MH484 - Sewing machine JUKI - Free user manual and instructions

USER MANUAL MH484 JUKI

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 specications of your product. The risk indications are classied into the following three di󰀨erent categories to help understand the meaning of the labels. Be sure to fully understand the following description and strictly observe the instructions. Warning label

• There is the possibility that slight to serious injury or death may be caused. • There is the possibility that injury may be caused by touching moving part.

• To perform sewing work with safety guard. • To perform sewing work with safety cover. • To perform sewing work with safety protection device.

• Be sure to turn the power OFF before carrying out "machine-head threading", "needle changing", "bobbin changing" or "cleaning". Electrical-shock danger label

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.

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 par-ty mishandles the machine or does not avoid the dangerous situation when operating or maintaining the machine. Items requiring special attention. 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 deciency 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. TO ENSURE SAFE USE OF YOUR SEWING MACHINE ( I ) Explanation of risk levels (II) Explanation of pictorial warning indications and warning labelsii

themachinebeforeusingthemachine.Carefullykeeptheinstructionmanualandtheexplanatorydocu- mentsathandforquickreference.

death.JUKIassumesnoresponsibilityfordamagesorpersonalinjuryordeathresultingfromthema- chinewhichhasbeenmodiedoraltered. Educationandtraining

1. Besuretoliftandmovethemachineinasafemannertakingthemachineweightinconsideration.Refer

personalinjuryordeath.Inthecasethemachineiscrated,inparticular,besuretocarefullychecknails. Thenailshavetoberemoved.

accident.Inaddition,besuretoremovetheconnectorwhileholdingitsconnectorsection. (III)Grounding

inpersonalinjuryordeath. Inaddition,checktobesurethatthedirectionofrotationofthepulleyagreeswiththearrowshownon pulley.

spreader,needlebar,hookandclothtrimmingknifeduringoperationinordertoprotectyourhands againstinjury.Inaddition,besuretoturnthepoweroffandchecktobesurethatthemachinecomplete- lystopsbeforechangingthethread.

toaskanelectricaltechnicianofyourcompanyorJUKIordistributorinyourareaforrepairandmainte- nance(includingwiring)ofelectricalcomponents.

4. Besuretocheckthatscrewsandnutsarefreefromloosenessaftercompletionofrepair,adjustment

maintenance,inspectionorrepairofthemachine.(Forthemachinewithaclutchmotor,themotorwill keeprunningforawhilebyinertiaevenafterturningthepoweroff.So,becareful.)

7. Ifthemachinecannotbenormallyoperatedafterrepairoradjustment,immediatelystopoperationand

occurs,usetheTVorradiowithkeptwellawayfromthemachine.

1. Keep your hands away from needle when you turn ON the power switch or while the machine

2. Do not put your fi ngers into the thread take-up cover while the machine is operating.

3. Turn OFF the power switch when tilting the machine head, or removing the belt cover or the V

4. During operation, be careful not to allow your or any other person’s head, hands or clothes to

come close to the handwheel, V belt and motor. Also, do not place anything close to them.

5. Do not operate your machine with the belt cover and fi nger guard removed.

6. When tilting the machine head, be sure to confi rm that the head support bar is properly at-

tached to your machine head, and be careful not to allow your fi ngers or the like to be pinched in the machine head. CAUTION : Note that safety devices such as “belt cover”, “fi nger 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.

1. To ensure safety, never operate the machine with the ground wire for the power supply re-

2. When inserting/removing the power plug, the power switch has to be turned OFF in advance.

3. In time of thunder and lightening, stop your work and disconnect the power plug from the re-

ceptacle so as to ensure safety.

4. If the machine is suddenly moved from a cold place to a warm place, dew condensation may be

observed. In this case, turn ON the power to the machine after you have confi rmed that there is no danger of water drops in the machine.

5. To prevent fi res, periodically draw out the power plug from the plug socket and clean the root

of the pins and the space between pins.

6. The loopers oscillate at a high speed during operation.

Be sure to keep your hands away from the vicinity of the loopers to protect hands from pos- sible injury during operation. Turn the power OFF before threading the machine head.

7. To avoid possible accidents due to abrupt start of the machine, be sure to turn OFF the power

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 fi ngers or the like are not caught in the machine.vi DECLARATION OF INCORPORATION OF PARTLY COMPLETED MACHINERY We hereby declare that the sewing machine (sewing head) described below ;

1. Must not be put into service until the machinery to which it is incorporated has been declared incon-

formity with the provisions of the Directive 2006/42/EC, and

2. Conforms to the essential requirements of the Directive 2006/42/EC, described in the technical

3. To be prepared with the above technical documentation compiled in accordance with part B of An-

4. Relevant information on which should be transmitted in response to a reasoned request by the na-

SPECIFICATIONS Model MH-481 MH-481-4/-5 MH-484 MH-484-4/-5 Sewing type 1-needle, double chainstitch machine 1-needle, double chainstitch, differential-feed machine Sewing speed Max. 5,500 sti/min Stitch length 1 to 4 mm Main feed : 1 to 4 mm Auxiliary feed : 1 to 5.6 mm Differential feed raito

Stretching stitch max. 1 : 0.5 Gathering stitch max. 1 : 3.0 Standard 1 : 1.5 Lift of presser foot Hand lifter lever : 5 mm, Knee lifter : 10 mm Stroke of needle bar 30 mm Needle TV × 7 #9 to #18 (Standard : #11) Stitch length adjustment method Dialtype Safety stitch Condensation stitch/reverse-feed stitch (by feed lever) Looper mech- anism Inclined crank type Looper stroke 21.5 mm (2.1 to 3.3 mm) 21.5 mm Lubrication system Fully automatic lubrication Oil JUKI New Defrix Oil No.1 Noise - Equivalent continuous emission sound pres- sure level (L

) at the workstation: A-weighted value of

88.5 dB; (Includes K

at 5,500 sti/min. - Equivalent continuous emission sound pres- sure level (L

) at the workstation: A-weighted value of

87.5 dB; (Includes K

at 5,500 sti/min. - Equivalent continuous emission sound pres- sure level (L

) at the workstation: A-weighted value of

88.5 dB; (Includes K

at 5,500 sti/min. - Equivalent continuous emission sound pres- sure level (L

) at the workstation: A-weighted value of

89.0 dB; (Includes K

• Before you put the machine into operation for the fi rst time after the set-up, clean it thoroughly . Remove all dust gathering during transportation and oil it well.

• Confi rm that voltage has been correctly set. Confi rm 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 oil pan has been fi lled with oil.

• For a test run, remove the thread.

• For the fi rst month, decrease the sewing speed and run the sewing machine at a speed of 4,500 sti/min or less.

When you carry the sewing machine, keep hands away from the detector located behind the handwheel.

• Operate the handwheel after the machine has totally stopped. CAUTION : Check the following so as to prevent maloperation of and damage to the machine. BEFORE OPERATION– 2

1) Carry the sewing machine with two persons.

(Caution) Do not hold the handwheel.

2) Do not put protruding articles such as the screw-

driver and the like at the location where the sewing machine is placed.

3) Attaching the hinge seats and the support rubbers of

the machine head Fix the hinge seats

supplied with the machine on the table using nails

into the opening in the machine bed, and fi t the machine head to table rubber hinge before placing the machine head on rubber seats on the four corners.

6) Securely attach head support rod

to the table until it goes no further.

4) Attaching the oil pan

Install the oil reservoir

in the way that it is sup- ported by four corners of the opening in the table. Nail two rubber cushions

to a protruded edge from the table opening at operator's side using nails

and also attach two head-rest cushions

to a protruded edge at the far end (hinge side) using nails

, and the place oil reservoir

Hinge sideOperator’s side– 3 – Assemble the thread stand, set it up on the machine table using the installation hole in the table and tighten nut

Adjust the belt tension with the height of the motor so that the belt sags 15 mm when the center of V belt is applied with a 9.8 N load. 15 mm

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior. 1– 4 –

abouttenminutesat3,500to4,000sti/mintorunitin. (Caution) 1. Verify that the lubricating oil is properly circulating by watching it through the oil sight window.

2. Removeanyberousdustfromtheoilpumplterscreenandtheoilreservoir.

3. When the lubrication oil has become dirty, drain it through the oil drain screw cap

5. Clean up the oil reservoir magnet with a cloth.

tomaximizetheamount ofoilmaximizetheamountofoil. (Caution)Theoilamountdoesnotchangeimmediatelyafteradjustment,sohavethisinmind whenadjustingtheoilamount. Appropriateamountofoil(small) 1mm 2mm Appropriateamountofoil(large) Oil splashing from the needle bar crank Oil splashing from the needle bar crank Sample showing the appropriate amount of oil supplied to the face plate parts

Feed direction Use a TV×7 needle. Different needle counts are applicable. However, select an appropriate one according to the thickness of thread and the type of material to be used. (#9 to #21)

1) Turn the handwheel to bring the needle bar to the highest position of its stroke.

2) Loosen needle clamp screw

so that its scarf faces toward the feeding direction of material.

fully into the needle clamp hole until it comes in contact with the deep end.

4) Firmly tighten needle clamp screw

Attach the needle so that its eyelet faces toward A for fi lament thread, or B for cotton thread so as to prevent stitch skipping of needle thread. To carry out reverse-feed stitching with consistency, do not allow the needle eyelet to face toward C.

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.

5. ATTACHING THE BELT COVER

1. Insert belt cover support

into the tapped hole in the machine arm.

2. Temporarily fi x belt cover

on the machine head with screws.

3. Slightly tilting the machine head, put rid

of the belt cover inside the outer pulley and fi x rid

5. Loosen the screws in the belt cover, and adjust the

position of belt cover

properly. Then securely tighten the screws in the belt cover.

6. Fix bobbin winder cover

7. Fix belt cover auxiliary plate

as illustrated in the fi gure. (Caution) 1. When tilting the machine, loosen wooden screw

in belt cover auxil- iary plate

and move the auxiliary plate in the direction of the arrow to such an extent that it does not come in contact with the belt cover as shown in the fi gure.

2. After you have raised the machine,

return belt cover auxiliary plate

the previous position.

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.– 8 –

[MH-481, MH-484] Pass the looper thread as shown in the fi gure.

1. Pass the looper thread through the looper thread guide plate as illustrated. When using a hard-twisted thread or

when sewing with a large feed pitch, pass it through 2 holes to form a loop. When sewing fi ne materials which tend to pucker, pass the thread through only one hole in order to lessen the thread tension.

2. Pull the plate spring in the direction of arrow as shown in the lower fi gure, and the thread guide

will come up. As the close-up fi gure shows, the thread guide

has two sets of thread holes; the holes

are used when a stitch is preferably formed with soft looper thread tension, a stretchable thread is used or stitch length is more than 3 mm (l/8"), and the holes

are used when a stitch having a normal thread tension is prefered.

3. In passing the thread to the looper, use a tweezer in the accessory box and after passing, pull it out 5 cm (2")

from the tip of the looper. (Caution) Detach the throat plate, bed slide and cam cover and remove any dust from the teeth of the feed dog with a brush. [MH-481-4, MH-481-5, MH-484-4, MH-484-5] Do not wind but just pass the thread through the thread guide (lower) of the thread stand.

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.

All other threading procedures are the same as those of model MH-481 and MH-484.– 9 – Needle thread tension Rotate to right to make the tension stronger.

Looper thread tension Rotate to right to make the tension stronger.

10. ADJUSTING THE REMAINING LENGTH OF TRIMMED THREAD (MH-481-4, MH-481-5,

MH-484-4, MH-484-5) The length of the thread remaining on the needle after thread trimming signifi cantly affects the occurrence of stitch skipping at the beginning of sewing. Loosen setscrew

and move wire drawing link

of the needle thread draw-out solenoid to the left to increase the thread take-up amount of draw-out pin

This increases the length of thread remaining at the bottom of the needle eyelet. On the contrary, moving the link to the right decreases it. Reduce the length of thread remaining on the needle after thread trimming when using elastic thread such as Tetoron thread and nylon thread. Long Short

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior. [MH-481-4, MH-481-5, MH-484-4, MH-484-5] [MH-481, MH-484]– 10 –

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior. The stitch length of this model can be adjusted by rotat- ing the feed adjusting dial on top of the feed lever. The fi gures on the graduation scale is shown in milli- meter (mm).

1. Rotate the feed adjusting dial either to right or left

2. Match the wanted fi gure with the pin coming out

• The maximum stitch length is 4 mm (5/32").

3. If the lever is pushed, it becomes reverse sewing

with the standard pitch of 2 mm (5/64").

4. If the position of the lever stopper is raised, the

pitch of the reverse sewing becomes small.

5. If the position of the lever stopper is raised up

further (loosen the nut and pull the stopper up) and the lever is pushed, it is possible to sew with normal sewing with small stitch length. Take advantage of this feature for bar-tacking at the start of sewing or end of sewing. (Caution) Thisfunctionisnotapplicable tothreadtrimminginthecaseof reverse-feedstitching.– 12 – Feed rocker shaft

15. HEIGHT AND ANGLE OF THE PRESSER FOOT

Presser bar clamp screw

14. DIFFERENTIAL FEED ADJUSTMENT (MH-484, MH-484-4, MH-484-5)

Rock nut Regulating lever

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior. When the height or the direction of the presser bar is to be changed due to the exchange of presser foot:

1. Remove the rubber plug of the face plate.

2. From this hole, adjust by loosening the presser bar

3. After the adjustment, securely tighten the set screw.– 13 –

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.– 14 –

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.– 15 –

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.

Adjust the needle and the looper as described below:

(Determining the needle bar height)

with the bottom end face of needle bar lower bushing

. Tighten needle bar connection setscrew

In the case ORGAN needle (TV×7) is used, use the marker lines on the left side of the needle bar. In the case Schmetz needle (such as UY-128GAS), use the marker lines on the right side of the needle bar.

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.– 16 –

and looper clamping screw

and carry out the adjustment.

6. Check to be sure that a distance of approximately

3.2 mm is provided between the center of the needle

and the blade point of the looper when the looper reaches its back end.

to adjust so that looper

reaches its back end when the needle bar is at the lower point of its stroke.

4. Carry out adjustment so that the blade point of looper

aligns with the center of the needle, so that the former is spaced 1.5 mm from the upper end of needle eyelet and so that a clearance of 0.05 mm is provided between the looper and the needle when second marker line

is aligned with the bottom end of needle bar lower bushing

4 mark Thread spreader Screw of thread spreader cam

2. Rotate the hand wheel with the hand.

3. The heads of the plated adjusting screw

clamp screw will appear in that order, so at fi rst, loosen the 2 screws, fl at top and clamp screw.

of the adjusting screw

brought to right side, the dimension of B becomes bigger.

5. Adjustment is made depending on the size num-

ber of the needle but normally it is adjusted to #11 needle.

6. The adjustment should be made so that the looper

goes as near the needle side as possible and returns. Then, after setting the position by tightening the fl at top screw, securely tighten the clamp screw.

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.– 18 – Inside line Needle Thread spreader Looper

Position of the thread spreader latch When the pointed end of the descending needle arrives the level of upper surface of the looper, adjust the thread spreader to the position shown by the fi gure.

The right and left direction should be such that the inside surface of the thread spreader should match with the center of the needle.

Adjust so that the front and back dimension A should be 2 mm (5/64") with the screw

The height should be adjusted so that the clearance between the bottom surface of the thread spreader and the upper surface of the looper to be 0.2 mm (1/100") with the screw

Needle Thread spreader Positioning of the thread spreader in terms of lateral direction Positioning of the thread spreader in terms of longitudinal direction Lower the needle. Position the thread spreader as illustrated above.

For the lateral direction, adjust the position of the thread spreader so that a clearance of 0.5 mm is provided be- tween the center line of the needle and the inner side line when the third marker line on the needle bar appears from the bottom end of the needle bar lower bushing.

For the longitudinal direction, adjust the position of the thread spreader using screw

so that the thread spreader aligns with the read surface of the looper.

Adjust the height of the thread spreader using screw

so that a clearance of 0.05 mm is provided between the bottom face of the thread spreader and the top face of the looper when the needle bar is in its upper dead point.– 19 – Triangle Looper MH-481, MH-484 MH-481-4, MH-481-5, MH-484-4, MH-484-5 Thread spreader Moving knife Function of the thread spreader (especially when the threads are trimmed). The thread spreader fi rmly holds the looper thread and the needle thread at 2 places of a loop before the needle goes up to it's upper dead position to stop. Then, the tip of the moving knife comes to hook these 2 threads and trims them off.

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.– 20 –

. Adjust the position of looper thread cam

is visible through guide hole

when third marker line

(third from the top) of the needle bar

aligns with the bottom end face of the needle bar lower bushing. After the adjustment, verify the following.

1. When the looper thread moves off tip

of the looper thread cam, the needle tip fully enters the looper thread triangle.

2. In the case puckering is particularly concerned, the

slightly earlier than the normal timing.

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.– 21 –

1. Moving knife mounting plate assembly

The preliminary test for thread trimming and thread clamping can be done independently on the moving knife mounting plate assembly. (After the following adjustments have been completed, hook the threads manually with the recessed part of the moving knife, pull the moving knife into the counter knife to clamp the threads and the thread will be trimmed off.) Dimensions of the counter knife When sharpening the counter knife, correct it with the part

so as to fi nish it in the size of 0.5±0.05 mm.

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior. The thread tension changes by moving intermediate thread guide

up and down. The thread tension is increased by moving the intermediate thread guide upward, or decreased by moving it downward. In general, adjust the position of setscrew

referring to the table below. Thread used Scale on the intermediate thread guide Cotton thread #80 to #50 2 to 3 #30 to #20 3 to 4 Synthetic thread #80 to #50 1 to 2 #30 to #20 2 to 3– 22 – Tension guage Moving knife mounting plate Adjustment of the clamping pressure The looper thread clamping pressure applied by the thread clamping spring is always constant regardless of the type of sewing threads, which you need not to change. If the looper thread is not clamped correctly, you must replace the moving knife assembly. When a cotton thread No.60 is clamped and is pulled away as shown in the illustration, the correct tension is between 70 and 100g. The top end of the spring and the bottom surface of the moving knife must evenly engage with each other. Do not change the thread clamping pressure since it has been properly factory-adjusted at the time of delivery.

2. Positioning the moving knife

The position of the moving knife is determined by those of the moving knife base, moving knife base mounting plate and the stopper. Lateral position of the moving knife base Adjust it within a range provided by the oval screw holes. If you move it to the right, the length of thread remain- ing on the needle is increased. Adjusting screws Longitudinal position of the moving knife base Provide a clearance of 0.1 mm to 0.5 mm between the moving knife and the thread spreader so that the knife does not hit the spreader when the former approached to the latter. Thread spreader Moving knife Looper

Longitudinal position of the moving knife The moving knife must go back accompanying 2 threads which had been held by the thread spreader without fail. If not, adjust the longitudinal position of the moving knife by moving the mounting plate so that the knife hooks 2 of the thread being held by the spreader regardless of the stroke. Moving knife hook Installing base of the moving knife mounting plate Thread spreader Stroke of the moving knife Loosening screw

, perform adjustment by knife driving fork

so that the rear end of moving knife

projects 1 mm from counter knife

with thread trimmer lever

in contact with stopper

Then adjust the position of solenoid

to make moving knife

stop at 3 mm from throat plate

at when it is moved to its farthest point.

Position of the wiper against the needle The vertical clearance between the wiper and the needle point must be 1 mm and the horizontal clearance with the needle center must be 2 mm. You can adjust it by loosening the screw on the wiper driving arm set screw

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior. Wiper Cushion Solenoid plunger

The most frontward position of the wiper The most frontward position of the wiper is determined by the position of the wiper driving solenoid. Adjust the position of the solenoid by means of the screw

so that the top end of the wiper reaches the left end of the presser foot when the solenoid plunger has gone up to it's highest position.

• After a proper position has been obtained, check that the wiper does not contact with the needle and also that the cushion attached to the wiper driving arm rests on the bottom surface of the arm when the wiper has been brought back. If the cushion does not rest on the arm surface, you must adjust the position of the solenoid, because the solenoid has been installed at a higher position or the stroke of the solenoid is shorter than the standard of 8.5 mm.– 25 –

28. ADJUSTING THE NEEDLE THREAD CLAMPING ARM (MH-481-4, MH-481-5, MH-484-4,

MH-484-5) The function of the needle thread clamping arm is to clamp the needle thread which was handled by the wip- er in order to prepare for the following sewing works. Adjust the tension of the spring so that the clamping pressure is in a range of 30 to 40 g when the cotton needle thread No. 60 is being pulled out. This pressure is common to all kinds of sewing threads. Therefore, you do not need to change the aforementioned pressure every time after a thread is replaced.

• Adjust it with care not to apply uneven pressure to the spring. Tension guage Needle thread clamping arm

29. ADJUSTING THE DRAW-OUT AMOUNT OF THE LOOPER THREAD (MH-481-4, MH-481-5,

MH-484-4, MH-484-5) The standard amount of looper thread is drawn out when looper thread draw-out lever

is spaced 3 mm from the thread path hole in cam thread guide

immediately before the thread trimmer is actuated. Loosen nut

and make adjustment by moving cam thread tension release slide block

to the right or left. For certain types of needle, the looper thread may slip off the looper. In such a case, make adjustment so that a longer thread is drawn out. Looper thread

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.– 26 –

30. GATHER SEWING ATTACHMENT (MH-484, MH-484-4, MH-484-5)

S060 (Gather sewing attachment) With S060, you can gather only the bottom cloth. Attachments S060 and S061 are available for the model MH-484. S061 (Intermittent gather sewing attachment) With S061 you can intermittently sew gathers as you wish by operating the pedal lever. Refer to the separate Instruction Book prepared for the S060, S061 for the details of adjustment. Lock nut Spring Stopper

3) The following table shows the relationship among the motor pulley and the sewing speed.

Model Sewing speed Effective diameter of handwheel Number of poles Frequency Rotational speed of motor Effective diameter of motor pulley MH-481 MH-484 5,500 sti/min

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

To avoid possible personal injury due to abrupt start of the machine, turn off the power to the machine and check to be sure that the motor has totally stopped rotating in prior.– 27 –

32. TROUBLES IN SEWING AND CORRECTIVE MEASURES

Troubles Causes Corrective measures

Thread quality is poor.

Use another thread of better quality.

Thread is too thick for the needle.

Change such thread or needle.

Thread breakage due to the heated needle.

This occurs on synthetic fi ber thread. Apply silicon oil lubricant (refer to “11. HOW

TO INSTALL THE SILICON OIL LUBRI-

CATING UNIT”) or reduce the sewing speed.

Thread tension is too high.

Lessen the thread tension. Refer to “9. THREAD TENSION”.

The thread path of needle, looper, throat plate, needle guard, looper guide and all other thread paths are bruised.

Make them smooth by means of oilstone or buffi ng.

Excessive thread is remained and hooked again.

Two consecutive Stitches are skipped on the needle thread. (This trouble is caused when the looper failed to hook the needle thread.)

Verify the clearance between the looper and the needle. Refer to “19. NEEDLE-TO-LOOPER RELA- TION”.

Check the timing of the looper and the needle. Refer to “19. NEEDLE-TO-LOOPER RELA- TION”.

Try to increase the tension of the thread take- up lever depending upon the type of thread. Refer to “24. POSITION OF THE THREAD TAKE-UP LEVER”.

Verify the needle is attached correctly. Refer to “6. ATTACHING THE NEEDLE”.

Check the position and the timing of the needle guard. Refer to “22. MATCHING THE MOTION OF

Verify the thread is correctly passed through. Refer to “7. THREADING THE MACHINE HEAD” and “8. THREADING THE LOOP- ERS”.– 28 – Troubles Causes Corrective measures

An independent seam is skipped on the looper thread. Needle Looper This trouble is caused when the needle failed ·to come down through a trian- gular loop formed by the looper thread.

Verify the looper motion. Verify the clearance between the looper and the needle. Refer to “19. NEEDLE-TO-LOOPER RELA- TION”.

Check the timing of the looper thread take-up. Refer to “23. POSITIONING THE LOOPER THREAD TAKE-UP”.

Adjust the position of the thread spreader hook. Refer to “21. THREAD SPREADER”.

Increase the looper thread tension slightly. Refer to “9. THREAD TENSION”.

Verify the thread is correctly passed through. Refer to “7. THREADING THE MACHINE HEAD” and “8. THREADING THE LOOP- ERS”.

Seam is skipped on the needle thread due to insuffi cient interlooping. Needle Looper This trouble is caused when the needle thread is inclined extremely to the left.

Verify the looper motion. Verify the clearance between the looper and the needle. Refer to “19. NEEDLE-TO-LOOPER RELA- TION”. If it is caused in the use of a chemical fi ber thread.

Reduce the sewing speed.

Use a needle for chemical fi ber threads. If it is caused in the use of a synthetic fi ber thread.

Make the scooping amount of looper greater. Refer to “19. NEEDLE-TO-LOOPER RELA- TION”.

Reduce the sewing speed.

3. Inadequate tight-

Needle thread tension is too low.

Tighten the needle thread tension nut. Refer to “9. THREAD TENSION”.

Looper thread tension is too high.

Loosen the looper thread tension nut. Refer to “9. THREAD TENSION”.

Looper thread take-up does not supply a suffi cient length of thread.

Change the threading order in the looper thread guide. Refer to “23. POSITIONING THE LOOPER THREAD TAKE-UP”.

Thread is too thick for the needle size.

Try to use a different needle. Refer to “6. ATTACHING THE NEEDLE”.– 29 – Troubles Causes Corrective measures

Set position of the frame thread eyelet is not suitable.

Try to lower the position. Refer to “25. POSITION OF THE FRAME THREAD EYELET”.

Position of the thread take-up lever is not suitable.

Try to push it up. Refer to “24. POSITION OF THE THREAD TAKE-UP LEVER”.

Throat plate does not fi t.

Replace it with other throat plate which has larger needle hole.

Replace it with a straight needle. Refer to “6. ATTACHING THE NEEDLE”.

The timing of the needle motion with that of needle is not correct.

Position of the presser foot is wrong.

See if the hole of presser foot, hole of throat plate and loop guide plate are placed in the center of needle.

Motion of the needle guard is not ad- equate.

Check the position and timing of the motion of the needle guard. Refer to “22. MATCHING THE MOTION OF

The tension of needle thread is too high.

Loosen the tension. Refer to “9. THREAD TENSION”.

Thickness of the needle is not suitable.

Replace it with a suitable needle in accordance with the quality and weight of the sewing ma- terial. Refer to “6. ATTACHING THE NEEDLE”.

Thread tension is too high.

Reduce the thread tension, especially the looper thread. Refer to “9. THREAD TENSION”.

Timing of the looper thread take-up is wrong.

Set the timing to a little earlier. Refer to “23. POSITIONING THE LOOPER THREAD TAKE-UP”.

Thread paths are not smooth.

Polish the thread path with lapping agent on thick thread #8.

Pressing force of the presser foot is too much

Tighten the adjusting screw. Refer to “12. ADJUSTING THE PRESSER FOOT”.

Use a throat plate designed for fi ne materials.

Ratio of differential feed; Apply 1:0.7 ratio for gathering.

Pressure of presser foot

Reduce the pressure. Refer to “12. ADJUSTING THE PRESSER FOOT”.DEUTSCHi

ammationouirritation.

Amountofoil(oilsplashes)conrmationpaper 25mm 70mm