Singer 621b Sewing Machine Manual

The Singer 621b is a classic mechanical sewing machine designed for home use, featuring a built-in straight stitch and zigzag capabilities, free arm for cylindrical sewing, built-in buttonholer, adjustable stitch length and width, reverse sewing lever, drop feed for darning and free-motion work, and a built-in light. Powered by a standard foot pedal or optional hand crank. Below are key sections for safety, features, setup, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Metal body construction, built-in stitch patterns, free arm, drop feed dog lever, stitch length/width selectors, reverse lever, built-in buttonholer, spool pins, thread tension dial, presser foot lifter.

Unpacking and Setup

Unpack and inspect contents. Place on a stable, level table.

1. Remove all packaging materials and protective covers.
2. Attach the foot pedal: Plug the pedal cord into the machine's pedal port.
3. Insert the needle: Loosen needle clamp screw, insert needle with flat side to the back, tighten screw.
4. Wind the bobbin: Place empty bobbin on winder, thread through tension disc, engage winder.
5. Thread the machine: Follow numbered threading guide on machine body.

WARNING! Machine is heavy; lift with care. Ensure it is placed on a sturdy surface to prevent tipping.

First-Time Operation

Plug in power cord and turn on power switch (if equipped).

1. Select straight stitch: Set stitch selector to straight stitch position.
2. Set stitch length: Adjust to medium setting (e.g., 2.5) for general sewing.
3. Thread tension: Set to 4-5 for balanced stitches on medium-weight fabric.
4. Practice on scrap fabric: Lower presser foot, gently press foot pedal to start sewing.
5. Reverse stitching: Hold reverse lever at beginning and end of seam to lock stitches.

CAUTION! Keep fingers away from moving needle. Always turn handwheel toward you (counter-clockwise).

Specifications

• Model: Singer 621b
• Type: Mechanical, Free Arm
• Stitches: Straight, Zigzag, Multiple decorative patterns
• Stitch Length: Adjustable 0-4 mm
• Stitch Width: Adjustable 0-5 mm
• Buttonhole: One-step automatic
• Max Sewing Speed: Up to 800 stitches per minute
• Needle System: 15x1 (HAx1)
• Bobbin: Class 15 metal bobbin
• Power: 110-120V AC, 60Hz (US/Canada)
• Weight: Approximately 25 lbs (11.3 kg)

Controls and Settings

Main controls located on the front and right side of the machine.

Stitch Selector Dial: Turn to choose stitch pattern (straight, zigzag, etc.). Stitch Length Dial: Controls distance between stitches. Stitch Width Dial: Adjusts width of zigzag and decorative stitches. Reverse Lever: Hold down to sew backwards. Thread Tension Dial: Higher numbers increase tension. Presser Foot Pressure Dial: Adjust for light or heavy fabrics. Drop Feed Dog Lever: Lowers feed dogs for darning.

Basic Stitching Guide

Follow these steps for successful sewing.

1. Raise presser foot and needle to highest position using handwheel.
2. Place fabric under presser foot, lower foot.
3. Gently press foot pedal to start sewing. Guide fabric lightly.
4. To finish, sew a few reverse stitches, raise needle, raise presser foot, and pull fabric away.
5. For zigzag: Select zigzag pattern, adjust width and length as desired.

Tip: Always test stitch settings on a scrap of your project fabric first.

Advanced Functions

Utilizing the machine's specialized features.

1. Buttonhole: Attach buttonhole foot, select buttonhole stitch, place fabric under foot. The machine will sew one complete buttonhole automatically.
2. Darning/Free Motion: Lower feed dogs, attach darning foot, move fabric manually in any direction.
3. Zipper Insertion: Use zipper foot for close stitching next to zipper teeth.
4. Blind Hem: Use blind hem foot and select blind hem stitch for nearly invisible hems.
5. Decorative Stitches: Select pattern on dial, adjust width and length for effect.

WARNING! Use correct presser foot for each function. Ensure needle is centered to avoid hitting foot.

Maintenance & Cleaning

Regular maintenance ensures optimal performance and longevity.

1. Daily: Brush out lint from bobbin area and feed dogs with small brush.
2. Monthly: Remove needle plate and bobbin case to clean thoroughly. Oil moving parts per diagram in manual (use only sewing machine oil).
3. Needle: Replace needle after every 8-10 hours of sewing or if bent/dull.
4. Exterior: Wipe with soft, dry cloth. Do not use solvents or sprays.

CAUTION! Always unplug machine before cleaning or maintenance. Never oil plastic parts.

Accessories

Standard accessories included with Singer 621b.

• All-purpose foot (on machine)
• Zipper foot
• Buttonhole foot
• Darning/Embroidery foot
• Class 15 metal bobbins (3)
• Needles (size 14/90)
• Seam ripper/Lint brush
• Screwdriver
• Spool pin felt
• Instruction manual

Regulatory Information

This appliance complies with relevant safety standards. The Singer 621b is a Class I appliance. For your safety, use only with the provided power cord and foot pedal. Copyright © Singer Manufacturing Company. Singer® is a registered trademark. For support, replacement parts, or authorized service, visit www.singer.com or contact Singer Customer Service at 1-800-4-SINGER.

Troubleshooting

Reset: Unplug machine for 5 minutes to reset electronic components (if applicable).

Service: For repairs, contact authorized Singer service center. 1-800-4-SINGER; www.singer.com