Singer 6233 Service Manual

The Singer 6233 is a versatile sewing machine designed for home use, featuring multiple stitch patterns, adjustable stitch length and width, built-in buttonholer, free arm capability, and easy threading system. This service manual provides detailed information for maintenance, troubleshooting, and repair procedures. Below are key sections covering safety precautions, machine overview, disassembly instructions, adjustment procedures, lubrication points, electrical specifications, and common troubleshooting.

1. Machine Overview 2. Safety Precautions 3. Disassembly Instructions 4. Adjustment Procedures 5. Lubrication Points 6. Electrical Specifications 7. Timing Adjustment 8. Needle & Hook Alignment 9. Tension System 10. Troubleshooting Guide 11. Parts List & Diagrams

Machine Overview

Key components: Main housing, stitch selection dial, stitch length/width controls, handwheel, bobbin winder, free arm, feed dog, presser foot, needle bar, hook assembly, motor, and foot pedal.

Component	Description
Stitch Selection Dial	Selects from straight, zigzag, decorative, and buttonhole stitches
Stitch Length Control	Adjusts stitch length from 0 to 4 mm
Stitch Width Control	Adjusts zigzag width up to 5 mm
Free Arm	Removable extension for sewing cuffs and sleeves
Bobbin Winder	Automatically winds bobbin; disengages when full
Feed Dog	Moves fabric under presser foot; can be lowered for darning
Presser Foot	Holds fabric in place; includes pressure adjustment
Needle Bar	Holds needle; moves vertically
Hook Assembly	Rotates to catch needle thread and form stitches
Motor	110-120V AC motor; controlled by foot pedal

Safety Precautions

Always unplug machine before servicing. Use proper tools.

Disconnect power: Unplug from outlet before any disassembly.
Remove needle: Take out needle to prevent injury.
Work on clean surface: Ensure area is well-lit and free of clutter.
Use correct tools: Employ screwdrivers, pliers, and lubricants specified in manual.

WARNING! Risk of electric shock. Do not operate with cover removed. Keep hands clear of moving parts.

Disassembly Instructions

Follow steps in order; keep screws organized.

Remove top cover: Unscrew two rear screws; lift cover off.
Remove face plate: Take out screws around dial; gently pry off.
Access hook area: Remove bobbin case and slide plate.
Remove motor cover: Unscrew bottom plate; disconnect motor wires if needed.
Extract needle bar: Loosen set screw; slide bar out carefully.

CAUTION! Label wires and parts for reassembly. Do not force components.

Adjustment Procedures

Stitch Length: Adjust via control; verify with test fabric.
Stitch Width: Set width dial; check zigzag symmetry.
Presser Foot Pressure: Turn screw at top of machine; increase for heavy fabric.
Bobbin Tension: Adjust small screw on bobbin case; test with thread pull.
Feed Dog Height: Set lever to raise/lower; ensure smooth fabric feed.

Tip: Make small adjustments; test after each change.

Lubrication Points

Use Singer sewing machine oil only.

Hook race: Apply one drop to hook bearing surfaces.
Needle bar: Oil where bar enters bushing.
Feed dog mechanism: Oil moving joints under throat plate.
Handwheel shaft: Oil at front and rear bearings.
Bobbin winder: Light oil on friction wheel spindle.

CAUTION! Over-oiling can attract lint and cause staining. Wipe excess oil.

Electrical Specifications

Voltage: 110-120V AC, 60Hz.
Motor Power: 0.5 Amp, 60 Watt.
Foot Pedal: Variable speed control; includes on/off switch.
Light Bulb: 15 Watt, screw base.
Fuse: Not user-replaceable; internal protection.
Cord Length: 6 feet standard.

WARNING! Only qualified personnel should repair electrical components.

Timing Adjustment

Critical for proper stitch formation.

Set machine to straight stitch, center needle position.
Turn handwheel to bring needle to lowest position.
Check hook point: Should pass 0.04-0.08 inches above needle eye.
Adjust timing gear: Loosen set screw on handwheel; rotate gear slightly.
Retighten screw; recheck timing.

Note: Incorrect timing causes skipped stitches or thread breakage.

Needle & Hook Alignment

Ensures smooth hook passage.

Install correct needle (Singer 2020 type); tighten fully.
Needle should be straight; check with ruler.
Hook should clear needle by 0.005-0.010 inches at closest point.
Adjust needle bar height if needed: Loosen set screw, reposition bar.
Check alignment with each needle change.

Tip: Use magnifier to inspect clearance.

Tension System

Upper and bobbin tension must balance.

Upper Tension: Adjust via numbered dial (higher number = tighter). Check discs for lint. Bobbin Tension: Adjust screw on case; test by holding thread and letting case drop slowly. Balanced Stitch: Threads lock in middle of fabric layers.

CAUTION! Do not overtighten bobbin screw; can damage spring.

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
Machine won't run	Power cord, pedal, motor	Check plug, outlet; test pedal switch; inspect motor brushes.
Skipped stitches	Needle, timing, thread	Replace needle; check timing; use correct thread.
Thread breaking	Tension, burrs, threading	Reduce tension; check for rough spots on needle/thread path; rethread.
Uneven stitches	Feed dog, pressure	Clean feed dog; adjust presser foot pressure.
Noisy operation	Lint, lack of oil, worn parts	Clean and oil; check for worn gears or bearings.
Buttonhole not forming	Settings, mechanism	Set to buttonhole stitch; check buttonhole lever engagement.

Reset: Unplug, wait 30 seconds, replug to reset electronic controls if applicable.

Parts List & Diagrams

Refer to exploded diagrams for part numbers.

Needle Bar Assembly: Part #123456
Hook Race: Part #123457
Bobbin Case: Part #123458
Foot Pedal: Part #123459
Handwheel: Part #123460
Stitch Selector Dial: Part #123461
Motor Brushes: Part #123462 (replace when worn to 1/4 inch)
Drive Belt: Part #123463

Ordering: Contact Singer Parts at 1-800-4-SINGER or www.singer.com.