Keeping the nozzle clean

[simon 1]

Has anyone come across a good way of keeping the UM2 nozzle clean. I'm only printing ABS. I don't actually mind the outside of the nozzle being black with burnt plastic, but I'm printing some white parts, the face against the glass is cosmetic. I'm really pleased with the quality and accuracy of the parts (they almost look like mouldings) but the face against the glass is slightly spoilt by 1 or 2 brown streaks. I'm not sure if this is contamination from brunt on plastic or slightly overheated filament caused by one of my settings. I'm printing at 250 C and 35mm/s. Bed is at 96C and seems to give nice parts with virtually no distortion.

I was wondering if anyone had tried putting something around the nozzle that would stop stray strands of plastic from hitting the side of the nozzle and burning on. Even a really clean nozzle seems to turn black with burnt plastic after a few hours printing. I was wondering if wrapping a few layers of PTFE tape around it might help. It's good for 370C I think.

[ian 32]

this might be of interest to you :-)

http://umforum.ultimaker.com/index.php?/topic/3749-clogged-um2/