Adjuster's Manual Singer 99 Sewing Machine

The Singer 99 is a classic 3/4 size sewing machine manufactured from 1920s to 1960s, featuring a vibrating shuttle bobbin system, reverse stitch capability, tension adjustment, stitch length control, and built-in bobbin winder. This manual covers proper setup, maintenance, adjustments, and troubleshooting for optimal performance. Below are key sections for operation, adjustments, maintenance, and troubleshooting.

1. Machine Overview 2. Basic Setup 3. Threading Instructions 4. Stitch Adjustments 5. Tension Settings 6. Bobbin Winding 7. Maintenance Procedures 8. Common Adjustments 9. Troubleshooting 10. Parts Reference

Machine Overview

Key components: Cast iron body, vibrating shuttle bobbin system, tension discs, stitch length regulator, reverse lever, presser foot, feed dogs, hand wheel, and built-in bobbin winder.

Component	Function
Hand Wheel	Manual control of needle movement
Tension Discs	Controls upper thread tension
Stitch Length Regulator	Adjusts stitch spacing (0-4mm)
Reverse Lever	Enables backward stitching
Presser Foot Lever	Raises and lowers presser foot
Bobbin Winder	Automatically winds bobbins
Shuttle Race	Holds vibrating shuttle bobbin
Feed Dogs	Moves fabric through machine
Thread Guides	Directs thread path
Needle Clamp	Secures sewing needle

Basic Setup

Unpack and inspect machine. Place on stable surface or in cabinet.

Position machine: Ensure stable, level surface with adequate lighting.
Install belt: Connect hand wheel to motor or treadle mechanism.
Oil points: Apply sewing machine oil to all designated points.
Install needle: Insert needle with flat side toward back, tighten clamp.
Power connection: Connect to electrical outlet or treadle mechanism.

WARNING! Machine is heavy; lift with care. Ensure belt tension is properly adjusted.

Threading Instructions

Proper threading is essential for smooth operation.

Upper threading: From spool pin, through tension discs, take-up lever, down to needle.
Needle threading: Thread from front to back, leave 4-inch tail.
Bobbin threading: Wind bobbin evenly, insert in shuttle with thread clockwise.
Bring up bobbin thread: Hold upper thread, turn hand wheel to catch bobbin thread.

CAUTION! Always raise needle to highest position before threading.

Stitch Adjustments

Stitch Length: Regulator dial controls spacing (0 for darning to 4mm for basting).
Reverse Stitching: Engage reverse lever for back-tacking.
Presser Foot Pressure: Adjust for different fabric weights.
Feed Dog Height: Adjust for specialized techniques like darning.

Tension Settings

Proper tension ensures balanced stitches.

Upper tension: Turn dial clockwise to increase, counterclockwise to decrease.
Bobbin tension: Small screw on shuttle case - turn slightly to adjust.
Test stitching: Use scrap fabric to check tension balance.
Balanced stitch: Threads lock in middle of fabric layers.

Tip: Upper tension typically set between 3-5 for medium weight fabrics.

Bobbin Winding

Built-in winder automatically stops when full.

Disengage clutch: Push hand wheel inward to disengage needle mechanism.
Place bobbin: Position on winder spindle.
Thread winder: Guide thread through tension and around bobbin.
Start winding: Press foot controller or turn hand wheel.
Automatic stop: Winder disengages when bobbin is full.

WARNING! Always disengage clutch before winding bobbin.

Maintenance Procedures

Regular maintenance ensures longevity and performance.

Daily: Brush out lint from bobbin area and feed dogs.

Weekly: Oil all designated points with sewing machine oil.

Monthly: Clean tension discs with folded fabric or dental floss.

Annually: Professional servicing recommended for timing adjustments.

Common Adjustments

Access internal mechanisms by removing face plate and slide plate.

Adjustment	Procedure
Needle Bar Height	Set so needle eye is level with shuttle point at lowest position
Hook Timing	Adjust so hook point passes needle eye at proper distance
Feed Dog Timing	Set to begin moving as needle rises from fabric
Presser Foot Pressure	Adjust spring tension for different fabric weights
Bobbin Case Tension	Fine-tune with small screwdriver for perfect balance

Troubleshooting

Symptom	Possible Cause	Corrective Action
Thread breaking	Incorrect threading/tension	Re-thread completely; check for burrs on needle plate.
Skipped stitches	Needle issues/timing	Replace needle; check needle bar height and hook timing.
Uneven feeding	Feed dog height/pressure	Adjust feed dog height; check presser foot pressure.
Bobbin thread nests	Incorrect bobbin insertion	Remove and reinsert bobbin; check bobbin case tension.
Machine jams	Thread caught in mechanism	Remove upper thread and bobbin; clear shuttle race area.

Reset: Remove all thread, oil points, and test with scrap fabric.

Parts Reference

Common replacement parts: Needles (15x1), Bobbins (Class 66), Belts, Shuttles, Tension Springs.

Service: Contact authorized Singer service center for genuine parts and professional repairs.