Pfaff 90 Owner's Manual - Page 20

79u1atis19 th '7ha '7nietn The bobbin thread tension has been set for a medium grade and need not be adjusted for all ordinary sewing operations. If a special sewing operation should require a looser or tighter tension, turn the small knurled screw on the bobbin case with the tip of your thumb as fol lov,s: Turn it left --E - for looser tension. Turn it right - for tighter tension, Determine whether the bobbin thread tension is set for 0 medium grade by holding the thread end between thumb and forefinger and letting the bobbin case hang freely. The tension should be strong enough to keep the bobbin case from being pulled down by its own weight. However, as you jerk your hand slightly, the bobbin case should gradually slide down. Do not turn the knurled screw too far to the left to keep it from falling out. Choose the lower tension slightly stronger when doing ornamental stitching to be sure you always have o neod satin stitch on the right side of thefobric. GIl 012 irr F' A The final stitch appearance can be reguloted by the upper tension knob, as follows: Turn left -(C - for looser tension. Turn right )?*m4 - for tighter tension. V The marks on the tension housing and the dot on the tension knob moke it easy to restore any ten sion setting whenever you hove hod to change the f tension for onother sewing job. (The longer the mark, the tighter the tension.) The upper tension [ has a third disc for two-needle work. 17 I 1.'