You may need to loosen your upper tension, or adjust both lower(on bobbin) and upper until it sews with out breaking. The bobbin spool should come out of the holder. There should be a wheel that you can turn to loosen. Thread needs to pull smooth if you are winding from the needle. Place the spool into the winder, Wind several times by hand to secure thread, push winder against wheel and depress foot feed. If done right the spool should stop when full. Hope this helps! Karen
Well give some oil to lower part of the machine because it get hard some time when the machines revolves so by oiling with it can be helpful for you to provide smooth sewing.