McKJim

My trick for cleaning the nozzle should the Atomic Method not work: Dismantle the Extruder Holding the extruder tip in a soft-jawed vice, put either the stick from a Q-Tip or a small wooden dowel into a Dremel Tool or power Drill. It will help if you form the tip of the dowel to a point to match the inside of the extruder tip. (sandpaper or concrete floor) Insert the "stick" into the extruder tip and let it do its thing. it will get hot enough to evacuate and remaining plastic and polish the inside of the extruder tip. Repeat as necessary. If you have some jewelers rouge for a really fine finish use it. Give it a final rinse in acetone, brake cleaner, carb cleaner or whatever cleaner you have that has the longest warning label. Do so in a well ventilated area away from flame and spark. I find this is the only thing that works for cleaning things up after I print with U-PET which seems to leave a nice carbon buildup. To thoroughly clean the tip I use a very fine copper wire- about .2mm dia from a stranded phone wire. I would avoid using steel because it would be easier to nick the orifice which could create snags as the filament exits the extruder. Happy printing.