ELNA 745 Service Manual
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ELNA 745 Service Manual

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SERVICE MANUAL
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Summary of Contents for ELNA 745

  • Page 1 2. 5 3. 5 6. 0 745/845 SERVICE MANUAL...

  • Page 2: Table Of Contents

    TABLE OF CONTENTS MODEL 745/845 A.General directions and recommendations B. Recommendations C. Mechanical sewing disorders D. Adjustment of the automatic tension unit E. Position of program selection - display drum indicator and display window F. Position of display drum indicator and upper looper shifting cam G.
  • Page 3 GENERAL DIRECTIONS AND RECOMMENDATIONS Safety For safety reasons, the sewing machine must be disconnected from the mains: - Whenever the machine is left unattended - Whenever preparing the machine for sewing - Whenever servicing - Whenever replacing mechanical or electrical parts or accessories Needles Usually needles of the system 130/705 H may be used.
  • Page 4 RECOMMENDATIONS 1. Never connect the machine to a different voltage than that marked on the specification plate. 2. For safety reasons, never perform any repairs on the power supply circuit without first removing the mains lead from the machine. Never plug in or run the machine unless all the connections are correctly set. When changing the light bulb, it is neccessary to disconnect the mains lead.
  • Page 5 MECHANICAL SEWING DISORDERS First of all, please refer to the paragraph entitled "maintenance" in the instruction manual, especially when machine does not turn freely by turning the flywheel by hand. If necessary, check and adjust tightness of motor belt. Given below are the most frequent disorders. In most cases, they can be remedied by checking the adjustments in the following order.
  • Page 6 MECHANICAL SEWING DISORDERS 3. Thread breakage Before checking the adjustment, make sure of the good quality of the thread and the needle, the correctness of threading and the smoothness of all the thread passages. Quite often, an injury to thread passage is the cause of thread breakage. If all these points are in order, check the following: - Dull point of needle or bent needle - replace.
  • Page 7 ADJUSTMENT OF THE AUTOMATIC TENSION UNIT 1. Remove: Mains lead - Front cover. 2. Select sewing program 1 "SAFETY 4 THREAD" 3. Make sure that all the tensiondials are set at "N" position 4. Use a 50 (3ply) cotton thread to check the tension values with the tension gauge. Blue tension 50 to 60 gr.
  • Page 8 POSITION OF PROGRAM SELECTION-DISPLAY DRUM INDICATOR AND DISPLAY WINDOW 1. Remove: Mains lead - Front cover. 2. Select sewing program 1 "SAFETY 4 THREAD" 3. Check and make sure that the lever "h" is facing the notch of tension cam "g" for blue needle thread.
  • Page 9 POSITION OF THE DISPLAY DRUM INDICATOR & UPPER LOOPER SHIFTING CAM 1. Remove: Mains lead - Front cover 2. Make sure if tension cams and levers are set in proper positions when selecting sewing program 1 "SAFETY 4 THREAD". (See and Check Page E). 3.
  • Page 10 THE ADJUSTMENT OF THE CHAIN LOOPER TENSION DIAL 1. Remove: Mains lead - Front cover 2. Open Front Flap. 3. Peel a label "a" from the surface of screw "b" with a needle or a tool with sharp point and remove a tension dial "c" (brown) by loosening a screw "b". 4.
  • Page 11 GAUGE FOR THE AFTER-SALES SERVICE Dimension 4.7mm Height of cloth presser bar 12.0mm Height of needle bar 2.8mm Angular position of lower looper to needle 65.0mm Height of lower looper Gauge Nb. 11951 5.6mm Angular position of upper looper to needle 1.5mm Chain looper angular position 46.0mm...
  • Page 12 REMOVING MACHINE BASE COVER 1. Remove: Mains lead 2. Remove Machine base Unit "1" by loosening screws "a".
  • Page 13 REMOVING BACK COVER 3. Remove Antenna Pole from Spool pin base. 4. Remove screw caps and screws "b" and "c" from Back Cover. 5. Remove Back Cover Unit "3" and Spool Stand "2". 6. Remove Side Cover. Note: To remove screw caps, use a wire pin No.11007. (10mm) (14mm) No.11007...
  • Page 14 REMOVING FRONT COVER 1. Remove: Mains lead 2. Remove screws "b", "c", "d" and Inside Cover Unit "7". 3. Remove Program Selection Dial and a screw cap from Front Cover. 4. Remove snap-on Noise Cover Unit "6". (Spread its sides.) 5.
  • Page 15 REMOVING FRONT COVER When mounting covers, please follow in reverse order (pages 2b-2a-1). Note: When mounting Snap-on Noise Cover "6" in front cover, make sure if a check spring takes its place in a slot as shown in view X . view X...

  • Page 16: Angular Position Of Balance Weights And Position Of Eccentrics

    ANGULAR POSITION OF BALANCE WEIGHTS AND POSITION OF ECCENTRICS Fig.2 Fig.1 Fig.3 Fig.4 Fig.5 Fig.6 Fig.7...
  • Page 17 ANGULAR POSITION OF BALANCE WEIGHTS AND POSITION OF ECCENTRICS 1. Remove: Mains lead - Back - Front cover - Machine base. 2. In case of dismantling the lower shaft or if one of the eccentrics is damaged or badly fixed, the positions shown in page 3a, allow resetting the eccentrics approximately. These should be adjusted correctly with each relative adjustment.

  • Page 18: Height And Alignment Of Cloth Presser Bar

    HEIGHT AND ALIGNMENT OF CLOTH PRESSER BAR...
  • Page 19 HEIGHT AND ALIGNMENT OF CLOTH PRESSER BAR 1. Remove: Mains lead. 2. Lower lever "a" and open lamp cover. 3. Loosen screws "b" to remove bracket with lamp holder. 4. Make sure that the shank holder of presser foot is in its highest position. 5.

  • Page 20: Height And Orientation Of Needle Bar In Relation To The Needle Plate Holes

    HEIGHT AND ORIENTATION OF NEEDLE BAR IN RELATION HEIGHT AND ORIENTATION OF NEEDLE BAR IN RELATION TO THE NEEDLE PLATE HOLES TO THE NEEDLE PLATE HOLES Fig.1 Fig.3 Fig.2...
  • Page 21 HEIGHT AND ORIENTATION OF NEEDLE BAR IN RELATION TO THE NEEDLE PLATE HOLES 1. Remove: Mains lead - Sewing foot. 2. Insert a new needle (No.90) in "R1". 3. With needle bar at its highest position, loosen screws "a" just enough so that needle bar slides with friction.(Fig.1) 4.

  • Page 22: Height - Clearance - Angular Position Of Lower Looper

    HEIGHT-CLEARANCE-ANGULAR POSITION OF LOWER LOOPER 1. Remove: Mains lead - Sewing foot 2. Make sure that there is no axial play on looper shaft "x". 3. Loosen screw "a", adjust height of lower looper as shown and tighten screw "a". 4.

  • Page 23: Clearance Of Needle Guards

    CLEARANCE OF NEEDLE GUARDS 1. Remove: Mains lead - Needle plate. 2. Insert 2 new needles (No.90) in "R1" and "R2" positions. 3. Check height - clearance - angular position of lower looper. 4. Turn the handwheel towardas you and bring needle bar in its lowest position. 5.

  • Page 24: Timing Of Lower Looper

    TIMING OF LOWER LOOPER Fig.1 Fig.3 Fig.2...
  • Page 25 TIMING OF LOWER LOOPER 1. Remove: Mains lead - Sewing foot. 2. Make sure that there is no axial play on lower looper shaft "a". 3. Insert a new needle (Nm 90) in "R1" and check height and orientation of needle bar (page 5), height and angular position of lower looper (page 6).

  • Page 26: Angular Position Of Upper Looper

    ANGULAR POSITION OF UPPER LOOPER 1. Remove: Mains lead - Machine base. 2. Make sure that there is no axial play neither on the upper looper shaft "a" nor on the 2 pivoting axles "b" and "c". 3. Bring upper looper to its far left swing position. 4.
  • Page 27 CLEARANCE AND TIMING OF UPPER LOOPER TO LOWER LOOPER 10 1. Remove: Mains lead - Sewing foot. 2. Check adjustments: - Height and orientation of needle bar (see page 5). - Height - clearance - angular position of lower looper (see page 6 ). - Timing of lower looper (see page 8a &...

  • Page 28: Chain Looper : Angular Position - Clearance - Orbital Timing - Clearance Of Chain

    CHAIN LOOPER : ANGULAR POSITION - CLEARANCE - ORBITAL TIMING - CLEARANCE OF CHAIN NEEDLES GUARD 1.5~1.8mm Fig.2 Fig.1 Motion Fig.3 0~0.1mm 1.0~2.0mm Fig.4 Fig.5...
  • Page 29 CHAIN LOOPER : ANGULAR POSITION - CLEARANCE - ORBITAL TIMING - CLEARANCE OF CHAIN NEEDLES GUARD 1. Remove: Mains lead - Sewing foot - Machine base - Needle plate. 2. Make sure that there is no axial play on chain looper shaft "a". If necessary, adjust with stop collar inside shaft "g"...
  • Page 30 CHAIN LOOPER : ANGULAR POSITION - CLEARANCE - ORBITAL TIMING - CLEARANCE OF CHAIN NEEDLES GUARD Fig.6 -1.0 ‘1.0mm Fig.7 Motion Fig.8 Fig.9...
  • Page 31 CHAIN LOOPER : ANGULAR POSITION - CLEARANCE - ORBITAL TIMING - CLEARANCE OF CHAIN NEEDLES GUARD 6. Orbital timing of Chain Looper - Eccentric: Make sure that there is no axial play on chain looper shaft. If necessary, adjust with stop collar inside shaft "g". Check angular position of Chain Looper and height and orientation of Needle Bar in accordance with pages 11a and 11b.
  • Page 32 LOWER LOOPER & CHAIN LOOPER AUTOMATIC ENGAGEMENT 7. Lower Looper: Turn handwheel towards you to bring lower looper to its far right position. Press lever "a" downwards. Turn handwheel towards you again and check if lever "a" returns automatically to its initial position. If not, loosen screw "h" and insert a washer under the plate "b" to get the gap 0.5 2.0 as shown in Fig.

  • Page 33: Chain Looper Thread Take Up Rotary Cam

    CHAIN LOOPER THREAD TAKE UP ROTARY CAM 1. Timing adjustment for chain looper thread take up rotary Cam "c": When the small hole "d" on "c" adjoins at the surface of chain looper thread guide plate "a", the needle "L2" in its downward movement must be positioned as shown in Fig.1. 2.

  • Page 34: Height Of Feed Dog

    HEIGHT OF FEED DOG 1. Remove: Mains lead - Sewing foot - Needles and Back cover 2. Set stitch length at "0.5" and differential feed at "1". 3. Turn the handwheel towards you and bring feed dogs to their highest position. 4.

  • Page 35: Moving Cutter And Vertical Feed Timing

    MOVING CUTTER AND VERTICAL FEED TIMING 1.0~1.5mm Fig.1 Fig.2 Fig.3 -0.5~0.5mm Fig.4...
  • Page 36 MOVING CUTTER AND VERTICAL FEED TIMING Caution: The eccentric "7" is used for feed and moving cutter timing. See page 3. 1. Remove: Mains lead - Sewing foot - Machine base. 2. Check height and orientation of needle bar - height of feed dog. See pages 5&13. 3.

  • Page 37: Horizontal Feed Timing Against Chainstitch Needle

    HORIZONTAL FEED TIMING AGAINST CHAINSTITCH NEEDLE Fig.1 Fig.2 +0.3mm -0.3mm Fig.3 Fig.4...

  • Page 38: Differential Feed

    HORIZONTAL FEED TIMING AGAINST CHAINSTITCH NEEDLE 15b Note: It is essential to precisely check and adjust this timing. This adjustment avoids bending the chain needle(s) when sewing through maximum thickness of materials. 1. Remove: Mains lead - Machine base 2. Check height of feed dog and vertical feed timing. (See page 13 and 14) 3.

  • Page 39: Differential Feed

    DIFFERENTIAL FEED 1. Remove: Mains lead - Machine base. 2. Set Stitch Length at "5" and differential feed dial at the neutral position "1". 3. Turn the handwheel towards you, check whether both front and back feed dogs move at equal lengths and the distance between them in motion does not vary, as shown on sketch (1) below.

  • Page 40: Position Of Fixed Cutter And Cutting Width Dial Setting

    POSITION OF FIXED CUTTER AND CUTTING WIDTH DIAL SETTING 0.2~ 0.3mm 0.1~ 0.3mm 0~0.05mm 0.1~0.2mm...
  • Page 41 POSITION OF FIXED CUTTER AND CUTTING WIDTH DIAL SETTING 1. Remove: Mains lead - Sewing foot - Needles. 2. Disengage moving cutter. 3. Basic position: Turn dial "a" to bring indicator to position mark "1" and check if clearance of 0.2 to 0.3mm is obtained between fixed blade "b" and needle plate edge. Make sure that there is no play among cutting width cam unit "d", lever "e"...

  • Page 42: Position Of Loopers Threads Take Up Lever

    POSITION OF LOOPERS THREADS TAKE UP LEVER 1. Remove: Mains lead and Inside cover unit ("7" in page 2a). 2. Turn the handwheel towards you and bring upper looper thread take up lever "a" in its highest position. 3. Check and make sure that the distance between thread take up lever guide and inside of the machine base is at 46.0 to 47.3 mm.

  • Page 43: Safety Device - Side Cover And Front Flap

    SAFETY DEVICE - SIDE COVER & FRONT FLAP The device is built in order to switch off the machine as soon as one (or both) of the covers is opened. In case that machine is still switch off by the device with both covers closed: check if switch clicks ON and OFF when opening / closing covers.
  • Page 44 SAFETY DEVICE - PRESSER FOOT & NEEDLE CLAMP 1. Remove: Mains lead 2. Open Lamp Cover. 3. Check and make sure that when presser foot lever "a" and needle clamp safety lever "c" are in up potition, lever "b" of Safety lever cam turns off the micro switch. 4.
  • Page 45 Adjustment of the Top Cover Device - Model 845 exclusive - Fig.1 1.5mm 1.5mm +0.3 1.0 mm -0.2 Fig.2...
  • Page 46 Adjustment of the Top Cover Device - Model 845 exclusive - 1.Remove: Mains lead 2.Select sewing program 10 "COVERHEM/CHAINSTITCH". 3.Turn handwheel towards you and make sure that the upper looper is set at disengaged position. 4.Change the presser foot from standard A/B foot to Top Cover foot (part No. 11636). 5.Lower the presser foot.
  • Page 47 Adjustment of the Top Cover Device - Model 845 exclusive - 0 }0.5mm Fig.4 Fig.3 2.0mm 0 ‘1.0mm 0 }0.5mm Fig.5 Fig.6...
  • Page 48 Adjustment of the Top Cover Device - Model 845 exclusive - 12. Turn handwheel towards you and bring the top cover hook to its far right side. (See Fig. 3). 13. Check if the right side edge of the round thread guide "h" is lapped over the right side edge of the triangle thread guide "g".
  • Page 49 ANNEX TOOLS FOR SETTING SL/DF DIALS Tool A (part No.11960) Fig.2 Tool B (part No.11961)
  • Page 50 ANNEX SETTING POSITIONS OF SL/DF DIALS 1. For easy adjustment, loosen screw "a" of the upper looper shifting cam first. 2. Use tools " A " and " B ". 3. Insert a tool " A " into a hole "b" from the right to the left through holes on Gear Shifting Levers as shown in Fig.1.
  • Page 51 ANNEX SETTING POSITIONS OF SL/DF DIALS...
  • Page 52 ANNEX SETTING POSITIONS OF SL/DF DIALS 4. Turn SL Dial upward to select "0.5" and DF Dial downward to select "0.5" as indicated by "c". 5. Turn handwheel towards you and bring a balancer to the lower side. Check and make sure if there is enough space around the area C to install the unit of SL/DF dials "c".
  • Page 53 ANNEX SETTING POSITIONS OF SL/DF DIALS Fig.2 SL Dial ( view Z ) DF Dial ( view Z ) Fig.4 Fig.3...
  • Page 54 ANNEX SETTING POSITIONS OF SL/DF DIALS 7. Check and make sure if a shaft "i" is parallel to a shaft "h". Fasten a screw "j". (See Fig. 2&3) 8. Check and make sure if gear shifting levers catch gears inside of SL/DF dials as shown in Fig.
  • Page 55 ANNEX CLEARANCE BETWEEN FEED DOG AND NEEDLE PLATE 1. To adjust a clearance between feed dog and needle plate, set SL dial at "5" and DF dial at "1". Turn the handwheel towards you until feed dog moves to far rear position.
  • Page 56 ANNEX TROUBLE SHOOTING - COVER HEMS - cover hems stitch being pulled - 1. If "L0 or L1" needle thread is being pulled to the right (Fig.1), then check the following points: 2. Insert new needles (No. 90) . 3. Check and make sure that needles are correctly inserted into the needle clamp. 4.
  • Page 57 ANNEX TROUBLE SHOOTING - COVER HEMS - irregular loop formation on the chain needles - Fig.1 Blue Yellow Blue Yellow Yellow Fig.2 Fig.3 Fig.4 Yellow Blue Yellow Fig.5 Fig.6...
  • Page 58 ANNEX TROUBLE SHOOTING - COVER HEMS - irregular loop formation on the chain needles - When chain needles start rising from their lowest positions, Chain looper also starts its motion from its far right position to the left. Turn handwheel towards you to bring Chain needles up and make sure if Chain looper passes into loops of Chain needle thread behind each needle.
  • Page 59 ANNEX COVER HEM STITCH FORMATIONS Needles rise to form loops. Chain looper Needles go down into the thread triangle, start its motion from right to left. and chain looper is moving to the right. Chain looper pass into neelde thread loops. Chain looper is releasing needle thread loops.
  • Page 60 ANNEX COVER HEM STITCH FORMATIONS Needles rise to form loops. Chain looper Needles go down into the thread triangle, start its motion from right to left. and chain looper is moving to the right. Chain looper pass into neelde thread loops. Chain looper is releasing needle thread loops.
  • Page 61 M E M O...

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