this bobbin case is very cheap to replace if damaged.look at l/h rearbehind bobbin case for a small funny shaped plate that can be moved,move it towards bobbin case as to hold it but leave approx ,5mm gap.also chech r/h front for a spring loaded "stopper",gap should also be aprox .5mm and spring but still work.always put drop of oil on bottom of bobbin case before inserting.hope it was of some help.happy new year
johan
January 2013