(2) Remove the old needle with a pair of tweezers.

(3) Insert a new needle into the needle clamp ② as far as it will go with facing its scarf to the right back. (Fig. 23 and 24)

(4) Tighten the screw① with the screw driver.

● Accessories include the screw driver.

NOTE

Tighten the screws ① with a tightening torque of 0.6 N·m (6 kgf·cm).

AZ7020G-8 AZ7500G-8 ① ② ① front

Fig. 22

NO × OK! ○ NO ×

Fig. 23

OK! NO

Fig. 24

5.3 Adjusting thread tension

Adjust the thread tension with the thread tension spring caps ① - ⑥ according to the type of fabric, the type of thread, seam width, stitch length, and other sewing conditions.

● To tighten the thread tension, turn caps clockwise.
- To loosen the thread tension, turn caps counterclockwise.

Thread\Model	AZ7000G-8 single needle overlock	AZ7020G-8 2-needle overlock	AZ7500G-8 2-needle safety stitch	AZ7520G-8 3-needle safety stitch
Left needle	1	1	1	1
Right needle		2		2
Double chain needle thread			2	3
Upper looper thread	3	3	3	4
Lower looper thread	4	4	4	5
Double chain looper thread			6	6

Table 6

① ② ③ ④ Tighten Loosen

Fig. 25 AZ7020G-8, AZ7500G-8

① ② ③ ④ ⑤ Tighten Loosen

Fig. 26 AZ7520G-8

Threading

WARNING

Before threading, ALWAYS turn the motor switch OFF and check that the motor has already stopped.

Threading correctly by referring to the threading figure which has been attached onto the back of the front cover.

CAUTION

Improper threading can cause thread breakage, skip stitch, and uneven stitch.

Loosen 6 Tighten Open the cloth plate

Fig. 27 AZ7500G-8, AZ7520G-8

5.4 Pressure of presser foot

Loosen the lock nut① and adjust the pressure of the presser foot by turning the adjusting screw②.

●To increase the pressure, turn the adjusting screw clockwise.
●To decrease the pressure, turn the adjusting screw counterclockwise.

Keep the pressure as low as possible for stable stitching.

Diagram illustrating the oil-in fuel system with labeled components: Increase, Decrease, and OIL-IN valve

Fig. 28

5.5 Releasing presser foot

WARNING

Before adjusting, ALWAYS turn the motor switch OFF and check that the motor has already stopped.

Rotate the machine pulley and position the needle at the highest point. Release the presser foot to the left while pressing the presser foot release lever ③.

To set the presser foot, slide and press the presser foot to the right while pressing the presser foot release lever ③. Then, release the lever.

Technical diagram of a mechanical assembly with numbered parts and directional arrows indicating motion or force

Fig. 29

WARNING

Make sure that the presser arm ④ gets into the groove of the presser bar ⑤.

If not, it can cause breakage to parts and injury to person.

5.6 Opening cover

Front cover ①

To open the front cover ①, slide it to the right and tilt toward you.

For closing, stand the cover. The spring tension makes it slide to the left.

Cloth plate②

To open the cloth plate②, shift it to the left while pressing the lever ③.

For closing, shift it to the right. Make sure that it has been locked securely.

Technical diagram showing hands operating a sewing machine with labeled parts and directional arrows indicating process flow.

Fig. 30

5.7 Adjusting differential feed dog

(1) Loosen the lock nut ④.
(2) For gathering sewing, lower the differential feed lever.
(3) For stretching sewing, raise the differential feed lever.

For fine adjustment of the lever ⑤, turn the screw ⑥.

● To lower the lever, turn the screw clockwise.
● To raise the lever, turn the screw counterclockwise.

Differential ratios up to 1:0.6 - 1:2 and 1:1 - 1:3 are available by adjusting internal mechanism.

Table 7 shows the differential ratios and maximum stitch length on each graduation.

④ ⑤ ⑥ S 1 2 3

Fig. 31

Graduation\Model	AZ7000G-8AZ7500G-8 classes
	Differential ratio	Max. stitch length (mm)
S	1:0.7	4
1	1:1	4
2	1:1.6	4
3	1:2.3	3

Table 7

5.8 Adjusting stitch length

WARNING

Before adjusting, ALWAYS turn the motor switch OFF and check that the motor has already stopped.

Each graduation on the machine pulley indicates the length( mm ) for one stitch.

Actual stitch length may different from the length on graduation. It may changes depending on the application, type, weight of material or the differential ratio.

(1) Rotate the pulley while pressing the push button ①. At the point that the push button can go in, press it again strongly.
(2) Then align the desired graduation of the pulley with the mark ② on the belt cover.
(3) Release the push button ①.

● To make stitch length smaller, turn the pulley in the direction "S".
● To make stitch length greater, turn it in the direction "L".

CAUTION

Make sure that push button is released completely and the pulley rotates smoothly.

The stitch length is adjustable 1 - 4 mm.

Table 9 shows the number of stitches per inch (25.4 mm) and 30 mm converted stitch length.

Line drawing of a hand operating a mechanical device with a finger, showing no text or symbols

Fig. 32

Line drawing of a hand holding a mechanical component with a dial indicator (no text or symbols)

Fig. 33

Model	Stitch length (mm)
AZ7000G-8, AZ7500G-8 class(except for below)	1-4
AZ7016G-8	0.6-2

Table 8

Stitch length (mm)	Number of stitch (per 1 inch) (25.4 mm)	Number of stitch (per 30 mm)
1	25	30
2	12	15
3	8	10
4	6	7.5

Table 9

5.10 Cleaning the machine

WARNING

Before cleaning, ALWAYS turn the motor switch OFF and check that the motor has already stopped.

The sewing machine should be cleaned at the end of every working day.

Grooves of stitch plate and the area around feed dogs should be cleaned once a week.

CAUTION

Clogged dust can cause breakage to parts and oil leakage.

Checking at sewing factory (maintenance by technician)

Daily maintenance:

(1) Before operating, remove the machine cover and re-thread correctly. Make sure there is no slack. Check that the thread hanger is right above the spool seat discs of the thread stands (the thread stands should be fixed securely).
(2) Check the lubricant and silicone oil amount. Supply them if necessary.
(3) Check the order of threading.
(4) Check the bend of needles, damage to tips, and the setting positions respectively.
(5) Check the sharpness of knives.
(6) Check the stitches by sewing a test fabric.

◆ stitch length, differential feeding
◆ adjusting knives and thread tension

Weekly maintenance:

(1) On weekends, clean the machine carefully after removing the presser foot and the stitch plate.
(2) Check the tension of V-belt.
(3) Check and supply the lubricating oil.

Line drawing of a sewing machine with hands operating it (no text or symbols visible)

Fig. 36

6. Adjustment of sewing machine

WARNING

Before adjusting, ALWAYS turn the motor switch OFF and check that the motor has stopped.

6.1 Needle thread tension for overlock stitch

To set the standard position of needle thread eyelet①, position the center of the screw② with the marks③.

To set the standard position of the needle thread pull-off④, align the portion⑤ with the eye⑥ of the needle thread eyelet(right) when the needle thread pull-off④ comes to the extreme front.

Loosen the screw ⑦ to adjust it.

● To loosen the needle thread tension, move the needle thread eyelet and the needle thread pull-off in the direction "L".

● To tighten the needle thread tension, move them in the direction "T".

Technical diagram of a mechanical device with labeled parts and directional arrows indicating L and T directions.

Fig. 37

Technical diagram showing mechanical assembly with labeled parts and directional arrows

Fig. 38

6.2 Looper thread tension for overlock stitch

Technical diagram of a mechanical assembly with numbered components and directional arrows indicating motion or force directions.

Fig. 39

The standard position of each looper thread eyelet:

Upper looper supplementary thread eyelet①

Move it to the extreme left.

Looper thread eyelet(left)②

Position the part A horizontally.

Upper looper thread eyelet③

Move its left end to the mark ④.

Lower looper thread eyelet⑤

Position the center of the width B with the mark ⑥.

Looper thread pull-off ⑦

Move its right end to the mark ⑧.

Upper looper thread pull-off ⑨

Align the eye of the thread pull-off with the mark ⑩ when the lower looper moves to the extreme right.

Lower looper thread pull-off ⑪

Tighten it with the screw at the center of the slot.

● To tighten the thread tension, move each thread eyelet or thread pull-off in the direction “T”.

● To loosen the thread tension, move them in the direction “L”.

6.3 Needle thread tension for double chainstitch

◆ To set the standard position of the needle thread eyelet(left) (double chain)③, adjust the needle thread of double chain on a level with the eyelet(left)③ when the needle bar is at the highest point. Loosen the screw④ to adjust it.
◆ To set the standard position of the needle thread eyelet holder (double chain) ①, position the center of the slot in the center of the screw ②.
◆ To set the standard position of the needle thread eyelet(right) (double chain)⑦, align the portion⑥ with the eye⑧ at the most front position of the needle thread pull-off⑤ when the needle thread eyelet holder (double chain) and the needle thread pull-off are at the standard position.

Loosen the screw⑨ to adjust it.

• To loosen the needle thread tension, move the needle thread eyelet and the needle thread pull-off in the direction "L".
  ● To tighten the needle thread tension, move them in the direction “T”.

L T ④ ② L T ① ③ ⑨

Fig. 40

Technical diagram of mechanical assembly with numbered components and labeled parts

Fig. 41

6.4 Looper thread tension for double chainstitch

◆ Align the eye of the double chaining looper thread eyelet ③ with the surface② of the double chaining looper thread take-up ① when being a level with the straight line A. Position the thread retaining finger ④ 1 mm above the eye of the looper thread eyelet ③.
◆ To set the standard position of the double chaining looper thread eyelet ③, position the center of the slot in the center of the screw ⑤.
● To loosen looper the thread tension, move the looper thread eyelet in the direction “L”.
- To tighten the looper thread tension, move it in the direction "T".
◆ At the standard timing of the looper thread take-up, the looper thread take-up starts taking up the looper thread when the needle starts lowering from the highest point.

NOTE

Set the thread retaining finger in the center of double looper thread take-ups when tightening the screw of it.

① ② ③ ④ ⑤ T L 1 mm A

Fig. 42

6.5 Width of overedge seam

Before adjusting, set the edge of the upper knife ① 0 - 0.5 mm above the lower knife ②.

To make wide overedge seam:

(1) Loosen the screw ③ on the upper knife holder.
(2) Tighten the screw③ securely after moving the holder as desired in the direction “W”.
(3) Loosen the screw ④ on the lower knife holder.
(4) The lower knife② touches the upper knife① closely with its spring.
(5) Tighten the screw ④ securely.

To make narrow overedge seam:

(1) Loosen the screw ④.
(2) Tighten the screw ④ slightly after moving the holder as desired in the direction “N”.
(3) Loosen the screw ③.
(4) Tighten the screw③ with applying the upper knife① to the lower knife②.
(5) Loosen the screw ④.
(6) The lower knife ② touches the upper knife ① closely with its spring.
(7) Tighten the screw ④ securely.

NOTE

1. After changing the width of overedge seam, check the sharpness of the blades. (See "6.6.4 Sharpness of knives")
2. Use a stitch plate applicable to the width of overedge seam.
   Adjustable range of overedge seam is within ± 0.5 mm based on the value indicated the gauge respectively. However, stitch plate of AZ7120G-Y5-8 is an adjustable range 5 - 5.5mm.
3. Dust clogged at the connecting part of the upper knife holder changes the installing angle of the knives. It will make them cut badly. Be sure to clean the parts by loosening the screw ③.

① 0 - 0.5 mm ② stitch plate

Fig. 43

N W ① ② ③ ④

Fig. 44

6.6 Upper and lower knives

6.6.1 Height of lower knife

Loosen the screw② to install the edge of the lower knife① on a level with the top surface of the stitch plate or 0-0.3 mm lower than it.

0 - 0.3 mm ① ②

Fig. 45

6.6.2 Height of upper knife (flat type)

Loosen the screw ④ to make the engagement between the upper knife ③ and the lower knife ① to 0.5 - 1.0 mm when the upper knife is at the lowest point.

0.5 - 1.0 mm ① ③ ④

Fig. 46

6.6.3 Height of upper knife (angled type)

Loosen the screw ⑦ and apply the upper knife ⑤ to the stopper ⑥ fully. It makes the height automatically. Then tighten the screw ⑦ securely.

Technical diagram of a mechanical assembly with numbered parts labeled ⑤, ⑥, and ⑦

Fig. 47

6.6.4 Sharpness of knives

After adjusting the knives and the width of overedge seam, check the sharpness of the blades by setting a thread between the upper and the lower knives while rotating the machine pulley by hand.

thread

Fig. 48

6.6.5 Sharpening knives

If the lower knife cuts badly, re-sharpen it. (See Fig. 49)

The upper knife made of super hard alloy is unnecessary to re-sharpen for about one year and normal grinder is not useful for re-sharpening it.

Keep another upper knife for spare.

If needed, contact us directly or the dealer for re-sharpening it.

10° 55°

Fig. 49

6.7 Height of feed dogs

To set the standard position, set the tops of the main and differential feed dogs parallel to that of the stitch plate when the tops of the feed dogs are raised and even with that of the stitch plate.

Make the height between the top of the stitch plate and the rear side of the main feed dog ③ to 0.8 mm when the feed dog is at the highest point.

Install the auxiliary feed dog depending on the machine class as below.

AZ7000G-8 class (Refer to Table 10)

Install the auxiliary feed dog⑤ 0.5 mm lower than the main feed dog③ in the standard.

AZ7500G-8 class (Refer to Table 10)

Install the auxiliary feed dog⑤ even with the main feed dog ③.

Loosen the screws ②, ④, and ⑥ to adjust the differential feed dog ①, the main feed dog ③, and the auxiliary feed dog ⑤ respectively.

NOTE

1. Be sure to make no difference of installing height between the main feed dog ③ and the differential feed dog ①. If different, it can cause the unstable feeding and feed scratch mark.
2. For sewing heavy weight knitted fabric or the material having uneven thickness parts, adjust differential feed dog ① and main feed dog ③ 1.0 mm higher than standard position respectively.

Difference between main feed dog and auxiliary feed dog

Model	Difference (mm)
AZ7000G-8 class(excluded below)	0.5(lower than the main feed dog)
AZ7016G-8	0
AZ7500G-8 class	0

Table 10

0.8 mm ③ ① stitch plate

Fig. 50

Technical diagram of a mechanical assembly with numbered components, likely a valve or connector assembly.

Fig. 51 AZ7000G-8 class

Technical diagram of a mechanical assembly with numbered components, likely a valve or connector assembly.

Fig. 52 AZ7500G-8 class

6.8 Tilt of feed dog

Remove the tail cover ① to loosen the screw ②. Move the feed bar block(rear) lid ③ to adjust it.

● To tilt the feed dog forward down, move it up.
● To tilt the feed dog forward up, move it down.

Technical line drawing of a mechanical assembly with no visible text or symbols

Fig. 53

② tilt forward down ③ tilt forward up

Fig. 54

6.9 Needles and loopers

Make adjustment by following the steps below:

In case of 2-needle overlock machines and 3-needle safety stitch machines

(1) Height of needle
(2) Installation angle of lower looper
(3) Fix the distance between needle and lower looper, the front-and-rear position of lower looper temporarily
(4) Parallel of needles
(5) Front-and-rear position of upper looper
(6) Distance between needle and upper looper
(7) Front-and-rear position of lower looper
(8) Distance between needle and lower looper
(9) Relation between lower looper and upper looper

In case of 1-needle overlock machines and 2-needle safety stitch machines

(1) Height of needle
(2) Front-and-rear position of upper looper
(3) Distance between needle and upper looper
(4) Installation angle of lower looper
(5) Front-and-rear position of lower looper
(6) Distance between needle and lower looper
(7) Relation between upper looper and lower looper

6.9.1 Height of needle

(1) Loosen the screws ① to remove the logo plate ②. (Fig. 55)
(2) Remove the screw ③.
(3) Rotate the machine pulley to raise the needle bar at the highest point.
(4) Loosen the screw④ and adjust the needle bar while moving it up and down.

When the needle bar is at the highest point, make the height "N" from the top of the stitch plate to the needle tip in Table 11.

② ① ③ ④

Fig. 55

Model	Height of Needle “N” (mm)	Fig.
AZ7000G-8 class	10.0 - 10.3	56-1
AZ7020G-8 class	10.0 - 10.3	56-2
AZ7120G-8 class	10.7 - 11.0
AZ7500G-8 class	10.0 - 10.3	56-3
AZ7520G-8 class	10.0 - 10.3	56-4

Table 11

NOTE

1. Tighten the screw ④ with a tightening torque of 1.5 N·m (15 kgf·cm).

2. Check the parallel setting of the needles for 2-needle machine and 3-needle machine. (See "6.9.4 Front-and-rear position of lower looper")

3. Apply the liquid packing to the thread of the screw when tightening it.

6.9.2 Installing angle of lower looper

The standard installation angle of lower looper① is value A in Table 12.
Make adjustment by loosening the screw② to make the height difference between the rear and the tip of the lower looper to value B in Table 12. (Fig. 57)

Model	A	B
2-needle overlock machines (AZ7020G-8 class, AZ7120G-8 class)3-needle safty stitch machines (AZ7520G-8 class)	2-4°	0.5-1.5mm
1-needle overlock machines (AZ7000G-8 class)2-needle safe stitch machines (AZ7500G-8 class)	2-3°	0.5-1.0mm

Table 12

6.9.3 Distance between needle and lower looper

Rotate the machine pulley clockwise and move the lower looper ① to the extreme left. Make the distance between the lower looper tip and the center of the needle to 3.3 - 3.8 mm.

Loosen the screw③ on the lower looper holder to adjust it.

N

AZ7000G-8 class single needle

Fig. 56-1

AZ7020G-8 class AZ7120G-8 class 2-needle

Fig. 56-2

Diagram showing a 3D object with labeled dimension 'N' and surrounding geometric shapes, likely illustrating a physics or engineering concept.

AZ7500G-8 class

Fig. 56-3

N

AZ7520G-8 class

Fig. 56-4

A B ①

Fig. 57

① 3.3 - 3.8 mm ② ③ 3.3 - 3.8 mm

Fig. 58

6.9.4 Front-and-rear position of lower looper

Single needle overlock stitch on AZ7000G-8 and AZ7500G-8 classes:

Loosen the screw③ to make the clearance between the lower looper tip and the needle to 0 - 0.05 mm.

2-needle overlock stitch on AZ7020G-8 and AZ7520G-8 classes:

(1) Loosen the screw③ to make the clearance between the lower looper tip and the left needle to 0—0.05 mm while loosening the screw③.
(2) Make sure that the clearance between the right needle and the lower looper is between 0 - 0.05 mm.

0 - 0.05 mm

Fig. 59

0 - 0.05 mm needles

Fig. 60

6.9.5 Parallel of needles

Loosen the screw ① and make adjustment by turning the needle clamp slightly. Make the clearance the same as the left needle to 0 - 0.05 mm when the right needle meets the lower looper.

Also, refer to "6.9.1 Height of needle" on page 29.

NOTE

Tighten the screw ④ after checking the height of needle. After adjusting the front-and-rear position of the lower looper, be sure to check the distance between the needle and the lower looper and tighten the screw ③ in Fig. 58.

G-AX ④

Fig. 61

6.9.6 Distance between needle and upper looper

Rotate the machine pulley clockwise and move the upper looper to the extreme left. Make the distance "U" between the upper looper tip and the center of the needle in Table 12.

(1) Remove the thread eyelet support, the looper thread eyelet, and the looper holder cover.
(2) Loosen the screw② of the upper looper bar crank arm to adjust it.

Model	Distance between needle and upper looper “U”
AZ7000G-8 classAZ7500G-8 class	4.7-5.2
AZ7120G-8, AZ7125G-8	5.0-5.5

Table 13

CAUTION

Apply the liquid packing to the mounting part of the frame when installing the looper holder cover. If not applied, it can cause oil leakage.

6.9.7 Front-and-rear position of upper looper

The thick portion (around eye) of the upper looper closes to the needle when the upper looper moves from the extreme left to the right while rotating the machine pulley clockwise. (On 2-needle machine, it closes to the right needle.)

Loosen the screw③ to make the clearance between the back side of the upper looper ① and the needle to 0.05 - 0.1 mm.

U ① ②

Fig. 62

0.05~ 0.1 mm ① ③ ①

Fig. 63

6.9.8 Timing between lower looper and upper looper

Make sure that the clearance between the back and forth is 0.05 - 0.1 mm and between the right and left is 0.05 - 0.3 mm when the lower looper① meets the upper looper② while rotating the machine pulley clockwise.

Be sure to let clearances between the above mentioned ranges.

0.05 - 0.1 mm 0.05 - 0.3 mm ① ②

Fig. 64

6.10 Needle and double chaining looper

Timing:

To set the height, insert the double chaining looper ③ into the looper holder until it touches the bottom of the holder.

Make the distance between the center of the double chaining needle④ and the double chaining looper tip to 2.0—2.2 mm when the double chaining looper ③ is at the extreme left. Loosen the screw⑤ to make adjustment.

Tighten the screw ⑥ slightly, and make it have an approximately 6^ angle to the looper. Adjust the distance so that the looper tip can touch the double chain needle ④ slightly.

Front-and-rear position:

Make the looper ③ tip pass the back of the needle and keep them as close as possible without touching each other.

Make the needle pass the back of the curved portion of the looper and let them touch each other slightly when the looper moves from the right to the left.

④ ③ ⑥ 2.0 - 2.2 mm ⑤

Fig. 65

Diagram illustrating a mechanical or fluidic device with labeled components and directional arrows, including a magnified inset showing a small object.

Fig. 66

about 6° 1.6 - 1.8 mm

Fig. 67

6.11 Needle and needle guards for AZ7000G-8 class

6.11.1 Needle and needle guard(rear)

This machine is equipped with the movable needle guard(rear) ① which is interlocked with the lower looper.

The needle guard(rear) ① holds the needle from the rear and protect the lower looper tip when the needle meets the lower looper tip during upward movement process from the lowest point.

Loosen the screw② to make the clearance between the lower looper tip and the needle to 0 - 0.05 mm.

In case of 2-needle machine, make adjustment based on the left needle in the same way as single needle machine.

0 - 0.05 mm ① ②

Fig. 68

6.11.2 Needle and needle guard(front)

Loosen the screw ④ to make the clearance between the needle guard(front) ③ and the needle to 0.02-0.05 mm.

In case of 2-needle machine, make adjustment based on the left needle in the same way as single needle machine.

0.02 - 0.05 mm ③ ④

Fig. 69

6.12 Needle and needle guards for AZ7500G-8 class

6.12.1 Needle and needle guard(rear)

This machine is equipped with the movable needle guard(rear) ① which is interlocked with the lower looper.

The needle guard(rear) ① holds the needle from the rear and protecting the lower looper tip when the needle meets the lower looper tip during upward movement process from the lowest point.

Loosen the screw② to make the clearance between the lower looper tip and the needle to 0 - 0.05 mm.

In case of 3-needle safety stitch machine, make adjustment based on the left needle for the overlock seam's needles in the same way as 2-needle overlock machine.

6.12.2 Needle and needle guard(front)

Loosen the screw ④ to make the clearance between the needle and the needle guard(front) ③ to 0.02 - 0.05 mm.

In case of 3-needle safety stitch machine, adjust it based on the left needle for the overlock seam's needles in the same way as 2-needle overlock machine.

6.12.3 Needle and needle guards for double chainstitch

Needle guard(rear) (double chain stitch):

Loosen the screw ⑥ to make the clearance between the needle and the needle guard(rear) ⑤ to 0 - 0.05 mm at the lowest point of the needle.

Needle guard(front) (double chain stitch):

Loosen the screw ⑧ to make the clearance between the needle and the needle guard(front) ⑦ to 0.1 - 0.2 mm.

0 - 0.05 mm ① ②

Fig. 70

0.02 - 0.05 mm ③ ④

Fig. 71

0 - 0.05 mm 0.1 - 0.2 mm

Fig. 73

6.13 Position of presser foot

Install the bottom surface of the presser foot parallel to the stitch plate when viewing from the front.

Slanted presser foot can cause feed scratch mark.

To set front-and-rear position, adjust the clearance between needle drop of the presser foot and that of the stitch plate to 0.2 - 0.3 mm as shown in Fig. 73.

Loosen the screw ① to make adjustment.

① 0.2-0.3 mm

Fig. 73

7.1 Outline

SC10 is a self-cleaning system that can keep a clean and comfortable environment for operators.

It eliminates clogged dust around the lower knife holder and under the stitch plate by cutting material during the sewing. And also makes maintenance easily and prevents troubles caused by the lint.

to lint collecting device air flow

Fig. 74

7.2 Adjusting ventilating amount

Select the type of setting by changing the position of the air deflector① depending on the sewing speed and sewing condition.

To set the standard position, insert the air deflector① into the guides ② and ③. (See Fig. 75)

For high speed and less dust during sewing, insert the air deflector ① into the guides ② and ④. (See Fig. 76)

When not using SC10 device, remove the air deflector ①.

① ② ③ standard setting

Fig. 75

Technical diagram of a mechanical assembly with numbered components and directional arrows indicating movement or force.

Fig. 76

7.3 Installation

7.3.1 Installing air deflector

(1) Drain the oil from the machine.
(2) Tilt the machine backward.
(3) Loosen two screws ④ and remove the wind guide plate ②.
(4) Install the air deflector ③ into the guides ⑤ of the oil reservoir ① securely.
(5) Reinstall the wind guide plate ②.
(6) Raise the machine upright and supply the oil.

Technical diagram of an automotive component with numbered parts for identification

Fig. 77

Technical diagram of a mechanical linkage system with labeled components and motion indicators

Fig. 78

7.3.2 Installing blowing hole screen

(1) Install the blowing hole screen ⑥ on the oil reservoir ①.
(2) Install the wind guide plate(front) ⑦ on the oil reservoir ① while pressing the blowing hole screen ⑥ with two screws ⑧.

Technical diagram of a mechanical assembly with numbered components and dashed lines indicating alignment or assembly steps.

Fig. 79

7.3.3 Installing lint removal pipe

(1) Put two pipe clamps ② to the lint removal pipe ①.
(2) Install the lint removal pipe① and the pipe clamps② on the machine frame with two screws③.
(3) Connect the lint removal pipe① to the pipe from the lint collecting device.

CAUTION

Suction will be insufficient if connecting another device to one lint collecting device for SC10. When using ventilation, air pressure should be 0.2 Mpa (2 kgf/cm²) or more.

Technical diagram showing mechanical assembly with numbered components and alignment lines

Fig. 80

8.1 AZ7000G-8 class

Model	AZ7000G-8 classAZ7020G-8 class	AZ7120G-8 class
Dimensions	380 (L) ×245 (W) ×310 (H) mm
Weight	26.5 kg
Construction	Dust-proof, Oil-tight and completely sealed
Stitch Type	ISO: 504, 505, 514	ISO: 514
Application	Overlock chain stitch for knitted or woven farics
Sewing Speed	up to 7000 rpm	up to 6500 rpm
Stitch LengthNumber of stitchesper inch(25.4 mm)per 30 mm	1.0-4.0 mm6.5-25 stitches7.5-30 stitches
Needle System	DC×1 Size#8~#14(60~90)
Needle Stroke	23.7 mm	24.7 mm
Presser Foot Lift	6.0 mm
Feed Regulation	Push button system
Differential Ratio	Max. Normal Differential (Gathering) 1:2.3
	Max. Reverse Differential (Stretching) 1:0.7(Available up to 1:0.6 by adjusting the position of the lever pin.)
Differential Feed Regulation	Adjustable by moving external lever even during operation
Knives for Fabric Cutting	Lower Knife : flat type, made of special steelUpper Knife : flat or angled type, made of super hard alloy
Lubricating Oil	YAMATO SF OIL No.28
Capacity of Oil Reservoir	900 cc
Lubrication	Forcedly by trochoid shaped pump
Installation	Semi-submerged type or fully-submerged type

Model	Presser Foot Lift (mm)
AZ7000G-8 class(except for below)	6.0
AZ7016G-8	5.0

Table 14

8.2 AZ7500G-8 class

Model	AZ7500G-8 class(excluded right models)	AZ7520G-8/AZ7525G-8
Dimensions	380 (L) ×245 (W) ×310 (H) mm
Weight	27 kg
Construction	Dust-proof, Oil-tight and completely sealed
Stitch Type	ISO: (504·401)	ISO: (514·405)
Application	Safety stitch for knitted or woven fabrics
Sewing Speed	up to 7000 rpm
Stitch LengthNumber of stitchesper inch(25.4 mm)per 30 mm	1.0-4.0 mm6.5-25 stitches7.5-30 stitches
Needle System	DC×27 (for both sides of overlock stitch and double chainstitch)Size#8~#14(60~90)
Needle Storke	23.7 mm
Presser Foot Lift	up to 6.0 mm	up to 5.5 mm
Feed Regulation	Push button system
Differential Ratio	Max. Normal Differential (Gathering) 1:2.3
	Max. Reverse Differential (Stretching) 1:0.7(Available up to 1:0.6 by adjusting the position of the lever pin.)
Differential Feed Regulation	Adjustable by moving external lever even during operation
Knives for Fabric Cutting	Lower Knife : flat type, made of special steelUpper Knife : flat or angled type, made of super hard alloy
Lubricating Oil	YAMATO SF OIL No. 28
Capacity or Oil Reservoir	900 cc
Lubication	Forcedly by gear pump
Installation	Semi-submerged type or fully-submerged type

1jamato

ヤマトミシン製造株式会社

YAMATO SEWING MACHINE MFG. CO., LTD.

4-4-12, NISHITENMA, KITA-KU, OSAKA, JAPAN

TEL:[phone] FAX:[phone]

〒530-0047 大阪市北区西天満4丁目4番12号

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