Explanation
The bobbin case is a small metal or plastic component that holds the bobbin with the bobbin thread in the embroidery machine.
It regulates the bobbin tension through a small tension spring.
Types
- Horizontal bobbin cases: lie flat inside the hook, common in modern household machines
- Vertical bobbin cases: inserted upright, mainly in industrial or older machines
Importance
- Critical for maintaining correct bobbin thread tension
- Should be cleaned regularly from lint and thread residues
- Incorrect or dirty bobbin cases are a common cause of thread breaks or skipped stitches
Practice
- Tension is adjusted with a small screw on the bobbin case spring
- Special adjustments may be required for delicate or specialty threads (e.g. metallic)
- Industrial embroidery often uses pre-set spare bobbin cases for consistency