I went to change nozzles and noticed that it was stuck and discolored. What causes this and is it normal? Its a P2S and I have only used Bambu PLA basic.
Filament wisps that attach to the hot parts, melt, and then oxidize at the extended high temperatures.
Wisps themselves can be caused by many things.
My 0.4 was stuck when I decided to do some maintenance. I was able to break mine loose with my angle nosed small needle nosed pliers. Then used my butane lighter to heat up the hot end and scrape away the cooked-on filament. (Mostly PETG)
I might be easier to simply replace the nozzle once you break it loose. But mine wasn’t too hard to de grunge after heating it up.
Just the nature of the beast to grunge up after a while. Ugly, but repairable.
If you watch while printing you will see the wisps MZip is referring to.
I heated the hotend up and it came off pretty easy. I ended up replacing the nozzle with a new one. Everything is working again.
It would be much healthier for nozzle and heater assembly to simply heat the nozzle instead of breaking it loose with force. It usually comes off easily when heated. While it is still hot you can brush of the residue with a soft metal brush.