Filament stuck - Needs reassembly?
Hi,
I've had the filament jam twice since reassembling the nozzle/hot end. I had a leak and this was solved by tightening the heating block vs the heat sink (fins). No more leaking, but now it's jamming. The first jam I followed a recommendation on the forum to heat to 230-240. Then I loaded filament and it was able to push past the stuck part. Trying this again it didn't work. 🙁 But maybe I have to disassemble the extruder like I did the last time.
My hypothesis is that I have a gap between the heat break and the heat sink. Printing something with high feed rate is fine as the plastic is moving past the gap quickly. Batman printed fine. Finer detail is harder as the flow is less. Both jams have been on the Gear Bearing.
Should I try and fix the filament jam by partly disassembling and trying the 230-240 heating again? (partial disassembly would cool less and maybe melt plastic higher up...) In the beginning the printer worked very reliably! (until the cooling fan snapped and was replaced) Now it jams regularly. 🙁
Re: Filament stuck - Needs reassembly?
➡ i would recommend to disassemble the hotend completely, clean it as good as possible, check the ptfe tube and reassemble it.
💡 have a look at this thread, all the required informations are linked there.
by the way, you've mentioned that the cooling fan snapped. which one did you mean ? the little 30x30 fan at the left side of the extruder, which is supposed to cool down the coldend ?
if that's the case and you've replaced it by another one, it might be that it's air flow is to low. between 4 and 5 cubic-feet/minute are required, which is quite a lot for that tiny chap.
this would absolutely explain your problems. so you first need to get a proper fan running ! not all the 30x30 fan's provide the required air flow.
dem inscheniör is' nix zu schwör...
Re: Filament stuck - Needs reassembly?
Ah, I think I tightened things too much. I didn't back it off the 1/2 to 1/4 turn, then heat, then tighten.
As for the fan it is the small 30mm one that blows in from the side against the cold end. It snapped fairly early on. The kinds folks at Prusa mailed me a replacement, same-day! (I live in London). So I suspect it is the right capacity...
Thanks for your suggestions! I'll take it apart again and clean it all out and re-assemble as directed. I'll probably need to find some more zip-ties. 🙂