Singer Class 15 Sewing Machine Manual

The Singer Class 15 is a classic vintage sewing machine known for its durability and reliability. This treadle or hand-crank model features a vibrating shuttle bobbin system, straight stitch capability, adjustable stitch length, tension control, and reverse stitching. Built with cast iron construction, it's designed for heavy-duty sewing on various fabrics. Below are key sections for safety, features, setup, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation & Setup 3. First-Time Operation 4. Specifications 5. Controls and Adjustments 6. Threading the Machine 7. Basic Sewing Techniques 8. Maintenance & Cleaning 9. Accessories 10. Safety Information 11. Troubleshooting

Features at a Glance

Key components: Cast iron body, vibrating shuttle, tension discs, presser foot, feed dogs, stitch length regulator, bobbin winder.

FeatureDescription
Stitch typeStraight stitch only
Stitch lengthAdjustable from 0-4mm
Bobbin systemVibrating shuttle
Tension controlUpper and lower thread tension adjustable
Reverse stitchLever for backward stitching
Presser feetStandard presser foot included
Power sourceTreadle, hand crank, or motor conversion
Needle system15x1 household needles
ThreadStandard sewing thread
WeightApproximately 25 lbs

Installation & Setup

Unpack and inspect contents. Place on stable surface or in treadle cabinet.

  1. Mounting: Secure machine in treadle cabinet or place on table for hand-crank use.
  2. Oil points: Lubricate all oil points with sewing machine oil before first use.
  3. Needle installation: Insert needle with flat side facing back, tighten screw.
  4. Bobbin winding: Wind bobbin using built-in bobbin winder.

WARNING! Machine is heavy; lift with care to avoid injury. Ensure stable mounting.

First-Time Operation

Prepare machine for sewing; follow step-by-step instructions.

  1. Thread upper path: Follow numbered guides from spool to needle.
  2. Load bobbin: Insert bobbin in shuttle, pull thread through tension spring.
  3. Adjust tension: Start with medium setting (4-5) and test on scrap fabric.
  4. Set stitch length: Begin with 2.5mm for general sewing.
  5. Practice stitching: Use scrap fabric to test stitch quality.

CAUTION! Keep fingers away from needle while machine is in motion.

Specifications

Controls and Adjustments

Main controls: Stitch length regulator, tension dial, reverse lever, presser foot lifter.

Stitch Length: Turn dial for shorter/longer stitches (0=no feed, 4=longest).

Tension: Higher numbers for tighter tension, lower for looser. Adjust based on fabric.

Presser Foot Pressure: Fixed pressure suitable for most fabrics.

Bobbin Tension: Adjust small screw on shuttle for lower thread tension.

Threading the Machine

Upper threading path and bobbin loading procedure.

  1. Raise presser foot and needle to highest position.
  2. Place thread spool on spindle.
  3. Follow numbered guides: Through tension discs, take-up lever, down to needle.
  4. Thread needle from front to back.
  5. For bobbin: Wind bobbin evenly, insert in shuttle with thread pulling clockwise.
  6. Bring bobbin thread up through throat plate.

Tip: Always thread with presser foot raised to open tension discs.

Basic Sewing Techniques

Fundamental sewing operations and stitch applications.

  1. Starting: Hold both thread tails, take 2-3 stitches forward.
  2. Reverse: Engage reverse lever to backstitch at beginning/end of seam.
  3. Straight seam: Guide fabric evenly, don't push or pull.
  4. Curves: Slow down, pivot fabric with needle down.
  5. Finishing: Backstitch, raise needle, lift presser foot, pull fabric away.
  6. Seam allowance: Use throat plate lines as guides.

WARNING! Never sew over pins; remove them before needle reaches them.

Maintenance & Cleaning

Regular maintenance ensures optimal performance and longevity.

  1. Daily: Brush out lint from bobbin area and feed dogs.
  2. Weekly: Oil all designated points with sewing machine oil.
  3. Monthly: Clean tension discs with folded fabric or dental floss.
  4. As needed: Check needle for damage, replace if bent or dull.

CAUTION! Unplug motorized machines before cleaning. Use only sewing machine oil.

Accessories

Standard accessories and available attachments.

AccessoryPurpose
Standard presser footGeneral sewing
Zipper footInstalling zippers
Buttonhole footManual buttonholes
Seam guideConsistent seam allowances
Extra bobbinsThread color changes
ScrewdriversAdjustments and maintenance

Safety Information

Important safety precautions for machine operation.

Troubleshooting

SymptomPossible CauseCorrective Action
Thread breakingIncorrect tension/threadingRethread completely; adjust tension; check for burrs.
Skipped stitchesWrong needle/damaged needleReplace needle; ensure correct type/size.
Uneven stitchesTension imbalanceAdjust upper/lower tension; test on scrap.
Machine jamsThread buildup/lintClean bobbin area; remove tangled thread.
Fabric not feedingFeed dogs lowered/dirtyCheck feed dog position; clean feed dogs.
Noisy operationNeed for oiling/lubricationOil all designated points; check for loose parts.

Service: For professional repair, contact authorized Singer service center.

Support: Visit www.singer.com or contact customer service for assistance.

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