Hi,
Please help me in solving below issue.
I start to print on my prusa i3x and after like 20-30min extruder is block. When i take out the filament is looking like the one from the below picture. I thought that is because of the aditional vent that I put on the extruder, but after removing it same thing happens.
Extruder is MK8.
Thanks.
The diameter of the filament is to thick. This is a defect of manufacturing. I got a filament spool of 1.75mm and on some places it was up to 2.1mm.
@Thomas_Bornhaupt i measure it and is 1.75 also where the clog happen. Ideea is that this happens în the heating chamber and then clogs.
Insufficient cooling of hotend heat sink can cause this.
@Oystein_Krog so i should put an aditional vent, or i should increase the existing one?
OMG no its not a defect in the filament. It’s heat creap. Pretty sure they didn’t manufacture faulty filament that the fault perfectly happens after 20 minutes of you printing. It’s caused by the barrel of your hotend. It can be fixed by replacing it with a ptfe lined barrel or a well made all metal one. What’s happening to you is that the filament liquifies in the hotend and as it gets to the cold section if solidifies and sticks to the inside of the barrel.
@Pop_Gheorghe got a link to the exact “i3x” you bought?
As others have noted, this is most likely heat creep. It started to bite me with my ubis hot end over time, and now that I’ve switched to an E3D w/ a fan, this problem has mostly gone away. I say mostly because as of late I’ve noticed with some filaments and higher retraction rates that I’ll get a similar swelling and jamming.
looks like a PTFE liner has swollen and the filament is expanding in it at the junction between the PTFE liner and the throat/melt zone. the step at the end is the metal to PTFE junction and the larger area and the taper indicate how wide and how far up the PTFE has been expanded from heat creep (lack of sufficient cooling on the heatsink of the hotend). Replacing the liner should fix it. I had filament look exactly like this in Monoprice i3 V2.1 and replacing the liner fixed it for PLA. Eventually got a Micro Swiss all metal hotend, I recommend that over replacing liners.
the heat issue might be the fan/heatsink and heatbreak surface contact is not good or there is something stopping the heatsink from cooling the heatblock. you said you did some work on it, a new vent? can we see? more pics of hotend well help us help you.
Me pasó que se atascó con suciedad del filamento, lo solucione poniendo un filtro para limpiarlo. No se si sera ese el problema.
Thanks to all for feedback. Below you can see a picture of my extruder în the moment of the jam.
https://plus.google.com/photos/110934688248807770572/albums/6339938773938901281/6339938773762667922
Too much retraction
I had the same kind off issue and the reason the heat started creeping up was a jam in the nozzle. The filament simply wasn’t allowed to flow thru as intended.
A clean nozzle later and my prints are better than ever!
I’m also using mk8 and its a plain threaded barrel between hotend and mount. I was thinking of adding a bunch of washers and some cooling paste to form some sort of heatsink.
Again thanks for all your help.
After reducing the retraction from 6.5 to 3.5 and burning the nozzle with a torch it seems that it start working again. I will see for how long. In the mean time i will order some pfte liner or a new extruder.
