Juki Sewing Machine DDL 5550 Manual

The Juki DDL 5550 is a high-speed, straight stitch, single needle lockstitch sewing machine designed for industrial use. It features automatic lubrication, reverse stitching, thread trimmer, and electronic speed control. With a maximum sewing speed of 5,500 SPM, it's ideal for garment manufacturing, upholstery, and other textile applications. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Threading and Bobbin 7. Operation Guide 8. Maintenance Schedule 9. Care & Cleaning 10. Safety Information 11. Troubleshooting

Features at a Glance

Key components: High-speed straight stitch mechanism, automatic lubrication system, reverse stitch lever, thread trimmer, electronic speed control pedal.

FeatureDescription
Maximum Speed5,500 stitches per minute
Stitch TypeStraight lockstitch
Needle SystemDBx1
LubricationAutomatic oil circulation
Reverse StitchingManual reverse lever
Thread TrimmerBuilt-in automatic trimmer
Stitch Length1.0mm to 5.0mm adjustable
Presser Foot LiftManual and knee lift options
Motor TypeClutch motor or servo motor
Machine WeightApproximately 45 kg

Installation

Unpack and inspect contents. Place on stable industrial table.

  1. Position machine: Ensure stable surface with adequate workspace.
  2. Install motor: Attach clutch motor or servo motor according to specifications.
  3. Connect power: Use proper industrial power supply (220V/380V depending on model).
  4. Oil filling: Fill oil tank with recommended sewing machine oil.
  5. Thread setup: Install upper thread and bobbin according to threading diagram.

WARNING! Machine is heavy; use proper lifting equipment. Ensure all electrical connections are secure and grounded.

First-Time Setup

Power on machine; perform initial setup procedures.

  1. Oil circulation: Run machine at low speed for 5 minutes to circulate oil.
  2. Needle installation: Install proper DBx1 needle with flat side facing correct direction.
  3. Thread tension: Adjust upper and bobbin thread tension for balanced stitches.
  4. Stitch length: Set desired stitch length using adjustment dial.
  5. Presser foot pressure: Adjust according to fabric thickness.

CAUTION! Always disconnect power before performing any adjustments or maintenance.

Specifications

Controls and Settings

Main controls: Handwheel, reverse stitch lever, thread trimmer knob, stitch length dial, tension discs.

Adjustment Points: Stitch length dial, upper thread tension, bobbin case tension, presser foot pressure, needle bar height, hook timing.

Operation: Foot pedal controls speed, handwheel for manual operation, reverse lever for back-tacking, thread trimmer for automatic thread cutting.

Threading and Bobbin

Upper Threading: Follow numbered guides from spool to needle.

  1. Place thread spool on spindle
  2. Thread through first tension disc
  3. Pass through take-up lever
  4. Thread through needle bar guide
  5. Insert thread through needle eye from front to back

Bobbin Installation:

  1. Wind bobbin with proper thread tension
  2. Insert bobbin into case with thread unwinding counterclockwise
  3. Pull thread through slot and under tension spring
  4. Insert bobbin case into hook race
  5. Pull bobbin thread up through needle plate

Operation Guide

Daily operation procedures for optimal performance.

  1. Power on: Connect to power source
  2. Fabric placement: Position fabric under presser foot
  3. Start sewing: Press foot pedal gently to begin
  4. Reverse stitching: Use reverse lever for back-tacking
  5. Thread trimming: Activate trimmer at seam end
  6. Fabric removal: Lift presser foot and remove fabric
  7. Power off: Disconnect power when not in use

Tip: Always test stitch on scrap fabric before starting production work.

Maintenance Schedule

Regular maintenance ensures long machine life and consistent performance.

Maintenance TaskFrequency
Oil level checkDaily
Clean lint and dustDaily
Needle replacementEvery 8 hours or when damaged
Bobbin case cleaningWeekly
Hook race cleaningWeekly
Full oil changeEvery 6 months
Complete overhaulAnnually

Care & Cleaning

Disconnect power before cleaning. Use soft brush for lint removal, cloth for oil spills.

  1. Remove needle plate and clean feed dog area
  2. Clean bobbin case and hook race
  3. Wipe exterior with soft, dry cloth
  4. Check oil passages for blockages
  5. Inspect for worn parts

CAUTION! Never use compressed air for cleaning as it can force lint into oil passages.

Safety Information

Always follow safety procedures to prevent accidents and injuries.

Troubleshooting

SymptomPossible CauseCorrective Action
Thread breakingIncorrect tension, burred needleAdjust tension, replace needle, check thread path
Skip stitchesWrong needle size, bent needleReplace needle, check needle bar height
Uneven stitchesImproper tension, worn feed dogBalance tension, replace feed dog
Machine noisyLow oil, loose partsCheck oil level, tighten all screws
Needle breakingWrong needle, timing issueUse correct needle, check hook timing
Fabric puckeringToo much tension, wrong presser footReduce tension, use correct foot
Oil stains on fabricOver-oiling, clogged wicksClean excess oil, replace oil wicks

Service Contact: Authorized Juki service center for major repairs and adjustments.

Technical Support: Contact Juki dealer or visit www.juki.co.jp for technical information.

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