Oracle jet grinder calibration too fine

Hey guys. I'm proud owner of a beautiful Oracle Jet. But I do have one issue - it seems that the internal grinder calibration is at a too fine level, is that possible? With my currently used beans (pretty decent, freshly beans from a local roaster) I need to set the grind size to 42 to get somewhere near to 1:2 ratio in about 30sec. That's ok, but what if another been needs even coarser grinding? Or what if i want to make a coffee crema, which needs coarser grinding? When I started with grind size 28, as suggested by the guidance, the extraction stopped after 60sec without a single drop of coffee in the cup... That doesn't seem right to me... Any suggestions? Does anybody have the same issues? Looking forward to your replys.