6. I sew with an extra spool filling bobbins as I go. So sewing away next thing I know the fly wheel isn't turning oh my god the thread for the bobbin jumped off and had been filling the fly wheel and of course it wasn't one of my old machines but my mothers elna. I spent years cutting and picking out thread with tweezers and seam ripper! And yes as thread was removed it would sew. When I finally got all the thread out I discovered I wasn't the only one to have done that. I was sewing with black thread but once the black was gone there was light blue and white!