The Singer Heavy Duty 6620C is a robust sewing machine designed for tackling thick fabrics like denim, canvas, and leather. It features a powerful motor, a variety of built-in stitches, a one-step buttonhole, an automatic needle threader, and a heavy-duty metal frame for stability. Below are key sections for safety, features, setup, operation, maintenance, and troubleshooting.
Key components: Heavy-duty metal frame, powerful motor, automatic needle threader, top drop-in bobbin system, built-in LED light, and a variety of presser feet.
| Feature | Description |
|---|---|
| Motor | High-performance motor for sewing through multiple layers of heavy fabric |
| Built-in Stitches | Includes essential, decorative, and stretch stitches |
| One-Step Buttonhole | Automatically creates buttonholes of precise size |
| Automatic Needle Threader | Easily threads the needle with a flip of a lever |
| Top Drop-in Bobbin | Easy to insert and see bobbin thread supply |
| Stitch Length/Width Dial | Adjustable for different fabric types and techniques |
| Presser Feet | Includes All-Purpose, Zipper, Buttonhole, and Button Sewing feet |
| Free Arm | Converts for sewing cuffs, sleeves, and other cylindrical items |
| LED Light | Brightens the sewing area |
| Reverse Stitch Lever | For reinforcing seams |
Carefully unpack all components and place the machine on a stable, flat surface.
WARNING! The machine is heavy; use caution when lifting. Ensure the work area is well-lit and free of obstructions.
Power on the machine; the LED light will illuminate.
CAUTION! Keep fingers away from the needle while the machine is in operation. Always turn the handwheel towards you.
Main controls are located on the right side of the machine.
Front Panel: Stitch Selection Dial, Stitch Length Dial, Stitch Width Dial, Reverse Stitch Lever.
Other Features: Handwheel, Power/Stop Button, Bobbin Winder Spindle, Thread Cutter, Presser Foot Lifter.
Stitch Settings: Adjust length for basting or dense seams; adjust width for zigzag and decorative stitches. Use the reverse lever to lock the beginning and end of seams.
Refer to the stitch chart printed on the machine or in the manual.
Tip: Use a longer stitch length for basting and a shorter one for reinforcing seams.
Correct threading is essential for proper stitch formation.
WARNING! Ensure the presser foot is raised when threading the upper thread to allow the thread to seat properly in the tension discs.
Regular cleaning ensures optimal performance and longevity.
CAUTION! Never use compressed air, as it can force lint deeper into the mechanism. Do not immerse the machine in water.
The following accessories are included:
This Singer machine is covered by a limited warranty. Proof of purchase is required. The warranty covers defects in materials and workmanship for a specified period from the date of retail purchase. Damage from misuse, neglect, commercial use, or unauthorized repair is not covered. For warranty service, contact Singer Customer Service at 1-800-4-SINGER or visit www.singer.com.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| Thread bunching underneath | Incorrect threading or bobbin insertion | Re-thread the upper thread and bobbin completely. Ensure bobbin turns counterclockwise when pulled. |
| Needle breaks | Wrong needle type, bent needle, or incorrect insertion | Install a new, correct needle (15x1). Ensure the flat side of the needle faces the back. |
| Skipped stitches | Dull/bent needle, wrong needle for fabric | Replace the needle. Use a Denim needle for heavy fabrics. |
| Machine won't run | Not plugged in, foot controller issue | Check power connections. Ensure the foot controller is firmly plugged in. |
| Uneven feed | Presser foot pressure, dirty feed dogs | Clean feed dogs. For very thick fabrics, use the included even-feed/walking foot (if applicable). |
Reset: Unplug the machine for 60 seconds to reset the electronic components if it becomes unresponsive.
Service: For technical support, contact Singer at 1-800-4-SINGER or visit www.singer.com.