JUNO HF3434D Service Manual
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JUNO HF3434D Service Manual

JUNO HF3434D Service Manual

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S E R V I C E M A N U A L
M o d e l H F 3 4 3 4 D

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Table of Contents
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Summary of Contents for JUNO HF3434D

  • Page 1 S E R V I C E M A N U A L M o d e l H F 3 4 3 4 D...

  • Page 2: Table Of Contents

    CONTENTS SERVICE ACCESS FACE PLATE UNIT ......................1 BACK COVER UNIT ......................2 FRONT COVER UNIT .......................3 SIDE COVER UNIT ......................4 MACHINE BASE ........................5 MECHANICAL ADJUSTMENT MACHINE SOCKET......................6 NEEDLE BAR HEIGHT......................7 PRESSER BAR HEIGHT ....................8 FEED DOG HEIGHT......................9 TIMING OF THE NEEDLE AND THE FEED DOG ............10 TIMING OF THE NEEDLE AND THE UPPER KNIFE ............11 HEIGHT OF THE LOWER LOOPER .................12 CLEARANCE BETWEEN THE NEEDLES AND THE LOWER LOOPER...

  • Page 3: Service Access

    MODEL 3434D SERVICE ACCESS FACE PLATE UNIT To remove: 1. Loosen the set screw A and remove the face plate unit. To attach: 2. Fit the U-groove of the face plate between the setscrew A and set plate, put the rib of face plate into the front cover unit and back cover unit and tighten the setscrew.

  • Page 4: Back Cover Unit

    MODEL 3434D SERVICE ACCESS BACK COVER UNIT To remove: 1. Remove setscrews A and the spool stand. 2. Remove setscrews B,C and D. 3. Remove the back cover unit. To attach: 4. Put the ribs of back cover into the front cover unit and tighten setscrews B, C and D. 5.

  • Page 5: Front Cover Unit

    MODEL 3434D SERVICE ACCESS FRONT COVER UNIT To remove: 1. Remove setscrews A and the looper cover unit. 2. Remove the face plate unit and the back cover unit. 3. Turn the hand wheel toward you with your hand, and set the upper looper at lowest position, and remove setscrews B, C, D,E and the front cover unit.

  • Page 6: Side Cover Unit

    MODEL 3434D SERVICE ACCESS SIDE COVER UNIT To remove: 1. Open the side cover unit. Remove the snap ring E-3 and pull out the shaft. To attach: 2. Attach the side cover unit and insert the shaft and attach the snap ring. Side cover unit Snap ring E-3 Shaft...

  • Page 7: Machine Base

    MODEL 3434D SERVICE ACCESS MACHINE BASE To remove: 1. Remove setscrews A, B, C, D and two hinge screws E, and remove two base cushions F and washers. 2. Remove the machine base. NOTE: Do not remove the remaining two base cushions. To attach: 3.

  • Page 8: Mechanical Adjustment

    MODEL 3434D MECHANICAL ADJUSTMENT MACHINE SOCKET To remove: 1. Remove the back cover unit. 2. Remove the setscrews (A, B) and the machine socket unit from the motor fixing plate. 3. Remove the two setscrews C, and pull out the cord connectors. To attach: 4.

  • Page 9: Needle Bar Height

    MODEL 3434D MECHANICAL ADJUSTMENT NEEDLE BAR HEIGHT Correct Setting: The distance between the tip of needle on the right and the surface of needle plate should be 11.6 to 12.2 mm when the needle bar is at the highest position. To adjust: 1.

  • Page 10: Presser Bar Height

    MODEL 3434D MECHANICAL ADJUSTMENT PRESSER BAR HEIGHT Correct Setting: The distance between the surface of needle plate and bottom of presser foot should be 4.7 to 5.3 mm when the presser bar lifter is raised. To adjust: 1. Remove the looper cover unit, face plate unit, back cover unit and front cover unit. 2.

  • Page 11: Feed Dog Height

    MODEL 3434D MECHANICAL ADJUSTMENT FEED DOG HEIGHT Correct Setting: When the presser foot is lowered and feed dogs are at their highest position, the distance between the surface of needle plate and bottom of presser foot should be 0.75 to 0.95 mm. To adjust: 1.

  • Page 12: Timing Of The Needle And The Feed Dog

    MODEL 3434D MECHANICAL ADJUSTMENT TIMING OF THE NEEDLE AND THE FEED DOG Correct Setting: With the presser foot lowered, the top of the feed dog should be level with the needle plate at the end of feeding movement, when the tip of the right needle is 2-4 mm above the needle plate. Before adjustment, check if the needle bar height and the feed dog height are correct.

  • Page 13: Timing Of The Needle And The Upper Knife

    MODEL 3434D MECHANICAL ADJUSTMENT TIMING OF THE NEEDLE AND THE UPPER KNIFE Correct Setting: The upper knife timing is the same as that of the needle bar. In fact, when the needle bar is at highest position, the upper knife should be also at its highest position. To adjust: 1.

  • Page 14: Height Of The Lower Looper

    MODEL 3434D MECHANICAL ADJUSTMENT HEIGHT OF THE LOWER LOOPER Correct Setting: The tip of the lower looper is 65.7 mm from the center of the lower shaft as shown below. To adjust: 1. Set the upper knife in down position and loosen the setscrew A. 2.

  • Page 15: Clearance Between The Needles And The Lower Looper /Needle Guards

    MODEL 3434D MECHANICAL ADJUSTMENT CLEARANCE BETWEEN THE NEEDLES AND THE LOWER LOOPER/NEEDLE GUARDS (1 of 3) Correct Setting: Both right and left needles should have an equal clearance from the front edge of the opening on the needle plate. The standard clearance between each needle and the lower looper is 0 mm to 0.5 mm. The standard clearance between each needle and the rear needle guard is 0 mm to 0.2 mm.
  • Page 16 MODEL 3434D MECHANICAL ADJUSTMENT CLEARANCE BETWEEN THE NEEDLES AND THE LOWER LOOPER/NEEDLE GUARDS (2 of 3) 2. Clearance between needles and the lower looper 1. Remove the left needle only. 2. Turn the handweel towards you to bring the tip of the lower looper from the left hand to the rear side of the right needle.

  • Page 17: Needle Guards

    MODEL 3434D MECHANICAL ADJUSTMENT CLEARANCE BETWEEN THE NEEDLES AND THE LOWER LOOPER/NEEDLE GUARDS (3 of 3) 3. Clearance between needles and the rear needle guard 1. Change the right needle from #11 to #14. 2. Push the front needle guard against the needle to get the clearance between the needle and the lower looper.

  • Page 18: Clearance Between The Needles And The Fixed Needle Guard

    MODEL 3434D MECHANICAL ADJUSTMENT CLEARANCE BETWEEN THE NEEDLES AND THE FIXED NEEDLE GUARD Correct Setting: The clearance between needle and the fixed needle guard should be 0.1 to 0.4 mm. To adjust: 1. Remove the presser foot and the needle plate and lower the needle to its lowest position. 2.

  • Page 19: Position Of The Chaining Finger

    MODEL 3434D MECHANICAL ADJUSTMENT POSITION OF THE CHAINING FINGER Correct Setting: There should be no gap between the chaining finger and the side of needle plate, and tip of chaining finger should be the same level with the tip of the needle on the needle plate when the needle plate setting knob is set at “S”.

  • Page 20: Position Of The Upper Looper

    MODEL 3434D MECHANICAL ADJUSTMENT POSITION OF THE UPPER LOOPER Correct Setting: The clearance between the bottom of the upper looper and the upper looper shaft guide should be 1.6 to 1.8 mm when the upper looper is at its lowest position. The distance between the center of needle on the right and the center of looper eye should be 4.8 to 5.2 mm when the upper looper is at its leftmost position.

  • Page 21: Timing Of The Needle And The Lower Looper

    MODEL 3434D MECHANICAL ADJUSTMENT TIMING OF THE NEEDLE AND THE LOWER LOOPER Correct Setting: The tip of the #11 needle on the right should be 2.8 to 3.2 mm above from its lowest position when the tip of the lower looper meets the left side of the needle. To adjust: 1.

  • Page 22: Timing Of The Upper And Lower Loopers

    MODEL 3434D MECHANICAL ADJUSTMENT TIMING OF THE UPPER AND LOWER LOOPERS Correct Setting: The distance between the tip of the upper looper and the left side of the lower looper eye should be 0.2 to 1.2 mm when the tip of the upper looper meets the lower edge of the lower looper in its travel from the left to the right as shown in Fig.

  • Page 23: Clearance Between The Loopers

    MODEL 3434D MECHANICAL ADJUSTMENT CLEARANCE BETWEEN THE LOOPERS Correct Setting: The clearance between the upper and lower loopers should be 0 to 0.1 mm when the loopers come to the position as shown in Fig. 1. To adjust: 1. Remove the presser foot and needle plate. 2.

  • Page 24: Clearance Between The Needle And The Upper Looper

    MODEL 3434D MECHANICAL ADJUSTMENT CLEARANCE BETWEEN THE NEEDLE AND THE UPPER LOOPER Correct Setting: When the upper looper meets with needle, the clearance should be: 0 to + 0.1 mm at the needle on the left. -0.05 to + 0.05 mm at the needle on the right. To adjust: 1.

  • Page 25: Position Of The Knives

    MODEL 3434D MECHANICAL ADJUSTMENT POSITION OF THE KNIVES Correct Setting: The edge of the lower knife should be level with the surface of needle plate. The front lower corner of the upper knife should be 0.8 to 1.5 mm below the edge of the lower knife when the upper knife is at the lowest position.

  • Page 26: Position Of The Lower Looper Thread Guide

    MODEL 3434D MECHANICAL ADJUSTMENT POSITION OF THE LOWER LOOPER THREAD GUIDE Lower Looper Thread Guide (3) Loosen the setscrew A, and adjust the lower looper thread guide (3) so that the hole of the thread guide lines up with the groove of lower looper as shown in Fig. 1. NOTE: After adjustment, make sure that the lower looper thread guide (3) dose not interfere with the arm or feed dog.

  • Page 27: Stitch Length

    MODEL 3434D MECHANICAL ADJUSTMENT STITCH LENGTH Correct Setting: The actual stitch length should be 2.8 to 3.0 mm when the stitch length dial is set at “ 3 “ and differential feed dial at “ 1.0 “. To adjust: 1. Set the stitch length dial at “ 3 “ and the differential feed dial at “ 1.0 “. 2.

  • Page 28: Thread Tension Dials

    MODEL 3434D MECHANICAL ADJUSTMENT THREAD TENSION DIALS Thread tension dials are already adjusted for general sewing at factory, however, if you wish stronger or weaker settings for special sewing, it can be altered as follow: To adjust: 1. Pull out the thread tension dial. 2.

  • Page 29: Play Of Main Shaft

    MODEL 3434D MECHANICAL ADJUSTMENT PLAY OF MAIN SHAFT The main shaft should turn smoothly without a detectable lateral play. To adjust: 1. Remove the looper cover unit, and front cover unit. 2. Remove the belt from the handwheel pulley. 3. From the bottom of the machine, loosen setscrews A on the balance weight (right). Press the balance weight to right against the bushing and tighten the setscrews A.

  • Page 30: Motor Belt Tension

    MODEL 3434D MECHANICAL ADJUSTMENT MOTOR BELT TENSION Correct Setting: To check for proper belt tension, press the belt in the middle of the span lightly with your finger (approximately 300 gr). The belt should bend 5 to 6 mm. To adjust: 1.

  • Page 31: Oiling

    MODEL 3434D OILING Apply a few drops of fine quality sewing machine oil to the parts indicated with arrows. It is recommended to apply oil once a week in normal use, once in ten working-hours in continuous use. Open the side cover and apply oil. Open the looper cover and apply oil.

  • Page 32: Gauges For Servicing

    MODEL 3434D GAUGES FOR SERVICING Servicing gauge Lower looper height Gauge Needle gauge Thickness O.L G05 No.787-G-01 No.787-G02 No.787-G03 Adjusting gauge O.L G05 This gauge is used for adjusting the following characteristics: (A): Needle bar height (B): Presser bar height 11.4 mm (C): Feed dog height &...

Table of Contents