Pfaff 339 Owner's Manual - Page 22

LI I Loops on underside of fabric Ill Loops on top of fabric Regulating the Thread Tensions After sewing a few inches, examine the stitch ing on both sides of the fabric. The tensions are set correctly if upper and bobbin thread lock in the centre of the cloth. If thin material puckers, both tensions are set too tight. Sketch I shows what a neat seam will look like when tensions are correctly set. Ii Upper thread tension is too strong or bob bin thread tension too weak Ill Upper thread tension is too weak or bob bin thread tension too strong When it becomes necessary to regulate the tension, do so on the upper thread as a change in tension is more likely to occur here than on the bobbin case where the tension should only be changed for special purposes. 24 ----- -..---