Brother 2340CV Operation Manual page 15

Tension adjustments
(1) First, set each thread tension dial to the number
shown below.
6 mm (15/64 inch) (Wide)
Right needle dial
3 mm (1/8 inch) (Narrow)
Right needle dial
Make sure that the thread is properly seated in
the tension discs by holding the tension release
button to the right while passing the thread
through the tension discs.
(2) Sew a test stitch. (Refer to "V. Sewing" on page 15.)
(3) Adjust the tension of each thread according to the
condition of the stitch.
Balanced tension
The needle thread sews a straight seam on the top
side and the looper thread forms loops on the under
side of the fabric.
Stitching direction
Needle thread is too loose
Turn the needle thread adjusting dial to a higher
number. Or turn the looper adjusting dial to a lower
number for looser tension.
Needle thread is too tight
Turn the needle thread adjusting dial to a lower
number. Or turn the looper adjusting dial to a higher
number for tighter tension.
A Tension selection mark
Left needle dial
(yellow)
4
(green)
4
Left needle dial
(yellow)
4
(green)
–
CAUTION
Center needle dial
(pink)
–
Looper needle dial
(blue)
4
Center needle dial
(pink)
4
Looper needle dial
(blue)
4
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