Sewing Machines, Tools and Equipment
This domain covers the sewing machine, its main parts, common tools and basic maintenance. The exam tests identification of parts, correct needle and thread selection, safe operation, and simple fault diagnosis.
Core concepts
- Main parts include the spool pin, bobbin winder, thread guides, tension discs, take-up lever, needle, presser foot, feed dog, bobbin case, hand wheel and stitch-length regulator.
- The upper thread and bobbin thread interlock in the fabric. Tension, threading, needle size and bobbin winding all affect stitch quality.
- Machine types include straight-stitch, zigzag, overlock and embroidery machines. An overlock trims and neatens edges; a straight-stitch machine forms lockstitch.
- Needle size should suit the fabric: fine needles for lightweight fabrics, stronger needles for denim or canvas. Match thread to fabric and needle.
- Tools include measuring tape, seam ripper, tailor’s chalk, pins, thimble, shears and pinking shears. Keep cutting tools sharp and dry.
- Maintenance: remove lint, oil according to the manual, check wiring, and keep the machine covered when not in use.
Worked example
A machine skips stitches on thin cotton. Check that the needle is straight and the correct size, rethread the upper path, check the bobbin, and adjust tension in small steps. A needle that is too large can push thin fabric into the needle plate, so a finer needle and a stabiliser may help. The reasoning is to correct the most common causes in order: needle, threading, bobbin, then tension.
Traps
- Using one needle for every fabric.
- Pulling fabric through the machine instead of letting the feed dog move it.
- Adjusting tension before checking threading and bobbin winding.
- Using blunt shears, which crush rather than cut fabric.