Pfaff 339 Owner's Manual - Page 24

a. Regulating the Pressure on the Sewing Fool There should be just enough pressure on the sewing foot to allow the fabric to move along easy. It is rarely necessary to change the pressure. The pressure is strongest when the inner pin is all the way down, but this strong pressure is seldom required and should be used only for extremely thick and stiff material. When making long stitches on several layers of thick material, you should not press the inner pin all the way down as the thick material by itself will force the sewing foot upwards which automatically increases the pressure. To release the pressure, press down on the outer ring to have the inner pin go all the way up. When you need only slight pressure for sewing fine and medium weight material you just press the pin down a short way to leave it between the two extreme settings, so that it will suit the thickness of the fabric. This is the normal setting most often required. When working on fabrics such as card and velvet which may easily be marked by the sewing foot, you should always sew with reduced pressure. With the inner pin in its highest position and the feed dog lowered, darning may be done with the normal sewing foot and without an embroidery hoop (see page 33). 26