Cleaning of your hot end... ever do it?

[3dkarma]

Cleaning your hot end should be a regular procedure. The best way I've found to do it is to heat up the hot end to a few degrees over the temperature you would normally print at, let it settle, then reduce the temperature to just above the glass transition temperature of the plastic you're working with. About 90 Celsius works best for me with the PLA I use. Once the lower temperature has settled, back the filament out of the printer. As per jimc, you should see a straw at the end of the filament you backed out, which means that the plastic has been dragged out of the hot end. It should bring any debris / old plastic out with it. Repeat as necessary until you're happy and make it part of your regular maintenance schedule.

[Egon van Engelen]

I don't see myself drilling out a 0.4mm in hole by hand, specially in brass. What kind of nozzles do you guys use?
@jimc, I would love to see those pictures if you have the chance to take some next time!

[brisinger]

I tend to use a small screwdriver and heat the hotend just enough for the plastic to start to melt then insert the screwdriver and ease the plastic back slowly up the hotend. It usually comes out in one piece that way.

[corim123]

I don't see myself drilling out a 0.4mm in hole by hand, specially in brass. What kind of nozzles do you guys use?
@jimc, I would love to see those pictures if you have the chance to take some next time!

It's not that you're redrilling, it's just a convenient tool sized for the job. Anything to just poke it out works. Just heat and push the plastic out of the way and you're golden.

[jimc]

small guitar strings work well also

[Egon van Engelen]

Right, well I never cleaned my hot-end and I'm not going to anytime soon. I only print in PLA so I imagine that helps a bit.
I did measure the filament string on the cooled down hot-end a few times after reading this thread but it's still 0.4mm

[Roxy]

Roxy, I ask because I've never used a drill bit on my nozzle. Do you use the back end of the bit and just push it in a hot end? I'd be afraid that by using the sharp end that you might begin to gouge the inside wall of your tiny hole. What's your experience?

I didn't see your question until now... I don't drill up through the nozzle. I have to take everything apart and usually the 3mm filament is broken off on the top side. I drill that out and kind of grind away all the stuff in there. But I don't push the drill bit into the hole of the nozzle. Sometimes I see some clear crystal like stuff come out. I don't know what that is. But I don't think it should be there and the fact my nozzle is plugged kind of makes me think it is the reason.

[Roxy]

i took my xacto knife and sliced the end off. in the cross section you could actually see the rainbow layers of each color i had printed with over the past 3 weeks or so. this was the first actual hard evidence i found that many plastics dont intermix welll and each time you switch you are left with a thin film that stays in there cooking and it gets harder and harder making the hot end tighter.

Ha!!!! I bet this is what is killing me!