I'm new in 3d printing tecnology. I bought an ultimaker printer a month ago and every thing was fine. But suddenly the PLA stopped comming out from nozzle. Yesterday i was trying to figure out what was happening i found that if i get the hot end at 230 or higher temperature i can print, but with 217, which was the temperature i have been printing before , tha PLA just doesn't come out ! I need tips to resolve it !!! Thanks every body !