Pfaff 73 Owner's Manual - Page 18

Regulating the Thread Tension DR 580 The bobbin thread tension has been set for a medium grade at the factory 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 as follows: Turn it left W\ for looser tension. Turn it right for tighter tension. The thread tension screw can be turned with the thumb tip. Determine whether the bobbin thread tension is set for a medium grade J 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. Iv A The final stitch appearance can be regulated by the upper tension knob, as follows: 4J Turn left '' for looser tension. Turn right f4 for tighter tension. Ttceohnemsipoulnpetpe- ertultroennossoeifontthoeitsitgeshnotsi- odnescidaginanle. bdTehtechoanvtueamrlelbdegrwrsaidtohensotnhoeef tension dial indicate different degrees of tension. The higher the number, the greater the tension. Only in very rare cases will it be necessary to reset the tension. For ordinary sewing, the upper tension should be set between 3 and 5. Your upper tension has a third tension disc for twoneedle work. R8029 17 4 [