JUKI LU-2800 Series Engineer's Manual
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JUKI LU-2800 Series Engineer's Manual

Unison-feed, lockstitch machine with vertical-axis large hook
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Unison-feed, Lockstitch Machine with Vertical-axis Large Hook
LU-2800 Series
LU-2810, 2810-7, 2860, 2860-7
LU-2810-6, 2860-6, 2828-6, 2828-7
LU-2818-7, 2868-7
ENGINEER'S MANUAL
40133310
No. E407-03

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Summary of Contents for JUKI LU-2800 Series

  • Page 1 Unison-feed, Lockstitch Machine with Vertical-axis Large Hook LU-2800 Series LU-2810, 2810-7, 2860, 2860-7 LU-2810-6, 2860-6, 2828-6, 2828-7 LU-2818-7, 2868-7 ENGINEER’S MANUAL 40133310 No. E407-03...
  • 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 instruction in detail. And this manual describes “Standard Adjust- ment”, “Adjustment Procedures”, “Results of Improper Adjustment”, and other important information which are not covered in the Instruction Manual.
  • Page 3 TO ENSURE SAFE USE OF YOUR SEWING MACHINE Adjustment : It means replacement of parts, disassembly, and repair assembly. 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.
  • Page 4 JUKI assumes no responsibility for damages or personal injury or death resulting from the use of the machine for any application other than the intended one.
  • Page 5 1. Be sure to use JUKI genuine table and table stand in order to prevent accident that can result in personal injury or death. If it is inevitable to use a table and table stand which are not JUKI genuine ones, select the table and table stand which are able to support the machine weight and reaction force during operation.
  • Page 6 7. If the machine cannot be normally operated after repair or adjustment, immediately stop operation and contact JUKI or the distributor in your area for repair in order to prevent accident that can result in per- sonal injury or death.
  • Page 7 5. Be sure to use JUKI genuine parts when replacing any of the machine parts. JUKI assumes no responsibility for any accident caused by any part other than JUKI genuine one. In addition, in the event you cannot replace parts within the specified range, immediately stop the re- placement work and ask JUKI or distributor in your area for replacement of the parts.
  • Page 8 Replacement of parts 1. In prevention of accident caused by unfamiliarity with the machine or electrical-shock accident, be sure to ask an electrical technician of your company or JUKI or distributor in your area for replacement of electrical components. 2. When it is necessary to open the control box containing electrical parts, be sure to turn the power off and wait for five minutes or more before opening the cover in order to prevent accident caused by un- familiarity with the machine or electrical-shock accident.
  • Page 9 2. In prevention of accident caused by unfamiliarity with the machine or electrical-shock accident, be sure to ask an electrical technician of your company or JUKI or distributor in your area for disassembly/as- sembly of electrical components. 3. When it is necessary to open the control box containing electrical parts, be sure to turn the power off and wait for five minutes or more before opening the cover in order to prevent accident caused by unfa- miliarity with the machine or electrical-shock accident.
  • Page 10 PRECAUTIONS TO BE TAKEN SO AS TO USE THE LU-2800 SERIES MORE SAFELY 1. Keep your hands away from needle when you turn ON the power switch or while the machine is in operation. 2. Do not put your fingers into the thread take-up cover while the machine is operating. DANGER 3.
  • Page 11 CAUTION BEFORE OPERATION WARNING : To avoid malfunction and damage of the machine, confirm the following. • Before you put the machine into operation for the first time after the set-up, clean it thoroughly. Remove all dust gathering during transportation and oil it well. •...

  • Page 12: Table Of Contents

    CONTENTS 1. Specifications ........1 3. Portion to which LOCKTITE is applied ..........74 2. Standard adjustment ......4 4. Selective parts and consumable (1) Needle entry position parts ............. 75 (Standard gauge type) ......4 (2) Needle entry position 5.

  • Page 13: Specifications

    20 Lubrication Automatic lubrication by oil tank (with oil gauge) 21 Lubricating oil JUKI New Defrix Oil No. 1 (equivalent to ISO standard VG7) or JUKI MACHINE OIL No. 7 22 Bed size 643 mm × 178 mm 23 Space under the 347 mm ×...
  • Page 14 20 Lubrication Automatic lubrication by oil tank (with oil gauge) 21 Lubricating oil JUKI New Defrix Oil No. 1 (equivalent to ISO standard VG7) or JUKI MACHINE OIL No. 7 22 Bed size 643 mm × 178 mm 23 Space under the 347 mm ×...
  • Page 15 *1 The speed setting according to the amount of the alternating vertical movement of the walking foot and presser foot is automatically carried out. *2 The noise level show in the table is the level generated in the case JUKI's control box (SC-922) is used. – 3 –...

  • Page 16: Standard Adjustment

    2. Standard adjustment (1) Needle entry position (Standard gauge type) WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment ❶ Dimension E Model Gauge type ❽...
  • Page 17 Adjustment procedures Results of Improper adjustment Set the feed pitch to the maximum (P=9). Stitch skipping or needle break- Turn the handwheel to turn the feed base arm ❹ in the direc- age will result. tion of the arrow. Poorly tensed stitches will result. Make sure that a clearance is secured in the hexagonal hole in clamping screw, right  of the feed base arm into which a tool can be inserted.

  • Page 18: Needle Entry Position (Europe Gauge Type)

    (2) Needle entry position (Europe gauge type) WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment Model group Z, Y Model group X ❷ Operator's side ❸...
  • Page 19 Adjustment procedures Results of Improper adjustment Set the feed pitch to the maximum. Stitch skipping or needle break- Turn the handwheel to turn the feed base arm ❹ in the direc- age will result. tion of the arrow. Poorly tensed stitches will result. Make sure that a clearance is secured in the hexagonal hole in clamping screw, right  of the feed base arm into which a tool can be inserted.

  • Page 20: Height Of The Feed Dog

    (3) Height of the feed dog WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment ❸ Dimension A Model (mm) LU-2810 ❷ LU-2810-6 LU-2810-7 ❶...
  • Page 21 Adjustment procedures Results of Improper adjustment When the height of the feed dog ❸ Set the stitch dial to “0”. Turn the handwheel to bring the height of the feed dog ❸ to is higher than the specified value : the maximum.

  • Page 22: Adjusting The Opener

    (5) Adjusting the opener WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment 1) Clearance of opener Model Dimension A (mm) LU-2810 LU-2810-6 0.7 to 0.9 ❷...
  • Page 23 Adjustment procedures Results of Improper adjustment 1) Clearance of opener When the clearance is larger than LU-2810, 2810-6, 2810-7 the specified value : Turn the handwheel in its normal rotational direction to bring Loose stitches or thread break- that opener ❶ comes nearest to the protruding portion of bob- age will result.

  • Page 24: Opener Timing

    WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment 2) Opener timing 1-needle 2-needle ❶ ❶ ❻ ❾ ❾ ❻ To be in contact ❾...
  • Page 25 Standard adjustment [With thread trimmer] [Without thread trimmer] ❽ ❼ ❷ ❶ ❷ Adjustment procedures Results of Improper adjustment 2) Opener timing Loosen setscrew ❻ of the opener cam ❾ . [With thread trimmer] Three marker dots D on the handwheel ❼ aligns with mark- er line E on the motor cover ❽...

  • Page 26: Needle-To-Hook Timing

    (6) Needle-to-hook timing WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment 1) Height of the needle bar Dimension Dimension Dimension Model A (mm) B (mm) C (mm) 2) Needle-to-blade point of hook timing...
  • Page 27 Adjustment procedures Results of Improper adjustment 1) Height of the needle bar Stitch skipping or thread break- Set the stitch dial to “0”. age will result. Loosen two setscrews ❶ of the face plate to remove the face Loose stitches will result. plate ❷...

  • Page 28: Lift Of The Presser Foot

    (7) Lift of the presser foot WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment 1) Hand lifter [Conditions] • State that the hand lifter is raised. ❼...
  • Page 29 Adjustment procedures Results of Improper adjustment 1) Hand lifter When the lifting amount is higher Loosen setscrews of the motor cover to remove the motor cov- than the specified value : The presser foot ❺ is held Loosen setscrews of the face plate to remove the face plate. raised from the top surface of Loosen clamping screw ❶...

  • Page 30: Knee Lifter (Without Thread Trimmer Only)

    WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment 2) Knee lifter (Without thread trimmer only) [Conditions] • Lifting amount when stopper screw of knee lifter rotation arm comes in contact with mahcine bed.
  • Page 31 Adjustment procedures Results of Improper adjustment 2) Knee lifter (Without thread trimmer only) When the lifting amount is higher Loosen setscrews of the face plate and the rear cover to re- than the specified value : move the face plate and the rear cover. The top end of the needle bar Loosen clamping screw ❶...

  • Page 32: Automatic Presser Foot Lifter (Machine With Thread Trimmer Only)

    WARNING : As the work is performed while the power is ON, never touch the switches other than the necessary one so as to prevent accidents caused by the malfunction of switches. Standard adjustment 3) Automatic presser foot lifter (Machine with thread trimmer only) ❷...
  • Page 33 Adjustment procedures Results of Improper adjustment 3) Automatic presser foot lifter (Machine with thread trimmer When the lifting amount is higher only) than the specified value : Turn the power ON. Carry out thread trimming once. Turn ON The top end of the needle bar the automatic presser foot lifter.

  • Page 34: Feed Adjustment

    (8) Feed adjustment WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment 1) Horizontal feed cam timing [Conditions] • Feed amount : maximum No. 2 screw •...
  • Page 35 Adjustment procedures Results of Improper adjustment 1) Horizontal feed cam timing Pitch error at high or low speed Set the stitch dial to the maximum. is apt to occur. Loosen two setscrews ❶ of the horizontal feed eccentric cam. Needle thread tension will vary. Turn the handwheel to adjust the timing as written on the left Stitch tightness at normal and page.

  • Page 36: Alternate Momentum

    WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment 3) Alternate momentum [Conditions] • Feed amount : 0 mm • Amount of alternate vertical movement : 3 mm Top surface of feed dog Top surface of...
  • Page 37 Adjustment procedures Results of Improper adjustment 3) Alternate momentum Adjust the amount of alternate verti- cal movement of the walking foot ❶ Set the stitch dial to “0”. so that it is larger than that of the Turn the handwheel to make sure that the amount of alternate vertical movement of walking foot ❶...

  • Page 38: (Adjusting The Bottom Feed Amount)

    (9) Needle sway (Adjusting the bottom feed amount) WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment ❶ ❸ ❷ ❷ Operator's side Anti-operator's side ❶...
  • Page 39 Adjustment procedures Results of Improper adjustment Set the standard stitch dial to “6”. Needle breakage or stitch skip- Loosen hinge screw ❶ of the horizontal feed rear arm. ping will result. Center of elongate hole of the horizontal feed rear arm ❷ is aligned with hinge screw nut ❸...

  • Page 40: Stitch Length Of Forward/Reverse Feed

    (10) Stitch length of forward/reverse feed WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment Except for LU-2828-6, 2828-7 Notched part [Conditions] • Feed amount : 6 mm ❶...
  • Page 41 Adjustment procedures Results of Improper adjustment Except for LU-2828-6, 2828-7 Respective stitch lengths of Set the stitch dial to “6”. normal and reverse feeds do not Loosen two setscrews ❶ of the feed adjusting eccentric pin. match. Turn feed adjusting eccentric pin ❷ to adjust the stitch length. Direction A →...

  • Page 42: Position Of The Reverse Feed Control Lever

    (11) Position of the reverse feed control lever WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment In case of LU-2810-6, 2810-7, 2860-6, In case of LU-2810, 2860 2860-7, 2828-6, 2828-7, 2818-7, 2868-7 ❺...
  • Page 43 Adjustment procedures Results of Improper adjustment In case of LU-2810-6, 2810-7, 2860-6, 2860-7, 2828-6, 2828-7, When the position of the reverse feed control lever ❷ is low : 2818-7, 2868-7 Reverse feed lever plate ❹ Set the stitch dial to the maximum. Loosen clamping screw ❶...

  • Page 44: Safety Clutch

    (12) Safety clutch WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment * Standard of release pressure ❶ ❹ ❹ 6 N·m ❸ 25 N·m 13.23 N·m –...
  • Page 45 Adjustment procedures Results of Improper adjustment The safety clutch functions when an excessive load is applied to the lower shaft or the like during sewing. When the safety clutch func- tions, the hook will not rotate even if turning the handwheel, and the lower shaft sprocket wheel ❹...

  • Page 46: Balancer

    (13) Balancer WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment Except for LU-2828-6, 2828-7 ❶ ❷ Operator's side ❺ ❸ ❶ Operator's side ❹...
  • Page 47 Adjustment procedures Results of Improper adjustment Except for LU-2828-6, 2828-7 Vibration becomes big. Loosen setscrews of the face plate to remove the face plate. Turn the handwheel so that the counterweight ❶ faces toward you. Place the balancer ❷ in the position shown in the figure. At this time, make a clearance so that the balancer ❷...

  • Page 48: Reverse Feed Cylinder

    (14) Reverse feed cylinder WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment LU-2810-7, 2860-7 LU-2810-6, 2860-6, 2828-6 ❻ ❹ ❸ ❽ ❶ ❼ ❺...
  • Page 49 Adjustment procedures Results of Improper adjustment LU-2810-7, 2860-7 Stitch lengths of the reverse feed Set the stitch dial to the maximum. may not be obtained. Loosen clamping screw ❺ of the reverse feed arm. Operate the reverse feed control lever to adjust so that the dis- tance between the cylinder support ❸...
  • Page 50 WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment LU-2828-7 LU-2818-7, 2868-7 ❾ ❾ – 38 –...
  • Page 51 Adjustment procedures Results of Improper adjustment LU-2828-7 Stitch lengths of the reverse feed Loosen the nut ❾ . may not be obtained. Adjust so that a clearance between the nut ❾ and the cylinder connecting screw  is 6 ± 0.5 mm. Securely tighten the nut ❾...

  • Page 52: Lubrication

    (15) Lubrication WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment Except for LU-2818-7 and 2868-7 LU-2810, 2810-6, 2810-7, 2828-6, 2828-7, 2818-7 ❶ Only for LU-2818-7 and 2868-7 ❽...
  • Page 53 Set filter clamp  to oil pan  , and fix it with clips ❾ . Pour the JUKI New Defrix Oil No. 1 into the oil tank. (Caution) Adjust the oil quantity so that the pointer of oil gauge ❽...

  • Page 54: Thread Trimmer Device (Except For Lu-2828-6 And 2828-7)

    (16) Thread trimmer device (Except for LU-2828-6 and 2828-7) WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment 1) Position of the counter knife and the clamp spring ❶...
  • Page 55 Adjustment procedures Results of Improper adjustment 1) Position of the counter knife and the clamp spring When dimension A is larger : [Position of the counter knife] Length of bobbin thread clamp Loosen setscrews ❶ (1-needle: 2 positions, 2-needle: 4 posi- is shortened and stitch skipping tions) of the counter knife.

  • Page 56: Position Of The Counter Knife Base

    WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment 2) Position of the counter knife base 1-needle ❷ To be in contact (LU-2818-7, 2868-7) ❶...
  • Page 57 Adjustment procedures Results of Improper adjustment 2) Position of the counter knife base When dimension C is larger : Loosen setscrews ❶ (1-needle: 2 positions, 2-needle: 4 posi- Knife pressure is increased. As a tions) of the counter knife base. result, motor stop will be caused.

  • Page 58: Vertical Position Of The Moving Knife

    WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment 3) Vertical position of the moving knife Model Dimension D (mm) LU-2810-6 0.3 to 0.4 LU-2810-7 ❽...
  • Page 59 Adjustment procedures Results of Improper adjustment 3) Vertical position of the moving knife When the clearance is larger : Loosen clamping screw ❻ of the moving knife driving arm. Clamp failure of needle thread Loosen setscrews ❼ of the moving knife shaft thrust collar. and bobbin thread occurs.

  • Page 60: Thread Trimmer Cam Timing

    WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment 4) Thread trimmer cam timing ❸ ❷ ❶ Most advanced position of moving knife [Conditions] •...
  • Page 61 Adjustment procedures Results of Improper adjustment 4) Thread trimmer cam timing When thread trimming timing is Loosen setscrews ❻ of the thread trimmer cam. retarded : Move the moving knife ❶ to most advanced position. Thread trimming action does not Turn the handwheel ❷...

  • Page 62: Position Of The Thread Trimmer Cam

    WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment 5) Position of the thread trimmer cam ❽ ❾ ❼ ❻ 0.1 ± 0.05 mm 6) Adjusting the knife pressure Knife pressure Model...
  • Page 63 Adjustment procedures Results of Improper adjustment 5) Position of the thread trimmer cam When there is no clearance be- Loosen setscrews ❻ of the thread trimmer cam and clamping tween the thread trimmer cam  screw ❼ of the lower shaft set collar. and the thread trimmer cam roller Set the thread trimmer solenoid to initial position.

  • Page 64: Adjusting The Thread Trimmer Components For Lu-2828-6 And 2828-7

    (17) Adjusting the thread trimmer components for LU-2828-6 and 2828-7 WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment 1) Adjusting the moving knife, the counter knife and the bobbin thread clamp [Adjusting the counter knife position] ❶...
  • Page 65 Adjustment procedures Results of Improper adjustment 1) Adjusting the moving knife, the counter knife and the bobbin thread clamp [Adjusting the counter knife position] Adjust so that the top end of counter knife ❶ is spaced 37.8 mm from the end face B of the auxiliary cover. Then, fix the counter knife ❶...

  • Page 66: Adjusting The Thread Trimmer Cam Timing

    WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment [Adjusting the knife pressure] [Adjusting the bobbin thread clamp position] ❸ ❾ ❽ [Adjusting the bobbin thread clamp pressure] 2) Adjusting the thread trimmer cam timing –...
  • Page 67 Adjustment procedures Results of Improper adjustment [Adjusting the knife pressure] Loosen screws ❽ . Adjust the knife pressure by moving the counter knife arm ❾ up or down. [Adjusting the bobbin thread clamp position] Loosen screw  . Adjust the lateral position of the clamp arm  so that a clearance of 0.05 to 0.2 mm is provided between the clamp arm  and the moving knife ❸...

  • Page 68: Detection Switch Of The Amount Of Alternate Vertical Movement

    (18) Detection switch of the amount of alternate vertical movement WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment Sewing speed Stitch length : Stitch length : Amount of alternate vertical Stitch length :...
  • Page 69 Adjustment procedures Results of Improper adjustment Turn the alternate vertical dial ❶ to adjust the scale between Sewing speed may not change "7.5" to "8". even when turning the alternate vertical dial ❶ . Loosen setscrews of the top cover to remove the top cover. Loosen installing screws ❷...

  • Page 70: Dl Device

    (19) DL device WARNING : As the work is performed while the power is ON, never touch the switches other than the necessary one so as to prevent accidents caused by the malfunction of switches. Standard adjustment The DL device is a device for maximizing the amount of alternate vertical movement when it is placed in When the cylinder is turned ON to maximize the amount of alternate vertical movement, tighten clamping screw ❸...
  • Page 71 Adjustment procedures Results of Improper adjustment Set the alternate vertical dial ❶ to “9”. Loosen clamping screw ❸ of the alternate vertical cylinder arm ❷ . Operate the DL device by 6-operations switch ❹ (or knee switch). Tighten clamping screw ❸ of the alternate vertical cylinder arm ❷...

  • Page 72: Adjusting The Bottom Feed Momentum

    (20) Adjusting the bottom feed momentum WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment Standard adjustment value is the location where the momentum is minimized. Fix hinge screw ❶...
  • Page 73 Adjustment procedures Results of Improper adjustment Loosen hinge screw ❶ of the vertical feed rod. Move the boss section A of the vertical feed cam rod ❷ to adjust the momentum. After the adjustment, tighten hinge screw ❶ of the vertical feed rod.

  • Page 74: Feed Adjustment

    (21) 2P feed adjustment WARNING : As the work is performed while the power is ON, never touch the switches other than the necessary one so as to prevent accidents caused by the malfunction of switches. Standard adjustment 1) LU-2810-6, 2810-7, 2860-6, 2860-7 ①...
  • Page 75 Adjustment procedures Results of Improper adjustment 1) LU-2810-6, 2810-7, 2860-6, 2860-7 ① Zero-point alignment for 2P feed adjustment Set the standard feed adjusting dial ❶ to “0”. Turn the 2P feed adjusting dial ❷ to counter-clockwise, remove the 2P feed adjusting dial screw ❸ . Loosen clamping screw ❹...

  • Page 76: Lu-2828-6, 2828-7

    WARNING : As the work is performed while the power is ON, never touch the switches other than the necessary one so as to prevent accidents caused by the malfunction of switches. Standard adjustment 2) LU-2828-6, 2828-7 ① Zero-point alignment for 2P feed adjustment ②...
  • Page 77 Adjustment procedures Results of Improper adjustment 2) LU-2828-6, 2828-7 ① Zero-point alignment for 2P feed adjustment Set the standard feed adjusting dial ❶ to “0”. Turn the 2P feed adjusting dial ❷ to counter-clockwise, remove the 2P feed adjusting dial screw ❺ . Turn 2P switch ❽...

  • Page 78: Lu-2818-7, 2868-7

    WARNING : As the work is performed while the power is ON, never touch the switches other than the necessary one so as to prevent accidents caused by the malfunction of switches. Standard adjustment 3) LU-2818-7, 2868-7 ① Zero-point alignment for 2P feed adjustment ❹...
  • Page 79 Adjustment procedures Results of Improper adjustment 3) LU-2818-7, 2868-7 ① Zero-point alignment for 2P feed adjustment Set the standard feed adjusting dial ❶ to “0”. Loosen two clamping screws ❷ of the feed adjusting dial to remove the 2P feed adjusting dial ❸ . Loosen three setscrews ❹...
  • Page 80 WARNING : As the work is performed while the power is ON, never touch the switches other than the necessary one so as to prevent accidents caused by the malfunction of switches. Standard adjustment ② Forward/reverse stitch pitch of 2P feed adjustment ❹...
  • Page 81 Adjustment procedures Results of Improper adjustment ② Forward/reverse stitch pitch of 2P feed adjustment [Confirmation items before adjustment] • Make sure that the forward/reverse feed adjustment is matching. • Set the standard feed adjusting dial ❶ to “12”. (Because of the mechanism, the 2P pitch can not be more than the standard pitch.) Turn ON the 2P switch, and check pitches of forward and re- verse stitches.

  • Page 82: Replacing The Motor

    (22) Replacing the motor WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment ❺ (Screw No.1) ❼ ❾ (Screw No.2) ❻ (Screw No.2) ❺ (Screw No.2) ❶...
  • Page 83 Adjustment procedures Results of Improper adjustment Remove the top cover  . Loosen setscrews ❸ and ❹ of the motor cover to remove the motor cover ❷ . Loosen setscrew No. 2 ❺ of the handwheel. Remove setscrew No. 1 ❺ (flat section) of the handwheel. Remove four setscrew ❼...

  • Page 84: Adjusting The Condensation Stitch (Lu-2828-6, 2828-7)

    (23) Adjusting the condensation stitch (LU-2828-6, 2828-7) WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Standard adjustment ❶ ❷ ❸ ❺ 5.2 ± 0.5 mm ❹...
  • Page 85 Adjustment procedures Results of Improper adjustment Adjust the distance from condensation stitch pin ❶ to nut ❷ to 5.2 ± 0.5 mm. Set stitch dial ❸ at the pitch corresponding to the condensation amount you want to set. (Pitch 2 in the case of condensation amount of 2 mm) Loosen clamping screw ❹...

  • Page 86: Portion To Which Locktite Is Applied

    3. Portion to which LOCKTITE is applied LOCKTITE has been applied to the following parts at the time of assembly at the factory. Avoid disassembling these parts to the most. When an assembly which includes the aforementioned parts has been forced to be disassembled, be sure to wash the LOCKTITE applied part using a paint thinner or the like, and reassemble it using LOCKTITE after removing any moisture from the mating faces.

  • Page 87: Selective Parts And Consumable Parts

    4. Selective parts and consumable parts Selective parts Part name Part No. Remarks Model Hook shaft selective washer B255728000A t=1.15 to 1.2 mm Hook shaft selective washer B255728000B t=1.05 to 1.1 mm Hook shaft selective washer B255728000C t=0.9 to 0.95 mm Hook shaft selective washer B255728000D t=0.8 to 0.85 mm...
  • Page 88 Consumable parts Part name Part No. Remarks Model Needle M13517B1600 GROZ-BECKERT 135 x 17 Nm 160 LU-2810, 2810-7 LU-2810-6, 2860-6 LU-2860, 2860-7 LU-2818-7,2868-7 MC321001402 SCHMETZ 134-35 Nm 140 LU-2828-6, 2828-7 Hook (asm.) 40131956 LU-2810-7, 2860-7 LU-2810-6, 2860-6 40126399 LU-2810, 2860 40147912 LU-2828-6, 2828-7 40147985...

  • Page 89: Applying Grease

    JUKI grease A (2) Greasing points 1) Needle bar rocking base Remove face plate. Remove rubber plugs ❶ . Fill grease holes with JUKI Grease A. Attach rubber plugs ❶ . Wipe off grease that was exposed. Attach face plate. Needle bar ❶...

  • Page 90: Alternate Vertical Change Base

    Apply JUKI grease A to felt ❸ . Apply JUKI grease A to sliding surfaces of alternate vertical change base and feed conversion link. Set felt clamp ❷ to alternate vertical change base, and fix it with setscrews ❶ of felt clamp.

  • Page 91: Greasing Point Indication Drawing (* Indicating The Points Where Grease Is Applied At Shipment.)

    4) Greasing point indication drawing (* Indicating the points where grease is applied at shipment.) ❶ : JUKI Grease A Part No.: 40006323 (10g tube) or 23640204 (100g tube) ❷ : Unirex N3..Part No.: 13525506 (10g tube) ❸ : Barch L1002 1.
  • Page 92 2. NEEDLE BAR COMPONENTS ❶ ❶ ❶ ❶ ❶ – 80 –...
  • Page 93 3. HOOK & OPENNER COMPONENTS ❶ ❶ – 81 –...
  • Page 94 4. UPPER FEED COMPONENTS ❸ ❷ ❸ ❷ ❶ ❷ ❷ ❶ ❷ ❷ ❷ ❷ ❸ ❶ ❷ ❷ ❶ ❶ ❷ ❶ ❷ ❷ ❶ ❷ ❷ ❶ ❷ ❷ ❷ ❷ ❶ ❶ ❷ ❶ – 82 –...
  • Page 95 5. HAND LIFTER & AUTO LIFTER COMPONENTS ❶ ❶ ❶ ❶ ❶ ❷ ❷ ❷ 6. KNEE LIFTER COMPONENTS (FOR LU-2810, 2860) ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ – 83 –...
  • Page 96 7. LOWER FEED COMPONENTS ❷ ❷ ❶ ❷ ❷ ❶ ❷ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ – 84 –...
  • Page 97 LOWER FEED COMPONENTS (FOR LU-2828-6, 2828-7) ❷ ❷ ❷ ❷ ❶ ❷ ❷ ❶ ❷ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ – 85 –...
  • Page 98 8. FEED ADJUST COMPONENTS ❶ ❶ ❶ ❷ ❷ ❷ ❷ ❷ ❶ ❶ ❶ ❷ ❷ ❷ ❷ ❷ ❷ ❷ ❷ – 86 –...
  • Page 99 FEED ADJUST COMPONENTS (FOR LU-2828-6, 2828-7) ❶ ❷ ❶ ❶ ❷ ❷ ❷ ❷ ❷ ❷ ❷ ❷ ❶ ❷ ❶ ❷ ❶ ❷ ❷ ❷ ❷ ❷ ❷ – 87 –...
  • Page 100 FEED ADJUST COMPONENTS (FOR LU-2818-7, 2868-7) ❶ ❶ ❶ ❶ ❷ ❶ ❶ ❶ ❶ ❷ ❶ ❶ ❷ ❷ ❷ ❷ ❷ ❷ ❷ ❷ ❷ ❶ ❶ ❶ ❷ ❶ ❶ ❶ – 88 –...
  • Page 101 9. DL COMPONENTS (FOR LU-2810-6, 2810-7, 2860-6, 2860-7) ❷ ❷ 10. AUTO BT COMPONENTS (FOR LU-2810-7, 2860-7) ❶ ❶ ❶ ❶ ❶ ❶ – 89 –...
  • Page 102 AUTO BT COMPONENTS (FOR LU-2810-6, 2860-6, 2828-6) ❶ ❶ AUTO BT COMPONENTS (FOR LU-2828-7) ❶ ❶ ❶ ❶ – 90 –...
  • Page 103 AUTO BT COMPONENTS (FOR LU-2818-7, 2868-7) ❶ ❶ ❶ – 91 –...
  • Page 104 11. THREAD TRIMMING COMPONENTS (FOR LU-2810-6, 2810-7, 2860-6, 2860-7, 2828-6, 2828-7, 2818-7, 2868-7) ❶ ❶ ❶ ❶ ❶ ❶ ❶ – 92 –...
  • Page 105 THREAD TRIMMING COMPONENTS (FOR LU-2828-6, 2828-7) ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ ❶ – 93 –...
  • Page 106 12. THREAD TENSION COMPONENTS (FOR LU-2810, 2810-6, 2810-7, 2828-6, 2828-7, 2818-7) ❷ ❷ ❸ ❸ ❸ ❸ – 94 –...
  • Page 107 13. THREAD TENSION COMPONENTS (FOR LU-2860, 2860-6, 2860-7, 2868-7) ❷ ❷ ❸ ❸ ❸ ❸ – 95 –...
  • Page 108 14. TENSION RELEASE COMPONENTS (FOR LU-2810-6, 2810-7, 2860-6, 2860-7, 2828-6, 2828-7, 2818-7, 2868-7) ❷ ❸ ❷ ❷ ❸ ❷ – 96 –...
  • Page 109 15. BOBBIN WINDER COMPONENTS ❸ ❸ ❸ ❸ – 97 –...
  • Page 110 16. CONDENSE COMPONENTS (FOR LU-2818-7, 2868-7) ❶ ❶ ❶ ❶ ❶ ❶ – 98 –...

  • Page 111: Engraved Marker Dots On The Handwheel (For The Machine With Thread Trimmer Only)

    6. Engraved marker dots on the handwheel (for the machine with thread trimmer only) UP stop position (One marker dot) Adjustment of thread trimmer cam (Two marker dots) Adjustment of opener timing (Three marker dots) – 99 –...

  • Page 112: Machine Head Wiring

    7. Machine head wiring (1) LU-2810-7, 2860-7 1) Connectors coming from machine head (Connect to control box) CN36 : 14P connector CN58 : 22P connector Pin No. Part name Remarks Pin No. Part name Remarks Thread release solenoid (lower side) —...

  • Page 113: Connectors That Are Connected In The Head Cover

    2) Connectors that are connected in the head cover CN100 : 14P connector CN102 : 12P connector Pin No. Part name Remarks Pin No. Part name Remarks Thread release solenoid (lower side) Solenoid valve Presser lifting cylinder Thread trimmer solenoid (right side) Solenoid valve Reverse feed cylinder Thread release solenoid (upper side)

  • Page 114: Details Of Connectors

    2) Details of connectors This clause explains details of connectors ① to ④ and layout of the pins shown in the wiring diagram. Identify the connector pin number as described below. Connector You may find the numeric characters indicated on the connector when The numeric character viewing from the direction of the arrow.
  • Page 115 ② CN36: 14P connector (solenoid, switch) 14 13 11 10 Pin No. Part name Color of cable Remarks Tension release solenoid (lower side) Black Tension release solenoid (upper side) Black － － － Knee switch White Reverse feed switch Black Thread trimming solenoid (left side) Black Thread trimming solenoid (right side)
  • Page 116 ④ CN102: 12P connector (Solenoid valve) Pin No. Part name Color of cable Remarks Solenoid valve (CN151) Black Presser bar lifting cylinder Solenoid valve (CN152) Black Reverse feed cylinder Solenoid valve (CN153) Black Alternate up/down cylinder － － － Solenoid valve (CN155) Black 2-pitch cylinder －...

  • Page 117: Connectors Coming From Machine Head (Connect To Control Box)

    (3) LU-2828-7 1) Connectors coming from machine head (Connect to control box) CN36 : 14P connector CN58 : 22P connector Pin No. Part name Remarks Pin No. Part name Remarks Thread release solenoid (lower side) — Thread release solenoid (upper side) —...

  • Page 118: Connectors That Are Connected In The Head Cover

    2) Connectors that are connected in the head cover CN100 : 14P connector CN102 : 12P connector Pin No. Part name Remarks Pin No. Part name Remarks Thread release solenoid (lower side) Solenoid valve Presser lifting cylinder Thread trimmer solenoid (right side) Solenoid valve Reverse feed cylinder Thread release solenoid (upper side)

  • Page 119: Details Of Connectors

    2) Details of connectors This clause explains details of connectors ① to ⑤ , ⑤ -1 and layout of the pins shown in the wiring dia- gram. Identify the connector pin number as described below. Connector You may find the numeric characters indicated on the connector when The numeric character viewing from the direction of the arrow.
  • Page 120 ② CN36: 14P connector (solenoid, switch) 14 13 11 10 Pin No. Part name Color of cable Remarks Tension release solenoid (lower side) Black Tension release solenoid (upper side) Black － － － Knee switch White Reverse feed switch Black －...
  • Page 121 ④ CN102: 12P connector (Solenoid valve) Pin No. Part name Color of cable Remarks Solenoid valve (CN151) Black Presser bar lifting cylinder Solenoid valve (CN152) Black Reverse feed cylinder Solenoid valve (CN153) Black Alternate up/down cylinder Solenoid valve (CN154) Black Condensation cylinder Solenoid valve (CN155) Black...

  • Page 122: Connectors Coming From Machine Head (Connect To Control Box)

    (5) LU-2818-7, 2868-7 1) Connectors coming from machine head (Connect to control box) CN36 : 14P connector CN58 : 22P connector Pin No. Part name Remarks Pin No. Part name Remarks Thread release solenoid (lower side) — Thread release solenoid (upper side) —...

  • Page 123: Connectors That Are Connected In The Head Cover

    2) Connectors that are connected in the head cover CN100 : 14P connector CN102 : 12P connector Pin No. Part name Remarks Pin No. Part name Remarks Thread release solenoid (lower side) Solenoid valve Presser lifting cylinder Thread trimmer solenoid (right side) Solenoid valve Reverse feed cylinder Thread release solenoid (upper side) Solenoid valve Alternate vertical movement cyl-...

  • Page 124: Troubles And Corrective Measures

    8. Troubles and corrective measures (1) With regard to sewing WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Trouble Cause Checking Corrective measures 1. Thread breakage 1-1) Thread path, needle point, hook blade 1-A) Check the sharp edge or burr Remove the sharp edges or burrs on the blade...
  • Page 125 WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Trouble Cause Checking Corrective measures 3. Needle thread trails 2 to 3 cm 3-1) Needle thread tension is too low. Adjust the needle thread tension.
  • Page 126 WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Trouble Cause Checking Corrective measures 4. Stitch skipping 4-1) Clearance between the needle and 1-A) Check the clearance. Refer to “2.-(6) Needle-to-hook timing”.
  • Page 127 WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Trouble Cause Checking Corrective measures 5. Loose stitches (Balloon stitches 5-1) Clearance between the opener and 1-A) Check the clearance. Refer to “2.-(5) Adjusting the opener”.
  • Page 128 WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Trouble Cause Checking Corrective measures 6. Loose stitches (Needle thread 6-1) Needle thread has not been fully Increase the needle thread ension.

  • Page 129: With Regard To Thread Trimming

    (2) With regard to thread trimming WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Trouble Cause Checking Corrective measures 1. One or several 1-1) Thread remaining at the needle top 1-A) Check the routing of needle thread.
  • Page 130 WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Trouble Cause Checking Corrective measures 2. Thread slips off the 2-1) Needle thread slips off the needle eye- 1-A) Check whether the needle thread re- Refer to the cause of previous section “Needle needle eyelet.
  • Page 131 WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Trouble Cause Checking Corrective measures From the previous page 3-3) Moving knife stops during operation. 3-A) Thread is too thick. Use thread within the specified value.
  • Page 132 WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Trouble Cause Checking Corrective measures From the previous page 3-6) Both needle and bobbin thread cannot 6-A) The blades of moving knife and counter Refer to “2.-(16)-6) Adjusting the knife pressure”.
  • Page 133 WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Trouble Cause Checking Corrective measures 5. Thread slips off the 5-1) Thread tension given by the tension Decrease the thread tension given by the tension needle eyelet at the controller No.
  • Page 134 WARNING : Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine. Trouble Cause Checking Corrective measures 10. When a heave- 10-1) Feed amount of the top feed is inade- Decrease the feed dog height and reduce the feed weight material is quate.

  • Page 135: Lubrication Route Diagram

    9. Lubrication route diagram Details of pump (1) LU-2810, 2810-6, 2810-7, 2828-6, 2828-7, 2818-7 : Lubrication : Circulation Oil tank To distributor Oil regulating valve Oil filter To oil pan Oil filter Pump To hook Details of distributor To hook shaft gear Distributor To oil regulating valve To pump...

  • Page 136: Lu-2860, 2860-6, 2860-7, 2868-7

    (2) LU-2860, 2860-6, 2860-7, 2868-7 To right hook Details of distributors, left and right Distributor, right Joint A Distributor, left : Lubrication : Circulation Joint B Oil tank To left hook Oil filter Oil filter To right hook Joint A Joint B Pump To oil pan...

  • Page 137: Drawing Of Table

    10. Drawing of table (1) For without thread trimming (LU-2810, 2860) W-W (3 locations) U-U (2 locations) V-V (2 locations) Y-Y (2 locations) A 4 × ø3.4 on the bottom surface, depth 20 (Drill a hole at the time of set-up.) B Installing position of drawer stopper (on the bottom surface) C ø16 depth 25 D ø17 drilled hole...

  • Page 138: For Sc-922 (Lu-2810-7, 2860-7)

    (2) For SC-922 (LU-2810-7, 2860-7) W-W (3 locations) U-U (2 locations) V-V (2 locations) Y-Y (2 locations) A 4 × ø3.4 on the bottom surface, depth 20 (Drill a hole at the time of set-up.) B Installing position of drawer stopper (on the bottom surface) C ø16 depth 25 D ø17 drilled hole E 3 ×...

  • Page 139: For V-Belt (Machine With Thread Trimmer) (Lu-2810-6, 2860-6)

    (3) For V-belt (Machine with thread trimmer) (LU-2810-6, 2860-6) 1200 202.5 +0.5 37.5 4×R8 318.5±1 104.2±0.5 265.2±1 4×R8 583.8±1 13.5 +0.5 +0.5 14.5 +0.5 52.5 -0.5 W-W (3 locations) U-U (2 locations) V-V (2 locations) (2ヶ所) Y-Y (2 locations) (2ヶ所) (3ヶ所) (2ヶ所) Ø26...

  • Page 140: For Sc-922 (Lu-2810-7, 2860-7, 2828-7, 2818-7, 2868-7)

    (4) For SC-922 (LU-2810-7, 2860-7, 2828-7, 2818-7, 2868-7) 1200 176.5 +0.5 171.5 318.5±1 104.2±0.5 265.2±0.5 583.8±1 14.5 +0.5 15.5 +0.5 52.5 +0.5 -0.5 (2ヶ所) W-W (3 locations) (3ヶ所) U-U (2 locations) (2ヶ所) V-V (2 locations) Y-Y (2 locations) (2ヶ所) Ø26 □8.5 A 4 ×...

  • Page 141: For V-Belt (Machine With Thread Trimmer) (Lu-2810-6, 2860-6, 2828-6)

    (5) For V-belt (Machine with thread trimmer) (LU-2810-6, 2860-6, 2828-6) 1200 +0.5 37.5 318.5±1 104.2±0.5 265.2±1 583.8±1 14.5 +0.5 15.5 +0.5 +0.5 52.5 -0.5 W-W (2 locations) U-U (2 locations) (2ヶ所) V-V (2 locations) Y-Y (2 locations) A 4 × ø3.4 on the bottom surface, depth 20 (Drill a hole at the time of set-up.) (2ヶ所) (2ヶ所) (2ヶ所)
  • Page 143 Please do not hesitate to contact our distributors or agents in your area for further information when necessary. * The description covered in this engineer's manual is subject to change for improvement of the Copyright © 2012-2014 JUKI CORPORATION commodity without notice.

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