SunStar SWF/B Series User Manual page 36

[CAUTION] Functions by Needle Shape
① Size of the hole and groove differs by needle.
• Front groove: protects the thread from the heat of
the sewing friction (which may cause thread
breaks).
• Back groove: helps regulate the hook timing and
prevents looping.
Prevention of looping is important for stitching. Adjust the hook point as close to the needle as possible to
achieve the perfect thread position.
② If thread breaks or stitches are unstable, turn the needle
slightly to the right.
[NOTE]
Shape of the loop varies by the type of thread or fabric. Unstable shape of the loop may result in
skipped stitches. The following pictures show different shapes of loop formed by different types of
thread.
Hook point
Cotton thread loop
Synthetic thread loop
5-18
Front groove
Needle eye
Hook point
Back
groove
[Fig.5-31]
[Fig.5-32]
[Fig.5-33]