to NJQUILTER and others with stuck bobbins:
DON'T try to just pull it off the spindle. Could damage your viking machine. Slow the speed down when you wind bobbins. To get a stuck bobbin off you have to remove ALL the thread from the bobbin. I had to cut all that thread of with a straight edge razor blade when mine got stuck.
Tedious, but much less costly than the repair bill to replace the bobbin winder mechanism on a Viking.