Singer 491 Industrial Sewing Machine Manual

The Singer 491 is a heavy-duty industrial sewing machine designed for professional use with high-speed stitching capabilities, automatic lubrication system, reverse stitching function, adjustable stitch length, built-in thread cutter, and powerful motor for handling thick fabrics. Below are key sections for safety, features, installation, setup, 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. Stitch Adjustments 8. Maintenance 9. Safety Features 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Heavy-duty metal frame, industrial motor, automatic lubrication system, reverse stitch lever, stitch length dial, thread tension control, built-in light, knee lift lever.

Feature	Description
Motor	Industrial-grade 550W motor for high-speed sewing
Stitch Length	Adjustable from 1-6mm
Reverse Stitch	Built-in reverse for securing stitches
Automatic Lubrication	Self-oiling system for continuous operation
Thread Tension	Adjustable upper and lower tension
Presser Foot	Quick-change system with multiple foot options
Bobbin System	Rotary hook with class 15 bobbins
Speed Control	Foot pedal with variable speed
Built-in Light	LED work area illumination
Knee Lift	Hands-free presser foot lifting

Installation

Unpack and inspect contents. Place on stable industrial table.

Assemble machine head: Mount onto industrial table using provided bolts.
Install motor: Attach motor bracket and connect drive belt.
Connect power: Plug into dedicated 110V outlet with proper grounding.
Install needle: Insert needle with flat side toward back, tighten screw.
Thread machine: Follow threading diagram from spool to needle.

WARNING! Machine is heavy; use proper lifting equipment. Ensure all connections are secure before operation.

First-Time Setup

Power on machine; test basic functions.

Oil machine: Fill oil reservoir with Singer recommended oil.
Thread machine: Follow numbered threading path precisely.
Wind bobbin: Use built-in bobbin winder with thread tension engaged.
Insert bobbin: Place bobbin in case with thread rotating clockwise.
Test stitches: Run machine on scrap fabric to check tension and stitch quality.
Adjust settings: Set stitch length and tension for your fabric type.

CAUTION! Always disconnect power when threading or changing needles.

Specifications

Machine Type: Industrial Straight Stitch
Stitch Length: 1-6mm adjustable
Speed: Up to 5,500 stitches per minute
Motor: 550W industrial clutch motor
Needle System: DBx1 135x17
Bobbin: Class 15 metal bobbins
Presser Foot Lift: 12mm with knee lift option
Thread: Tex 40 to Tex 120
Power: 110V, 60Hz, single phase
Weight: 65 lbs (machine head only)

Controls and Settings

Access controls via front panel and side adjustments.

Front Panel: Stitch length dial, reverse stitch lever, thread tension dial, handwheel.

Side Controls: Bobbin winder disengagement, motor pulley, belt tension adjustment.

Stitch Length: Rotate dial from 1 (short) to 6 (long). Thread Tension: Adjust dial higher for thicker fabrics, lower for delicate materials. Reverse: Engage lever for back-tacking. Handwheel: Manual operation for precise needle positioning.

Threading and Bobbin

Proper threading is essential for optimal performance.

Upper threading: Follow numbered path from spool pin through tension discs to needle.
Bobbin winding: Disengage clutch, wind bobbin evenly, re-engage clutch.
Bobbin insertion: Drop bobbin in case with thread exiting clockwise.
Bring up bobbin thread: Hold upper thread, rotate handwheel to catch bobbin thread.
Thread tension: Adjust until stitches lock in middle of fabric layers.

Tip: Always pull threads under presser foot and toward back before starting.

Stitch Adjustments

Customize stitches for different fabrics and applications.

Stitch length: Short (1-2mm) for delicate fabrics, long (4-6mm) for basting.
Thread tension: Increase for heavy fabrics, decrease for lightweight materials.
Presser foot pressure: Adjust spring for thick or multiple layers.
Needle position: Centered for straight stitching.
Reverse stitch: Use at beginning and end of seams for reinforcement.

WARNING! Always test settings on scrap fabric before sewing your project.

Maintenance

Regular maintenance ensures long machine life.

Daily: Clean lint from bobbin area and feed dogs.
Weekly: Oil machine according to lubrication chart.
Monthly: Check belt tension and motor alignment.
Annually: Professional service for timing and gear inspection.

CAUTION! Use only Singer recommended oils and parts. Disconnect power before maintenance.

Safety Features

Motor brake: Stops needle quickly when foot pedal is released. Safety clutch: Prevents motor overload. Needle guard: Protects fingers during operation. Grounded plug: Prevents electrical shock.

Regulatory Information

UL Listed: Complies with UL 987 standards for industrial sewing machines. OSHA compliant: Meets workplace safety requirements. Copyright © 2024 Singer Manufacturing Company. For support, visit www.singer.com or contact 1-800-4-SINGER.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Thread breaking	Incorrect threading/tension	Re-thread completely; adjust tension; check for burrs on needle.
Skip stitches	Wrong needle/damaged needle	Replace needle; ensure correct needle type for fabric.
Bobbin thread bunching	Incorrect bobbin insertion	Remove and reinsert bobbin; check bobbin case tension.
Machine won't start	Power/pedal issues	Check power connection; inspect foot pedal cord; reset circuit breaker.
Uneven feeding	Dirty feed dogs/pressure	Clean feed dogs; adjust presser foot pressure; check feed dog height.

Reset: Turn power off for 30 seconds to reset electronic components.

Service: 1-800-4-SINGER; www.singer.com