Pfaff 3117 - Flat Buttonhole Bobbin Tension

Preparation
Fig. 11 - 07
8
43
4 cm
11 - 6
5
6
1
2
7
11.06 Threading the bobbin case, adjusting the thread tension
on flat buttonholes
● Insert bobbin 1 into bobbin case2.
● Pass the thread through slot 3 and under spring 4.
● Then pass the thread into slot 5.
● Then pass the thread into slot 6 again.
● Pass the thread through eye 7.
● Adjust the thread tension by turning screw 8.
● Use the enclosed tool for this process.
When sewing flat buttonholes the bobbin thread must have enough tension so
that the knotting of the bobbin thread takes place on the underside of the
material.