Ihave used my bobbin winder so many times and never had a lumpy or loose bobbin full of thread, be sure you push the bobbin all the way down on the post. I hold the thread with the left hand and turn it on, runs by itself and I cut the holding thread after a moment or two. I love the convenience. And be sure to thread it right, through the little loop, around the tension spool and through the hole in the bobbin and it does its thing.
Carol J.