1-needle, unison-feed, lockstitch machine with vertical-axis large hook and automatic thread trimmer (needle thread roll-in and short tail type) (4 pages)
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CONTENTS BEFORE OPERATION ......................1 SPECIFICATIONS ........................1 1. INSTALLATION ......................2 2. ADJUSTING THE BELT TENSION ................3 3. ADJUSTING THE STOP POSITION ................3 4. ATTACHING THE BELT COVER ...................4 5. THE AIR DRIVE UNIT OF THE SEWING MACHINE EQUIPPED WITH AUTOMATIC REVERSE FEED DEVICE AND AUTO-LIFTER ............4 6.
Vertical-axis 2.0-fold capacity hook Lift of presser foot Hand lifter lever : 9 mm, Auto-lifter : 16 mm Lubricating oil JUKI New Defrix Oil No. 2 - Equivalent continuous emission sound pressure level (L ) at the workstation : Noise A-weighted value of 80.0 dB;...
1. INSTALLATION 1) Carry the sewing machine with two persons. ❸ (Caution) Do not hold the handwheel. ❶ 2) Do not put protruding articles such as the screw- driver and the like at the location where the sew- ❷ ing machine is placed. 3) Attaching the hinge seats and the support rub- bers of the machine head Fix the hinge seats ❶...
8) Securely attach head support rod to the table until it goes no further. 2. ADJUSTING THE BELT TENSION WARNING : To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest. Adjust the belt tension with the height of the motor so that the belt sags 15 mm when the center of V belt is applied with a 9.8 N load.
4. ATTACHING THE BELT COVER WARNING : To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest. ❹ ❾ ❽ ❸ ❶ ❼ 10 mm ❷ ❺ ❻ 1) Attach belt cover stud ❼ to the screw hole in the arm. 2) Fix belt cover (right) ❶ on the arm with screws ❷ and ❽ . 3) Fit belt cover (left) ❸...
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3) Adjust the number of the air hose to the number of the air cylinder joint and insert the hose to the joint. Solenoid valve Cylinder ① ② ③ ③ ② ⑤ Condensed stitches – – – – (Caution) Do not run the sewing machine while ①...
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2) Install solenoid valve (asm.) ❽ for the needle ❽ ❾ thread clamp device on the back side of regulator mounting plate ❾ with screws (two pieces) supplied with the unit. 3) Insert air hose ❼ which you have detached in ❸...
6) Insert two wires (red and black wires of solenoid Insertion position of 18-pin connector valve (asm.) ❽ into the 18-pin connector of sole- noid valve (asm.) ❸ . (Insert the black wire into (←Red wire) No. 8 and red wire into No. 17.) (←Black wire) * The above diagram represents the model without DL device. For the DL device equipped model, a cord is connected to No.3 and No.12.
❷ into the waste oil hole of the oil pan. (4) Insert oil pipe ❸ into filter ❹ of the oil tank and fix the pipe with a clip. (5) Pour the JUKI New Defrix Oil No. 2 into the oil ❸ tank ❷ until HIGH level is reached.
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❼ in order in the oil tank ❷ , and fix them with butterfly nut ❻ . 7) Insert the oil pipe ❸ into the oil tank ❷ and fix it with a clip. Fill the oil tank with JUKI New Defrix Oil No. 2 up to HIGH level. – 9 –...
(9) Adjusting the amount of oil in the hook 1) Turn the oil amount adjustment screw to adjust the amount of oil in the hook. Turning the screw clockwise will decrease the amount of oil in the hook or counterclockwise will increase it.
9. ATTACHING AND REMOVING THE BOBBIN WARNING : To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest. 1) Lift latch ❶ of hook, and take out the bobbin. 2) Put the bobbin into the shaft in the hook correctly and release the latch ❶ . (Caution) 1. Do not make the machine run idle with the bobbin (bobbin thread). The bob- ❶...
12. WINDING A BOBBIN 1) Pass the thread in the order of ❶ through ❹ . Then, wind it several turns round the bobbin. 2) Tilt bobbin winder lever A. 3) Loosen setscrew B and adjust the position of the adjusting plate to wind a bobbin about 80 % of its ❶...
13. THREADING THE MACHINE HEAD WARNING : To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest. ❷ ❼ ❺ ❸ ❾ ❶ ❹ When using thin thread ❺ ❺ ❻ ❹ ❹ ❼ ❼ * ❽ ❻ ❻ ❽ ❽ 1. Attach arm thread guide A to the top cover with set- Needle thread screw B.
(3) Automatic reverse feed stitching Provided that a JUKI motor and control box, it is possible to automatically carry out reverse feed stitching respectively at the beginning and end of sewing. Refer to "How to operate sewing patterns" in the Instruction Manual for the JUKI motor and control box for details.
15. THREAD TENSION (1) Adjusting the needle thread tension 1) Turn thread tension nut No. 1 ❶ clockwise (A) to shorten the length of thread remaining on the top of needle after thread trimming. Turn the nut ❶ ❷ counterclockwise (B) to lengthen it. 2) Turn thread tension nut No.
18. ADJUSTING THE PRESSURE OF THE PRESSER FOOT Turn presser spring regulating dial ❶ clockwise (A) to increase the pressure of the presser foot, or coun- ❶ terclockwise (B) to decrease it. After the adjustment, tighten nut ❷ . (Caution) Be sure to operate the sewing machine with the pressure of the presser foot ❷...
20. ADJUSTING THE HOOK NEEDLE GUARD WARNING : To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest. When a hook has been replaced, be sure to check ❹ the position of the hook needle guard. ❶ As the standard position of the hook needle guard, ❶ hook needle guard ❷ must push the side face of needle ❶...
22. ADJUSTING THE POSITION OF COUNTER KNIFE AND MOVING KNIFE WARNING : To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest. 1) Bring moving knife ❶ to its initial position. 2) Loosen setscrews ❸ and adjust the posi- tion of counter knife ❷ so that the follow- ing two items are satisfied.
23. ADJUSTING THE KNIFE PRESSURE WARNING : To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest. Loosen screw ❶ , and move the counter knife arm ❸ up and down by turning the eccentric screw ❷ to adjust the knife pressure. ❶ (Caution) Make the knife pressure as low as pos- sible to such an extent that both needle ❸ and bobbin threads can be trimmed. ❷...
25. ADJUSTING THE CLAMP PRESSURE WARNING : To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest. Loosen screw ❶ . Adjust the clamp pressure by turn- ❶ ing the cramp arm ❷ in the direction of the arrow. Adjust the clamp pressure so that the bobbin thread comes off at the pressure of 0.3 N.
29. ADJUSTING THE AUTOMATIC PRESSER FOOT LIFTER WARNING : To protect against possible personal injury due to abrupt start of the machine, be sure to start the following work after turning the power off and ascertaining that the motor is at rest. 1) Loosen adjustment nut ❶ , turn cylinder rod ❷ and adjust so that the lifting amount of the press- er foot is 16 mm when the cylinder is fully com- pressed.
13) After adjustment, tighten the screw ❷ . Repeat step 9) to 12) and check the stop position. 14) After adjusting the stop position, set "1" for SC-922 function No. 56. (Restore.) * Steps of procedure 8) through 14) represents the checking procedure which helps reduce variation in the stop position. * In the case of LU-1520NCS-7, the signals related to the thread trimming are detected with reference to the upper position, therefore, if the upper stop position (white engraved point C and the center of the white engraved point C) are off, it may cause malfunction of the thread trimming. – 22 –...
33. TROUBLES IN SEWING AND CORRECTIVE MEASURES Troubles Causes Corrective measures ① Thread path, needle point, hook blade 1. Thread breakage ◦ Remove the sharp edges or burrs on the (Thread frays or is worn point or bobbin case resting groove blade point of hook using a fine emery pa- out.) on the throat plate has sharp edges or...
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Troubles Causes Corrective measures ① Bobbin thread does not pass through 4. Loose stitches ◦ Thread the bobbin thread correctly. the tension spring of the inner hook. ② Thread path has been poorly finished. ◦ Remove rough parts with a fine emery pa- per or buff it up.
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