JUKI MF-7700D Series Engineer's Manual
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JUKI MF-7700D Series Engineer's Manual

JUKI MF-7700D Series Engineer's Manual

Semi-dry head, flat-bed top and bottom coverstitch machine
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Semi-dry head, Flat-bed Top and Bottom Coverstitch Machine
MF-7700D Series
ENGINEER'S MANUAL
40084333
No.E386-00

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Summary of Contents for JUKI MF-7700D Series

  • Page 1 ® Semi-dry head, Flat-bed Top and Bottom Coverstitch Machine MF-7700D Series ENGINEER’S MANUAL 40084333 No.E386-00...
  • Page 2 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.

  • Page 3: Table Of Contents

    1. SPECIFICATIONS....................1 2. CONFIGURATION OF THE MACHINE COMPONENTS ........2 3. MODEL NUMBERING SYSTEM ................3 (1) MF-7700D Series ........................3 (2) MF-7700D Series Thread trimmer..................4 4. MOTOR PULLEY AND BELT ................. 5 5. STANDARD ADJUSTMENT ................... 6 (1) Threading the machine head .
  • Page 4 7. MF-7724DU10D60 (4 needles) ................77 (1) Specifications ........................77 (2) Needle ............................ 77 (3) Standard adjustments ......................78 1) Needle mounting ..........................78 2) Threading the machine head ......................80 3) Adjusting the rocking thread take-up ................... 82 4) Adjusting the position of the needle thread guide rod ...............

  • Page 5: Specifications

    Looper mechanism Spherical rod drive method Lubricating system Forced lubrication method by gear pump Lubricating oil JUKI MACHINE OIL 18 (Equivalent to ISO VG18) Oil reservoir capacity Oil gauge lower line : 600 cm to upper line : 900 cm Installation...

  • Page 6: Configuration Of The Machine Components

    2. CONFIGURATION OF THE MACHINE COMPONENTS Presser spring regulator Oil gauge Rocking thread take-up Needle bar thread take-up cover Feed regulating knob Front cover Oil circulation identification window Eye guard cover Slide cover Oil hole cap Throat plate Needle bar thread take-up Micro-lifter Needle tip silicon oil lubricating unit thread receiver...

  • Page 7: Model Numbering System

    3. MODEL NUMBERING SYSTEM (1) MF-7700D Series Semi-dry head, flat-bed top and bottom coverstitch machine Applicable model : MF-7700D Series 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 M F 7 7 –...

  • Page 8: Mf-7700D Series Thread Trimmer

    (2) MF-7700D Series Thread trimmer Semi-dry head, flat-bed top and bottom coverstitch machine Applicable model : MF-7700D Series Thread trimmer 10 11 12 13 14 15 16 17 18 19 20 21 22 M F 7 7 – 3 to 6...

  • Page 9: Motor Pulley And Belt

    4. MOTOR PULLEY AND BELT MF-7700D Series Sewing speed of the 50Hz 60Hz machine (sti/min) Pulley size (mm) Belt size (inch) Pulley size (mm) Belt size (inch) 3,500 ø80 M-34 ø65 M-33 4,000 ø90 M-35 ø75 M-34 1 . The table shows the numbers when a 3-phase 2-pole 400 W clutch motor (1/2 HP) is used.

  • Page 10: Standard Adjustment

    5. STANDARD ADJUSTMENT (1) Threading the machine head Standard Adjustment 1. Threading for standard seam Broken lines when stretcher thread is used When covering thread is When covering thread is excessively loosened = excessively tense = When covering thread is When using more When using less stretchable thread...
  • Page 11 Adjustment Procedure Results of Improper Adjustment 1. When motion of thread is very rough, and stable seams can not be o When threading is not properly obtained, there are cases where the condition can be improved by performed, not only sewing trouble occurs, but also needle the following threading.

  • Page 12: Adjusting The Rocking Thread Take-Up

    (2) Adjusting the rocking thread take-up Standard Adjustment 1. Length of the rocking thread take-up (1) It is the standard that the length of rocking thread take-up from the center of the shaft of rocking thread take-up support arm to the thread hole face of rocking thread take-up is 95 mm.
  • Page 13 Adjustment Procedure Results of Improper Adjustment 1. Length of the rocking thread take-up o When length of rocking thread (1) Loosen screws and move rocking thread take-up to the right take-up is lengthened, needle or left to adjust the length. thread is tightened.

  • Page 14: Adjusting The Position Of The Needle Thread Guide Rod

    (3) Adjusting the position of the needle thread guide rod Standard Adjustment 1. Position of the needle thread guide rod (1) It is the standard that the height of needle thread guide rods is the position where the dimensions from the top surface of needle thread guide base to the bottom end of the hole are as follows.
  • Page 15 Adjustment Procedure Results of Improper Adjustment o When needle thread guide rod 1. Loosen setscrews , adjust the height of respective needle thread is raised, needle thread is guide rods , and fix the rods with setscrews loosened. (Caution) 1. Move the lateral position of needle thread guide base o When needle thread guide rod fully to the right of slot.

  • Page 16: Adjusting The Position Of The Thread Receiver

    (4) Adjusting the position of the thread receiver Standard Adjustment 1. Position of the needle bar thread take-up thread receiver (in case of standard seams) (1) It is the standard that the height of needle bar thread take-up thread receiver is in the position where the bottom end of thread hole to the center of needle bar thread take-up aligns with the top surface of needle...
  • Page 17 Adjustment Procedure Results of Improper Adjustment 1. Loosen setscrew and move needle bar thread take-up thread o When the needle bar thread receiver up or down to adjust the height. take-up thread receiver 2. When desired to make needle bar thread take-up thread receiver raised, loop becomes large.

  • Page 18: Adjusting The Position Of The Spreader Thread Guide And Spreader Thread Take-Up

    (5) Adjusting the position of the spreader thread guide and spreader thread take-up Standard Adjustment 1. Relation of the position between spreader thread take-up and spreader thread guide is the standard when the top end of thread hole of spreader thread guide aligns with the bottom end of slot spreader thread take-up when spreader thread take-up...
  • Page 19 Adjustment Procedure Results of Improper Adjustment o When the relation of position 1. Loosen setscrews in spreader thread guide and adjust the between spreader thread take- position of spreader thread guide . (Spreader thread take-up and the spreader thread is fixed to rocking thread take-up and can not be adjusted in the guide is not proper, sewing height direction.)

  • Page 20: Adjusting The Spreader

    (6) Adjusting the spreader Standard Adjustment 1. Height of the spreader It is the standard that the height from the top surface of throat plate to the bottom surface of spreader is 8.3 to 8.7 mm. 8.3 to 8.7mm 2. Longitudinal position of the spreader It is the standard that when spreader returns from the extreme left position to the right and top end thread hooking section reaches to the front of left needle, the clearance between the spreader and the left...
  • Page 21 Adjustment Procedure Results of Improper Adjustment 1. Adjusting the height of the spreader o Height of the spreader is improper, stitch skipping of spreader occurs. 2. Adjusting the longitudinal position of the spreader o Adjust the height in accordance Loosen setscrew and adjust the height and longitudinal position with the needle gauge.
  • Page 22 (6) Adjusting the spreader Standard Adjustment 6. Adjustment figures of the spreader thread guide (1) It is the standard that the clearance provided between spreader and spreader thread guide is 0.4 to 1.0 mm. (2) It is the standard that the clearance provided between spreader thread guide and needle clamp thread guide is 0.8 to 1.2 mm.
  • Page 23 Adjustment Procedure Results of Improper Adjustment 6. Spreader thread guide o When height or position of the (1) Adjust the height of spreader to 8.3 to 8.7 mm. Loosen setscrews spreader thread guide is im- in the spreader thread guide and adjust the clearance provided p r o p e r, s t i t c h s k i p p i n g o f between the top surface of spreader and spreader thread guide...

  • Page 24: Adjusting The Timing Relation Between The Looper And Needle Bar

    (7) Adjusting the timing relation between the looper and needle bar Standard Adjustment 1. Timing relation between the looper and the needle bar (synchronization) It is the standard that dimension from the top end of needle eyelet to the blade point of looper passes the rear of the needle and comes to the position of the right end of left needle is the same as dimension from the top end of needle eyelet to the blade point of looper when needle bar comes down from the upper dead...
  • Page 25 Adjustment Procedure Results of Improper Adjustment o When the difference in timing 1. To adjust the timing relation between the needle and the looper, (going and returning) of looper is remove the top cover, loosen four setscrews in the sprocket and excessively large, stitch skipping turn upper pulley in the state that the sprocket is held.

  • Page 26: Returning Amount Of The Looper

    (8) Returning amount of the looper Standard Adjustment 1. It is the standard that returning amount of looper from top end of looper to the center of needle bar is 6.5 mm regardless of the needle gauge when looper is in the extreme right position. 6.5mm 2.
  • Page 27 Adjustment Procedure Results of Improper Adjustment 1. Loosen setscrew in the looper holder and move looper indicator o When the returning amount is to the right and left for adjust. large, loop of needle thread be- 2. After the adjustment, tighten setscrew in the looper holder.

  • Page 28: Height Of The Needle

    (9) Height of the needle Standard Adjustment 1. It is the standard that the top end of needle eyelet of left needle aligns with the bottom end of looper when the top end of looper passes the rear of the needle from the extreme right position and protrudes from the left end of left needle by approximately 1 mm (1.1 mm), dimension B.
  • Page 29 Adjustment Procedure Results of Improper Adjustment 1. Remove rubber cap in the face plate, loosen setscrew in the o When the height of the needle needle bar bracket and adjust the height of the needle bar. is excessively different, stitch 2.

  • Page 30: Locus And Longitudinal Motion Of The Looper

    (10) Locus and longitudinal motion of the looper Standard Adjustment 1. Standard longitudinal motion of the looper (1) It is the standard that the top end of left needle touches the position of 1/4 to 1/3 from the bottom face of the back of the looper when the looper returns from the extreme left position.
  • Page 31 Adjustment Procedure Results of Improper Adjustment o When the longitudinal motion of 1. Changing the longitudinal motion of the looper the looper is small, the rate that (1) Remove 11 setscrews in bed top cover and remove the cover. needle touches the back of the (2) When increasing the longitudinal motion of the looper, loosen nut looper is increased and blunt and lower the arm downward...

  • Page 32: Adjusting The Needle Guard

    (11) Adjusting the needle guard Standard Adjustment   1. Standard position of the rear needle guard (1) Lateral position of rear needle guard It is the standard that the lateral position of rear needle guard is the position where the rear needle guard receives the needle in the range of B.
  • Page 33 Adjustment Procedure Results of Improper Adjustment 1. Loosen setscrew in the rear needle guard holder and perform o When the pressing amount of the adjustment in the lateral direction. rear needle guard is small, needle deflection increases and stitch skipping, thread breakage, needle breakage and worn-out of the top end of looper will be...
  • Page 34 (11) Adjusting the needle guard Standard Adjustment For MF-7700D-U10 (4) Timing of the rear needle guard The standard position of rear needle guard cam is the position where timing mark in rear needle guard cam aligns with the center of the notch of looper longitudinal cam To align 2.
  • Page 35 Adjustment Procedure Results of Improper Adjustment o The cam is excessively changed For MF-7700D-U10 from the standard position, 4. Remove the bed top cover. Loosen two setscrews in rear needle guard cam and adjust needle breakage or stitch skip- ping will be caused. the timing.

  • Page 36: Installing Cover Of The Looper And Needle Guard After Adjusting

    (12) Installing cover of the looper and needle guard after adjusting Standard Adjustment   1. Installing bed top cover – 32 –...
  • Page 37 Adjustment Procedure Results of Improper Adjustment 1. When the adjustment of (10) Locus and longitudinal motion of the o When removing bed top cover looper or (11) Adjusting the needle guard has been performed, apply for adjustment or the like, seal- sealant to section and install bed top cover ant is peeled off and oil leakage...

  • Page 38: Adjusting The Feed Dog

    (13) Adjusting the feed dog Standard Adjustment 1. Height of the feed dog It is the standard that the height of feed dogs (main feed dog and differential feed dog ) is 1 mm from the top surface of the throat plate when feed dogs are in the highest position.
  • Page 39 Adjustment Procedure Results of Improper Adjustment o When the position of the feed Loosen setscrew in the differential feed dog and setscrew dog is high, stitch skipping, de- the main feed dog, and adjust the height. fective chain-off, return of feed, (1) Adjust the top surface of throat plate and the height of the rear etc.
  • Page 40 (13) Adjusting the feed dog Standard Adjustment 3. Lateral position of the feed dog It is the standard of the lateral position of the feed dog that the left and right clearances A of the feed dog in terms of the slots of the throat plate are parallel and equal. –...
  • Page 41 Adjustment Procedure Results of Improper Adjustment o When the lateral position of the 3. Adjusting the lateral position of the feed dog feed dog is incorrect, worn-out of (1) Remove the bed top cover and remove setscrews in rocking bar throat plate and feed dog will be guide 2 caused.
  • Page 42 (13) Adjusting the feed dog Standard Adjustment 4. Longitudinal position of the feed dog (1) Position of the main feed dog : it is the standard that the position where the clearance from the edge of the slot of the throat plate to the front face of the main feed dog is 0.6±0.2 mm at the position where the main feed dog travels to the extreme front position (operator’s side) when feed momentum is set to 3.6 mm (maximum).
  • Page 43 Adjustment Procedure Results of Improper Adjustment o When the fixing position of the 4. Longitudinal position of the feed dog (condition : feed momentum main feed lever slips greatly out 3.6 mm (maximum)) of position, abnormal noise or (1) When fixing setscrew in the main feed lever, adjust the clearance abrasion will be caused.

  • Page 44: Adjusting The Feed Relation

    (14) Adjusting the feed relation Standard Adjustment 1. Changing the stitch length It is possible for the standard stitch length to adjust up to 1.2 to 3.6 mm. Turning feed adjust knob clockwise increases the stitch length and turning it counterclockwise decreases the stitch length.
  • Page 45 Adjustment Procedure Results of Improper Adjustment o When the stitch length is set to 1. When making the stitch length more than 3.6 mm, loosen setscrew more than 3.6 mm, the contact of the feed adjustment stopper pin, turn feed adjust knob of main feed dog, differential feed clockwise, and adjust the stitch length.

  • Page 46: Adjusting The Presser Foot

    (15) Adjusting the presser foot Standard Adjustment 1. Height of the presser foot Height of the presser foot has to be the position the presser foot does not come in contact with other components at the position where lifter lever is lowered and comes in contact with height adjustment screw Dimension A...
  • Page 47 Adjustment Procedure Results of Improper Adjustment o When the position of the presser 1. Adjusting the height of the presser foot foot is too high, it comes in con- Loosen adjustment nut . Lower lifter lever , adjust height tact with the spreader, and break- adjustment screw , and fix nut at the position where the presser...

  • Page 48: Adjusting The Micro-Lifter

    (16) Adjusting the micro-lifter Standard Adjustment 1. Micro-lifter Adjust the micro-lifter in accordance with sewing conditions for use. Major applicable process 1. When twist occurs in the hemming bottom process. 2. When tape is twisted in collecting. Down – 44 –...
  • Page 49 Adjustment Procedure Results of Improper Adjustment 1. Adjusting the micro-lifter (1) When micro-lifter knob is turned counterclockwise, micro-lifter stopper lower and comes in contact with presser lifting lever Then the presser foot goes up. Adjust the height accordance with the sewing conditions. (2) When micro-lifter knob is turned clockwise, micro-lifter stopper is raised and comes in contact with presser lifting lever...

  • Page 50: Adjusting The Looper Thread Cam

    (17) Adjusting the looper thread cam Standard Adjustment 1. Adjust so that thread comes off from the highest place of looper thread cam when needles come down and the top end of left needle aligns with the bottom surface of looper .
  • Page 51 Adjustment Procedure Results of Improper Adjustment o When the position of looper 1. Loosen setscrews in the looper thread cam and adjust while thread cam slips greatly out checking that looper thread comes off from the periphery of the looper of position, stitch skipping or de- thread cam.

  • Page 52: With Regard To Lubrication

    Lubricating oil has been taken out at the time of delivery. Be sure to supply lubricating oil before using the sewing machine for the first time. Oil used : JUKI MACHINE OIL 18 (Caution) Do not use oil addition agent since deterioration of lubricating oil or machine trouble will be caused.
  • Page 53 Adjustment Procedure Results of Improper Adjustment 1. Inspection and replacement o In case oil cannot be observed Loosen setscrews in the oil filter cap and remove oil filter cap from oil circulation identification Draw out oil filter to inspect it. When it is clogged with dust, replace window even when the sew- it with a new one.
  • Page 54 (18) With regard to lubrication Standard Adjustment 3. Oiling No oiling 4. Replacing the lubricating oil – 50 –...
  • Page 55 4. Replacing the lubricating oil In case of the new sewing machine, replace the lubricating oil (JUKI MACHINE OIL 18) with new one after using it for approximately one month. Then replace the lubricating oil every six months.

  • Page 56: Setting For Functions Of Sc-500

    (19) Setting for functions of SC-500 Functions can be selected and specified by means of the four setting switches and light emitting diode located inside the front cover of the SC-500. Specified No. Specified value Switch for entering specified value changed Down switch (DOWN) and updating setting No.
  • Page 57 (4) When you want to advance the setting No., press switch to advance the setting No. Specified When you want to return the setting No., press switch to return the setting No. (Caution) 1. When switch (switch ) is held pressing, the setting No.

  • Page 58: Adjusting And Setting Sc-510

    (20) Adjusting and setting SC-510 1. When SC-510 is used, install the motor referring to the Instruction Manual for SC-510. 2. Installation of the synchronizer 1) Synchronizer can be installed by the method be- low. 2) Using two setscrews , mount synchronizer fixing plate on the sewing machine.
  • Page 59 3. Synchronizer adjustments The synchronizer can be adjusted in the procedures specified below. WARNING : To protect against possible injury to hands or fingers due to abrupt start of the machine during performing adjustment, perform the adjustment of the stop position under the function setting mode. Loosen screw and remove cover Turn disk...
  • Page 60 4. Setting procedure of the machine head Refer to “3-3 Setting for functions of SC-510” in the INSTRUCTION MANUAL for SC-510, and call the function setting No. 95. The type of machine head can be selected by press- ing switch (switch After determining the type of machine head, by pressing switch...
  • Page 61 5. Machine head list Machine head Type Contents Sewing speed set at Max. sewing of display the time of delivery speed (sti/min) from factory (sti/min) — MF Semi-dry (MF-7700D/7800D) MF.d 4000 4000 MF (4 needles) MF.S3 3200 4200 MF Roller MF.S1 4000 5000...

  • Page 63: E10/Md10

    6. E10/MD10 (1) Specifications (E10) Model MF-7700D-E10 Class name Elastic tape attachment with fabric trimmer Max. sewing speed 4,000sti/min (4,000 sti/min with MD) 3-needle 5.6mm, 6.4mm Needdle gauge 2-needle 4.0mm Differential feed ratio 1: 0.7 to 1 : 1 Stitch length 0.9 to 3.6mm (Adjustable to 4.5mm) (2) Specifications (MD10) Model...

  • Page 64: Adjusting The Needle Guard

    (3) Adjusting the needle guard E10/MD10 Standard Adjustment   For MF-7700D-E10 1. Most advanced position of the needle guard Present status (E10) (E10) ° ° Screw position is used as a mark. – 60 –...
  • Page 65 E10/MD10 Adjustment Procedure Results of Improper Adjustment For MF-7700D-E10 195° Present status (E10) Position where the root of rod for looper front-rear motion almost coincides with the center of first screw of the balancer when the rear needle guard is in the most advanced position. 180°...

  • Page 66: Adjustment Of Knife

    E10/MD10 (4) Adjustment of knife Standard Adjustment 1. Adjustment procedure of the knife pressure Strong Weak 2. Adjustment procedure of knife cutting position Left needle Right needle Elastic tape Body part Cutting position – 62 –...
  • Page 67 E10/MD10 Adjustment Procedure Results of Improper Adjustment o Too weak knife pressure may 1. Adjustment procedure of the knife pressure cause the knife to be displaced The fabric trimmer pressure or the pressing force to mesh with the due to the presence of the step counter knife should be made as small as possible within the range section or the like, and the cut where the material cloth can be cut smoothly.
  • Page 68 E10/MD10 Standard Adjustment 3. Adjustment procedure of engagement amount of knives 0.5mm Lowest knife position 4. Replacement procedure of fabric trimmer and fixed knife Processed plane A – 64 –...
  • Page 69 E10/MD10 Adjustment Procedure Results of Improper Adjustment o If the amount of engagement is 3. Adjustment procedure of engagement amount of knives insufficient, the cutting amount (1) Loosen setscrew where fabric trimmer stays in the lowest becomes smaller compared with position so that fabric trimmer can be moved vertically.

  • Page 70: Presser Adjustments

    E10/MD10 (5) Presser adjustments Standard Adjustment – 66 –...
  • Page 71 E10/MD10 Adjustment Procedure Results of Improper Adjustment 1. Adjustment procedure of front-up amount of the presser foot When sewing a thick rubber sheet or the like together, fabric can be smoothly fed by raising the front of presser foot Loosen nut , turn setscrews to the right (clockwise), and raise the front of presser foot...

  • Page 72: Method Of Lubrication

    E10/MD10 (6) Method of lubrication Standard Adjustment 1. Lubrication to bearings Left side Right side 2. Lubrication to clutches – 68 –...
  • Page 73 2. At the time of delivery or starting operation after replenishment, a surplus grease may leak out of the clutch through of the section. In such a case, wipe off the leaking grease. (Appropriate grease: JUKI Part No. 13525506) – 69 –...

  • Page 74: Adjustment Of The Amount Of Feeding

    E10/MD10 (7) Adjustment of the amount of feeding Standard Adjustment 1. Adjustment of the amount of feeding with a cam For tape feeding of 1.4 to 3.3mm For tape feeding of 0.6 to 1.5mm (Shipment from the factory) – 70 –...
  • Page 75 E10/MD10 Adjustment Procedure Results of Improper Adjustment By adjusting eccentric cam B , the amount of tape feed, 0.6 to 1.5mm (at the time of shipment from the factory), can be adjusted within the range of 1.4 to 3.3mm. (1) Remove the pulley cover and the pulley. (2) Loosen two screws at eccentric cam B For tape feeding of 0.6 to 1.5mm: Where the notch of eccentric cam B...

  • Page 76: Adjustments For Heavy Material Sewing

    E10/MD10 (8) Adjustments for heavy material sewing Standard Adjustment 1. Standard adjustments Engraved line B Engraved marking dot Standard adjustments (Shipment from the factory) 2. Adjustments for heavy materials (3.5mm or above) Engraved line A Engraved marking dot Adjustments for heavy materials (3.5mm or above) –...
  • Page 77 E10/MD10 Adjustment Procedure Results of Improper Adjustment 1. Standard adjustments For standard adjustments, the status is that engraved line B meets the engraved marking dot. (Shipment from the factory) 2. Adjustments for heavy materials (3.5mm or above) These adjustments are applicable where heavy materials of 3.5mm or above are processed by joining fabrics and tapes.

  • Page 78: Mounting Position Of The Eccentric Cam

    E10/MD10 (9) Mounting position of the eccentric cam Standard Adjustment – 74 –...
  • Page 79 E10/MD10 Adjustment Procedure Results of Improper Adjustment Mounting position of the eccentric cam (1) Assume the state that eccentric cam B is kept contact with the section of eccentric cam A , as illustrated. (2) Tighten screws (2 pcs. each) of eccentric cams A , respectively as illustrated, so that clearances among washer...
  • Page 80 MEMO – 76 –...

  • Page 81: Mf-7724Du10D60 (4 Needles)

    Looper mechanism Spherical rod drive method Lubricating system Forced lubrication method by gear pump Lubricating oil JUKI MACHINE OIL 18 (Equivalent to ISO VG18) Oil reservoir capacity Oil gauge lower line : 600 cm to upper line : 900 cm Installation...

  • Page 82: Standard Adjustments

    MF-7724DU10D60 (3) Standard adjustments 1) Needle mounting Standard Adjustment 1. Attaching the needle GOOD NG Scart – 78 –...
  • Page 83 MF-7724DU10D60 Adjustment Procedure Results of Improper Adjustment 1) Loosen setscrew and needle with a screwdriver. o If needle is not entered 2) Hold the new needle with its scart made to face the rear and insert completely, this can be a cause it to the end of the hole of needle clamp of stitch skipping.

  • Page 84: Threading The Machine Head

    2) Threading the machine head MF-7724DU10D60 Standard Adjustment When covering thread is excessively When covering thread is excessively tense = loosened = When covering thread is excessively loosened even after passing Broken line when using more stretchable thread When using more stretchable thread –...
  • Page 85 MF-7724DU10D60 Adjustment Procedure Results of Improper Adjustment 1. When motion of thread is very rough, and stable seams can not be o When threading is not properly obtained, there are cases where the condition can be improved by performed, not only sewing the following threading.

  • Page 86: Adjusting The Rocking Thread Take-Up

    3) Adjusting the rocking thread take-up MF-7724DU10D60 Standard Adjustment 1. Length of the rocking thread take-up (1) It is the standard that the length of rocking thread take-up from the center of the shaft of rocking thread take-up support arm to the thread hole face of rocking thread take-up is 90 mm.
  • Page 87 MF-7724DU10D60 Adjustment Procedure Results of Improper Adjustment 1. Length of the rocking thread take-up o When length of rocking thread (1) Loosen setscrews move rocking thread take-up to the right take-up is lengthened, needle and left, adjust so that 90 mm is given from the thread hole to the thread is tightened.

  • Page 88: Adjusting The Position Of The Needle Thread Guide Rod

    4) Adjusting the position of the needle thread guide rod MF-7724DU10D60 Standard Adjustment 1. Position of the needle thread guide rod (1) It is the standard that the height of needle thread guide rods is the position where the dimensions from the top surface of needle thread guide base to the bottom end of the hole are as follows.
  • Page 89 MF-7724DU10D60 Adjustment Procedure Results of Improper Adjustment 1. Position of the needle thread guide rod o When needle thread guide rod is (1) Loosen setscrews and adjust so that the heights of the respective r a i s e d , n e e d l e t h r e a d i s needle thread guide rods are the dimensions as shown in the loosened.

  • Page 90: Adjusting The Rocking Thread Take-Up Thread Receiver

    5) Adjusting the rocking thread take-up thread receiver MF-7724DU10D60 Standard Adjustment 1. Position of the needle bar thread take-up thread receiver (in case of standard seams) Front needle thread – 86 –...
  • Page 91 MF-7724DU10D60 Adjustment Procedure Results of Improper Adjustment (1) Loosen four setscrews in the needle thread receiver plate, and o When the needle bar thread take- adjust the height. Adjust the left medium needle only to 5 mm and up thread receiver is raised, securely tighten the setscrews loop becomes large.

  • Page 92: Adjusting The Looper

    6) Adjusting the looper MF-7724DU10D60 Standard Adjustment 1. Right and left looper positions 3.5mm 2. Front and rear looper positions 7) Adjusting the height of the needle Standard Adjustment 1. Equally adjust clearance A between needles and needle holes in the throat plate. 2.
  • Page 93 MF-7724DU10D60 Adjustment Procedure Results of Improper Adjustment 1. Right and left looper positions o When the returning amount is Clearance between looper and the center of right needle (looper large, loop of needle thread be- return amount) is 3.5 mm. comes large and it is apt to fall.

  • Page 94: Adjusting The Rear Needle Guard

    8) Adjusting the rear needle guard MF-7724DU10D60 Standard Adjustment 0 to 0.05mm 0 to 0.05mm 0.1 to 0.2mm ± A (0 0.2mm) 9) Adjusting the looper thread cam Standard Adjustment Adjust so that thread comes off from the highest place of looper thread cam when needles come down and the top end of left needle aligns with the bottom surface of looper...
  • Page 95 MF-7724DU10D60 Adjustment Procedure Results of Improper Adjustment Adjust the lateral position of rear needle guard so that it receives the o When the pressing amount of needle within the range of B when the needle is in its lowest position. rear needle guard is small, (1) When the blade point of looper comes to the right end left needle,...

  • Page 96: Installing Position Of The Spreader

    10) Installing position of the spreader MF-7724DU10D60 Standard Adjustment 1. Height of the spreader It is the standard that the height from the top surface of throat plate to the bottom surface of spreader is 7.9 to 8.4 mm. 7.9 to 8.4mm 2.
  • Page 97 MF-7724DU10D60 Adjustment Procedure Results of Improper Adjustment 1. Adjusting the height of the spreader o Height of the spreader is improper, To adjust the height of spreader , loosen spreader setscrew stitch skipping of spreader occurs. for adjustment. o Adjust the height in accordance with the needle gauge.

  • Page 98: Ut31

    UT31 8. UT31 (1) Installation of SC-500 Standard Adjustment 1. Installing procedure of the synchronizer 2. Installing procedure of the resistor pack (asm.) 3. Installing procedure of the exclusive cord for MF – 94 –...
  • Page 99 UT31 Adjustment Procedure Results of Improper Adjustment 1. Installing procedure of the synchronizer (1) Using two setscrews , mount synchronizer fixing plate on the sewing machine. Then, install synchronizer on it. (2) Fix a cord of synchronizer to synchronizer fixing plate means of cable clip band .

  • Page 100: Change Of The Setting

    UT31 (2) Change of the setting Standard Adjustment 1. Automatic presser lifting FL ON : Auto-lifter device becomes effective. FL OFF : Auto-liffter function does not work. (Standard at the time of delivery) (Similarly, the presser foot is not automatically lifted when programmed stitching is completed.) 1.
  • Page 101 UT31 Adjustment Procedure Results of Improper Adjustment In order to utilize the setting of SC-500 for MF-7700D, the operations below are necessary. 1. Selection of the auto-lifter function When the auto-lifter device is attached, this function makes the function of auto-lifter work. (1) Turn ON the power switch while pressing switch inside the control box.

  • Page 102: Adjusting The Synchronizer

    UT31 (3) Adjusting the synchronizer (Adjusting procedure of both SC-500 and SC-510 is common.) Standard Adjustment 1. Adjusting DOWN position 2. Adjusting UP position 10mm – 98 –...
  • Page 103 UT31 Adjustment Procedure Results of Improper Adjustment [Adjusting procedure] 1. Adjusting DOWN position (1) Turn the handwheel to adjust the down position of the needle to the position where top end of the looper has scooped loop of the left needle thread. (2) Loosen and remove screw in the cover of synchronizer.

  • Page 104: Installation Of Sc-510

    UT31 (4) Installation of SC-510 Standard Adjustment 1. Wiring SC-510 – 100 –...
  • Page 105 UT31 Adjustment Procedure Results of Improper Adjustment Installing procedure of the exclusive cord for MF Connect the exclusive cords for MF to the respective designated con- nectors as follows. • Synchronizer cord → CN33 • Thread trimmer sensor cord → CN42 •...
  • Page 106 UT31 Standard Adjustment 2. Change of the setting Type A Type B As so the control box of SC-510, there are two types. Type A is displayed in one of them, and type B is dis- played in the other when the power is turned ON. For the control box in which type B is displayed, per- form setting 3.
  • Page 107 UT31 Adjustment Procedure Results of Improper Adjustment 2. Change of the setting (1) Set up the control box again if a display of Type B is presented. 3. Setting method of SC-510 (1) Pressing (+) switch , turn ON the power supply. Remove your finger from (+) switch when the display is presented.
  • Page 108 UT31 Standard Adjustment 4. Automatic presser lifting Solenoid drive display (+33V) Air drive display (+24V) – 104 –...
  • Page 109 UT31 Adjustment Procedure Results of Improper Adjustment (3) Pressing (+) switch or (–) switch to change the type of ma- chine head and select LU.2u to MF.d. (4) After selecting MF.d of the type of machine head, press ( ) switch and ( ) switch .

  • Page 110: Adjusting The Looper Thread Trimmer Mechanism

    UT31 (5) Adjusting the looper thread trimmer mechanism Standard Adjustment 1. Adjusting the looper thread trimmer solenoid 18mm 18mm – 106 –...
  • Page 111 UT31 Adjustment Procedure Results of Improper Adjustment (1) Stroke of looper thread trimmer solenoid is 18 mm. When adjusting the stroke, loosen setscrew of collar move collar to the right or left to adjust. (2) After adjusting the stroke, loosen screw from the lower side, and move collar to the left and right to adjust so that the stroke be-...
  • Page 112 UT31 Standard Adjustment 2. Adjusting the counter knife 167.5mm 3. Adjusting the moving knife – 108 –...
  • Page 113 UT31 Adjustment Procedure Results of Improper Adjustment 2. Adjusting the counter knife (1) loosen setscrews , and move the counter knife in the direction of the arrow to adjust so that the distance from the right end of counter knife stopper to the top end of counter knife is 167.5 mm.
  • Page 114 UT31 Standard Adjustment 4. Adjusting the initial position of the looper thread trimmer mechanism 1.5mm 5. Adjusting the longitudinal position of the moving knife – 110 –...
  • Page 115 UT31 Adjustment Procedure Results of Improper Adjustment 4. Adjusting the initial position of the looper thread trimmer mechanism Adjust so that the clearance between counter knife stopper thread trimmer base is 1.5 mm when looper thread trimmer so- lenoid moves to the extreme left-hand position. (1) Remove pin screw (2) When turning the screw section of adjustment link clockwise,...
  • Page 116 UT31 Standard Adjustment 6. Adjusting the clamp pressure To come in close contact 2.5mm A : To strong B : To weak 7. Adjusting the thread release amount D D : To decrease C : To increase 8. Adjusting the height of the moving knife –...
  • Page 117 UT31 Adjustment Procedure Results of Improper Adjustment 6. Adjusting the clamp pressure (1) Looper thread is held by clamp plate after thread trimming. Adjust the holding force by loosening setscrews and moving clamp plate up and down (A ←→ B). In addition, adjust so that the distance from the top end of moving knife to the top end of clamp plate...
  • Page 118 UT31 Standard Adjustment 9. Adjusting the thread trimmer sensor – 114 –...
  • Page 119 UT31 Adjustment Procedure Results of Improper Adjustment The safety switch is installed so that the sewing machine does not start unless the lower thread trimmer device returns to its home position. (1) Loosen setscrews (2) Adjust switch plate so that LED of thread trimmer sensor lights up in the state that the thread trimmer device is fully returned to its home position.
  • Page 120 UT31 Standard Adjustment 10. Adjusting the disk-rise Clearance between click section and thread tension disk : 0 to –0.5mm (5 positions) 0 to –0.5mm (Click section enters thread tension disk 11. Adjusting the thread release hook 33 to 36mm – 116 –...
  • Page 121 UT31 Adjustment Procedure Results of Improper Adjustment 10. Adjusting the disk-rise (1) Loosen setscrew in adjustment cam , turn adjustment cam and disk-rise plate moves up down. (2) Adjust the clearance between the click section of disk-rise plate and thread tension disk to 0 to –0.5mm (Click section enters thread tension disk .) and tighten setscrew...
  • Page 122 UT31 Standard Adjustment 12. Adjusting the top covering thread trimmer mechanism 0.5mm 18mm Top covering thread – 118 –...
  • Page 123 UT31 Adjustment Procedure Results of Improper Adjustment Adjusting the engagement of knife (1) Adjust so that the engagement of counter knife with moving knife is 0.5 mm. (2) When adjusting the engagement, loosen setscrew and adjust lever Adjusting the moving knife stroke (1) Adjust so that the stroke of moving knife is 18 mm.

  • Page 124: Ut33

    9. UT33 (Only adjustments different from those for UT33 UT31 are described.) (1) Installation of SC-500 Standard Adjustment 1. Installing procedure of the resistor pack (asm.) 2. Installing procedure of the exclusive cord for MF SC-500 – 120 –...
  • Page 125 UT33 Adjustment Procedure Results of Improper Adjustment 1. Installing procedure of the resistor pack (asm.) Install resistor pack (asm.) on cylinder installing base with set- screw 2. Installing procedure of the exclusive cord for MF Connect the exclusive cords for MF to the respective designated con- nectors as follows.

  • Page 126: Installation Of Sc-510

    UT33 (2) Installation of SC-510 Standard Adjustment 1. Installing procedure of the exclusive cord for MF SC-510 – 122 –...
  • Page 127 UT33 Adjustment Procedure Results of Improper Adjustment Connect the exclusive cords for MF to the respective designated con- nectors as follows. • Synchronizer cord → CN33 • Thread trimmer sensor cord → CN42 • Thread trimmer code → CN36 • Presser lifter cord →...

  • Page 128: Piping Of The Thread Trimmer Device

    UT33 (3) Piping of the thread trimmer device Standard Adjustment 1. Piping drawing with the needle thread trimmer 2. Piping drawing for air blow – 124 –...
  • Page 129 UT33 Adjustment Procedure Results of Improper Adjustment Adjusting the air regulator Air hose (1) Insert the air hose to air regulator (2) Use the air pressure at 0.5 MPa (5 kgf/cm (3) Draw up regulator knob , and adjust the pointer to 0.5MPa by turning knob to adjust the air pressure.

  • Page 130: Adjusting The Looper Thread Trimmer Mechanism

    UT33 (4) Adjusting the looper thread trimmer mechanism Standard Adjustment 1. Adjusting the thread trimmer air cylinder 18mm 2. Adjusting the initial position of the looper thread trimmer mechanism 1.5mm – 126 –...
  • Page 131 UT33 Adjustment Procedure Results of Improper Adjustment 1. Adjusting the thread trimmer air cylinder (1) Stroke of air cylinder is 18mm. (2) When adjusting the stroke, loosen setscrew of collar move collar to the right or left to adjust. 2. Adjusting initial position of the looper thread trimmer mechanism Adjust so that the clearance between counter knife stopper and thread trimmer base...
  • Page 132 UT33 Standard Adjustment 3. Adjusting the thread trimmer sensor 4. Adjusting the speed of lower thread trimmer – 128 –...
  • Page 133 UT33 Adjustment Procedure Results of Improper Adjustment 3. Adjusting the thread trimmer sensor The safety switch is installed so that the sewing machine does not start unless the lower thread trimmer device returns to its home position. (1) Loosen setscrews (2) Adjust switch plate so that LED of thread trimmer sensor lights up in the state that the thread trimmer device is fully returned...

  • Page 134: Adjusting The Top Covering Thread Trimmer Mechanism

    UT33 (5) Adjusting the top covering thread trimmer mechanism Standard Adjustment 1. Adjustment of needle thread trimming 0.5mm Top covering thread 2. Adjustment of moving knife speed – 130 –...
  • Page 135 UT33 Adjustment Procedure Results of Improper Adjustment 1. Adjustment of needle thread trimming Adjusting the engagement of knives (1) Adjust so that the engagement of counter knife with moving knife is 0.5 mm. (2) When adjusting the engagement, loosen setscrews and move knife holder up or down to adjust.

  • Page 136: Adjusting The Air-Blow Wiper

    UT33 (6) Adjusting the air-blow wiper Standard Adjustment 1. Installing the air-blow wiper 2. Adjusting the air-blow wiper : To air-blower : To solenoid valve – 132 –...
  • Page 137 UT33 Adjustment Procedure Results of Improper Adjustment 1. Installing the air-blow wiper (1) When using air-blow wiper , remove the top covering thread trim- mer device. (2) Tighten air-blow wiper with setscrews Perform piping referring to the "Air piping drawing" in the Instruc- tion Manual.

  • Page 138: Tc13 (Tape Cutter)

    10. TC13 (Tape cutter) (1) Specifications Applicable model : MF-7700D-C10, MF-7700D-E10/MD10 Tape width used : Max. 40 mm (Finished width) Applicable motor Name of device Type Clutch motor TC13A With control box (220 to 440V) TC13B With control box (100 to 240V) SC-510 TC13C For servo-motor...
  • Page 139 3) TC13C Type for servo-motor Part No. 40020250 SM6051402TP 40019893 40020122 Description Tape cutter unit Tape cutter unit Tape guide Knee switch A (asm.) setscrew Q’ty Part No. D2113555B00 SK3514000SC EA9500B0100 Description Cord clamp fitting Knee switch wood Clip band screw Q’ty –...

  • Page 140: Adjustment Of Knife

    TC13 (2) Adjustment of knife Standard Adjustment 1. Replacement procedure of moving knife and counter knife – 136 –...
  • Page 141 TC13 Adjustment Procedure Results of Improper Adjustment When the moving knife or the counter knife is worn out and replace- ment is necessary, perform the replacement by the procedure below. (1) Remove the whole of tape cutter unit from the sewing machine. (2) Loosen four setscrews and remove the whole of safety cover (3) Loosen two setscrews...
  • Page 142 TC13 Standard Adjustment 2. Adjusting the angle of the counter knife To improve the sharpness of the cutter, it is necessary for the moving knife to engage with the counter knife sightly slantwise. A : Less than 0.1mm It is the standard that there is a clearance of less than B : Small A : Large 0.1 mm at the root of plane of engagement...
  • Page 143 TC13 Adjustment Procedure Results of Improper Adjustment 2. Adjusting the angle of the counter knife (1) Slightly loosen two setscrews in the counter knife (temporarily tightened state) and turn adjustment screw for adjustment. (2) When turning adjustment screw counterclockwise, the angle of counter knife in terms of the moving knife is increased and the knives are set to the state that they engage with each other more slantwise.

  • Page 144: Tc13C

    TC13 (3) TC13C Standard Adjustment 1. Wiring to SC-510 Connector–CN36 1–8 MG output 5–12 Knee switch input SW (5-12) Mg (1-8) CN36 2. Change of the setting As to the control box of SC-510, there are two types. Type A is displayed in one of them, and type B is displayed in the other when the power is turned ON.
  • Page 145 TC13 Adjustment Procedure Results of Improper Adjustment 1. Wiring to SC-510 2. Change of the setting (1) Insert the solenoid cords in No. 1 and No. 8 of Connector CN36. (Cords may be inserted in any connector numbers.) (2) Insert the knee switch cords in No. 5 and No. 12 of Connector CN36. (Cords may be inserted in any connector numbers.) –...
  • Page 146 TC13 Standard Adjustment 3. Setting method of SC-510 – 142 –...
  • Page 147 TC13 Adjustment Procedure Results of Improper Adjustment (1) Pressing (+) switch , turn ON the power. Detach your finger from (+) switch when the display on the left-hand side had appeared. (2) Press ( ) switch to make the type of machine head change- able.
  • Page 148 TC13 Standard Adjustment 4. Release of the thread trimmer sensor When the power supply is turned ON, Error E302 is displayed. Release the thread trimmer sensor in this state. Method of release 0 : Without the thread trimmer 1 : With the thread trimmer –...
  • Page 149 TC13 Adjustment Procedure Results of Improper Adjustment (1) Pressing (+) switch , turn ON the power. Detach your finger from (+) switch when the display on the left-hand side had appeared. (2) Press ( ) switch and select [74]. (3) Press (+) switch or (–) switch and make a change of 1 →...

  • Page 150: Other Cautions

    Wet section in the feed mechanism (2) Application of appropriate grease 1. Where lubrication is needed in any parts other than the lubricating sections, the appropriate grease (Juki Grease A; 23640204, Juki Grease B; 40013640) is already applied. Never use any other type of grease.
  • Page 151 2. There is a grease groove inside the metal of needle bar crank rod Asm. (No. 2). When the needle bar connection (No. 4) is pulled out, fill this groove section with Juki Grease B. 3. There is a lead groove inside the presser lifting shaft Asm. (No. 46). When the presser lifting shaft Asm.

  • Page 152: Adhesives Application Spots

    2 Parts related to spreader (Caution) There is a grease groove inside the spreader longitudinal metal (No. 28). When the spreader longitudinal shaft is pulled out, fill this groove section with Juki Grease B. (3) Adhesives application spots • Needle clamp After degreasing the threaded part of the needle clamp, apply “Lock Tight 242”...
  • Page 162 One chain stitch by right needle One chain stitch by middle needle One chain stitch by left needle Right needle thread miss Middle needle thread miss – 158 –...

  • Page 167: Drawing Of Table

    (On the reverse side) 4-ø10.5, hole, depth 26, spot facing depth 3.5 2-ø3.4, on the bottom surface, depth 10 (Drill a hole at the time of set-up) JUKI logtype Detailed Dimension Drawing (2:1) Style of type: Helvetics Reg. Condensed: Voided letters Y-Y (3-places) Thickness: 1.5...

  • Page 168: For Mf-7700D/E10 (Semi-Submerged Type)

    (On the reverse side) 4-ø10.5, hole, depth 26, spot facing depth 3.5 Refer to Caution.6 2-ø3.4, on the bottom surface, depth 10 JUKI logtype (Drill a hole at the time of set-up) Detailed Dimension Drawing (2:1) Style of type: Helvetics Reg.
  • Page 169 ISO14001 : 2004 REG.NO.JSAE389 CM001 Juki Corporation operates an environmental management system to promote and conduct the following as the company engages in the research, development, design, sales, distribution,and maintenance of industrial sewing machines, household sewing machines, industrial robots, etc., and in the provision of sales and maintenance services...

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