Bobbin case tension screw loose

Too much foot pressure flattens pile and stretches knits; too little lets fabric wander or fail to feed. Adjust the pressure dial to suit the fabric weight, lowering it for delicate or bulky fabrics.

Persistent skipped stitches across all needle types and tensions, especially after a hard jam or drop, points to hook timing out of sync with the needle. This needs professional service, not a home fix.

A needle that clicks against the plate or skips stitches is often bent from nicking a pin or age. Replace it immediately, since a bent needle can also throw off hook timing.

Fabric that stalls under the presser foot is typically caused by dropped feed dogs, too-light foot pressure, or lint packed under the plate. Check the feed dog setting, raise foot pressure, and clean out lint.

Fabric pulled down into the needle plate at the start of a seam happens when feed dogs grab thin fabric before the stitch locks. Start on a scrap leader and hold both threads taut behind the foot.