Hello Pauline,
You have not said what make or model machine you have, if you have the normal turn stop motion and it is jammed the favourite thing to do if you have grooves on the stop motion wheel is to take a wide blade screwdriver and place it on one of the grooves on the left hand side of the stop motion wheel as you are looking at it end on, then give a sharp thump on the screwdriver and it should free off.
Ken
drivewithken, August 2010
