Fixing stuck filament in Bambulab P1S
Last weekend I was building something using my Raspberry Pi Touch 2 with a Raspberry Pi 4 (will post a blog on this too soon). For my display and the Raspberry Pi, I needed to 3D print a case and I found really good model here.
Side Quest
Unfortunately, when I started my printer I got a message on Bambu Studio that my filament is stuck somewhere in my extruder. I have got broken filament issues multiple times usually in the AMS unit and I have opened it up quite a few times to quickly get it resolved.
There have been a few times when I have found this issue of filament getting stuck in the extruder and in all those times, just disconnecting the PTFE tubes and pulling it out had worked out fine. But this time, I couldn’t see loose filament stuck anywhere from wherever I could disconnect the PTFE tube from. I realized that I will need to open up the nozzle/extruder unit.
It was kind of a tangent from my main project that I really wanted to finish up but I was not fussed about it as I anyway wanted to replace the stock stainless steel nozzle/gear assembly with a hardened steel one. I had replacements with me for more than a year now but never got the chance to upgrade it so I thought I can take this opportunity to swap the extruder gears and the nozzle with hardened ones.
Hardened steel nozzle replacement
Hardened steel extruder gear replacements
A small rant: It was so much simpler when for any issue encountered while printing, on Bambu Studio, I could straight up get links to appropriate wiki to fix things. Now it guides you through “Bambu AI” which I have felt as a little annoying.
Dissassembly
I like how easy it is to work with these printers. This is unlike the tough times I faced with my Ender3 V2 previously. Major frustration was the frequent maintenance that my Ender3 V2 required.
It was quite straightforward to pop open the front cover and get the entire unit out in minutes. After disassembling the gears and the nozzle, I was expecting to find some broken filament in the detached PTFE tube but I didn’t see anything.
Toolhead without the cover
After removing extruder gears & nozzle
Broken Filament Reveal
After not finding anything in detached the PTFE, I was now expecting something to be stuck in the the gears and I saw a tiny broken orange filament stuck in the gears.
This little shit
Broken filament that was stuck
After this, I replaced the stainless steel extruder gear assembly with the hardened steel one.
The Unexpected
After removing the broken piece of filament from the extruder gear, I noticed that there was another piece of white filament jammed and broken in the nozzle. This is what was originally loaded in the nozzle through the AMS before all this happened.
This was not easy to pull out as it is slotted in extremely tight. Since this is the nozzle, the filament was once molten at 220°C just before to be spewed out from the nozzle on the print bed for printing and now, this was frozen at room temperature inside the nozzler
Broken white filament stuck in nozzle
To remove this, I read somewhere to heat up one end of a thin allen/hex key (this is the same size that comes with the printer), shove it in the nozzle so that it’s a few millimiters in, let it sit there and cool down for a few seconds. Once it’s cooled down, pull the key and the stuck filament inside the nozzle should come out easily completely. This worked out perfectly.
Toolhead without the cover
Disassembled tool head (extruder gears & nozzle)
Another rant: Since I wanted to swap out the stainless steel nozzle with a hardened steel one, I could have just replaced it without going through the effort of pulling out the stuck filament but Bambulab doesn’t give the wiring attached with the nozzle which doesn’t look too straightforward TBH to swap out.
It requires some re-wiring the same wires on the old nozzle to the new one with some thermal pasting which I didn’t expect. I chose to settle with hardened steel extruder gear and put the existing stainless steel nozzle back in after removing the stuck filament. Since just removing the nozzle is easy, I’ll probably do it later.