1. Due to the loose fit between the taper surface and the taper hole of the small top screw on the feed shaft, the stitch length is generated; remove the feed shaft and re-adjust the fitting clearance of the feed shaft.
2. Due to the excessive clearance between the feed rod, the eccentric wheel ferrule and the feed eccentric wheel; the clearance between the stitch link, the feed rod and the stitch adjuster is loose, resulting in a long stitch , short; reasonable adjustment can be made according to the position of loose parts.
