i have several machines without this feature. i can wind a bobbin without rethreading, though. i take the spool off of the spindle and set it aside with the thread still threaded through the machine. then i put a different spool on the spindle threaded to the empty bobbin and wind away. when done, i put the original spool back on the spindle winding up the excess that was needed to move it away. if the first part of the threading is shared, that is undone first, threaded with bobbin thread and then the original put back.