rotary drive from sewing machine 28 in the particular embodiment shown rotary drive for bobbin 10 is provided by a drive boss 40 which receives rotational drive from sewing machine 28 drive boss 40 provides drive to bobbin 10 when seated on winder spindle 30 by frictional engagement therewith for this purpose drive boss 40 has a cylindrical shape with a cylindrical outer surface 42 a flat or domed top surface 44 and a peripheral recess 46 around the upper circumference edge of drive boss 40 drive boss 40 is mounted on a drive shaft 48 which is drivingly connected or connectable with the sewing machine drive not shown drive shaft 48 extends through an aperture 50 in the top housing of sewing machine 28 drive boss 40 may have either a solid or hollow structure and outer surface 42 usefully has a matt or textured finish to help provide good driving engagement with flanges 14 and 16 of bobbin 10 if desired transmission of drive to drive boss 40 may be controlled by a user actuated control means such as a switch not shown outer surface 42 of drive boss 40 can radially engage the periphery of smaller lower flange 14 of bobbin 10 when bobbin 10 is located in its drive engaging position to apply drive thereto also in another useful but not essential feature of the invention when bobbin 10 is properly seated on winder spindle 30 against stops 38 larger upper flange 16 of bobbin 10 engages in peripheral recess 46 such engagement of flange 16 in recess 46 assists in the transmission of drive to bobbin 10 and in maintaining alignment of bobbin 10 on winder spindle 30 during winding the axial position of one or.