I know of a cure for the knee bar falling out. I tend to sew very fast and that makes the machine vibrate and the knee bar fall out. I complained to the dealer and he took the knee bar and made some adjustments. What he did was basically bang the end of the metal against a hard object enough to flatten it a little. He then stuck the kneebar back in the machine. If it still didn't fit tight enough he repeated the process. As the wife of a machinist I have had experience with that kind of fixes by my husband. It works. Metal is surprisingly maluable.