julian tao
StitchDiag helps home lockstitch sewing machine users turn photos of a controlled test seam and a short questionnaire into a ranked list of possible causes, supporting evidence, one reversible next check, and clear stop conditions. It covers skipped stitches, loops on the underside, bird nesting, thread breakage, puckering, zigzag tunneling, uneven stitch length, and fabric-feed problems. The free public guides explain controlled baselines, one-variable-at-a-time testing, and when to stop and seek professional service. It does not provide a certain diagnosis, promise a repair, or replace a qualified technician. It does not guide industrial, overlock, embroidery, electrical, internal timing, or opened-machine repairs, and users should stop for smoke, heat, electrical smells, repeated metal strikes, or hard jams.
