DSU-145 - Sewing machine JUKI - Free user manual and instructions

Product Type	Cylinder-bed 1-needle, top & bottom feed lockstitch sewing machine (DSU-145); with automatic thread trimmer (DSU-145-7)
Maximum Sewing Speed	2,000 sti/min
Stitch Length Range	0 to 6 mm
Presser Foot Lift	Hand lifter: 7 mm (DSU-145) / 6 mm (DSU-145-7); Knee lifter: 15 mm (DSU-145) / 13 mm (DSU-145-7)
Needle Type	Groz-Beckert 135×17, Nm90 to Nm140 (standard Nm130)
Needle Bar Stroke	37 mm
Lubrication Method	Hand oiler; automatic oiling for hook section via plunger pump
Recommended Oil	Juki New Defrix Oil No.1
Motor	400W AC clutch (Electro-stop) or AC servo motor
Noise Level	77 dB(A) at 2,200 sti/min (DSU-145); 76.5 dB(A) at 2,000 sti/min (DSU-145-7)
Thread Take-up	Link type
Stitch Adjustment	Dial
Reverse Feed	Manual lever (DSU-145) or one-touch switch (DSU-145-7)
Thread Trimming	None (DSU-145) / Automatic (DSU-145-7)
Safety Features	Belt cover, finger guard, eye guard; requires proper grounding
Maintenance	Regular lubrication, clean air vent, use genuine Juki parts
Spare Parts Availability	Genuine Juki parts including needles, bobbin case, knives (for DSU-145-7)
Intended Use	Medium weight materials

Frequently Asked Questions - DSU-145 JUKI

How do I thread the machine head?

Thread the machine head in the order of 1 through 13 as shown in the manual (diagram 9). Ensure the thread passes through all guides, tension discs, take-up lever, and needle. Use the supplied thread guide for synthetic threads to prevent slipping.

How do I adjust the needle thread tension?

Turn the tension nut clockwise to increase tension, counterclockwise to decrease. Adjust so that the stitch is balanced. The bobbin thread tension is adjusted via the screw on the bobbin case.

How do I change the needle?

Turn off the power and handwheel to raise the needle bar to its highest position. Loosen the needle setscrew, insert a new needle (Groz-Beckert 135×17, Nm130 standard) with the long groove facing left, fully up, and tighten the screw.

How do I wind a bobbin?

Route the thread through A, B, C on the bobbin winder, then wind several turns around the bobbin. Set the bobbin presser down to engage. Adjust screw so the bobbin is wound about 80% full. The winder stops automatically when full.

How do I adjust the stitch length?

Turn the stitch length dial to the desired value (0 to 6 mm). The value appears at the top. For reverse stitching, push the feed lever down; the machine stitches reverse as long as held.

How do I engage reverse feed stitching?

On DSU-145, push the feed lever down. On DSU-145-7, press the one-touch switch. Release to resume forward stitching.

What oil should I use and how often?

Use Juki New Defrix Oil No.1. Check the oil reservoir; fill to H mark if below L. Oil points marked with arrows before each use, and adjust hook oil amount via the knob on the arm.

How do I clean and maintain the sewing machine?

Turn off power and unplug. Remove dust from the fan air vent and around wiring periodically. Clean the hook area and throat plate. Lubricate as specified. Use genuine parts for replacements.

Why is my thread breaking?

Common causes: scratches on needle/hook, excessive needle thread tension, incorrect needle-to-hook timing, inadequate hook lubrication, or weak bobbin case spring. Refer to the troubleshooting section in the manual.

How do I adjust the needle-to-hook timing?

First set needle bar height: lower needle bar fully and align its marker line with the bottom of the lower bushing, then tighten clamp screw. For timing, raise needle bar so marker aligns with bushing bottom again; adjust hook point to meet needle center at that moment, with 0.02-0.05 mm clearance.

USER MANUAL DSU-145 JUKI

NOTE : Read safety instructions carefully and understand them before using. Retain this Instruction Manual for future reference.

日本語

安全にご使用していただくために

(取り付け順序)

Technical line drawing of a sewing machine with visible wiring and mounting points (no text or labels)

Line drawing of a mechanical device with a dial and handle (no text or symbols)

● ミシンを運転される前に

● ボビンケースの取りはずし

● 上糸張力の調節

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

- 送り足の前後位置の調整

- 送り足と押え足の交互上下運動量

- 送り足の送り量調節

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

補助糸調子ナット①で調整します。

Mechanical assembly diagram showing hands operating a mechanical component (no text or symbols visible)

Mechanical assembly diagram showing a hand operating a bracket with no visible text or symbols

★スイッチの位置

★逆送りマグネットの位置

TO ENSURE SAFE USE OF YOUR SEWING MACHINE

For the sewing machine, automatic machine and ancillary devices (hereinafter collectively referred to as "machine"), it is inevitable to conduct sewing work near moving parts of the machine. This means that there is always a possibility of unintentionally coming in contact with the moving parts. Operators who actually operate the machine and maintenance personnel who are involved in maintenance and repair of the machine are strongly recommended to carefully read to fully understand the following SAFETY PRECAUTIONS before using/maintaining the machine. The content of the SAFETY PRECAUTIONS includes items which are not contained in the specifications of your product.

The risk indications are classified into the following three different categories to help understand the meaning of the labels. Be sure to fully understand the following description and strictly observe the instructions.

( I ) Explanation of risk levels

	DANGER:This indication is given where there is an immediate danger of death or serous injury if the person in charge or any third party mishandles the machine or does not avoid the dangerous situation when operating or maintaining the machine.
	WARNING:This indication is given where there is a potentiality for death or serious injury if the person in charge or any third party mishandles the machine or does not avoid the dangerous situation when operating or maintaining the machine.
	CAUTION:This indication is given where there is a danger of medium to minor injury if the person in charge or any third party mishandles the machine or does not avoid the dangerous situation when operating or maintaining the machine.
	Items requiring special attention.

(II) Explanation of pictorial warning indications and warning labels

Pictorial warning indication		There is a risk of injury if contact-ing a moving section.	Pictorial warning indication		Be aware that holding the sewing machine during operation can hurt your hands.
		There is a risk of electrical shock if contacting a high-voltage section.			There is a risk of entanglement in the belt resulting in injury.
		There is a risk of a burn if contact-ing a high-temperature section.			There is a risk of injury if you touch the button carrier.
		Be aware that eye deficiency can be caused by looking directly at the laser beam.	Indication label		The correct direction is indicated.
		There is a risk of contact between your head and the sewing ma-chine.			Connection of a earth cable is indicated.

1. When it is necessary to open the control box containing electrical parts, be sure to turn the power off and wait for five minutes or more before opening the cover in order to prevent accident leading to electrical shock.

CAUTION

Basic precaution

1. Be sure to read the instruction manual and other explanatory documents supplied with accessories of the machine before using the machine. Carefully keep the instruction manual and the explanatory documents at hand for quick reference.
2. The content of this section includes items which are not contained in the specifications of your product.
3. Be sure to wear safety goggles to protect against accident caused by needle breakage.
4. Those who use a heart pacer have to use the machine after consultation with a medical specialist.

Safety devices and warning labels

1. Be sure to operate the machine after verifying that safety device(s) is correctly installed in place and works normally in order to prevent accident caused by lack of the device(s).
2. If any of the safety devices is removed, be sure to replace it and verify that it works normally in order to prevent accident that can result in personal injury or death.
3. Be sure to keep the warning labels adhered on the machine clearly visible in order to prevent accident that can result in personal injury or death. If any of the labels has stained or come unstuck, be sure to change it with a new one.

Application and modification

1. Never use the machine for any application other than its intended one and in any manner other than that prescribed in the instruction manual in order to prevent accident that can result in personal injury or death. JUKI assumes no responsibility for damages or personal injury or death resulting from the use of the machine for any application other than the intended one.
2. Never modify and alter the machine in order to prevent accident that can result in personal injury or death. JUKI assumes no responsibility for damages or personal injury or death resulting from the machine which has been modified or altered.

Education and training

1. In order to prevent accident resulting from unfamiliarity with the machine, the machine has to be used only by the operator who has been trained/educated by the employer with respect to the machine operation and how to operate the machine with safety to acquire adequate knowledge and operation skill. To ensure the above, the employer has to establish an education/training plan for the operators and educate/train them beforehand.

Items for which the power to the machine has to be turned off

Turning the power off: Turning the power switch off, then removing the power plug from the outlet. This applies to the following.

1. Be sure to immediately turn the power off if any abnormality or failure is found or in the case of power failure in order to protect against accident that can result in personal injury or death.
2. To protect against accident resulting from abrupt start of the machine, be sure to carry out the following operations after turning the power off. For the machine incorporating a clutch motor, in particular, be sure to carry out the following operations after turning the power off and verifying that the machine stops completely.
   2-1. For example, threading the parts such as the needle, looper, spreader etc. which have to be threaded, or changing the bobbin.
   2-2. For example, changing or adjusting all component parts of the machine.
   2-3. For example, when inspecting, repairing or cleaning the machine or leaving the machine.
3. Be sure to remove the power plug by holding the plug section instead of the cord section in order to prevent electrical-shock, earth-leakage or fire accident.
4. Be sure to turn the power off whenever the machine is left unattended between works.
5. Be sure to turn the power off in the case of power failure in order to prevent accident resulting of breakage of electrical components.

PRECAUTIONS TO BE TAKEN IN VARIOUS OPERATION STAGES

Transportation

1. Be sure to lift and move the machine in a safe manner taking the machine weight in consideration. Refer to the text of the instruction manual for the mass of the machine.
2. Be sure to take sufficient safety measures to prevent falling or dropping before lifting or moving the machine in order to protect against accident that can result in personal injury or death.
3. Once the machine has been unpacked, never re-pack it for transportation to protect the machine against breakage resulting from unexpected accident or dropping.

Unpacking

1. Be sure to unpack the machine in the prescribed order in order to prevent accident that can result in personal injury or death. In the case the machine is crated, in particular, be sure to carefully check nails. The nails have to be removed.
2. Be sure to check the machine for the position of its center of gravity and take it out from the package carefully in order to prevent accident that can result in personal injury or death.

Installation

(I) Table and table stand

1. Be sure to use JUKI genuine table and table stand in order to prevent accident that can result in personal injury or death. If it is inevitable to use a table and table stand which are not JUKI genuine ones, select the table and table stand which are able to support the machine weight and reaction force during operation.
2. If casters are fitted to the table stand, be sure to use the casters with a locking mechanism and lock them to secure the machine during the operation, maintenance, inspection and repair in order to prevent accident that can result in personal injury or death.

(II) Cable and wiring

1. Be sure to prevent an extra force from being applied to the cable during the use in order to prevent electrical-shock, earth-leakage or fire accident. In addition, if it is necessary to cable near the operating section such as the V-belt, be sure to provide a space of 30 mm or more between the operating section and the cable.
2. Be sure to avoid starburst connection in order to prevent electrical-shock, earth-leakage or fire accident.
3. Be sure to securely connect the connectors in order to prevent electrical-shock, earth-leakage or fire accident. In addition, be sure to remove the connector while holding its connector section.

(III) Grounding

1. Be sure to have an electrical expert install an appropriate power plug in order to prevent accident caused by earth-leakage or dielectric strength voltage fault. In addition, be sure to connect the power plug to the grounded outlet without exceptions.
2. Be sure to ground the earth cable in order to prevent accident caused by earth leakage.

(IV) Motor

1. Be sure to use the specified rated motor (JUKI genuine product) in order to prevent accident caused by burnout.
2. If a commercially available clutch motor is used with the machine, be sure to select one with an entanglement preventive pulley cover in order to protect against being entangled by the V-belt.

Before operation

1. Be sure to make sure that the connectors and cables are free from damage, dropout and looseness before turning the power on in order to prevent accident resulting in personal injury or death.
2. Never put your hand into the moving sections of the machine in order to prevent accident that can result in personal injury or death. In addition, check to be sure that the direction of rotation of the pulley agrees with the arrow shown on pulley.
3. If the table stand with casters is used, be sure to secure the table stand by locking the casters or with adjusters, if provided, in order to protect against accident caused by abrupt start of the machine.

During operation

1. Be sure not to put your fingers, hair or clothing close to the moving sections such as the handwheel, hand pulley and motor or place something near those sections while the machine is in operation in order to prevent accident caused by entanglement that can result in personal injury or death.
2. Be sure not to place your fingers near the surround area of the needle or inside the thread take-up lever cover when turning the power on or while the machine is in operation in order to prevent accident that can result in personal injury or death.
3. The machine runs at a high speed. Never bring your hands near the moving sections such as looper, spreader, needle bar, hook and cloth trimming knife during operation in order to protect your hands against injury. In addition, be sure to turn the power off and check to be sure that the machine completely stops before changing the thread.

4. Be careful not to allow your fingers or any other parts of your body to be caught between the machine and table when removing the machine from or replacing it on the table in order to prevent accident that can result in personal injury or death.

5. Be sure to turn the power off and check to be sure that the machine and motor completely stop before removing the belt cover and V-belt in order to prevent accident caused by abrupt start of the machine or motor.

6. If a servomotor is used with the machine, the motor does not produce noise while the machine is at rest. Be sure not to forget to turn the power off in order to prevent accident caused by abrupt start of the motor.
7. Never use the machine with the cooling opening of the motor power box shielded in order to prevent fire accident by overheat.

Lubrication

1. Be sure to use JUKI genuine oil and JUKI genuine grease to the parts to be lubricated.
2. If the oil adheres on your eye or body, be sure to immediately wash it off in order to prevent inflammation or irritation.
3. If the oil is swallowed unintentionally, be sure to immediately consult a medical doctor in order to prevent diarrhea or vomiting.

Maintenance

1. In prevention of accident caused by unfamiliarity with the machine, repair and adjustment has to be carried out by a service technician who is thoroughly familiar with the machine within the scope defined in the instruction manual. Be sure to use JUKI genuine parts when replacing any of the machine parts. JUKI assumes no responsibility for any accident caused by improper repair or adjustment or the use of any part other than JUKI genuine one.
2. In prevention of accident caused by unfamiliarity with the machine or electrical-shock accident, be sure to ask an electrical technician of your company or JUKI or distributor in your area for repair and maintenance (including wiring) of electrical components.
3. When carrying out repair or maintenance of the machine which uses air-driven parts such as an air cylinder, be sure to remove the air supply pipe to expel air remaining in the machine beforehand, in order to prevent accident caused by abrupt start of the air-driven parts.
4. Be sure to check that screws and nuts are free from looseness after completion of repair, adjustment and part replacement.
5. Be sure to periodically clean up the machine during its duration of use. Be sure to turn the power off and verify that the machine and motor stop completely before cleaning the machine in order to prevent accident caused by abrupt start of the machine or motor.
6. Be sure to turn the power off and verify that the machine and motor stop completely before carrying out maintenance, inspection or repair of the machine. (For the machine with a clutch motor, the motor will keep running for a while by inertia even after turning the power off. So, be careful.)
7. If the machine cannot be normally operated after repair or adjustment, immediately stop operation and contact JUKI or the distributor in your area for repair in order to prevent accident that can result in personal injury or death.
8. If the fuse has blown, be sure to turn the power off and eliminate the cause of blowing of the fuse and replace the blown fuse with a new one in order to prevent accident that can result in personal injury or death.
9. Be sure to periodically clean up the air vent of the fan and inspect the area around the wiring in order to prevent fire accident of the motor.

Operating environment

1. Be sure to use the machine under the environment which is not affected by strong noise source (electromagnetic waves) such as a high-frequency welder in order to prevent accident caused by malfunction of the machine.
2. Never operate the machine in any place where the voltage fluctuates by more than "rated voltage ± 10% in order to prevent accident caused by malfunction of the machine.
3. Be sure to verify that the air-driven device such as an air cylinder operates at the specified air pressure before using it in order to prevent accident caused by malfunction of the machine.
4. To use the machine with safety, be sure to use it under the environment which satisfies the following conditions:

Ambient temperature during operation 5°C to 35°C Relative humidity during operation 35 % to 85 %

1. Dew condensation can occur if bringing the machine suddenly from a cold environment to a warm one. So, be sure to turn the power on after having waited for a sufficient period of time until there is no sign of water droplet in order to prevent accident caused by breakage or malfunction of the electrical components.

2. Be sure to stop operation when lightning flashes for the sake of safety and remove the power plug in order to prevent accident caused by breakage or malfunction of the electrical components.

3. Depending on the radio wave signal condition, the machine may generate noise in the TV or radio. If this occurs, use the TV or radio with kept well away from the machine.

4. In order to ensure the work environment, local laws and regulations in the country where the sewing machine is installed shall be followed. In the case the noise control is necessary, an ear protector or other protective gear should be worn according to the applicable laws and regulations.

5. Disposal of products and packages and treatment of used lubricating oil should be carried out properly according to the relevant laws of the country in which the sewing machine is used.

FOR SAFE OPERATION

1. To avoid personal injury, never put your fingers under the needle when you turn ON the power switch or operate the sewing machine.2. To avoid personal injury, never put your fingers into the thread take-up cover while the sewing machine is in operation.3. Turn OFF the power switch when tilting the machine head, or removing the belt cover or the V belts.4. To prevent possible personal injury caused by being caught in the machine, keep your fingers, head and clothes away from the handwheel and the thread take-up while the sewing machine is in operation. In addition, place nothing around it.5. Do not operate the sewing machine with the belt cover and the finger guard removed.6. Make sure that the head support rod is attached to the table before tilting the machine head so as to prevent the risk of pinching fingers under the machine head.

1. For the safety, never operate the sewing machine with the ground wire for the power supply removed.2. Be sure to turn OFF the power switch in prior when connecting/disconnecting the power plug.3. When thunders occurs, stop the work for the safety and disconnect the power plug.4. When the sewing machine is suddenly moved from a cold place to a warm place, there is a case where dew condensation may occur. Turn ON the power after there is no worry of the drop of water.5. To prevent fires, periodically draw out the power plug from the plug socket and clean the root of the pins and the space between pins.6. The hook rotates at a high speed while the machine is in operation.To prevent possible injury to hands, be sure to keep your hands away from the vicinity of the hook during operation. In addition, be sure to turn OFF the power to the machine when replacing the bobbin.7. To avoid possible accidents due to abrupt start of the machine, be sure to turn OFF the power to the machine.8. Be careful of handling this product so as not to pour water or oil, shock by dropping, and the like since this product is a precision instrument.9. When tilting or returning the sewing machine to the home position, hold the upper side of the machine head with both hands and perform the work quietly so that fingers or the like are not caught in the machine.

CAUTION : Note that safety devices such as “eye guard”, “finger guard”, etc. may be omitted from the illustrations in this Instruction Manual for easy explanation. When operating the machine, be sure not to remove these safety devices.

CAUTION : Check the following so as to prevent maloperation of and damage to the machine.

• Before you put the machine into operation for the first time after the set-up, clean it thoroughly. Remove all dust gathering during transportation and oil it well.
• Confirm that voltage has been correctly set. Confirm that the power plug has been properly connected to the power supply.
• Never use the machine in the state where the voltage type is different from the designated one.
• The direction of normal rotation of the machine is counterclockwise as observed from the pulley side. Take care not to allow the machine to rotate in the reverse direction.
• Never operate the machine unless the machine head and the oil tank have been filled with oil.
• For a test run, remove the bobbin and the needle thread.
• For the first month, decrease the sewing speed and run the sewing machine at a speed of 1,800 sti/min or less.
• Operate the handwheel after the machine has totally stopped.
• Observe the standard thread trimming speed, 185 sti/min.

CONTENTS

SPECIFICATIONS ....1

1. SETTING UP THE SEWING MACHINE ....2
2. INSTALLING THE THREAD STAND ....2
3. INSTALLING THE BELT COVER AND THE BOBBIN WINDER ....3
4. LUBRICATOIN ....3
5. ATTACHING THE NEEDLE ....4
6. WINDING A BOBBIN ....4
7. THREADING THE BOBBIN CASE ....4
8. INSTALLING THE TAKE-UP THREAD GUIDE ROD ....5
9. THREAD THE MACHINE HEAD ....5
10. ADJUSTING THE STITCH LENGTH 6
11. FORWARD/REVERSE SEAM RATIO ....6
12. THREAD TENSION....6
13. THREAD TAKE-UP SPRING ....7
14. PRESSURES OF THE PRESSER FOOT AND WALKING FOOT ....7
15. HEIGHT OF THE FEED DOG ....7
16. ADJUSTING THE WALKING FOOT AND THE PRESSER FOOT ....8
17. ADJUSTING THE LOGITUDINAL POSITION OF THE FEED DOG ....9
18. NEEDLE-TO-HOOK RELATIONSHIP....9
19. AUXILIARY THREAD TENSION CONTROLLER ....10
20. ADJUSTING THE PRESSURE OF THE FIXED KNIFE (DSU-145-7) 10
21. HOW TO USE THE ONE-TOUCH TYPE MANUAL REVERSE-FEED STITCHING (DSU-145-7) 10
22. HOW TO ADJUST THE ONE-TOUCH TYPE MANUAL REVERSE-FEED STITCHING (DSU-145-7) 11
23. ADJUSTING THE THREAD TRIMMING TIMING (DSU-145-7) 11
24. ADJUSTING THE CAM ROLLER ARM AND CAM ROLLER ARM PRESSER (DSU-145-7) 12
25. ADJUSTING MAX. MOVING STROKE OF THE ROTARY KNIFE (DSU-145-7) .....12
26. ADJUSTING THE OPERATING STROKE OF THE PICKER (DSU-145-7) ......13
27. HOW TO REPLACE THE KNIVES (DSU-145-7) 13
28. MOTOR PULLEY AND SEWING SPEED (DSU-145) 13
29. TROUBLES AND CORRECTIVE MEASURES ....14

SPECIFICATIONS

Model DSU-145 DSU-145-7
Type of sewing machine head	Cylinder-bed 1-needle, top & bottom feed lock-stitch machine	Cylinder-bed 1-needle, top & bottom feed lock-stitch machine with automatic thread trimmer
Usage Suited for sewing medium weight materials
Sewing speed Max. 2,000 sti/min
Stitch length 0 to 6 mm
Lift of presser foot	Hand lifter 7 mmKnee lifter 15 mm	Hand lifter 6 mmKnee lifter 13 mm
Thread take-up lever	Link thread take-up lever
Needle bar stroke	37 mm
Needle to be used	GROZ-BECKERT 135×17 Nm90 to Nm140 (Standard Nm130)
Needle system #50 to #8
Stitch adjusting method	Dial
Lubrication method	With a hand oiler (automatic oiling by means of plunger pump only for the hook section)
Motor to be used	400W Electro-stop motor (4P) AC servo motor
Oil to be used New Defrix Oil No.1
Noise - Equivalent continuous emission sound pressure level (LpA) at the workstation :A-weighted value of 77.0 dB; (Includes K pA = 2.5 dB); according to ISO 10821- C.6.2 -ISO 11204 GR2 at 2,200 sti/min.		- Equivalent continuous emission sound pressure level (LpA) at the workstation :A-weighted value of 76.5 dB; (Includes K pA = 2.5 dB); according to ISO 10821- C.6.2 -ISO 11204 GR2 at 2,000 sti/min.

1. SETTING UP THE SEWING MACHINE

1. Mounting position of the knee lifter (Caution) The knee lifter should be mounted before the moter is installed.
2. Carry the sewing machine with two persons.

(Caution) Do not hold the handwheel.

1. Do not put protruding articles such as the screwdriver and the like at the location where the sewing machine is placed.
2. Setting the sewing machine

Holding countersunk scr ①; washer ② and nut ③ supplied with the unit, fix the sewing machine on the table with aligned with rubber packing ④ at four locations.

1. Securely attach head support rod to the table until it goes no further.

2. INSTALLING THE THREAD STAND

Assemble the thread stand, and insert it in the hole in the machine table, and fix it by tightening nut ①.

3. INSTALLING THE BELT COVER AND THE BOBBIN WINDER

WARNING :

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

(Installing procedure)

1. Insert support ① of the belt cover into the tapped hole in the machine arm. Install belt cover support ② and belt cover support plate ③ in the tapped holes in the machine bed.

2. Set locknut ⑤ in synchronizer support shaft ④ and install it in the tapped hole in the machine arm.

3. Install belt cover ⑥

4. Fit bobbin winder ⑦ in the belt cover, and adjust the position of the bobbin winder so that it does not come in contact with the sewing machine and the belt cover. Then fix the bobbin winder using the wooden screws.

5. Install cover ⑧ of the belt cover.

6. Tilt the machine head and check that the belt cover does not come in contact with the belt groove in the table.

(Caution)

Tilt the machine head after removing the hook for the knee lifter.

4. LUBRICATION

WARNING :

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

Technical line drawing of a sewing machine with attached wiring and components (no text or symbols)

★ Before starting the sewing machine

1. Prior to operation, be sure to properly lubricate the points marked with the arrows.

• Refilling the oil reservoir

1. Fill Juki New Defrix Oil No. 1 up to H mark ①.

2. When the oil level drops under L mark ②, refill it.

- Adjusting the amount of oil supplied to the hook.

1. Adjust the amount of oil using knob ③ attached in the machine arm. Turn the knob ⊖ direction to decrease the oil amount, and turn it ⊕ direction to increase it.

5. ATTACHING THE NEEDLE

WARNING :

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

The standard needle is GROZ-BECKERT 135 x 17 Nm130.

1. Turn the handwheel to move the needle bar up to its highest position.
2. Loosen needle setscrew ②, and hold needle ① so that long groove A faces exactly to the left. Insert the needle into the needle bar until it will go no further. Securely tighten the needle setscrew.

6. WINDING A BOBBIN

1. Route the thread in the order of A, B and C before winding it round the bobbin several times.
2. Set bobbin presser ① down to bring the winder in contact with the belt.
3. Adjust screw ② so that the bobbin is wound with thread about 80%. Turning the screw clockwise increases the amount of thread wound on the bobbin, and vice versa.
4. If thread is wound unevenly, move winder tension adjustor base ③ to the right or left to correct it.
5. The moment the bobbin has been wound up, the bobbin presser is released, and the bobbin winder will stop automatically.

7. THREADING THE BOBBIN CASE

WARNING :

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

★ Removing the bobbin case
Raise the bobbin case latch to remove the bobbin case.
★ Threading the bobbin case

1. Pass the thread through threading slit ① in the bobbin case, and route it under tension spring ②.

2. Hold the latch of the bobbin case, and set the bobbin case into the hook.

8. INSTALLING THE TAKE-UP THREAD GUIDE ROD

Insert take-up thread guide rod ① (attaching section is tapered off) into attaching hole ②.

9. THREAD THE MACHINE HEAD

WARNING :

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

Thread the machine head in the order of ① through to ⑬.

★ A synthetic thread, such as Tetron, may slip off the eyelet at sewing start and after thread trimming. In this case, it is advisable to use thread guide A supplied with the machine. (See the enlarged figure.)

10. ADJUSTING THE STITCH LENGTH

Turn stitch length dial ① counterclockwise or clockwise to bring the desired value at the top.

★ How to engage the reverse feed stitching

1. Push feed lever ② down.
2. The machine performs reverse feed stitching as long as the lever is held depressed.
3. The moment you release the lever, the machine resumes the normal stitching mode.

11. FORWARD/REVERSE SEAM RATIO

WARNING :

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

The seam ratio of forward stitch and reverse stitch is adjusted to be
1:1, but sometimes it shifts according to the sewing condition.
In order to adjust it to 1:1.
1. Loosen four feed regulating stud metal setscrews ①.
2. When increasing the forward stitch pitch, turn the slotted portion of eccentric bushing ② clockwise in the direction A by the screw-driver.
3. When decreasing the forward stitch pitch, turn eccentric bushing ② counterclockwise in the direction B.
4. After adjustment, tighten four setscrews ①.

12. THREAD TENSION

WARNING :

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

★ Adjusting the needle thread tension

Turning tension nut ① clockwise (toward A) increases the needle thread tension. Turning it counterclockwise (toward B) decreases the tension.

★ Adjusting the bobbin thread tension

Turning tension screw ② clockwise (toward A) increases the bobbin thread tension. Turning it counterclockwise (toward B) decreases the tension.

13. THREAD TAKE-UP SPRING

Standard stroke ② of thread take-up spring ① is 8 to 10 mm. To adjust the stroke, loosen setscrew ③, and turn whole thread controller ④.

The standard spring tension is 40 to 50 g.

To adjust the tension, turn the thread tension post, using a screwdriver.

14. PRESSURES OF THE PRESSER FOOT AND WALKING FOOT

1. It is possible to adjust the pressure of presser foot A to standard 25 mm and that of walking foot B to standard 10 mm according to the type of material.

※ It is advisable to minimize the pressures of both feet.

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

1. Feed dog ③ is factory-adjusted to jut out 1.2 mm from the surface of throat plate ①.

How to adjust the height of the feed dog.
1) Remove throat plate ①, bed upper cover ② and spring support shaft ④ to extract feed bar ⑤.
2) Remove pin 6.
3) Replace pin 6.

(Note) Marker lines are marked.

When making the height of the feed dog high, use the pin having more marker lines, and when making the height low, use the pin having less marker lines.

16. ADJUSTING THE WALKING FOOT AND THE PRESSER FOOT

WARNING :

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

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

★ Longitudinal position of the walking foot

1. Set the stitch length at the maximum, and turn the handwheel until walking foot ① reaches its front end position. With the walking foot in that position, loosen screw ②.
2. Bring the walking foot as close to presser foot ③ as possible to the extension that it does not come in contact with the back face of the presser foot.
3. Securely tighten screw ②.

★ Height of the walking foot and the presser foot

The height of the walking foot and the presser foot are normally minimized. Their height may be changed, depending on the type of materials.

• To change their height, loosen nut ③, then adjust the position of the cam rod boss.
  When you set the cam rod boss at the height position within the slot, the height will be set at maximum (5 mm)
  ○ When you set it at the lowest position, the height will be set at minimum (2 mm) Ⓑ.

★ Alternate vertical motions of the walking foot and the presser foot

The alternate vertical strokes of the walking foot and the presser foot are normally equal. Depending on the type of materials, however, the vertical stroke of the presser foot may be set smaller than that of the walking foot.

1. Loosen screw ②.
2. Raise the thread take-up to its highest position, and lower the hand lifter.
   ○ When you move the top feed crank to the right (toward A), the vertical strokes of both feet will be identical.
   ○ As you move the top feed crank to the left (toward Ⓑ), the stroke of the presser foot decreases.

★ Feed pitch of the walking foot

The ratio of the bottom feed to the top feed is factory-adjusted to 1:1. If necessary, the top feed amount may be changed as follows:

- Loosen nut ④, and move the slide block up (toward ⑤) to decrease the feed pitch, or move it down (toward ⑥) to increase the pitch.

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

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

1. Turn the feed regulator dial to maximum.
2. Turning the handwheel slowly to this side, loosen and adjust screw in the rear arm of the feed bar frame so that the feed bar does not contact with the front and back of the slot of the throat plate at the time of normal/reverse stitch motion.
3. After adjustment, tighten the setscrew.

18. NEEDLE-TO-HOOK RELATIONSHIP

WARNING :

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

• Positioning the needle bar
  

• Positioning the hook
  

★ Set the needle bar at the proper height first as follows:
1. Bring the needle bar down to its lowest position, and adjust so that the marker line on the needle bar aligns with the bottom end of needle bar lower bushing ① . Then, tighten screw ③ of needle bar clamp ② .
★ Adjust the timing between the needle and the hook as follows:
2. Adjust so that the marker line on the ascending needle bar aligns with the bottom end of lower bushing ① . Further adjust to make hook point ④ nearly meet the center of needle ⑤ , then tighten hook setscrew ⑥ .
3. Adjust the clearance between needle ⑤ and hook point ④ to 0.02 to 0.05 mm.
★ How to remove the hook
1. Turn the handwheel to bring the needle bar up to its highest position.
2. Remove the hook cover, the bobbin case, the throat plate and the top cover of the bed.
3. Loosen four throat plate frame setscrews.
4. Loosen the hook setscrew, and extract the hook so as to lift the front edge of the throat plate frame.
(Note) When installing the hook, tighten the throat plate after checking that the protruding portion of the hook stopper in the throat plate frame are properly inserted in the slot in the bobbin case retainer.

19. AUXILIARY THREAD TENSION CONTROLLER

Adjust the auxiliary thread tension using nut ①.

• Turn the nut in direction A Tension increases and the needle thread shortens.
• Turn the nut in direction B Tension decreases and the needle thread lengthens.
• Decrease the tension when using a thin thread or if cloth slippage often occurs.
• Increase the tension when using a thick thread or if upper cloth tends to slip forward.

20. ADJUSTING THE PRESSURE OF THE FIXED KNIFE (DSU-145-7)

WARNING :

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

1. Loosen two setscrews ① of the fixed knife and move adjusting plate ② for the knife pressure to direction A resulting in a higher knife pressure. After adjustment, tighten the setscrews.
2. The knife pressure should be increased for a thicker thread. However, it is advisable to minimize (by turning the adjust screw in direction B) the knife pressure as long as the knife trims threads.

21. HOW TO USE THE ONE-TOUCH TYPE MANUAL REVERSE-FEED STITCHING (DSU-145-7)

Technical line drawing of a mechanical assembly with hands operating a component (no text or symbols)

1. The moment you press switch ①, the sewing machine performs reverse feed stitching.
2. The machine continues reverse feed stitching as long as the switch is held pressed.
3. When you release the switch, the machine resumes normal stitching.

22. HOW TO ADJUST THE ONE-TOUCH TYPE MANUAL REVERSE-FEED STITCHING (DSU-145-7)

WARNING :

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

Mechanical assembly diagram showing a hand operating a bracket with a numbered component (no text or symbols present)

★ Position of the switch

Set the switch in an easy-to-operate position.

Loosen screws ①, and move the switch up or down to adjust its position.

★ Position of the reverse feed solenoid

1. Set the stitch length dial at the maximum.
2. Loosen two setscrews ① of the solenoid mounting base.
3. Push feed lever ② down until it bottoms, and move solenoid mounting base ③ up or down to adjust the inner clearance between rubber packing ④ on the plunger and reverse feed solenoid ⑤ to 0.5 to 1 mm. Tighten setscrew ①.

23. ADJUSTING THE THREAD TRIMMING TIMING (DSU-145-7)

WARNING :

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

1. Turning the handwheel, align red marker dot ① in the machine arm with white marker dot ② in the handwheel.

2. Turn the thread trimming cam until first screw ③ in the thread trimming cam aligns with cam roller shaft ④ in the cam roller arm, and tighten the screw at the aligned position.

24. ADJUSTING THE CAM ROLLER ARM AND CAM ROLLER ARM PRESSER (DSU-145-7)

WARNING :

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

1. Adjust clearance so as to be 0.3 to 0.5 mm between cam roller arm ① and cam roller arm presser ② in case of no thread trimming by loosening setscrew ③ in the cam roller arm presser.

2. After adjustment, tighten the screw.

25. ADJUSTING MAX. MOVING STROKE OF THE ROTARY KNIFE (DSU-145-7)

WARNING :

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

1. Turn the handwheel by hand and insert the trimmer.
2. Loosen setscrew ④ in the driving plate and adjust the length of driving plate ⑤ so that the edge of the rotary knife moves to marker line ③ in the throat plate frame ② when the moving stroke of rotary knife ① is max.
   ○ When the driving plate is lengthened, the moving stroke of the knife decreases, and when it is shortened, it increases.

26. ADJUSTING THE OPERATING STROKE OF THE PICKER (DSU-145-7)

WARNING :

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

1. Turning the handwheel, align the red marker dot in the machine arm with the white marker dot in the handwheel.
2. Loosen setscrew ① in the picker driving plate and push picker driving plate ② by hand.
3. Adjust the position of the picker driving plate so that picker ③ operates 2 mm longer from the end face of hook cover ④.
4. After the completion of adjustment, tighten the setscrew.
   When the clearance between the picker driving bar and the picker driving plate is large, the operating stroke decreases, and when it is small, the operating stroke increases.

27. HOW TO REPLACE THE KNIVES (DSU-145-7)

WARNING :

To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest.

1. Remove the throat plate and the feed dog.
2. Rotary knife ① can be removed by removing connecting screw ③ in driving plate ②, and fixed knife can be done by removing setscrew ⑤ of the fixed knife.
3. After replacement, adjust the knife pressure.

28. MOTOR PULLEY AND SEWING SPEED (DSU-145)

1. Use the 3-phase 400 W AC clutch motor.
2. Use an M type V belt.
3. The following table shows the relationship among the motor pulley and the sewing speed.

Model Serving speed Effective diameter of handwheel			Number of poles	Frequency Rotational speed of motor		Effective diameter of motor pulley
DSU-145 2,000 sti/min φ76.0 4				50Hz 1430	rpm φ105
				60Hz 1715	rpm φ95

(Caution) The effective diameter of the motor pulley is obtained by subtracting 5 mm from the outside diameter.

1. TROUBLES AND CORRECTIVE MEASURES

Trouble	Cause	Corrective measures
1. Thread breakage (Thread frays or wears out.) (Needle thread remains 2 to 3 cm on the wrong side of the cloth.)	(1) The thread path, needle point, hook point or bobbin case positioning finger has scratches.(2) The needle thread tension is too high.(3) The needle hits the hook point.(4) Lubrication to hook is inadequate.(5) The needle thread tension is too low.(6) The thread take-up spring has an excessively high tension while it has an excessively small stroke.(7) The timing between the needle and hook is too early or late.(8) The bobbin case frequently.	○ Remove the scratches on the hook point using a fine sand paper. Buff the bobbin case positioning finger.○ Properly adjust the needle thread tension.○ See “18. NEEDLE-TO-HOOK RELATIONSHIP”.○ Properly adjust the lubrication.See “4. LUBRICATION”.○ Properly adjust the needle thread tension.○ Decrease the tension, and increase the stroke.○ See “18. NEEDLE-TO-HOOK RELATIONSHIP”.○ Increase the spring pressure. Alternating reduce the thread trimming speed.
2. Stitch skipping	(1) The clearance between the needle and the hook point is too large.(2) The timing between the needle and the hook point is too early or late.(3) The presser foot pressure is too low.(4) The clearance between the top edge of the needle eyelet and the hook point is not correct.(5) The size of the needle is wrong.(6) A synthetic fiber thread or thin thread is used.(7) A sewing material is heavy-weight.	○ See “18. NEEDLE-TO-HOOK RELATIONSHIP”.○ See “18. NEEDLE-TO-HOOK RELATIONSHIP”.○ Increase the presser foot pressure.○ See “18. NEEDLE-TO-HOOK RELATIONSHIP”.○ Replace the needle by one which is one grade thicker.○ Wind the thread round the needle as illustrated.○ Adjust the timing of the needle and the hook to 2.7 mm, 0.8 mm.
3. Loose stitches	(1) The thread has not been passed through the notch of the bobbin case tension spring.(2) The thread path is poorly finished.(3) The bobbin does not rotate smoothly.(4) The bobbin thread tension is too low.(5) The bobbin thread has been wound too tight.(6) An untwisted synthetic thread is used.(7) A coated cloth or nylon yarn is used.	○ Properly thread the bobbin case.○ Grind it using a fine sand paper or a buff.○ Replace the bobbin or hook.○ Properly adjust the tension.○ Decrease the bobbin thread winding tension.○ Slightly reduce the sewing speed. (1,800sti/min)○ Use a ball-point needle.
4. A few stitches are skipped	(1) The bobbin thread is too short.(2) The bobbin thread breaks.(3) A nylon thread is used.when sewing light-weight material.	○ Replace the bobbin by a standard one (aluminum).○ Decrease the bobbin thread tension and the thread trimming speed.○ Use the soft start function.
5. The thread slips off the needle upon being trimmed.	(1) The tension of the auxiliary thread tension controller is too high.(2) The thread trimming timing is too early.(3) The returning force of the thread take-up spring is too high.(4) The operating stroke of the picker is small.	○ Decrease the tension.○ See “23. ADJUSTING THE THREAD TRIMMING TIMING”.○ See “9. THREADING THE MACHINE HEAD”.○ Replace the thread guide.○ See “26. ADJUSTING THE OPERATING STROKE OF THE PICKER”.
6. The needle thread cannot be trimmer. (The bobbin thread can be trimmed.)	(1) The last stitch has been skipped. (The clearance between the needle and the hook is too large.)	○ See “18. NEEDLE-TO-HOOK RELATIONSHIP”.
7. Both needle and bobbin threads cannot be trimmed.	(1) The thread trimming timing is wrong.(2) The knife has been damaged.(3) The knife pressure is inadequate.(4) The movement of the rotary knife is short.(5) The thread trimming solenoid fails to work.	○ See “23. ADJUSTING THE THREAD TRIMMING TIMING”.○ Replace the knife.○ Increase the knife pressure.○ See “25. ADJUSTING MAX. MOVING OF THE ROTARY KNIFE”.○ Check the motor solenoid for proper operation.
8. Thread cannot be trimmed sharply.	(1) The thread trimming timing is wrong.(2) The knife pressure is inadequate.(3) The knife blade is blunt.	○ See “23. ADJUSTING THE THREAD TRIMMING TIMING.○ Increase the knife pressure.○ Replace the knife.
9. Stepped part is clogged.	(1) The presser foot slips when riding on the stepped part.	○ Use B1525 145 00A presser foot (option) and B1526 145 00A walking foot (option).
10. A sewing material is scratched by the feed dog	(1) The pressure of the presser foot is too strong.(2) The shape of feed dog is defective.	○ Adjust the pressure of the presser foot.○ Use B1613 145 00A (for DSU-145) feed dog and D1613 145 E0A (for DSU-145-4, -5) feed dog (option)
11. When the alternate lift is increased, the pitch cannot be achieved as per the scale.	(1) Sewing speed is too fast, resulting in reducing the feed force.	○ Reduce the sewing speed.

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