Constant clog issues

Hi, I've been using a prusa Mendel model that I'm borrowing from a friend, and I am having issues with the hot end nozzle clogging up.

After printing normally for some time (anywhere between 5 minutes and 3 hours) the extruder will simply stop extruding material. I can clear the clog pretty easily, by either removing the filament and leaving the hot end on while the junk material leaves, or by removing the filament, cutting it, and re in setting it. However, these methods have so far only temporarily fixed the problem as clogs always reappear within some time.

The material is PLA that i am melting at 210c, using Wade's Geared extruder. Any suggestions?

Edited 2 time(s). Last edit at 06/27/2014 06:28PM by erreib.

Try turning off retraction completely.

You probably need some cooling on the upper part of the hotend, to prevent that heat creeps up through the barrel where the filament enters.

This is what seems to be the most constantly suggested solution online. Does the fan need to be directly attached to the upper part of the hotend, or can I just place a fan next to the rep rap and point it at the hot end? I'm only wondering because the extruder doesn't really have a great place to mount a small fan, and wiring it might be a bit difficult.

Well that depends..

If the heater is insulated, a fan blowing on the whole hotend assembly will most likely do the job, and also cool the print, if the heater block isn't insulated, you will probably need to duct the air in some way.

For a start you can try with just a big fan blowing on the whole printer, it might be enough to just create some circulation around the printer.

Examine (and replicate) the E3D fan shroud. It is a simple solution for only cooling the top of a hotend.....

i'm having exactly this problem too. the top of the hotend isnt hot .. even slightly. i'd say 100F (not c). I'm using a gregg wades extruder and an e3d v5 hotend i bought after i got sick of a non-all metal hotend melting. I can print very small things fine and right now i have been printing a new extruder and got about 1/4" high when it clogged on this piece. ive played with extrusion rates temp etc.. right now i'm at 265 hotend 115 headbed (it clogs much faster at lower temps... it's black abs i think the temp is about right). It's driving me nuts. I know the stock extruder isnt perfectly aligned for the e3d with 1.75 but i cant print long enough to print another one. I may try filing the inside of the extruder near the bottom to lower tension but it's driving me NUTS

I don't know about plain ABS, but my ABS/PA alloy is very, very soft and a bit flexible, especially in filament form. My first attemps resulted in 5 jams within a few minutes. I quickly found it was almost purely temp, and I am printing on my E3D at 270C and no lower. Could be the PA that makes the difference, but just giving that for comparison. Ever since I raised it to 270C I haven't come close to a jam, and my hotend is slightly offset from my driver gear, with a good gap between the two. I've printed as high as 290C with no noticable difference, along with a larger retract.

---

Realizer- One who realizes dreams by making them a reality either by possibility or by completion. Also creating or renewing hopes of dreams.
"keep in mind, even the best printer can not print with the best filament if the user is the problem." -Ohmarinus

i'll try raising to 270. ive been avoiding going higher as when you get at these temps the plastic is VERY liquid

Quote
cdreid9999
... it's black abs i think the temp is about right

Black filament seems to be the industry's dumping ground for recycled plastic, regrinds, floor sweepings, and anything else that they can throw in as filler that will ultimately jam your hotend. Try a lighter color filament, and see if the jamming problem goes away.....

thanks. 265 actually works very well for the most part. and i bet youre right about the abs. It does however eventually clog on bigger prints (say x ends and whatnot). However i live in nc in what is technically a temperate rainforestso humidity is astronomical here and ideally i should dry all abs before i use it if i had that kind of time. I just got some clear and blue in from an american ebay supplier so i'll try that at various temps when i have time. the black actually works very well once you learn that the wiki is completely full of crap and experiment with temperature.

Just an update i bought some clear and blue abs from a different vendor. the clear works astonishingly well and no clogs so far (knock on wood).

Having said that i think my big clog issue was due to the hot end nozzle throat on my e3dv5. I had a big problem with a clog and took it apart and started runnign various paperclips through it.. found a hard obstruction i couldnt remove so i tried to completely disassemble the hotend. The nozzle throat snapped........... that tells me theyre using garbage metal and probably not honing the inside. I plan on finding some Higher quality nozzle throats (and nozzles) and polishing them. I really like the e3d andthat was deeply disappointing