SINGER W951 - Manual (Page 7)

Disengage the hand wheel (Fig. 6) from the stitching mechanism
by turning the stop motion knob toward you or counterclockwise.
Place a spool of thread on one of the spool pins, lead thread through
the upper thread guides on the arm, and down through the tension disc
11 (Fig. 7) at the base of the machine. Run end of thr^d through a
hole in the bobbin edge and place bobbin on spindle B of winder
"4", fitting the notch in bobbin over small pin on spindle. Push bobbin
winder pulley against hand wheel.
WINDING THE BOBBIN
Hold thread end loosely and start machine slowly.
Bobbin will be released automatically when it is filled. Break off loose
thread end used to start the winding.
Turn stop motion knob av»ray from you until sewing mechanism is
again engaged so that needle moves when you turn the hand wheel.
If the bobbin winds unevenly, adjust bobbin winding tension disc
11, (Fig. 7) to the right or left by loosening the Kirew. When disc is
in proper position, tighten screw.
Fig. 7