Ricoma Quick Start Guide
52
screw counterclockwise.
Bobbin tension that is too tight may result in a narrow column,
or even a single strand of bobbin thread down the center of
the satin column stitched during the “I” test. This can cause
the embroidery to unravel easily if the bobbin thread ever gets
snagged. See Figure 123.
Even if the bobbin thread stays put underneath the embroidery,
chances are, the columns will not have clean, crisp edges.
Erratic bobbin tension usually results from a catch in the
bobbin case. If this is the case, try pulling a few feet of bobbin thread to see if there is a point in the
rotation of the bobbin in the case that is not smooth. This catch can be the result of an ill-fitting bobbin
that has been overfilled or that has a manufacturing defect.
If you suspect the bobbin is not rotating smoothly in the machine, check by placing the bobbin case face
down on the machine table or a flat surface. Then, pull a few inches of thread out. If the bobbin isn’t
spinning freely on the surface, the odds are that it isn’t spinning freely in the machine either. Retest the
case with another bobbin.
If you are still experiencing bobbin tension issues after adjusting your bobbin thread, be sure that you
are not using a damaged bobbin case, as this may cause undesirable results. Other factors can include
improper top thread tensioning and damaged needles.
Figure 123
• The color of the thread is a factor that affects thread tension because the dye affects
the texture of the thread. The texture of the thread affects how smoothly it slides
through the machine and the needle.
• Another factor that contributes to tension is the weight of the thread. If you change
the weight of the thread, you will need to adjust the tension.
• The speed of the machine may also affect tension. The slower the speed of the
machine, the better quality designs it will stitch.
• Excess dust and lint along the thread path may also affect the thread tension.
Other factors that affect tension
TIP:
One tip-off that you need to adjust the bobbin case rather than the top tension knob is when similar
symptoms are exhibited on all needle bars.
