Binding Machine Skipped Stitches and Timing

Skipped stitches are the most common binder complaint, and they usually trace back to the needle, dirt in the shuttle area, or a timing adjustment. The checks below follow the National BindPro manual.^[1] Other models are similar, but follow your own manual.

Skipped stitches

Work through the usual causes in order, cheapest first.^[1]

1. Bad needle: deburr or replace it. A bent or burred needle is the most common cause.
2. Needle installed wrong: the long groove faces left and the scarf (notch) faces right.
3. Wrong needle size: use a Schmetz #23 or #22. The #23 deflects less.
4. Dirty shuttle area: clean out lint and carpet fiber.
5. Puller timing: the puller should turn while the needle is up.
6. Needle height or clearance out of adjustment. The hook driver should just touch the needle without deflecting it.
7. Damage to shuttle hook or race cover spring. Replace damaged parts.

Thread breaking

Broken thread usually comes from tension or a rough surface.

• Upper tension set too high.
• A burr on the hook or race.
• A bad bobbin case spring.
• With correct tension, the threads knot in the middle of the carpet. Turn clockwise to increase.^[1]

Poor feed

If the carpet doesn't feed evenly, adjust feed roller pressure at the upper pivot pin screw, a half turn at a time.^[1] Don't pull on the carpet to help it along; it bends needles.

Machines without adjustable timing

Some binders have factory-set feed timing that isn't meant to be adjusted in the field; check your manual. On a fixed-timing machine, focus on the needle, cleaning, tension and worn shuttle parts.

Lubrication

Oil only the parts the manual specifies.^[1] Too much oil collects lint and makes skipping worse.

Setup basics are in Binding machine setup.

Common mistakes

These turn a simple fix into a service call.

• Adjusting timing before changing the needle.
• Big tension changes. Go a quarter turn at a time.
• Over-oiling.
• Pulling the carpet through.

Parts we carry

These are the needles and shuttle parts that fix most skipping.

• National 126-B2A Needles (10)
• 126-113 Shuttle Hook, 126-116 Shuttle Drive, 126-112-1 Bobbin Case
• Nylon Bobbins
• 126 parts and 155 parts

References

1. National BindPro instruction manual

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