ONCE! I forgot to check and ran out of thread on one of the paths...took me two days of trying, screaming, stomping of feet, crying, threatening to throw it out of the window....finally disconnected it, went to shop....she threaded it in seconds.....I will NEVER let it run out of thread again...Wish I could get the new self threading one...but I don'T use one enough to justify the $$$$$$