Extruder clicking mystery
I have been getting extruder clicking and filament not advancing and the usual fixes haven't worked. I first did a cold pull and when that didn't help I completely replaced the hot end (nozzle, heat block, heat break, examined PTFE tube). This fixed the issue for perhaps 50 print hours, but now the clicking is back and filament is not advancing. I believe the gears can spin freely and don't look warn. I've also tried to adjust the idler door tension with no different results.
What are some other causes of this, other than the hot end?
I'd also like to mention that I have 6 printers that print almost constantly, so while I don't consider myself an expert on this stuff I do have lots of experience. Whenever this has happened to other machines in the past either a cold pull or hot end replacement has always taken care of the problem.
Any advice would be much appreciated.
RE: Extruder clicking mystery
Well, it's clear that the nozzle jammed up. I just don't understand what could have caused that to happen after only 50hrs of use. This is a micro-swiss wear resistant nozzle. Tried another cold pull, but when that didn't work replaced the nozzle and it's all good. Hopefully this one will last longer.
RE: Extruder clicking mystery
Lots of things can cause a jam. Everyone who uses a 3d printer has encountered it or will encounter it.
Even running a filament below its proper temperature can cause it. The most tricky cause I've seen (not on a Prusa) was where flakes of scorched filament accumulated along the internal sides of the nozzle and would occasionally break off and clog the orifice. This required disassembly and chasing out with a drill bit. I had a jam which occurred when I left PC Blend filament in the printer overnight and the printer and extruder cooled to room temperature.
I had one case where a small piece of filament was wedged in the tube opening right below the gears. When I figured out that was the cause, it was a simple fix to pry it out with a dental explorer.
Sometimes you can clear a jam by heating up the hot end to a very high temperature, like 275 or so, letting it sit to allow the heat to work its way upward, and forcing filament down through it.
Sometimes 'needling' with an acupuncture needle upward into the nozzle will help clear it.
And occasionally the jam is so bad that you need to take the machine down, disassemble the hot end, and clean it out manually. I've had to do this only once with the Prusa.
RE: Extruder clicking mystery
Yeah I've certainly dealt with my share of nozzle jams. What puzzles me is why this particular printer (of 6) keeps jamming. With my other printers I get a jam maybe once every six months or longer. I just replace the nozzle and move on. With this printer I've had three in the last month.
However your experience might confirm a suspicion I've had. My go to filament (Paramount) sells "master spools" that just have a cardboard core that I put on reusable spools to cut down on spool trash. The filament is held onto the cardboard core with thin strips of plastic that use an adhesive to keep the plastic strip together, but the problem is that some of that adhesive gets on the filament and leaves behind a sticky residue on the filament. Now I'm wondering if that residue is causing this. I mentioned this to Paramount a few weeks ago and I have now run out of those master spools. So I'm going to stick with the regular spools until they address this residue issue.