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® HIGH SPEED SEMI-DRY HEAD OVERLOCK/INTERLOCK/ SEWING MACHINE MO-6700D Series ENGINEER’S MANUAL 40033638 No.E368-00...
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PREFACE This Engineer’s Manual is written for the technical personnel who are responsible for the service and maintenance of the machine. The Instruction Manual for these machines intended for the maintenance personnel and operators at an apparel factory contains operating instructions in detail. And this manual describes “Standard Adjustment”, “Adjustment Procedures”, “Results of Improper Adjustment”, and other important information which are not covered by the Instruction Manual.
CONTENTS 1. SPECIFICATIONS ..................(1) MO-6700D SERIES ...................... 1 2. MODEL NUMBERING SYSTEM ..............2 3. STANDARD ADJUSTMENT ................4 (1) Adjusting the needle height ..................4 (2) Positioning the throat plate ..................4 (3) Installing position of the needle clamp ..............6 (4) Adjusting the length of the lower looper holder (Applicable only to MO-6716D series) ..............
2) Pat No. of frame support plate bolt ....................46 5. ADJUSTMENT VALUES OF THE NEEDLE HEIGHT AND LOOPER TIMING ................47 (1) MO-6700D SERIES ....................47 6. TROUBLES AND CORRECTIVE MEASURES ........... 48 7. DIMENSIONS OF TABLE ................60 (1) Semi-sunken type ..................... 60 (2) Semi-sunken type (synchronizer is used) ..............
2. MODEL NUMBERING SYSTEM MO-6700D SERIES MODEL NUMBERING SYSTEM 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 M O 6 7 Type classification 3 to 6 Model classification Semi-dry head...
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Special machine classification (special classification of machine, structure and specs. other than gauge set) Standard Upper looper high throw Swim suits Upper looper extra high lift Puckering prevention 15 to 22 Device and attachment classfication G39/Q141 Presser for tape attaching (for sharp curve)/tape guide L121 Blind stitch hemming attachment S159...
3. STANDARD ADJUSTMENT (1) Adjusting the needle height Standard Adjustment When the needle(s) is in the highest position, the needle height from the throat plate surface should be as shown below. (Unit : mm) 6704D Model Dimension Dimension Dimension 6705D MO-6704D-0A -150 10.5...
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Adjustment Procedure Results of Improper Adjustment 1) Take off the upper cover, loosen setscrew of needle driving forked o Any other needle height than crank and move needle driving forked crank up or down to adjust specified here will badly affect the action of the lower looper, the the needle height.
(3) Installing position of the needle clamp Standard Adjustment Needle clamp connecting stud should fit with the bottom end of needle bar or be spaced within 0 to 0.5 Butt the needle clamp with the bottom end of the needle bar. (4) Adjusting the length of the lower looper holder (Applicable only to MO-6716D series) Standard Adjustment The center-to-center distance should be 26 mm.
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Adjustment Procedure Results of Improper Adjustment o I f t h e c l e a r a n c e p r o v i d e d 1) Loosen setscrew and adjust, by slightly turning needle clamp between the needle and the the clearance provided between the right-hand side needle and the looper is excessive, the needle lower looper (for 2-needle overlock machine) and the clearance...
(5) Adjusting the lower looper Standard Adjustment 1) Returning amount of the lower looper (Unit : mm) The distance between the blade point of the lower looper and the center of the needle should be as Model Dimension follows when the lower looper is at the extreme MO-6704D-0A -150 left of its stroke.
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Adjustment Procedure Results of Improper Adjustment o Excessive return of the lower 1) Returning amount of the lower looper looper tends to cause stitch Loosen setscrew of lower looper support arm and adjust lower skipping when filament thread is looper to make adjustment of the returning amount.
(6) Position of the upper looper guide Standard Adjustment Vertical position : To be in close contact with the frame guide surface. Laternal position : To be pressed against the upper looper guide support gauge (Unit : mm) 6.3 4.7 13131909 13132006 Marker dot...
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Adjustment Procedure Results of Improper Adjustment o If the upper looper guide has 1) Fit upper looper guide support gauge over gauge fixing pin which improperly positioned vertically, has been driven in frame and secure the gauge with an O ring. it will cause oil leakage or Then position the gauge taking the marker dot engraved on it or the disturbed path of the upper...
(7) Positioning the upper looper holder Standard Adjustment The distance between the bottom surface of the frame and the upper end of the upper looper holder pin should be as shown below when the upper looper holder is at the highest point of its stroke. (Unit : mm) Dimension Model...
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Adjustment Procedure Results of Improper Adjustment o Inaccurately positioned upper 1) Loosen the setscrew of upper looper ball arm and setscrew l o o p e r h o l d e r w i l l c a u s e the upper looper holder.
(8) Positioning the upper looper Standard Adjustment 1) Height of the upper looper The distance between the throat plate surface and the blade point of the looper should be as follows when the upper looper is at the extreme left of its travel. (Unit : mm) Model Dimension...
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Adjustment Procedure Results of Improper Adjustment 1) Height of the upper looper o If the upper looper has been Set a hexagon wrench key onto setscrew at the end of upper looper positioned too high, an excessive bracket to adjust height clearance will be produced When adjusting the height, pay attention also to the clearance pro- between the upper looper and...
(9) Adjusting the double chain looper (Applicable only to MO-6716D series) Standard Adjustment 1) Returning amount of the double chain looper The distance between the needle center and the blade point of the double chain looper should be 1.5 to 1.7 mm when the looper is at the extreme left of its travel.
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Adjustment Procedure Results of Improper Adjustment o Excessive return of the double 1) Returning amount of the double chain looper chain looper will cause frequent Loosen setscrew of double chain lopper driving arm to make stitch skipping when filament this adjustment. thread is used.
(10) Adjusting the height and clearance of the needle guard Standard Adjustment 1) For 1-needle or 2-needle overlock machine The overlock machine has two needle guards, The needle guard should be located 1 mm below the throat plate bottom surface. Needle guard Needle guard Throat plate...
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Adjustment Procedure Results of Improper Adjustment o Excessively close contact 1) For 1-needle or 2-needle overlock machine between the needle guard Adjust needle guard with setscrews in the needle guard so that and the needles will lead to it lightly comes in contact with the needle when the blade point of the needle bend or stitch skipping.
(Unit : mm) Needle Model Dimension A entry MO-6700D series (30P excluded) MO-67 -30P [Standard] Auxiliary feed dog is 0.5 mm lower than main feed dog B = 0.5 mm...
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Adjustment Procedure Results of Improper Adjustment 1) Adjust the height of main feed dog to dimension A with setscrew o If the feed dogs are too high, the needles will be deflected and 2) Adjust the height of differential feed dog with setscrew so that broken when sewing heavyweight...
(13) Adjusting the differential feed ratio Standard Adjustment Pin at its highest position Washer Pin at its lowest Center of position nut Lower marker line (Max, gathering) (Max, stretching) (Standard) Gathering: 1: 4 Gathering: 1:1.6 Gathering: 1: 2 Stretching: 1: 1.3 Stretching: 1:0.6 Stretching: 1: 0.7 (14) Longitudinal position of the feed dog...
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Adjustment Procedure Results of Improper Adjustment 1) Remove cover on the rear of the frame and loosen main feed pin and nut 2) Move main feed pin up or down to adjust the differential feed ratio. 3) Adjust so that the lower engraved marker line on main feed rocker aligns with the center of nut .
(15) Adjusting the presser foot Standard Adjustment 1) Adjusting the tilt of the presser foot The presser foot should be positioned so that the feed dogs go down under the specified presser foot pressure, and the presser foot sole comes in contact evenly with the throat plate surface. Throat plate 2) Adjusting the micro-lifting mechanism of the presser foot –...
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Adjustment Procedure Results of Improper Adjustment 1) Adjusting the tilt of the presser foot o Uneven contact will result in bad Turn the handwheel and place the feed dog in the position where the straight material feed and weak feed dog does not jut out the top surface of the throat plate. feed force.
(16) Positioning the upper knife arm shaft Standard Adjustment The upper knife shaft should be positioned 34 mm above the top surface of the throat plate when it is at its highest position. 34mm (17) Positioning the upper and lower knives, and available overedge widths Standard Adjustment 1) Lower knife Throat plate...
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Adjustment Procedure Results of Improper Adjustment 1) Remove the upper cover, loosen setscrew in upper knife driving o Improperly positioned upper , and turn upper knife shaft to adjust the position from the knife arm shaft will come in top surface of the throat plate to 34 mm. contact with the frame.
(18) Resharpening of the knife Standard Adjustment ° ° (19) Position of the thread cam (Applicable only to MO-6716D series) Standard Adjustment 1) Adjustment of the thread cam Level 2) Adjusting looper thread cam thread guides A and B and the looper thread cam nail Level –...
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Adjustment Procedure Results of Improper Adjustment 1) When the knives have become dull, fully resharpen lower knife o If the 10∞ angle of the lower knife until the contact mark of it disappears. is exceeded, the durability of the 2) When the upper knife has become dull, replace it with a new one. knife will be deteriorated, often (This is because the upper knife is a serrated carbide knife.) resulting in blade chipping.
(19) Position of the thread cam (Applicable only to MO-6716D series) Standard Adjustment 3) Adjusting looper thread auxiliary thread take-up lever (Exclusive for 30P) When lopper thread auxiliary thread take-up lever is in its lower dead point, the thred hole should align with the hole in lopper thread auxiliary thread take-up lever guide The holes should align with each other at the...
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Adjustment Procedure Results of Improper Adjustment 1) Open the cloth base cover and loosen setscrew 2) When looper thread auxiliary thread take-up lever is in its lower dead point (when the feed dog goes back to the end), tighten set- screw so that the thread hole in looper thread auxiliary thread take-up lever...
(20) Adjusting the throat plate support Standard Adjustment Uniform contact (21) Adjusting the feed mechanism cover presser Standard Adjustment – 32 –...
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Adjustment Procedure Results of Improper Adjustment 1) Loosen setscrews and adjust so that throat plate support should o If the throat plate support comes not come in single-sided contact but come in uniform contact with in single sided contact with the throat plate using setscrews throat plate or does not come in...
(22) Adjusting the looper cover Standard Adjustment o The looper cover should smoothly close without coming in contact with upper knife when slowly closing looper cover with upper knife in its lowest position of its troke. Cloth chip cover Frame (23) Adjusting the cloth chip cover Standard Adjustment o When cloth chip cover...
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Adjustment Procedure Results of Improper Adjustment 1) Close looper cover , loosen setscrew , and move looper cover guide plate back and forth until the looper cover is brought to a position where the cover smoothly closes. 2) Move looper cover guide plate until it slightly comes in contact with looper cover receiving bracket .
(24) Position of the thread guides and the looper thread take-ups Standard Adjustment MO-6704D MO-6714D MO-6716D Needle thread take-up lever of Needle thread guide 2-needle machine Needle thread take-up Needle thread take- Needle thread Needle thread guide of up lever of double- Needle thread take-up guide guide 2-needle machine...
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Adjustment Procedure Results of Improper Adjustment 1) Perform the adjustment by the setscrews. Position of the needle thread o Distance guide and needle thread take up lever is a very important decisive When set smaller, better tight- factor when making soft chains since the needle thread take-up ness of needle thread stitches will be obtained.
(25) Adjusting soft chain making mechanism Standard Adjustment 1) Replacing the parts with those exclusively designed for making soft chains Needle thread presser plate C ..12112504 Driving cam ........12112603 Needle thread presser spring B ..12112702 Cam face Throat plate ........(only for 1-needle overlock machine) 0D4-300 .........
3) Important points in adjustment Increase the thread take-up amount of the needle thread take-up lever. Refer to the adjustment values related to the needle thread guide and needle thread take-up lever. Reduce the feed of the looper threads. (Mainly lower looper thread) Set J, K, L and M for the soft chain distances.
4. ADDITIONAL INFORMATION AND PRECAUTIONS (1) Thread tension 1) Strength of tension spring Part No. Color Natural length Operating length Weight required to compress (mm) (mm) spring to working length 13137807 19.5mm 11.5mm 4.21±0.49N (430±50g) 13138508 Yellow 17.8mm 9.8mm 3.14±0.34N(320±35g) 13138805 Blue 17.3mm...
, which contacts with the frame surface. After assembling the front edge of the upper looper guide support (JUKI seal), apply the sealant to the gap of the contact surface between the frame and the upper looper guide support ( section in the illustration).
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Various sealants Maker’s name Part No. * : It is commonly called “JUKI seal”. Three Bond 1104D Three Bond 1104 Three Bond 1212 JUKI exclusive part Nos. of the above 3 kinds of the sealants are not set. – 42 –...
2) Precautions to be taken with respect to the lubricating components Feed bar components o Be careful of the orientation of the oil shield rubber and the dust-proof rubber * Assembling as shown in the illustration will result in oil leakage. So, be careful. o Assemble the feed bar presser and the dust- proof rubber case...
3) Applying the exclusive grease o The exclusive grease (23640204) is applied to the necessary components other than the lubricating com- ponents. Never use any grease other than the exclusive one. It is not necessary to additionally apply grease to the components when the sewing machine is used under the normal condition.
(5) Kinds of motor pulleys, belts and frame support plate bolts 1) Motor pulleys and belts Sewing 50Hz 60Hz speed of Outside diameter Outside diameter V-belt V-belt sewing of motor pulley mm of motor pulley mm Semi-sunken type Fully-sunken type Semi-sunken type Fully-sunken type machine (effective diameter...
6. TROUBLES AND CORRECTIVE MEASURES Trouble Case (1) Case (2) Check and Corrective measures Page 1. Needle thread breakage Threading The thread is entangled with the thread Refer to the threading diagram. guide, or the machine head has been (Refer to the Instruction Manual) incorrectly threaded.
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Trouble Case (1) Case (2) Check and Corrective measures Page 2. Looper thread breakage Thread path Scratches, burrs, rust, etc, on the paw of Remove such scratches, burrs, etc. and carry the throat plate, stitch tongue, looper, out thread path finishing. Replace loopers or looper thread take-up, thread guide, other components which have been deformed, or tension discs causes friction.
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Trouble Case (1) Case (2) Check and Corrective measures Page From the previous page Needle guards A needle guard has been improperly Refer to the pertinent Standard Adjustment. positioned, causing the needle point to strike it. Needle No. The needle is too thin for the materials. Replace the needle with a thicker one.
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Trouble Case (1) Case (2) Check and Corrective measures Page From the previous page Height of needle The needle has incorrect height and does Refer to the related Standard Adjustment. 4, 8 not properly pick up loops even if the looper has a correct return.
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Trouble Case (1) Case (2) Check and Corrective measures Page 7. Upper looer thread stitches are skipped. Threading The thread has been entangled with a See the threading diagram. thread guide. (Refer to the Instruction Manual) Threading has not been done correctly. The needle does not take the upper looper thread.
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Trouble Case (1) Case (2) Check and Corrective measures Page From the previous page Adjustment of looper Clearance or returning amount is not correct. Refer to the related Standard Adjustment. Thread tension The thread tension is too high, preventing Reduce the tension. However, be careful not formation of good loops.
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Trouble Case (1) Case (2) Check and Corrective measures Page 10. Triangle double chain needle Double chain looper The chain looper is too high and too close Correct the height of the chain looper by thread stitches are skipped. to the throat plate, or has bad shape. pushing it down until it cones into contact with the stopper.
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Trouble Case (1) Case (2) Check and Corrective measures Page 12. Problems with double chain stitch Adjustment of loopers Adjustment of the loopers for producing Refer to the related Standard Adjustment. chain-off thread. chain-off thread without materials requires higher accuracy. Needle Guard The needle guard (C) is too high, Refer to the related Standard Adjustment.
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Trouble Case (1) Case (2) Check and Corrective measures Page 13. Overlocking needle thread is loose. Position of the needle thread take-up They are positioned too high, and the thread Refer to the pertinent Standard Adjustment. guide and needle thread guide take-up draws out excessive needle thread.
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Trouble Case (1) Case (2) Check and Corrective measures Page 16. Uneven double chain stitches Thread tension The looper thread tension is not enough. Slightly increase the tension. Presser foot The presser foot comes into contact with Make the presser foot come into contact with the throat plate unevenly.
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Trouble Case (1) Case (2) Check and Corrective measures Page 20. Uneven material feed Presser foot pressure The presser foot pressure is too high. Reduce the presser foot pressure except for the uneven material feed due to puckering. Presser foot The hinge is too stiff.
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Trouble Case (1) Case (2) Check and Corrective measures Page From the previous page Presser foot pressure The presser foot pressure is not high Increase the presser foot pressure. enough, providing poor ironing effect. Differential feed ratio The differential feed ratio has been set for Set it for stretching.
(26) 125±1 37.5 Leg installing position Push button switch installing position (806) JUKI logotype Top of table Type : Helvetica Reg. Condensed Detail drawing of measure (2:1) Condensed voided letters (ø26) This plane is finished (ø26) in the method same as 37.5...
125±1 (37.5) Leg installing position Push button switch installing position (806) JUKI logotype Top of table Type : Helvetica Reg. Condensed Detail drawing of measure (2:1) Condensed voided letters This plane is finished (ø26) (ø26) in the method same as 37.5...
Brand label location indicating of drawing Lid support plate Screw Section Z-Z Section Y-Y Section X-X ø26 (ø26) 30˚ JUKI logotype (silk screening) (Note) All dimensions are in millimeter. (ø10) Part No. of table : 11959558 (ø8.5) – 62 –...
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