Yes, twice. The first one was a cheaper little machine with plastic gears. I always called it a boat anchor. I don't even remember what it was.
Then recently I bought a Sparrow because of the light weight. Took it to Bonnie Hunter's workshop where it all but died. The first day it ran fine, then the 2nd day it just would not run. It was like a magic fairy had been playing with it and screwed it up. Right now it is in a shop. I would sell it in a heartbeat.