Hello, I started a print on our Ultimaker 3 and after 20 minutes a "blob" of PLA had built up around the nozzle. As the printer apparently had printed continously on one place, the PLA entered the printhead and everything is clogged. On a side note, I started the print on our second printer and it printed fine, so it wasn't the file. I can't remove it mechanically while applying moderate force. Do you have any tips for cleaning up the printhead in this case? External view: Internal view: Is there a tutorial how to disassemble the printhead?