US Patent 10099889 String serving jig

A string serving jig preferably includes a frame, a quick change spool, a first spindle, a second spindle and a third spindle. The frame preferably includes a first half frame and a second half frame. The quick change spool preferably includes a spool reel, a spool spindle, a spool drive, a drag cup, a plurality of friction washers, a drag cover, a spool lock plate and a spool knob. The spool drive preferably includes a tubular shaft, a flange plate and a pair of drive pins. An even number of drive holes are formed in one of the two opposing flanges to receive the pair of drive pins. The drag cup includes a washer bore to receive the plurality of friction washers. The drag cover preferably includes a cup counter bore, which is sized to receive an outer perimeter of the drag cup.