Janome MyLock 644D Instruction Manual

The Janome MyLock 644D is a professional-grade overlock sewing machine designed for creating clean, finished edges on fabrics. It features 2/3/4-thread overlocking capabilities, differential feed for stretch fabrics, rolled hem function, easy threading system, adjustable stitch length (1-4mm) and width (3.1-7mm), built-in rolled hemming, free-arm capability, and built-in needle threader. Below are key sections for safety, features, setup, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Overlock machine body, presser foot, loopers, needles, stitch width/ length dials, differential feed control, free arm, built-in needle threader.

Installation & Setup

Unpack and inspect contents. Place on stable sewing table.

1. Remove packaging materials and protective covers.
2. Place machine on flat, stable surface at comfortable working height.
3. Connect foot controller to machine and power outlet.
4. Install needles following threading diagram.
5. Thread machine according to color-coded threading system.

WARNING! Machine is heavy; lift with care to avoid injury. Ensure stable placement before operation.

First-Time Operation

Power on machine; test stitches on scrap fabric.

1. Thread machine: Follow color-coded threading path for upper looper, lower looper, and needles.
2. Select stitch type: Choose 2, 3, or 4-thread overlock as needed.
3. Adjust stitch settings: Set length and width according to fabric type.
4. Test on scrap: Always test stitch on fabric scrap before starting project.
5. Begin sewing: Guide fabric under presser foot, keeping edges aligned with stitch guide.

CAUTION! Keep fingers away from moving needles and cutting blade during operation.

Specifications

• Machine Type: Overlock/Serger
• Stitch Types: 2, 3, and 4-thread overlock, rolled hem
• Stitch Length: 1-4mm adjustable
• Stitch Width: 3.1-7mm adjustable
• Differential Feed: 0.7-2.0 ratio
• Speed: Up to 1300 stitches per minute
• Needles: HAx1 SP system needles (included)
• Power Requirements: 120V AC, 60Hz
• Weight: 15.4 lbs (7 kg)
• Warranty: 25-year limited warranty

Controls and Settings

Main controls located on machine front and side panels.

Front Panel: Power switch, handwheel, presser foot lever, stitch length dial, stitch width dial, differential feed control.

Stitch Length: Adjust from 1mm (short) to 4mm (long). Stitch Width: Adjust from 3.1mm to 7mm. Differential Feed: Adjust from 0.7 (gather) to 2.0 (stretch). Rolled Hem: Engage for narrow hemming. Presser Foot Pressure: Automatic adjustment for different fabrics.

Threading Instructions

Follow color-coded threading path for proper operation.

1. Upper looper: Follow blue threading path.
2. Lower looper: Follow red threading path.
3. Right needle: Follow green threading path (for 3/4-thread).
4. Left needle: Follow yellow threading path (for 4-thread only).
5. Use built-in threader: For easy needle threading.

Tip: Always thread with presser foot raised and power off.

Stitch Selection & Techniques

Various stitches for different fabric types and finishes.

1. 2-thread overlock: For lightweight fabrics and decorative edges.
2. 3-thread overlock: Standard for most woven fabrics.
3. 4-thread safety stitch: For extra strength on seams.
4. Rolled hem: For narrow hems on lightweight fabrics.
5. Differential feed: Adjust for stretch fabrics to prevent waving.
6. Flatlocking: For decorative seams and joining stretch fabrics.
7. Gathering: Use differential feed set above 1.0.

WARNING! Always use appropriate needle and thread for fabric type.

Maintenance & Cleaning

Regular maintenance ensures optimal performance.

1. Daily: Brush away lint from loopers and feed dogs.
2. Weekly: Oil machine according to lubrication points diagram.
3. Monthly: Check needle plate for burrs, replace if damaged.
4. As needed: Replace needles after 8 hours of sewing.
5. Storage: Cover machine when not in use to prevent dust accumulation.

CAUTION! Unplug machine before cleaning or maintenance.

Safety Information

Always follow safety guidelines to prevent injury.

• Keep fingers away from moving needles and cutting blade
• Unplug machine when not in use or during maintenance
• Use proper lighting in work area
• Keep work area clean and organized
• Do not operate with damaged power cord
• Keep machine away from water and moisture
• Supervise children and beginners

Troubleshooting

Service: Contact authorized Janome service center for repairs.

Support: 1-800-631-0183; www.janome.com