M Size Metal Bobbin is the studio-standard longarm bobbin in dimensionally stable metal — the self-winding counterpart to pre-wound jars, for machines that take the M format.
Product Details
- Format: M size — the standard for most major longarms (Gammill, APQS, Handi Quilter, Janome); not domestic-compatible
- Material: Metal — no flex, warp, or deformation under winding tension
- Thread: All standard longarm weights — 40wt Glide/Omni, 50wt So Fine!
- Winding: Moderate consistent speed to ~80–90% full for best tension behavior
- Maintenance: Inspect for burrs and nicks; discard damaged bobbins — a rough edge shreds thread
Frequently Asked Questions
- Metal or plastic bobbins?
- Stability — plastic can flex under winding tension, subtly changing wind density and downstream tension; metal doesn't. Quality plastic works, but studios chasing tension consistency default to metal.
- Self-wound metal or Magna-Glide pre-wounds?
- Color economics — pre-wound jars win on the core neutrals used daily; self-winding on metal wins for the hundreds of colors that don't justify a jar. Most studios run both systems.
- How many should be on hand?
- 12–20 wound — enough to run a queen without stopping to wind, with the day's colors pre-loaded before the first quilt goes on the frame.
- Why the 80–90% fill rule?
- Overfilled bobbins bind against the case and drag; the last 10% of capacity costs more in tension trouble than it saves in changes.
- The burr inspection habit?
- One nicked bobbin edge can shred thread for weeks before being identified — a periodic finger-test of edges catches it early and costs nothing.
