Beginner at 3d printing. PLA oozing over heater block and down the nozzle in Ultimaker 3D printers Posted February 19, 2017 Hi, I am new to 3d printing and only managed a handful of small prints so far on my UM2+. On the last print the PLA has oozed out over the heater block and over the nozzle which caught on the print and separated it from the bed. Although I have tightened up the nozzle I think I should probably tighten something on the top side but can't see how. Can anyone help? Please??