Sunstar Sewing Machine Service Manual

The Sunstar Sewing Machine is a versatile household and light industrial sewing device featuring multiple stitch patterns, automatic thread tension, built-in needle threader, adjustable speed control, free arm capability, LED lighting, and various presser feet for different sewing applications. This service manual covers essential information for maintenance, troubleshooting, and proper operation of your Sunstar sewing machine.

1. Features at a Glance 2. Machine Setup 3. Basic Operation 4. Technical Specifications 5. Controls and Functions 6. Stitch Selection Guide 7. Maintenance Procedures 8. Common Adjustments 9. Cleaning Instructions 10. Warranty Information 11. Troubleshooting Guide

Features at a Glance

Key components: Main body with built-in stitch patterns, Bobbin case, Presser feet set, Foot pedal, Power adapter, Instruction manual.

Feature	Description
Stitch patterns	30 built-in stitches including straight, zigzag, and decorative
Automatic needle threader	Easy threading with built-in mechanism
Adjustable stitch length	0-4mm range for different fabric types
Free arm capability	For sewing sleeves and circular items
LED work light	Bright illumination of sewing area
Speed control lever	Adjustable sewing speed
Reverse stitch button	For reinforcing seams
Bobbin winding system	Automatic bobbin winding with thread cutter
Drop feed mechanism	For free-motion sewing and darning
Presser foot pressure adjustment	For different fabric thicknesses

Machine Setup

Unpack and inspect all components. Place on stable, level surface.

Connect power: Plug foot pedal into machine, then connect power adapter to electrical outlet.
Install needle: Loosen needle clamp screw, insert needle with flat side facing back, tighten screw.
Thread upper thread: Follow numbered threading path on machine.
Wind bobbin: Place bobbin on winder, thread through tension disc, press foot pedal to wind.
Insert bobbin: Open bobbin case, insert bobbin with thread unwinding counterclockwise.

WARNING! Always unplug machine when changing needles or performing maintenance. Keep fingers away from moving parts.

Basic Operation

Power on machine; select desired settings before sewing.

Select stitch: Turn stitch selection dial to desired pattern.
Adjust stitch length: Set dial to appropriate length for fabric (2.5mm for medium weight).
Adjust tension: Start with setting 4, adjust based on fabric and thread.
Place fabric: Lower presser foot onto fabric before starting.
Begin sewing: Press foot pedal gently to start, increase pressure for faster speed.
Reverse stitching: Hold reverse button to reinforce beginning and end of seams.

CAUTION! Always use the correct needle size for your fabric type. Never pull fabric while sewing.

Technical Specifications

Machine Type: Electronic sewing machine
Stitch Patterns: 30 built-in stitches
Stitch Length: 0-4mm adjustable
Stitch Width: 0-5mm for zigzag stitches
Maximum Sewing Speed: 800 stitches per minute
Needle System: HAx1 standard domestic needles
Bobbin Type: Class 15 transparent bobbins
Presser Feet: 6 included (zigzag, zipper, buttonhole, button, blind hem, darning)
Power Requirements: 110-120V AC, 60Hz
Weight: 12.5 lbs (5.7 kg)
Dimensions: 15.4" x 7.1" x 12.2"

Controls and Functions

Main control panel includes stitch selection dial, stitch length dial, stitch width dial, reverse button, and thread tension dial.

Front Panel: Power switch, Stitch selection dial, Stitch length dial, Stitch width dial, Reverse stitch button, Thread tension dial.

Stitch Selection: Straight stitch (pattern 1), Zigzag (pattern 2-5), Buttonhole (pattern 6), Decorative (patterns 7-30). Stitch Length: 0-4mm adjustment for different fabrics. Stitch Width: 0-5mm for zigzag and decorative stitches. Tension Control: 0-9 settings (4 is standard). Reverse: Reinforce seams at beginning and end.

Stitch Selection Guide

Choose appropriate stitch for your sewing project.

Straight Stitch (1): Basic sewing, seams, topstitching - use length 2.5mm
Zigzag Stitch (2-5): Finishing edges, stretch fabrics, appliqué - width 3-4mm
Buttonhole Stitch (6): Automatic 4-step buttonholes - follow markings
Blind Hem Stitch (7): Nearly invisible hems on garments
Elastic Stitch (8-10): For knit and stretch fabrics
Decorative Stitches (11-30): Various patterns for embellishment

Tip: Always test stitch on scrap fabric before sewing your project.

Maintenance Procedures

Regular maintenance ensures optimal performance and longevity.

Daily: Clean lint from bobbin area and feed dogs
Weekly: Oil hook race and moving parts (use sewing machine oil only)
Monthly: Check needle plate for burrs, replace if damaged
Quarterly: Inspect electrical cord for damage
Annually: Professional servicing recommended for heavy use

WARNING! Always unplug machine before cleaning or oiling. Use only sewing machine oil.

Common Adjustments

Thread Tension: Upper tension dial 0-9 (standard setting 4). Adjust if stitches are loose or puckered. Presser Foot Pressure: Adjust screw for thick or thin fabrics. Needle Position: Center position for most sewing, left position for zippers.

Cleaning Instructions

Unplug machine before cleaning. Use soft brush to remove lint from bobbin area and feed dogs. Wipe exterior with soft, dry cloth.

CAUTION! Do not use compressed air as it can force lint into mechanisms. Never spray cleaners directly on machine.

Warranty Information

Sunstar sewing machines come with a 25-year limited warranty on the machine head and 5-year warranty on electronic components. Warranty covers defects in materials and workmanship. For warranty service, contact authorized Sunstar service centers. Keep original receipt as proof of purchase. Copyright © 2025 Sunstar Sewing Machines; all rights reserved.

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
Thread breaking	Incorrect threading/tension	Rethread completely; reduce tension; check for burrs on needle plate.
Needle breaking	Bent needle/wrong size	Replace needle; ensure correct size for fabric; don't pull fabric.
Uneven stitches	Tension issues	Adjust upper and bobbin tension; rethread both upper and lower threads.
Machine jams	Thread buildup	Remove bobbin case and clear tangled thread; clean feed dogs.
No power	Connection issues	Check power cord connections; ensure foot pedal is properly connected.
Skip stitches	Dull/bent needle	Replace needle; ensure correct needle type for fabric.
Fabric not feeding	Presser foot pressure	Adjust presser foot pressure; clean feed dogs; check stitch length setting.

Reset: Unplug machine for 5 minutes to reset electronic components.

Service: 1-800-SUNSTAR; www.sunstar-sewing.com