I’ll start off with a recent one. I forgot to connect the hotend cooling fan when remounting the hotend. After a while the printer jammed and the whole toolhead got so hot that it started to melt. The brass inserts were coming out of their sockets and the hotend stood at an angle instead of straight down.

I also noticed that the “teflon” tube connecting the extruder to the hotend was not in fact teflon. The slowly melting ABS was blowing a bubble in that tube and it was clearly starting to melt.

It was quite a pain in the ass to fix as I did not have a second toolhead nor a second 3D printer to print a new one so I had to fix the extruder/hotend in place using 2-part glue hoping that the printer lasts long enough to print a new toolhead.

I should probably have either a thermal fuse or a smart filament sensor that notices jams as well. When your hotend cooling fan fails, or the operator forgets to connect it, the filament will jam in the heatbreak and if it goes long enough the whole hotend will be plastic-meltingly hot. A jam sensor should see it before the toolhead starts to melt.

  • dual_sport_dork 🐧🗡️@lemmy.worldEnglish
    9·
    3 days ago

    I tried to do an ABS print at PLA temperature once. That sure didn’t work. Vise-versa is also an interesting time, especially if you have the lid on the enclosure shut. If you think you’ve ever seen heat creep, try having PLA in the extruder but running it at 260°C and the chamber heater on. The resultant jam required stripping the entire extruder head down to its individual components and prying it apart in the process, but I put it all back together and it still works. I didn’t even have any screws left over by the time I was done.

    Like all Qidi X-Max 3 owners will eventually do at some point, I also once homed my machine without the steel build plate installed. This causes the machine to helpfully drill the nozzle straight into the soft magnetic surface between it and the heater plate. I shaved the high points off of the crater with a straight razor and continued to run that plate without any problems for several months after that. You’d never notice the difference, despite the hole in it.